Continental rifting requires the existence of extensional forces great enough to break the lithosphere.
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When the lithosphere is subject to a horizontal extensional force it will stretch, becoming thinner.
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"All of the observed tectonics is extensional, meaning the crust of Charon is being stretched and pulled apart," James Tuttle Keane, a planetary scientist at Caltech who was not involved with the new study, told Gizmodo.
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Extensional viscosity (also known as elongational viscosity) is a viscosity coefficient when applied stress is extensional stress.Barnes, H.A. "A handbook of elementary rheology", Institute of non-Newtonian Fluid Mechanics, 2000 :This parameter is often used for characterizing polymer solutions. Extensional viscosity can be measured using rheometers that apply extensional stress. Acoustic rheometer is one example of such devices.
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A fundamental distinction is extensional vs intensional type theory. In extensional type theory definitional (i.e., computational) equality is not distinguished from propositional equality, which requires proof. As a consequence type checking becomes undecidable in extensional type theory because programs in the theory might not terminate.
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The volcanic material will contract as it cools, and this cooling generates extensional stresses. The orientation of a graben is determined based on the stress at the time of its formation. Radial graben form when basin-circumferential stresses are the most extensional. When radial stresses are the most extensional, circumferential graben form.
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An acoustic rheometer employs a piezo-electric crystal that can easily launch a successive wave of extensions and contractions into the fluid. It applies an oscillating extensional stress to the system. System response can be interpreted in terms of extensional rheology. :This interpretation is based on a link between shear rheology, extensional rheology and acoustics.
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It is a large extensional pull-part basin in extensional continental marginal setting, developed along the Red River fault zone, which located at the suture of the Indochina Plate and Yangtze Plate (South China Plate).
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An extensional statement is a non-intensional statement. Substitution of co-extensive expressions into it always preserves logical value. A language is intensional if it contains intensional statements, and extensional otherwise. All natural languages are intensional.
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Array of extensional faults cutting Triassic to Lower Jurassic Blomidon Formation rocks, near Clarke Head, Minas Basin North Shore, Nova Scotia, position of faults highlighted in black, marker bed highlighted in green Students examine an extensional fault, up close An extensional fault is a fault caused by stretching of the Earth's crust. Stretching reduces the thickness and horizontally extends portions of the crust and/or lithosphere. In most cases such a fault is also a normal fault, but may create a shallower dip usually associated with a thrust fault. Extensional faults are generally planar.
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The difference between this and an extensional definition is that extensional definitions list members, and not subsets.Katerina Ierodiakonou, "The Stoic Division of Philosophy", in Phronesis: A Journal for Ancient Philosophy, Volume 38, Number 1, 1993, pp. 57–74.
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Such relationships are then amenable to mathematical treatment by the established methods of continuum mechanics. The characterization of flow or deformation originating from a simple shear stress field is called shear rheometry (or shear rheology). The study of extensional flows is called extensional rheology. Shear flows are much easier to study and thus much more experimental data are available for shear flows than for extensional flows.
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The Herald Arch is named after Herald Island. Type: Early Tertiary extensional basin (mainly).
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This dissipated energy is then measured and converted into a viscosity reading. A higher viscosity causes a greater loss of energy. Extensional viscosity can be measured with various rheometers that apply extensional stress. Volume viscosity can be measured with an acoustic rheometer.
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A collapsing coronae coupled with extensional stressing may result in rifting, creating a chasmata region.
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Two lambda terms are equal if they are alpha convertible. The extensional definition of function equality is that two functions are equal if they perform the same mapping; : f = g \iff (\forall x f\ x = g\ x) One way to describe this is that extensional equality describes equality of functions, where as intensional equality describes equality of function implementations. The extensional definition of equality is not equivalent to the intensional definition. This can be seen in the example below.
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Rheometers that control the applied shear stress or shear strain are called rotational or shear rheometers, whereas rheometers that apply extensional stress or extensional strain are extensional rheometers. Rotational or shear type rheometers are usually designed as either a native strain-controlled instrument (control and apply a user-defined shear strain which can then measure the resulting shear stress) or a native stress- controlled instrument (control and apply a user-defined shear stress and measure the resulting shear strain).
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By the time of intrusion of the Florida dyke swarm, Piedra Alta Terrane was experiencing extensional tectonics.
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Fúquen, 2011, p.45 The overall tectonic regime represented an extensional basin setting.Fúquen et al., 2011, p.
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This leads to a kind of orogeneses in extensional settings, which is referred as to rifting orogeny.
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However, the Rheotens is useful to compare the extensional flow properties of a homologous set of materials.
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The faults of this age are extensional in type and thought to be a result of caldera formation.
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Ridge belts: are they compressional or extensional structures? Earth Moon Planets 50/51, 471–491.Kryuchkov, V.P., 1992.
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The Sentmanat extensional rheometer (SER) is actually a fixture that can be field installed on shear rheometers. A film of polymer is wound on two rotating drums, which apply constant or variable strain rate extensional deformation on the polymer film. The stress is determined from the torque exerted by the drums.
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Cook, Roy T. "Intensional Definition". In A Dictionary of Philosophical Logic. Edinburgh: Edinburgh University Press, 2009. 155. This is the opposite approach to the extensional definition, which defines by listing everything that falls under that definition – an extensional definition of bachelor would be a listing of all the unmarried men in the world.
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All of these depressions are likely pull-apart basins, the result of extensional stresses from the two nearby spreading centers.
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The northwestern side of Honshu lies on the southeastern margin of the Sea of Japan, an area of oceanic crust created by back-arc spreading from the late Oligocene to middle Miocene. The extensional tectonics associated with the spreading formed a series of N-S trending extensional faults and associated basins. The crust in this area is subjected to east-west compression associated with the convergent boundary between the Amur Plate and the Okhotsk Plate. As a result of this strain, the north-south trending extensional faults are reactivated in a reverse sense.
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Satisfactory accounts of general semantics extensional devices can be found easily.For example, a source reference for "scare quotes" and other extensional devices not treated in this article is Postman, Neil. "Alfred Korzybski," ETC: A Review of General Semantics, Winter 2003 This article seeks to explain briefly only the "indexing" devices. Suppose you teach in a school or university.
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Extensional tectonic activity followed the Laramide Orogeny and was accompanied by voluminous felsic volcanic eruptions. Numerous low-angle normal faults formed during this time. These faults have been particularly important in the Rosemont area. The extensional tectonics eventually produced the large- scale block faulting that produced the present Basin and Range Province throughout the southwestern United States.
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An outcrop view of the extensional faulting that can produce tilting fault blocks. The faults have been highlighted in black, with the green line showing a marker horizon. The photograph is of an extensional fault array on cliffs west of Clarke Head, Minas Basin, North Shore, Nova Scotia. Core complexes containing rotational fault blocks occur throughout the world.
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Gold mineralization here is formed during extensional faulting (probably due to Sagaing fault) and intense hydrothermal alteration and silicification in late Eocene.
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The Aegean Sea is an area of mainly extensional tectonics caused by the subduction of the African Plate beneath Aegean Sea Plate.
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Areas of extensional tectonics are typically associated with: Horst and graben structure, typical rift related structure (direction of extension shown by red arrows).
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The only extensional languages are artificially constructed languages used in mathematical logic or for other special purposes and small fragments of natural languages.
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Capillary breakup rheometry is an experimental technique used to assess the extensional rheological response of low viscous fluids. Unlike most shear and extensional rheometers, this technique does not involve active stretch or measurement of stress or strain but exploits only surface tension to create a uniaxial extensional flow. Hence, although it is common practice to use the name rheometer, capillary breakup techniques should be better addressed to as indexers. Capillary breakup rheometry is based on the observation of breakup dynamics of a thin fluid thread, governed by the interplay of capillary, viscous, inertial and elastic forces.
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Intensive logic is treated as the ground of all extensional logic, and extensional logic (along with all mathematical thinking above basic counting) is grounded in rearrangements of operational sign relations. Infinitely many extensional schemes are possible of the basis of intensive symbol functions, but all are well encompassed by the four-term semiotic schema Auxier provides. He treats Bergson's qualitative calculus and Whiteheads genetic and coordinate analyses as exemplars of his sign-theory. Auxier favors and teaches the analytical syllogistics of Delton Thomas HowardFor more, see: Delton Thomas Howard, Analytical Syllogistics: A Pragmatic Interpretation of the Aristotelian Logic (New York: AMS Press, 1970).
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Extensional faults form parallel to the axis of the rift. An extensional fault may be seen as a crack in the crust that extends down at an angle to the vertical. As the two sides pull apart, the hanging wall ("hanging over" the sloping fault) will move downward relative to the footwall. The crust thins and sinks, forming a rift basin.
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Rheotens is a fiber spinning rheometer, suitable for polymeric melts. The material is pumped from an upstream tube, and a set of wheels elongates the strand. A force transducer mounted on one of the wheels measures the resultant extensional force. Because of the pre-shear induced as the fluid is transported through the upstream tube, a true extensional viscosity is difficult to obtain.
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The formation of the Haungling dome is still unknown. There are three evolutionary models established including those driven by both compressive and extensional forces.
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Extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary body's crust or lithosphere.
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The result was substantial crustal thinning, forming a major extensional graben and causing isolated volcanic activity. The stretch factor is estimated to be ~2.
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This fault system has imparted the Chivinar centre an extensional characteristic. The Chivinar centre itself formed over an Eocene-Miocene basement containing evaporites and sediments.
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This is the perfect example of an oceanic back-arc basin experiencing extensional forces. The Oriente in Ecuador (the eastern part of the country covered by rainforest) is also a good example of an extensional back-arc basin, this time in a continental setting. The continental crust in this area east of the Andes has been stretched out and covered by layers of sediments.
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The orogen at southern Finland with its presumed mountains and thick continental crust collapsed under the influence of gravity and spread out. By 1850 million years ago this collapse had evolved to a dynamic of extensional tectonics. In this extensional milieu short-lived sedimentary basins formed. The Svecobaltic orogeny developed when subduction bought the Fennoscandian Craton into an oblique collision with the Sarmatian Craton.
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Steven Best has coined the term "extensional self-defense" to describe actions carried out in defense of animals by human beings acting as "proxy agents."Best, Steven. "Gaps in Logic, Lapses in Politics: Rights and Abolitionism in Joan Dunayer's Speciesism", drstevebest.org. He argues that, in carrying out acts of extensional self-defense, activists have the moral right to engage in acts of sabotage or even violence.
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When one or more salt layers are present during extensional tectonics, a characteristic set of structures is formed. Extensional faults propagate up from the middle part of the crust until they encounter the salt layer. The weakness of the salt prevents the fault from propagating through. However, continuing displacement on the fault offsets the base of the salt and causes bending of the overburden layer.
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The creation of the dome was caused by a phase of east- west directed extension in the Miocene that occurred throughout the Eastern and Central Alps. This extensional phase was probably a result of slab detachment in the upper mantle. Similar large extensional structures appear in more places in the Alps, examples are the Hohe Tauern window and the smaller Engadin and Rechnitz windows.
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Philosopher Steven Best has coined the term "extensional self-defense" to describe actions carried out in defense of animals by human beings acting as proxy agents.Best, Steven. "Gaps in Logic, Lapses in Politics: Rights and Abolitionism in Joan Dunayer's Speciesism" , drstevebest.org. He argues that, in carrying out acts of extensional self-defense, activists have the moral right to engage in acts of sabotage or even violence.
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Steven Best has coined the term "extensional self-defense" to describe actions carried out in defense of animals by human beings acting as "proxy agents."Best, Steven. "Gaps in Logic, Lapses in Politics: Rights and Abolitionism in Joan Dunayer's Speciesism", drstevebest.org. He argues that, in carrying out acts of extensional self-defense, activists have the moral right to engage in acts of sabotage or even violence.
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Some fundamental formulations in the field of general semantics rely heavily on a valuation of extension over intension. See for example extension, and the extensional devices.
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Shield volcanoes are also observed in this zone. Þingvellir Graben is clear evidence as proof of divergent plate movement in Iceland. It shows a clear extensional feature.
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To accommodate the compression of the Somali plate due to two extensional edges of the plate the oceanic plate might begin to subduct below the continental plate.
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The likely source rocks for the GMS suite are not easily deduced, but chemistry and εNd values of the Boesmanskop syenite suggest a hybrid mantle- crustal source. This type of hybrid source might also explain the features of the monzogranitic batholiths. Close associations between syenite and monzogranites are common, particularly in post-orogenic extensional/transtensional settings. Although extensional activity has not been documented in Barberton, ∼3.1 Ga strike-slip activity has.
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A second rift, named the Ammavuro-Quetzalpetlatl extensional belt, is a long and wide rift which lies in the northeast region of Lada Terra. These two massive rifts intersect in the northern region of Lada Terra, and the observed deformation of the two extensional belts seems to have occurred at the same time, although the larger Alpha-Lada rift most likely continued to be deformed for a longer period.
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In logic, philosophy, and mathematics, extensional and intensional definitions are two key ways in which the object(s) or concept(s) a term refers to can be defined.
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The unique tessera terrain, which is interpreted to be a deformation product of the high regional stresses on Venus, is the oldest type of terrain found in the Lada Terra Region. The extensional belts and several corona, including the Quetzalpetlatl Corona, are observed to be cutting across the tessera terrain, implying these structures to be formed after this heavily deformed material. The extensional belts in some areas cross cut the corona whereas the corona embay the extensional belts in other areas, implying a coevolution of the two. As a result, shield volcanoes formed around the corona and began intense episodic volcanism, with the flows from these events now covering 48% of the Lada Terra region.
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Steep normal faults produced prominent seafloor scarps but resulted in only a minor extensional component. At this stage, in terms of horizontal motion, the Adare Basin is nearly locked.
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Geological map of the region around the Tharsis plateau. Extensional and compressional features – e.g., graben and wrinkle ridges – have been mapped and are visible in the image. (USGS, 2014).
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In the case of acoustic rheometers, the raw data are converted into extensional viscosity or volume viscosity. Instruments that employ ultrasound attenuation spectroscopy are referred to as Acoustic spectrometers.
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C. Mercier, Insight into the upper mantle beneath an active extensional zone: The spinel-peridotite xenoliths from San Quintín (Baja California, México), Contrib. Mineral. Petrol., 100, 374-382, 1988.
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Rollover anticline associated with a listric normal fault Rollover anticlines are anticlines related to extensional normal faults. They must be differentiated from fault-propagation folds, which are associated with reverse faults. A rollover anticline is a syn-depositional structure developed within the downthrown block (hanging wall) of large listric normal faults. Such faults are typically regional in nature and develop as a response to extensional collapse of a passive continental margin (i.e.
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The (reactivate) Precambrian extensional faults guided the deposition of glacial sediments (Edaga Arbi Glacials and Enticho Sandstone). Later alluvial plain sediments were deposited (Adigrat Sandstone). The break- up of Gondwana (Late Palaeozoic to Early Triassic) led to an extensional tectonic phase, what caused the lowering of large parts of the Horn of Africa. As a consequence a marine transgression occurred, leading to the deposition of marine sediments (Antalo Limestone and Agula Shale).
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Tilted block faulting, also called rotational block faulting, is a mode of structural evolution in extensional tectonic events, a result of tectonic plates stretching apart. When the upper lithospheric crust experiences extensional pressures, the brittle crust fractures, creating detachment faults. These normal faults express themselves on a regional scale; upper crust fractures into tilted fault blocks, and ductile lower crust ascends. This results in uplift, cooling, and exhumation of ductily deformed deeper crust.
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Other features include grabens, troughs and lineaments. Chains of pit craters located throughout the Ganiki Planitia Quadrangle have been found to influence the formation and deformation of these extensional features.
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Major lateral offsets between large extensional or thrust faults are normally connected by diffuse or discrete zones of strike-slip deformation allowing transfer of the overall displacement between the structures.
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Lambda calculus is usually interpreted as using intensional equality. There are potential problems with the interpretation of results because of the difference between the intensional and extensional definition of equality.
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A Forward Modeling Strategy for Balancing Cross Sections (1). AAPG Bulletin, 74(5), 521–531.Nunns, A. G. (1991). Structural Restoration of Seismic and Geologic Sections in Extensional Regimes (1).
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In a 4D ontology, an individual is identified by its spatio-temporal extent. Examples of formal extensional ontologies are BORO, ISO 15926 and the model in development by the IDEAS Group.
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Near the thickest part of the upper plate, extensional faulting may be negligible or absent, but as the upper plate thins, it loses its ability to remain coherent and may behave as a thin-skinned extensional terrane. # Décollements can form from high angle normal faults. Uplift in a second stage of extension allows the exhumation of a metamorphic core complex (see Fig. 2). A half graben forms, but stress orientation is not perturbed due to high fault friction.
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Current convergence across the fold and thrust belt are estimated at up to 15 mm per year. The thrusting is thick-skinned in type, involving reverse reactivation of much older extensional faults.
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The technique was applied to areas of extensional tectonics initially using vertical simple shear. Over the next decade several types of commercial restoration software became available, allowing the technique to be routinely applied.
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Felsic magmatism dominates this time period. The cause of the magmatism is debated between an extensional setting or a continental-margin arc. The name is in relation to the ensuing orogeny and metamorphism.
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Thermal subsidence and Arabian plate stretching (that resulted from the fragmentation of Gondwana in the Late Permian) resulted in extensional faulting and the early rifting of Zagros that opened the Neo-Tethys Sea.
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On the other hand, north–south extensional movements, yet unexplained, are pulling the plate apart, creating normal extensional faults and generating a parallel sequence of horsts and grabens, or rift valleys, running in a north–south direction. Mount Taygetus is a limestone horst bordering the Eurotas Rift Valley. Below its eastern face is the Sparta fault, a normal fault striking perpendicular to the direction of extension. Footwall scarps are visible on the eastern side of Taygetus at the base of its spurs.
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This orogeny formed a cordillera-type volcanic arc where oceanic crust subducted below Gondwana. When a mid-oceanic ridge subducted at an oblique angle, extensional basins developed along the northern margin of Gondwana.Scenario from During the late Cambrian to Early Ordovician these extensional basins had evolved a rift running along the northern edge of Gondwana.; The rift in its turn evolved into a mid-oceanic ridge that separated small continental fragments such as Avalonia and Carolina from the main Gondwanan land mass.
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The fluids originated from a shallowly dipping extensional fault system to the west, which bounded an extensional half-graben. Fossils were formed as silica formed in the hot springs themselves; when silica-rich water flooded the surrounding areas; and when it permeated into the surrounding soil. The texture of the sinter formed resemble those found today in freshwater streams at Yellowstone which are typically alkaline (pH 8.7) and tepid . The springs were periodically active, and flowed into an alluvial plain containing small lakes.
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The Hormuz Formation is known from a wide area of the Zagros Mountains and around and beneath the Persian Gulf. Two main depositional basins have been recognised, the North Gulf and South Gulf Basins, separated by the Qatar Arch. The basins were formed as a result of extensional tectonics towards the end of the Pan-African Orogeny. The main structure formed during this period were NW- SE trending dextral (right lateral) strike-slip faults and NE-SW trending extensional faults.
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An extensional definition of a concept or term formulates its meaning by specifying its extension, that is, every object that falls under the definition of the concept or term in question. For example, an extensional definition of the term "nation of the world" might be given by listing all of the nations of the world, or by giving some other means of recognizing the members of the corresponding class. An explicit listing of the extension, which is only possible for finite sets and only practical for relatively small sets, is a type of enumerative definition. Extensional definitions are used when listing examples would give more applicable information than other types of definition, and where listing the members of a set tells the questioner enough about the nature of that set.
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With the influence of Tian Shan collision and anorogenic magmatism from local extensional events, Junggar area subsides to form Junggar basin. Modified from Zhao et al. (2003), Carroll et al. (1990), Buckman et al.
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Cenozoic extensional tectonics of the U.S. Cordillera. In Burchfiel, B. C.; Lipman, P.W.; and Zoback, M. L., eds. The Cordilleran Orogen: conterminous U.S. (Geology of North America, Vol. G-3). Boulder, CO, Geol. Soc.
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Some dykes are deformed and metamorphosed into amphibolite. Radiometric dating has shown that the dyke swarm is about 1421 million years old. Geologists have suggested that the dyke swarm is related to extensional tectonics.
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The Cenozoic fluvial deposits including sandstone, siltstone and mudstone are iron oxides-rich, so they appear as red. They formed the basins and grabens on dome flanks. It shows there were extensional settings during Cenozoic.
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The FiSER (filament stretching extensional rheometer) is based on the works by Sridhar et al. and Anna et al.Sridhar, J. Non-Newtonian Fluid Mech., vol 40, 271–280 (1991); Anna, J. Non-Newtonian Fluid Mech.
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Extensional self-defense is justified, he writes, because animals are "so vulnerable and oppressed they cannot fight back to attack or kill their oppressors."Best, Steven. "Who's Afraid of Jerry Vlasak?" , Animal Liberation Press Office.
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Extensional self-defense is justified, he writes, because animals are "so vulnerable and oppressed they cannot fight back to attack or kill their oppressors."Best, Steven. "Who's Afraid of Jerry Vlasak?" , Animal Liberation Press Office.
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Fractures formed in this way are sometimes called axial cleavage, longitudinal splitting, or extensional fractures, and are commonly observed in the laboratory during uniaxial compression tests. High horizontal or surface-parallel compressive stress can result from regional tectonic or topographic stresses, or by erosion or excavation of overburden. With consideration of the field evidence and observations of occurrence, fracture mode, and secondary forms, high surface- parallel compressive stresses and extensional fracturing (axial cleavage) seems to be the most plausible theory explaining the formation of exfoliation joints.
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The most accepted hypothesis suggests that crustal shearing associated with the San Andreas Fault caused spontaneous extensional faulting similar to that seen in the Great Basin. However, plate movement alone does not account for the high elevation of the Basin and Range region. The western United States is a region of high heat flow which lowers the density of the lithosphere and stimulates isostatic uplift as a consequence. Lithospheric regions characterized by elevated heat flow are weak and extensional deformation can occur over a broad region.
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Best argues that the principle of extensional self-defense mirrors the penal code statues known as the "necessity defense," which can be invoked when a defendant believes that the illegal act was necessary to avoid imminent and great harm. In testimony to the Senate in 2005, Jerry Vlasak stated that he regarded violence against Huntingdon Life Sciences as an example of extensional self- defense.Miller, John J. "In the name of the animals: America faces a new kind of terrorism" , National Review, 3 July 2006.
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The East African Rift System became active 22 to 25 million years ago in the Miocene and its offshore extent is the youngest. The rift system causes seismicity, extensional deformation and created the offshore Kerimbas Graben.
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However, some authors have argued that the implausibly high porosity requirement could be overlooked if extremely high pore pressures were supplied by tectonic activity associated with the concurrent formations of the Elysium and Tharsis Rises, likely through the effects of extensional faulting. If extensional stresses built up gradually in the vicinity of Cerberus Fossae, any tectonic activity would relieve this extensional stress, causing a relative compression that would pressurize the reservoir. Nearby diking, however, would add large amounts of material into the vicinity of the reservoir, compressing it and rapidly pressurizing it. Any rupturing and faulting associated with this tectonic activity would penetrate the overlying cryosphere (in a dry and cold Amazonian Mars); to compensate for its pressurization, reservoir fluids would be forced upwards through the fissure, forming the outflow channel morphologies observed on the surface.
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The rocks have shoshonitic, mafic and calc-alkaline composition. The magma feeding these volcanic centres appears to come from the asthenosphere and the ascent of mafic magmas is facilitated by the extensional tectonic regime and by faulting.
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In Basement Tectonics 13 (pp. 33–48). Springer Netherlands. The batholith originated and was emplaced in an anorogenic tectonic setting during a period of extensional tectonics. The batholith intrudes the Valentines Granulitic Complex of Nico Perez Terrane.
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28, no. 2, p. 151-154Lori Bettison- Varga, Robert J. Varga and Peter Schiffman, Relation between ore-forming hydrothermal systems and extensional deformation in the Solea graben spreading center, Troodos ophiolite, Cyprus, Geology, 1992, v. 20 no.
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The northward dip of thrusts at the base of, and within, the ophiolitic rocks is interpreted to be caused by rotation of initially south-dipping thrust planes due to the dominantly south-dipping post-Variscan extensional faults.
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The cause of the Knoydartian metamorphic event has yet to be established. Some authors interpret this to be a result of a high heatflow due to extensional tectonics, while others interpret it to be an orogenic event.
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Tilted block development adapted from 2013 Whitney et al., "Continental and oceanic core complexes". The cartoon illustrates how the fault blocks tilt as time progresses in an extensional environment. Time A shows the pre-deformed rock unit.
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The northwestern side of Honshu lies on the southeastern margin of the Sea of Japan, an area of oceanic crust created by back-arc spreading associated with the convergent boundary where the Pacific Plate is subducted beneath the Okhotsk Plate. The spreading was active from the late Oligocene to middle Miocene. The extensional tectonics associated with the spreading formed a series of N-S trending extensional faults and associated sedimentary basins. Currently the area is being deformed by contractional tectonics, causing inversion of these earlier basins, forming anticlinal structures.
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The homomorphism F is an isomorphism if and only if R is extensional. The well- foundedness assumption of the Mostowski lemma can be alleviated or dropped in non-well-founded set theories. In Boffa's set theory, every set-like extensional relation is isomorphic to set-membership on a (non-unique) transitive class. In set theory with Aczel's anti-foundation axiom, every set- like relation is bisimilar to set-membership on a unique transitive class, hence every bisimulation-minimal set-like relation is isomorphic to a unique transitive class.
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Image of a pull-apart basin redrawn from Frisch et al. 2010 The inhomogeneity and structural complexity of continental crust causes faults to deviate from a straight course and frequently causes bends or step-overs in fault paths. Bends and step-overs of adjacent faults become favorable locations for extensional and compressional stress or transtension and transpression stress, if the shear motion is oblique. Pull-apart basins form in extensional to transtensional environments along fault bends or between two adjacent left-lateral faults or two right- lateral faults.
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If the coronae formed through downwelling from a catastrophic disruption, then the concentric faults would present as compressed. If they formed through upwelling, such as by diapirism, then they would be extensional tilt blocks, and present extensional features, as current evidence suggests they do. The concentric rings would have formed as ice moved away from the heat source. The diapirs may have changed the density distribution within Miranda, which could have caused Miranda to reorient itself, similar to a process believed to have occurred at Saturn's geologically active moon Enceladus.
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At time B, incipient normal faulting begins. At time C, faulting continues as extension continues. The associated extensional basins begin to fill with eroded material from the exposed blocks. A time lapse view of the fault block progression.
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Mechanism Bimodal volcanism is the eruption of both mafic and felsic lavas from a single volcanic centre with little or no lavas of intermediate composition. This type of volcanism is normally associated with areas of extensional tectonics, particularly rifts.
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After the uplift of Huangling dome during Triassic, the environment changed to extensional. Brittle deformation forming rifts and grabens followed. High-angle normal faulting can be found in Yuanan Graben and Jingmen Graben on the east side of Huangling Complex.
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A passive margin built out over a weaker layer, such as an overpressured mudstone or salt, tends to spread laterally under its own weight. The inboard part of the sedimentary prism is affected by extensional faulting, balanced by outboard shortening.
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Post-collisional magmatism is a result of decompression melting associated with isostatic rebound and possible extensional collapse of the thickened crust formed during the collision. Slab detachment has also been proposed as a cause of late to post-collisional magmatism.
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This inequivalence is created by considering lambda terms as values. In typed lambda calculus this problem is circumvented, because built-in types may be added to carry values that are in a canonical form and have both extensional and intensional equality.
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The NE-SW trending extensional faults that developed as a result of the convergent margin and loading provide pathways for the movement of the hydrocarbon from the Miocene shales to the fluvio-deltaic Orinoco Delta sands of the Pliocene-Pleistocene.
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In late Permian to Triassic times the Lake District Boundary Fault was an active extensional structure, forming part of the margin to the East Irish Sea Basin. Activity on this structure continued episodically through the Triassic up to the Early Cretaceous.
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Some of the orogens were accompanied by slab rollback. This created short-lived extensional basins that accumulated sand and high-silica volcanic debris to form Proterozoic quartzite-rhyolite successions. Subsequent convergent tectonics closed the basis and thrust imbricated the successions.
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This form of landscape can be seen in East Africa, the Vosges, the Basin and Range Province of Western North America and the Rhine valley. These areas often occur when the regional stress is extensional and the crust is thinned.
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The basin's inversion mechanism can be traced back to the movements of the Alpine orogeny that resulted in a series of monoclines along the boundary faults and the uplift of pre-Cenozoic sediments. Inversion can happen along reactivated fault lines and in this case the faults involved are the Mesozoic extensional growth faults. The reverse movements of the extensional faults in response reactivated the basement faults but this time as thrust faults. Former structural highs underwent inversions to become areas where large amounts of sediments began being deposited, while also slowly deepening to the basement faults.
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As the Jeanne d'Arc rift basin subsided, it was gradually in- filled with sediments eroded from adjacent areas of crustal uplift. Characteristics of the sedimentary basin fill and their relationships to the extensional history of the Jeanne d'Arc Basin have been variably described by numerous authors with general agreement on the applicability of rift concepts to the basin. There are, however, divergent conclusions regarding the number of Mesozoic rift episodes which affected the Jeanne d'Arc Basin (i.e. two or three), their ages of initiation and duration, and the orientations of extensional stresses that created different fault sets active during the rift episodes.
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The tectonic structures in the Niger Delta Basin are typical of an extensional rift system, but the added shale diapirism due to loading makes this basin unique. The main method of deformation is gravitational collapse of the basin, although the older faulting and deformation in the basin are related to the continental breakup and rifting of the African plate and South American plates. The overall basin is divided into a few different zones due to its tectonic structure. There is an extensional zone, which lies on the continental shelf, that is caused by the thickened crust.
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Subsequent Triassic to early Jurassic thermal subsidence was abruptly terminated by a phase of Middle Jurassic thermal doming. # Middle Jurassic domal uplift - development of transient mantle plume head leading to erosion of central North Sea, volcanism, and subsequent rift system. # Late Jurassic to earliest Cretaceous extensional tectonics - led to fault-block rotations and formation of major structural traps within and adjacent to the Viking and Central Grabens. In contrast to areas west of Shetland, the phase of extensional basin development was followed by a phase of post-rift thermal subsidence in the North Sea during the later Cretaceous and Cenozoic.
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The Aegean Sea is an area of mainly extensional tectonics caused by the subduction of the African Plate beneath Aegean Sea Plate. In the northwest Aegean, extension on approximately W-E trending extensional faults is accompanied by dextral (right lateral) strike-slip on SW-NE trending faults, and minor sinistral (left lateral) movement on NW-SE trending faults, accommodating the diffuse plate boundary zone between the Eurasian Plate and the Aegean Sea Plate. The earthquake has been attributed to movement on the Stratoni fault, one of the W-E trending faults that shows predominantly dip-slip extension.
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Extensional suffixes, a term used in the Igbo literature, refer to morphology that has some but not all characteristics of derivation. The words created by these suffixes always belong to the same lexical category as the root from which they are created, and the suffixes' effects are principally semantic. On these grounds, Emenanjo (2015) asserts that the suffixes called extensional are bound lexical compounding elements; they cannot occur independently, though many are related to other free morphemes from which they may have originally been derived. In addition to affixation, Igbo exhibits both partial and full reduplication to form gerunds from verbs.
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The development of extensional rheometers has proceeded more slowly than shear rheometers, due to the challenges associated with generating a homogeneous extensional flow. Firstly, interactions of the test fluid or melt with solid interfaces will result in a component of shear flow, which will compromise the results. Secondly, the strain history of all the material elements must be controlled and known. Thirdly, the strain rates and strain levels must be high enough to stretch the polymeric chains beyond their normal radius of gyration, requiring instrumentation with a large range of deformation rates and a large travel distance.
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However, this doesn't prevent extensional type theory from being a basis for a practical tool, for example, NuPRL is based on extensional type theory. In contrast in intensional type theory type checking is decidable, but the representation of standard mathematical concepts is somewhat more cumbersome, since intensional reasoning requires using setoids or similar constructions. There are many common mathematical objects, which are hard to work with or can't be represented without this, for example, integer numbers, rational numbers, and real numbers. Integers and rational numbers can be represented without setoids, but this representation isn't easy to work with.
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The category representations discussed above are all extensional in nature; that is, a category or complex class is simply the sum of all its members. To represent a category is, then, just to be able to list or identify all the objects belonging to that category. However, extensional category representations have very limited practical use, because they provide no insight for deciding whether novel (never-before-seen) objects are members of the category. What is generally desired is an intentional description of the category, a representation of the category based on a set of rules that describe the scope of the category.
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Cliffs of Upper Globogerina Limestone Formation at Il-Ħofra l-Kbira near Marsaxlokk The Geology of Malta consists of a sequence of sedimentary rocks of late Oligocene to late Miocene age cut through by a set of extensional faults of Pliocene age.
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Both Rayleigh and Lamb waves are constrained by the elastic properties of the surface(s) that guide them. Figure 1: Upper and lower, respectively: Extensional (S0) mode with d/\lambda=0.6. Flexural (A0) mode with d/\lambda=0.3. (This is a simplified graphic.
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Rachmaninoff is the fourth impact crater on Mercury (after Caloris, Rembrandt and Raditladi), where extensional tectonic features have been observed. The formation mechanism of the graben remains unknown. The crater is named after Sergei Rachmaninoff, a Russian composer, pianist, and conductor (1873–1943).
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The area experienced the effects of the early stages of Alpine collision during the Late Cretaceous to Palaeogene, with reverse reactivation of many of the extensional faults, creating the most visible of the structures in the Dorset area, such as the Purbeck Monocline.
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Crafton Hills Fault Zone or the Crafton Hills Horst-and-Graben ComplexUSGS. Western Earth Surface Processes Team. San Andreas Fault System in the Inland Empire and Salton Trough. Extensional Fault Zones which stretches between the San Jacinto fault and the San Andreas Fault.
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The Pearl River Mouth basin (PRMB) is an extensional sedimentary basin located in the northern part of the South China Sea. The basin covers an area of about 175,000 km2 where the Pearl River meets the South China Sea near Hong Kong.
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"Structure, stratigraphy, and hydrocarbon system of a Pennsylvanian pull-apart basin in north-central Texas." AAPG bulletin 86, no. 1 (2002): 1–20. The shallow extensional regime of pull-apart basins also facilitates the emplacement of felsic intrusive rocks with high copper mineralisation.
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Volcanic activity within the Kari-Kari-Fraile region may be influenced by extensional tectonics. The Kari-Kari caldera is ellipse- shaped and has a granitoid complex also named Kari-Kari at its centre. The caldera itself has dimensions of . Other dimensions given are .
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During this time, in the Late Jurassic, there is widespread fault-controlled subsidence. The final phase, initiated between the latest Late Jurassic and the earliest Early Cretaceous, triggered salt movement and the development of salt structures. Extensional tectonics ended during the Early Cretaceous.
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The upper ontology developed by the IDEAS Group is higher-order, extensional and 4D. It was developed using the BORO Method. The IDEAS ontology is not intended for reasoning and inference purposes; its purpose is to be a precise model of business.
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The Hilina Slump is the largest of the active slumps around the Hawaiian islands. The to the slump is formed by the Hilina extensional fault system, which is known to have moved in both the 1868 event and the 1975 Kalapana earthquake.
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Earthquakes are common along convergent boundaries. A region of high earthquake activity, the Wadati- Benioff zone, generally dips 45° and marks the subducting plate. Earthquakes will occur to a depth of along the Wadati-Benioff margin. Both compressional and extensional forces act along convergent boundaries.
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On the upper slope and shelf the current style of faulting is extensional with a series of WSW-ENE trending normal faults, such as the Ponce Fault and the Bajo Tasmanian Fault. Several faults are also known to cross parts of the main island.
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One of these uplifts was called the Afar dome. It began rising 40 Mya. This uplift caused massive crustal extension leading to horst and graben structures associated with normal, extensional, faults. The uplift of the Afar dome ultimately led to its collapse around 25 Mya.
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Extensional tectonics in the peninsula begun no later than in the Early Miocene and has resulted in the formation of two half graben basins. The uplift that the peninsula had in the Pliocene and Pleistocene has been attributed to subcrustal accretion in the subduction system.
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Some of the orogens were accompanied by slab rollback. This created short-lived extensional basins at 1700 and 1650 Mya that accumulated sand and high-silica volcanic debris to form Paleoproterozoic quartzite- rhyolite successions. Subsequent convergent tectonics closed the basis and thrust imbricated the successions.
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Some of the orogens were accompanied by slab rollback. This created short-lived extensional basins at 1700 and 1650 Mya that accumulated sand and high-silica volcanic debris to form Paleoproterozoic quartzite- rhyolite successions. Subsequent convergent tectonics closed the basins and thrust imbricated the successions.
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The Carboniferous geology of northern England consists of a series of relatively high and stable "blocks", such as the Alston Block separated by actively subsiding "basins", generally referred to as "troughs", such as the Stainmore and Gainsborough Troughs. Some of the blocks are underpinned by granitic intrusions of either Ordovician or Devonian age. The block and basin terrain was a result of active extensional faulting, with a dominant N-S extension direction, possibly related to the effects of back-arc spreading related to north-directed subduction beneath Avalonia. Later in the Carboniferous, the onset of continental collision to the south of Avalonia, caused widespread reactivation of the extensional faults in reverse.
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Uniaxial extensional flow created within necked filament by a capillary instability The linear stability analysis introduced by Plateau and Rayleigh can be employed to determine a wavelength for which a perturbation on a jet surface is unstable. In this case, the pressure gradient across the free-surface can cause the fluid in the thinnest region to be "squeezed" out towards the swollen bulges, thus creating a strong uniaxial extensional flow in the necked region. As the instability grows and strains become progressively larger, the thinning is governed by non-linear effects. Theoretical considerations on the fluid motion suggested that the behaviour approaching the breakup singularity can be captured using self-similarity.
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The Northern Cordilleran Volcanic Province (NCVP), formerly known as the Stikine Volcanic Belt, is a geologic province defined by the occurrence of Miocene to Holocene volcanoes in the Pacific Northwest of North America. This belt of volcanoes extends roughly north-northwest from northwestern British Columbia and the Alaska Panhandle through Yukon to the Southeast Fairbanks Census Area of far eastern Alaska, in a corridor hundreds of kilometres wide. It is the most recently defined volcanic province in the Western Cordillera. It has formed due to extensional cracking of the North American continent—similar to other on-land extensional volcanic zones, including the Basin and Range Province and the East African Rift.
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The rifting of cratons produced intracratonic basins and passive margin. Extensional periods were interrupted by orogenies, uplift, magmatism, and hydrothermal activity, ultimately creating the landscape seen today. Thus, the rocks exposed in the Wernecke mountains reveal the events responsible for the early formation of western North America.
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A period of significant continental collision and shortening of the crust affected the area in the Miocene.Marko, F., 2004: Fault controlled evolution of the ALCAPA region. Geolines, 17, pp. 68–69 Later, primarily extensional and strike-slip movement in the Neogene generated new or reactivated older faults.
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A graviquake is an earthquake occurring in an extensional tectonic setting, where the gravitational energy stored during the interseismic period is delivered by the collapse of a brittle upper crustal volume, slipping along a normal fault and generating the double couple recorded in the moment tensor solution.
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Schlische, Roy W. Geology of the Newark Rift Basin. Department of Geological Sciences, Rutgers University, Piscataway, NJ. Accessed October 24, 2009.Schlische, R.W., 1992. Structural and stratigraphic development of the Newark extensional basin, eastern North America: Evidence for the growth of the basin and its bounding structures.
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The cause of the earthquake is not known with certainty, although from contemporary reports, it appears unlikely to have been a megathrust event. It may have been either an extensional event within the Benioff zone, or a shallow focus intraplate event, possibly along the San Ramón Fault.
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The troughs are generally younger than the ridges, because they cut the latter. The width of the troughs varies from . Some radial troughs closely follow wrinkle ridges forming a unique wheel spoke pattern. Troughs are interpreted to be extensional features—grabens, while wrinkle ridges are contractional.
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Typically (although it depends on the type theory used), the axiom of choice will hold for functions between types (intensional functions), but not for functions between setoids (extensional functions). The term "set" is variously used either as a synonym of "type" or as a synonym of "setoid".
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Eventually, it collapsed to the mantle during the Cretaceous (130–120 million years ago). Due to the weight loss of the lower crust, the upper crust popped up and pulled apart. Therefore, the Eastern Block has a thinner crust and extensional structure, such as Bohai Bay basin.
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The question is still debated. The conceptual extensional difference between plume models and the superplume model placed beneath the East African Rift. Modified from Hansen et al. 2012. Maps of four different depth slices of the Shear-velocity (Vs) model developed by Emry et al. 2018.
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Transtensional shear zones are characterized by the co-existence of different structures, related to both strike-slip shear and extension. End member structures include pure strike- slip faults and purely extensional ("normal") dip-slip faults. Faults which have components of both (termed 'oblique' slip faults) are abundant.
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The earthquake was located near the southern end of the extensional Basin and Range Province. The western margin of the Sierra Madre Occidental plateau is formed by a series of west-dipping normal faults, over a distance of at least . The earthquake occurred within this zone.
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Figari et al. in 2015 describe two Jurassic megasequences, J1 in the Early Jurassic and J2 in the Late Jurassic. During these phases, the basin went through an extensional tectonic regime, with transtensional movements. Several distinct tectonic reactivation cycles occurred, with block rotation due to transpressional forces.
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Lithostratigraphical framework for Carboniferous successions of Great Britain (Onshore). British Geological Survey Research Report, RR/07/01. 60pp It has a large normal fault on its southern margin and has the form of a half- graben.Waters, C.N.; Davies, S.J.. 2006 Carboniferous : extensional basins, advancing deltas and coal swamps.
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Extensional geological settings like the foreland basin and rift basin settings are found, Zigui Basin and Danyang Basin, which are the two sedimentary basins lying on the western and eastern flank of Huangling dome, were formed during Late Triassic and Jurassic. It shows there were crustal extension during Mesozoic.
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This interpretation has been disputed, with counterclaims that the diking or extensional fracturing that formed Cerberus Fossae would have had to uniformly breach the entirety the thick protective cryosphere in order to allow groundwater to escape in sufficient quantities to hydrodynamically satisfy the Athabasca Valles' megaflood formation scenario.
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Décollement () is a gliding plane between two rock masses, also known as a basal detachment fault. Décollements are a deformational structure, resulting in independent styles of deformation in the rocks above and below the fault. They are associated with both compressional settings (involving folding and overthrusting) and extensional settings.
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Often the extensional fault systems are segmented in these rifts. Rift border faults with lengths over are separated by relay ramp structures. The relay ramps may provide pathways for sediment to be carried into the basin. Typically the rift is broken along its axis into segments about long.
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The uplift and exhumation led to a reduction of dip in these reactivated thrusts, making them progressively less mechanically viable. At this point Mode II extension took over, with development of large extensional shear zones that cross-cut the Caledonian thrust pile, such as the Nordfjord-Sogn Detachment.
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The Lancaster Aulacogen is a geological structure underlying Lancaster Sound and Prince Regent Inlet in the Arctic Archipelago of Nunavut, Canada. It formed as a result of extensional tectonics during the Eurekan Rifting Episode, which took place in the Canadian Arctic Rift System from the Cretaceous to the Tertiary.
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Thus, the "seven deadly sins" can be defined intensionally as those singled out by Pope Gregory I as particularly destructive of the life of grace and charity within a person, thus creating the threat of eternal damnation. An extensional definition, on the other hand, would be the list of wrath, greed, sloth, pride, lust, envy, and gluttony. In contrast, while an intensional definition of "Prime Minister" might be "the most senior minister of a cabinet in the executive branch of parliamentary government", an extensional definition is not possible since it is not known who the future prime ministers will be (even though all prime ministers from the past and present can be listed).
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The northwestern side of Honshu lies on the southeastern margin of the Sea of Japan, an area of oceanic crust created by back-arc spreading from the late Oligocene to middle Miocene. The extensional tectonics associated with the spreading formed a series of N-S trending extensional faults and associated basins. Currently the area is being deformed by contractional tectonics, causing inversion of these earlier basins, forming anticlinal structures. It has been suggested that the northwestern coast of Honshu represents an incipient subduction zone, but there remain significant uncertainties about the existence of the Okhotsk Plate and the nature and precise location of its boundary in the Sea of Japan, if it does exist.
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The Coastal Batholith of Peru () is a group of hundreds, if not thousands, of individual plutons that crop out near or at the coast of Peru. The batholith runs a length of ca. 1600 km. Most of the plutons of the batholith were intruded in an elongated coast-parallel extensional basin.
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The geological deformation of Iceland is mainly caused by the active spreading of the mid- oceanic ridge. Extensional cracks and transform faults are found perpendicular to the spreading direction. The transform-fault zones are also known as fracture zones. These fracture zones allow large volumes of lava to be erupted.
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The Western Cape lies on the Cape Fold Belt, which is characterised by many thrust faults. Some of these thrust faults were reactivated during Cretaceous rifting as extensional faults, such as the Worcester Fault, which comes to the surface close to the epicentral area, but does not appear to be active.
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Compression machines can also be used in reverse for simulating extensional tectonics, such as lithospheric extension, the formation of rifts, normal faulting, boudinage and diapirs. These models can also be built in a glass box which is similar to the above, but instead of thrust force, tensile force is applied.
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American Psychologist, 49, 709–724. More recently, Amos Tversky and Daniel Kahneman introduced the idea of heuristics, and concluded that there are natural and extensional forms of reasoning. However, CEST differs from past dual-processing models in a number of important ways. First, CEST presents the idea of an adaptive unconscious.
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He is a token (instance) of the type (kind). So the linguistic difference is: types (or kinds) have tokens (or instances); classes, on the other hand, have members. The concept of a class is similar to the concept of a set defined by its members. Here, the class is extensional.
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The northern fringes of Cacheuta sub-basin reaches into San Juan Province. The basin existed already during the Triassic but its current shape is derivative of the Andean orogeny. The basin originated as a rift basin in the context of extensional tectonics and crustal thinning that followed the Paleozoic Gondwanide orogeny.
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Fault-bend folds are caused by displacement along a non-planar fault. In non-vertical faults, the hanging-wall deforms to accommodate the mismatch across the fault as displacement progresses. Fault bend folds occur in both extensional and thrust faulting. In extension, listric faults form rollover anticlines in their hanging walls.
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La Hoyada is usually considered a back-arc volcanic centre, and has been associated with extensional tectonics. The volcanic complex was active in the Miocene and Pliocene. An age of 7.04 ± 0.03 million years ago has been determined for the ignimbrites. Another date for the complex is 9.8 ± 0.6 million years ago.
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This region is a major volcanic rise and was formed as the result of mantle upwelling. The Ganiki Planitia Quadrangle was strongly influenced by mantle flow tectonics derived from these two regions. The area contains many volcanic, tectonic, and impact features. Ganis Chasma is one of the extensional features located in the region.
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Some nonaccretionary forearcs are subjected to strong extensional stresses, for example the Marianas, and this allows buoyant serpentinite to rise to the seafloor where they form serpentinite mud volcanoes. Chemosynthetic communities are also found on non-accretionary margins such as the Marianas, where they thrive on vents associated with serpentinite mud volcanoes.
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The speed of sound in any chemical element in the fluid phase has one temperature-dependent value. In the solid phase, different types of sound wave may be propagated, each with its own speed: among these types of wave are longitudinal (as in fluids), transversal, and (along a surface or plate) extensional.
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Lau Basin is a young basin (<= 5 m.y. old) that separates a previously continuous island arc by extensional rifting. During the Pliocene, the Pacific plate was subducting beneath the Australian plate. The slab of the Pacific plate melted as it was thrust down, and then rose to form the original Tonga-Kermadec Ridge.
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It is often below sea level. Depressions are typically formed by tectonic processes acting on the lithosphere, providing "accommodation space" for sediment to be preserved. Basins are formed in a variety of tectonic settings: extensional, compressional, strike-slip and intraplate. Geological basins are one of the most common places which collect sediment.
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The Dead Sea has been studied extensively and thinning of the crust in pull- aparts may generate differential loading and instigate salt-diapirs to rise,Al-Zoubi, Abdallah, and Uri S. ten Brink. "Salt diapirs in the Dead Sea basin and their relationship to Quaternary extensional tectonics." Marine and Petroleum Geology 18, no.
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The Dniepr-Donets Paleorift was the site of Devonian magmatic activity that begun in Late Frasnian and peaked in the Famennian caused by a mantle plume. Extensional tectonics were also most active during the Famennian. There have been suggestions that the Dnepr-Donets Paleorift is related to the coeval Kola Alkaline Province.
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For example in the case of Criterion of identity, the method adopts an extensional approach. As an example, take “Waterloo Bridge” as a term. The first thing we ask is “does it refer to an object that has a spatial and temporal extent ?”. It has spatial extent; it spans the River Thames.
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Commercially available extensional rheometers have been segregated according to their applicability to viscosity ranges. Materials with a viscosity range from approximately 0.01 to 1 Pa.s. (most polymer solutions) are best characterized with capillary breakup rheometers, opposed jet devices, or contraction flow systems. Materials with a viscosity range from approximately 1 to 1000 Pa.s.
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The uplift and erosion which followed is evidenced by an unconformity across Africa and South America. It is related to the breakup of Gondwanaland. Following the Gondwanide orogeny southwestern Gondwana entered a period of extensional tectonics and crustal thinning leading to formation of various rift basins (e.g. Cuyo Basin) in the Triassic.
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The cooling near-surface layer contracted, while the interior expanded. This caused strong extensional stresses in the moon's crust leading to cracking. Some of the present-day canyons may be a result of this. The process lasted for about 200 million years, implying that any endogenous activity ceased billions of years ago.
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Since then, similar deformational patterns have been identified in MCCs in the Basin and Range and has led geologists to examine them as a group of related geologic features formed by Cenozoic crustal extension. The study of metamorphic core complexes has provided valuable insight into the extensional processes driving Basin and Range formation.
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This study acted as a reinforcement to previous work and was very consistent with previous data collected. Additionally, this seismic data presented is significant in extensional terms as a direct link between reflectors on the West and East sides of the Rocky Mountain trench correlate to the same stratigraphic unit, where extension can be restored and an extensional distance of about 10 km was calculated by the difference of the pre extension and post extension. There is controversy over how the overthrust movement occurred and the effect this movement had on the surrounding geology. More specifically, attempting to determine if the thrust movement was continuous or if movement was subject to a more stick-slip style of movement remains inconclusive.
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These may be expressed as ordered pairs for some purposes, but the semiotic system of reasoning is non-monotonic and yields to W.V. Quine's critiques of under-determination and radical translation.For more of Quine's work on the radical translation problem, and related work on ontological relativity, see: W. V. Quine, Word and Object (Cambridge, MA: MIT Press, 2013), 23-66; W. V. Quine, Ontological Relativity, and Other Essays (New York: Columbia University Press, 1969), 26-68. The mode of reasoning is extensional in semiotics and can be articulated (incompletely) in extensional logics of the sort devised by Gottlob Frege,For more, see: Gottlob Frege, The Foundations of Arithmetic a Logico-mathematical Enquiry into the Concept of Number, 2nd Revised ed. (Evanston, IL: Northwestern University Press, 1980).
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At 200 million years before the present, prior to the beginning of oceanic spreading, the Central Atlantic Magmatic Province created igneous sills and dykes that overlay the late Triassic sedimentary rocks.Hafid, M., 2000. Triassic-early Liassic extensional systems and their Tertiary Inversion/Essaouira Basin, Morocco. Marine and Petroleum Geology, Issue 6, pages 409-429.
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Clay smears in the sediments seal the formations so oil does not escape out. ;Basinward dipping reflectors Basinward dipping reflectors are a common feature of extensional type rift basins. As fault blocks extend they rotate to dip towards the center of the basin. At the top of these fault blocks sub basins can form.
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They are best studied through several other rheological properties that relate stress and strain rate tensors under many different flow conditions—such as oscillatory shear or extensional flow—which are measured using different devices or rheometers. The properties are better studied using tensor-valued constitutive equations, which are common in the field of continuum mechanics.
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Extensional faults were reactivated during the Eocene Alpine orogeny. The Ionian Zone is thrust westward over the Preapulian Zone and overlain by molasse facies. The Gavrovo-Tripolis Zone underlies Crete, the Dodecanese islands and much of the western mainland. Bauxites indicate a dry time in the Eocene and Oligocene flysch unconformably overlies older carbonates.
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Igbo is an agglutinating language that exhibits very little fusion. The language is predominantly suffixing in a hierarchical manner, such that the ordering of suffixes is governed semantically rather than by fixed position classes. The language has very little inflectional morphology but much derivational and extensional morphology. Most derivation takes place with verbal roots.
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" (1909 p. 66) Propositional functions: "The characteristic of a class concept, as distinguished from terms in general, is that "x is a u" is a propositional function when, and only when, u is a class-concept." (1903:56) Extensional versus intensional definition of a class: "71. Class may be defined either extensionally or intensionally.
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A depocenter or depocentre in geology is the part of a sedimentary basin where a particular rock unit has its maximum thickness. Depending on the controls on subsidence and the sedimentary environment the location of basin depocenters may vary with time, such as in active rift basins as extensional faults grow, link or become abandoned.
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Moreover, it has been proposed that the marine transgression is related to extensional tectonic setting, such that the Late Albian has detached from India and has started to drift from the Gondwana supercontinent, Also, the Neotethys has subducted northwards beneath Asia. This event is accompanied with the Late Cretaceous global eustatic sea-level high stand as well.
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The IDEAS work has been presented at a number of conferences.Bailey, Ian; Partridge, Chris. Working with Extensional Ontology for Defence Applications. Ontology in Intelligence Conference, 2009, GMU, Fairfax, VA It has also been cited in a Cutter Consortium white paper and in a book on Systems Engineering from Springer VerlagTolk, Andreas; Jain, Lakhmi C. (Eds.) Intelligence-Based Systems Engineering.
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The Brawley Seismic Zone (BSZ), also known as the Brawley fault zone, is a predominantly extensional tectonic zone that connects the southern terminus of the San Andreas Fault with the Imperial Fault in Southern California. The BSZ is named for the nearby town of Brawley in Imperial County, California, and the seismicity there is characterized by earthquake swarms.
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Major fault boundaries within rift systems tend to expand with time based on the assumption that the extensional stress and strain is consistent in a given rift system. Transfer zones have been identified according to the fault propagation evolution; they include approaching, overlapping, collateral, and collinear. This classification assists in visualization and deformational history of the transfer zone.
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Science and Sanity (5th ed.). p. 36 To be conscious of abstracting is to differentiate among the "levels" described above; levels II-IV being abstractions of level I (whatever level I "is"--all we really get are abstractions). The techniques Korzybski prescribed to help a person develop consciousness of abstracting he called "extensional devices". Korzybski, Alfred.
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During the Triassic, the central High Atlas extensional basin was characterized by the synrift deposition of red beds and localized evaporites capped by extensive basaltic lava flows.Martín Martín et al., 2016, p.4 Following the Triassic red bed deposition, marine conditions prevailed during the Early and Middle Jurassic resulting in the development of carbonate and mixed depositional systems.
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If the differential stress is less than four times the tensile strength of the rock, then extensional failure will occur. If the differential stress is more than four times the tensile strength of the rock, then shear failure will occur.Cosgrove. J. W. (1998) The role of structural geology in reservoir characterization. Geological Society, London, Special Publications, v.
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Passive rifting, unlike active rifting, occurs principally by extensional tectonic forces as opposed to magmatic forces originating from convection cells or mantle plumes. Isostatic forces allow mantle material to rise under the thinning lithosphere. Subsidence and sedimentation occur during both the initial rifting stage and the post rifting stages. Only after initial rifting does any mantle melting occur.
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Two different types of folding may occur at a décollement. Concentric folding is identified by uniform bed thickness throughout the fold, and is necessarily accompanied by detachment or a décollement as part of the deformation that occurs with a thrust fault. Disharmonic folding does not have uniform bed thickness throughout the fold. Décollement formation in an extensional setting.
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OptimJ associative arrays are very handy when associated to their specific initialization syntax. Initial values can be given in intensional definition, as in: int[String] age = { "Stephan" -> 37, "Lynda" -> 29 }; or can be given in extensional definition, as in: int[String] length[String name : names] = name.length(); Here each of the entries `length[i]` is initialized with `names[i].length()`.
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The Niger Delta Basin is an extensional basin surrounded by many other basins in the area that all formed from similar processes. The Niger Delta Basin lies in the south westernmost part of a larger tectonic structure, the Benue Trough. The other side of the basin is bounded by the Cameroon Volcanic Line and the transform passive continental margin.
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Then the CLSC, as well as an extensional transform zone (ETZ) linking the two spreading centers were formed. The CLSC propagated southwards and replaced the northern segment ELSC. The region of overlap of CLSC and ELSC is characterized by strike-slip earthquakes. Recent measurements have shown that the opening rates are increasing at ELSC and CLSC.
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Intensional logic is an approach to predicate logic that extends first-order logic, which has quantifiers that range over the individuals of a universe (extensions), by additional quantifiers that range over terms that may have such individuals as their value (intensions). The distinction between intensional and extensional entities is parallel to the distinction between sense and reference.
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There are many different types of crustal deformation depending on whether the rocks are brittle or ductile. The aspects that determine these properties are due to certain temperatures and pressures that rocks experience within the Earth. Therefore, temperature and pressure control deformation processes. Ductile rocks tend to bend, fold, stretch, or flow due to compressional or extensional forces.
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The North Anatolian Fault is similar in many ways to the San Andreas Fault in California. Both are continental transforms with similar lengths and slip rates. The Sea of Marmara near Istanbul is an extensional basin similar to the Salton Trough in California, where a releasing bend in the strike-slip system creates a pull- apart basin.
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From the latitude of Santiago to Rancagua the base of the formation becomes progressively younger and outcrops more scarce. In the mentioned latitudes the formation has been deformed by a diachronous tectonic inversion that produced reverse faults and destroyed the extensional sedimentary basin were the rocks deposited and contributed to the uplift of the Andes in the Late Miocene.
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The presence of surface flow patterns, in conjunction with crosscutting valleys, has given rise to the hypothesis that these plains likely formed by global lava flows over a short timescale and were subsequently exposed to compressional and extensional stresses. Structurally, plains are often deformed in belts of ridges (dorsa) or fractures (lineae) of various orientation and morphology.
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Model of crustal plateau and tessera terrain formation after Hansen (2006). In the downwelling model, mantle downwelling, possibly due to mantle convection, causes compression and thickening of the crust, creating the compressional elements of tessera terrain. Isostatic rebound occurs due to the crustal thickening. After downwelling ends, a delamination event within the mantle produces extensional elements of tessera.
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Pull- apart basins represent an important exploration target for oil and gas, porphyry copper mineralisation, and geothermal fields. The Matzen fault system in the Matzen Oil field has been recast as extensional grabens produced by pull-apart basins.Fuchs, Reinhard, and Walter Hamilton. "New depositional architecture for an old giant: the Matzen Field, Austria." (2006): 205–219.
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The sediments accumulated in the Abanico Extensional Basin within a context of the Andean orogeny. The basin had a north-south elongated shape that spanned the latitudes of 29–38° S. Tectonic inversion from 21 to 16 million years ago made the basin collapse and the sediments to be incorporated to the Andean ranges.Charrier et al., 2006, pp.
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Bickenbach, Jerome E., and Jacqueline M. Davies. Good reasons for better arguments: An introduction to the skills and values of critical thinking. Broadview Press, 1996. p. 49 Definitions can be classified into two large categories, intensional definitions (which try to give the sense of a term) and extensional definitions (which try to list the objects that a term describes).
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Philosophical investigations, Part 1 §27–34 An enumerative definition of a concept or a term is an extensional definition that gives an explicit and exhaustive listing of all the objects that fall under the concept or term in question. Enumerative definitions are only possible for finite sets (and in fact only practical for relatively small sets).
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This type of deformation can occur during processing, such as injection molding, fiber spinning, extrusion, blow-molding, and coating flows. It can also occur during use, such as decohesion of adhesives, pumping of hand soaps, and handling of liquid food products. A list of currently and previously marketed commercially available extensional rheometers is shown in the table below.
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Acoustic rheometers employ a piezo-electric crystal that can easily launch a successive wave of extensions and contractions into the fluid. This non-contact method applies an oscillating extensional stress. Acoustic rheometers measure the sound speed and attenuation of ultrasound for a set of frequencies in the megahertz range. Sound speed is a measure of system elasticity.
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Extensional tectonics in the north led to mafic volcanic activity within the Shan-Thai Block in the Carboniferous, continuing into the Permian. Some red beds also formed during the same period. During the Permian, almost the entire region was submerged during a major marine transgression. Carbonates deposited in shallow, shelf seas and today form dramatic karst landscapes.
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The Cyclades island group lies within a zone of extensional tectonics in the Aegean Sea Plate, between the South Aegean Volcanic Arc to the south and the continuation of the North Anatolian Fault to the north. The extension is a result of the bulging out of the Hellenic arc due to flat-slab subduction of the African Plate.
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Fig. 1. Sketch showing a well-developed growth fault and accompanying structures. Growth faults are syndepositional or syn-sedimentary extensional faults that initiate and evolve at the margins of continental plates. They extend parallel to passive margins that have high sediment supply. Their fault plane dips mostly toward the basin and has long-term continuous displacement.
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View of Storehesten in Gaular, part of the Kvamshesten Basin, formed of Devonian conglomerates and sandstones in tectonic contact with thick mylonites of the Nordfjord-Sogn Detachment Devonian age continental sediments are exposed in three main areas in and around mainland Norway; the Solund, Kvamshesten, Håsteinen and Hornelen basins along the west coast between Sognefjord and Nordfjord, on the islands of Smøla, Hitra and the western end of the Fosen Peninsula in Trøndelag and at Røragen near Røros close to the Swedish border. Further Devonian deposits are found on Svalbard. During the Devonian Period the thickened welt of crust formed by the Caledonian orogeny began to collapse. Some thrust surfaces show evidence of reactivation as low-angle extensional faults, but the main structures formed at this time were large-scale extensional detachments.
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The Hornelen sequence, in common with other Old Red Sandstone sequences in Norway, Scotland and Greenland was originally described as deposited in an intermontane depression with most faulting being post-depositional. The first tectonic model for the basin was developed in 1964, with an eastward migrating depocentre proposed in a downthrown basin between two high-angle normal faults with sedimentation keeping pace with eastward propagation of the faults. In 1977 a strike-slip pull-apart basin model was proposed, by analogy with basins developed along the San Andreas Fault system, with the cyclicity explained as a result of periodic fault activity. In 1984 another extensional model was proposed and this was supported in 1986 by the recognition of the underlying Nordfjord-Sogn Detachment, a major extensional structure with tens of kms of displacement.
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The volcanic complex has been affected by faulting. Ignimbrites erupted at La Hoyada have been described as moderately welded andesites, of green-grey colour. The intermediate composition of dykes at La Hoyada contrasts with that of other volcanic rocks associated with extensional tectonics in the Puna, which tend to be of mafic composition. Some of the rocks underwent supergene mineralization later.
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Late Mesozoic crustal thinning created normal faulting associated with rifts and grabens. The Cretaceous growth strata formed during deformation had non-uniform thickness of beds. In the Late Mesozoic, the thinning of the eastern Eurasia produced extensional features such as high-angle faults, rifts, grabens, drag-folds and exposed the metamorphic basement core. The high-angle normal faults are associated with grabens formation.
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The Kutai is an extensional basin in a general foreland setting. Its geologic evolution begins in the mid Eocene and involves phases of extension and rifting, thermal sag, and isostatic subsidence. Rapid, high volume, sedimentation related to uplift and inversion began in the Early Miocene. The different stages of Kutai basin evolution can be roughly correlated to regional and local tectonic events.
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The central part of the Apennines has been characterised by extensional tectonics since the Pliocene epoch (i.e. about the last 5 million years), with most of the active faults being normal in type and NW-SE trending. The extension is due to the back-arc basin in the Tyrrhenian Sea opening faster than the African Plate is colliding with the Eurasian Plate.
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Furthermore, high heat flow is necessary to produce granulite facies metamorphic rocks in orogens, indicating extreme metamorphism at high thermal gradients. In-situ granitisation by the extreme metamorphism is possible if crustal rocks would be heated by the asthenospheric mantle in rifting orogens, where collision-thickened orogenic lithosphere is thinned at first and then underwent extensional tectonism for active rifting.
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At the same time, the internal zones of the orogenic belt were affected by large extensional structureDolton, G.L., 2006, Pannonian Basin Province, Central Europe (Province 4808)—Petroleum geology, total petroleum systems, and petroleum resource assessment. U.S. Geological Survey Bulletin 2204–B, 47 p. of the back-arc Pannonian Basin.Royden, L.H., Horváth, F., Rumpler, J., 1983, Evolution of the Pannonian basin system. 1. Tectionics.
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Birefringence measurements have been made with phase-modulated systems for examining the transient flow behaviour of fluids.Frattini, P., Fuller, G., "A note on phase-modulated flow birefringence: a promising rheo-optical method", J. Rheol., 28: 61 (1984).Doyle, P., Shaqfeh, E. S. G., Spiegelberg, S. H., McKinley, G. H., "Relaxation of dilute polymer solutions following extensional flow", J. Non- Newtonian Fluid Mech.
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19, Issue 11, pp. 1104-1107. This could have caused the Charleston thrust fault to reactivate as an extensional fault. The Charleston transverse zone contained high angle faults which suggests it initiated as a response to connecting the low angle thrust faults of the Sevier. The Charleston transverse zone outlines a main sidewall ramp that would have been part of the Sevier belt.
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Passive margins above a weak layer develop a specific set of extensional structures. Large listric regional (i.e. dipping towards the ocean) faults are developed with rollover anticlines and related crestal collapse grabens. On some margins, such as the Niger Delta, large counter-regional faults are observed, dipping back towards the continent, forming large grabenal mini-basins with antithetic regional faults.
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If the stress field is oriented with the maximum stress perpendicular to the Earth's surface, extensional faults will create an initial dip of the associated beds of about 60° from the horizontal. The faults will typically extend down to the base of the seismogenic layer. As crustal stretching continues, the faults will rotate, resulting in steeply-dipping fault blocks between them.
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The result is an anticline feature in a completely extensional setting. As rollover anticlines develop during sedimentation, each layer typically shows thickening toward the controlling fault. As the underlying layers bend, they create more accommodation space along the controlling fault versus the crest of the anticline. In the opposite direction, the layers exhibit thinning toward the crest of the rollover anticline.
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This loading caused the underlying shale Akata Formation to be squeezed into shale diapirs. Then in the Oligocene the Benin formation was deposited, which is still being deposited today. The overall basin is divided into a few different zones due to its tectonic structure. There is an extensional zone, which lies on the continental shelf, caused by the thickened crust.
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Wagner Basin is a submarine depression in the far northern part of the Gulf of California. The basin is currently tectonically active. It is the northernmost underwater depression associated with the East Pacific Rise and is located near the southern end of the Cerro Prieto fault. The depression is a result of subsidence caused by the extensional forces imparted by a spreading center.
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The first phases of Andean orogeny in the Jurassic and Early Cretaceous were characterized by extensional tectonics, rifting, the development of back-arc basins and the emplacement of large batholiths. This development is presumed to have been linked to the subduction of cold oceanic lithosphere. During the mid to Late Cretaceous (ca. 90 million years ago) the Andean orogeny changed significantly in character.
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Ribbon Terrain is characterized by ribbons and folds that are typically orthogonal to one another. Ribbons are long and narrow extensional troughs that are separated by narrow ridges. Ribbon terrain can be found both in large crustal plateaus and within tessera inliers. S-C Terrain is named such due to its geometric similarity to S-C tectonic fabrics on Earth.
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During the Variscan, the fault may have acted as either a strike-slip fault or a thrust fault or indeed both; its nature remains uncertain.Woodcock, N.H. and Strachan, R.A. (eds) 2000 Geological History of Britain and Ireland Blackwell Science, (p230, 263) During the Triassic to Jurassic, the fault zone was active as an extensional fault, controlling the development of the Bristol Channel Basin.
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This new phase of spreading caused considerable disturbance to the sediments that were deposited, which created an unstable situation as the crust and sediments parted and the axial trough evolved. Normal faulting along the rift valley during earthquakes shows that the extensional motion is continuing.Girdler, RW, and P Styles. “Two Stage Red Sea Floor Spreading.” Nature 247 (1974): 7–11.
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In the geological past, the majority of VMS deposits were formed in rift environments associated with volcanic rocks. In particular, they formed throughout geological time associated with mid-ocean ridge spreading centres, back-arc spreading centres, and forearc spreading centres. A common theme to all environments of VMS deposits through time is the association with spreading (i.e., an extensional geodynamic regime).
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A philosopherStanford University primer, 2006. might characterize this state of affairs thus: "Although the concepts of bipartiteness and absence of odd cycles differ in intension, they have identical extension."Meanings, in this sense, are often called intensions, and things designated, extensions. Contexts in which extension is all that matters are, naturally, called extensional, while contexts in which extension is not enough are intensional.
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The first phases of Andean orogeny in the Jurassic and Early Cretaceous were characterized by extensional tectonics, rifting, the development of back-arc basins and the emplacement of large batholiths. This development is presumed to have been linked to the subduction of cold oceanic lithosphere. During the mid to Late Cretaceous (ca. 90 million years ago) the Andean orogeny changed significantly in character.
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He also introduced contexts as a separate concept in it (see p. 161). There are identity types with the J-eliminator (which already appeared in MLTT73 but did not have this name there) but also with the rule that makes the theory "extensional" (p. 169). There are W-types. There is an infinite sequence of predicative universes that are cumulative.
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This extensional component can come from a slight shift in the position of a plate's Euler Pole. In order to accommodate oblique motion along the plate boundary, these leaky transform faults can break up into a series of small transforms linked by short segments of spreading ridges. These new transforms will follow small circles centred on the new Euler Pole.
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Pull-apart basins have short-lived subsidence that forms from transtensional strike-slip faults. Moderate strike-slip faults create extensional releasing bends and opposing walls pull apart from each other. Normal faults occur, inducing small scale subsidence in the area, which ceases once the fault stops propagating. Cooling occurs after the fault fails to propagate further following the crustal thinning via normal faulting.
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In the Jurassic there are NNE-NE trending folds and thrusts related to transpressional tectonics, and WNW trending normal faults with some strike-slip movement and widespread calc-alkaline magmatism, while the Cretaceous is characterized predominantly by extensional tectonics with NE-NNE trending normal faults, WNW trending folds and thrusts and highly alkaline acid magmatism located along faults, or at fault intersection.
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Block view of a rift formed of three segments, showing the location of the accommodation zones between them at changes in fault location or polarity (dip direction) Gulf of Suez Rift showing main extensional faults In geology, a rift is a linear zone where the lithosphere is being pulled apartRift valley: definition and geologic significance, Giacomo Corti, The Ethiopian Rift ValleyDecompressional Melting During Extension of Continental Lithosphere, Jolante van Wijk, MantlePlumes.org and is an example of extensional tectonics.Plate Tectonics: Lecture 2, Geology Department at University of Leicester Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben with normal faulting and rift- flank uplifts mainly on one side. Where rifts remain above sea level they form a rift valley, which may be filled by water forming a rift lake.
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In the Central Apennines the zone of extension is about 30 km wide, closely matching the zone of observed extensional strain as shown by GPS measurements. Recent large earthquakes in this area have been caused by movement on SW-dipping normal faults. This was the largest tremor since 2009, when an earthquake near L'Aquila in the Abruzzo region killed over 300 people and displaced about 65,000.
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360 It is exposed in the central Tusas Mountains, where it is distinctive enough to be an important stratigraphic marker bed. Its thickness is typically . Detrital zircon geochronology yields a minimum age for the source regions of 1665 Mya, consistent with the formation being deposited in an extensional basin (the Pilar basin) opened during the transition from the Yavapai orogeny to the Mazatzal orogeny.Jones et al.
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Ganis Chasma consists of a group of rift zones located in the Ganiki Planitia Quadrangle on Venus. A chasma is defined as a long, narrow, steep sided depression on a planet. These depressions, or canyons, formed as a result of extensional tectonics due to volcanism. Ganis Chasma is associated with volcanism of Sapas Mons, a coronae feature located in the Alta Regio region of Venus.
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Mud volcano systems are fairly common on Earth, and particularly in the Indonesian province of East Java. Beneath the island of Java is a half-graben lying in the east–west direction, filled with over-pressured marine carbonates and marine muds. It forms an inverted extensional basin which has been geologically active since the Paleogene epoch. The basin started to become overpressured during the Oligo- Miocene period.
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Grande Comore is the youngest at only 10,000 years old. Some geologists have proposed that the Comoros is an example of one of 11 primary mantle plumes worldwide. The East African Rift System became active 22 to 25 million years ago in the Miocene and its offshore extent is the youngest. The rift system causes seismicity, extensional deformation and created the offshore Kerimbas Graben.
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The Pantheon Fossae are a radial set of troughs in a region in the middle of Caloris Basin on Mercury. They appear to be a set of graben formed by extensional faults, with a 40 km crater located near the center of the pattern. The exact origin of this pattern of troughs is not currently known. The feature was nicknamed "the Spider" before receiving its official name.
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UHT rocks are now identified in all major continents and span different geological ages ranging from c. 3178 to 35 million years associated with major geological events. More than 46 localities/terranes with diagnostic UHT indicators have been reported over the globe, related to both extensional and collisional tectonic environments; the two fundamental types of Earth orogenic systems.Kelsey, D.E., 2008, On ultrahigh-temperature crustal metamorphism.
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Such materials are therefore best described as possessing both elasticity (reaction to deformation) and viscosity (reaction to rate of deformation); that is, being viscoelastic. Viscoelastic solids may exhibit both shear viscosity and bulk viscosity. The extensional viscosity is a linear combination of the shear and bulk viscosities that describes the reaction of a solid elastic material to elongation. It is widely used for characterizing polymers.
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25-33 Later sinistral transtension and lateral extension modified the structure of the belt during the Late Miocene and Pliocene. Extensional deformation on the eastern and western edge of the belt interacted with development of the Vienna and Transcarpathian basin. After the marine regression at the end of Miocene younger marls and turbidites were eroded faster than more competent Jurassic limestones forming distinctly looking klippes.
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Transfer zones can be farther identified by its maturity or (fault propagation evolution); whether the major fault relationship is approaching, overlapping, collateral or collinear. Since transfer zones are normally found in extensional settings many studies have been done within the East African rift system and the Gulf of Suez rift system. Transfer zones have also played a role in hydrocarbon exploration and extraction within the Albertine graben.
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In the 1946 "Silent and Verbal Levels" diagram,Kendig, M., "Alfred Korzybski's 'An Extensional Analysis of the Process of Abstracting from an Electro-Colloidal Non-Aristotelian Point of View.'" General Semantics Bulletin, Autumn-Winter 1950-51, Numbers Four & Five. Institute of General Semantics, Lakeville, CT. pp. 9-10. the arrows and boxes denote ordered stages in human neuro-evaluative processing that happens in an instant.
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When adjoining walls between pits in a pit crater chain collapse, they become troughs. In these cases, the craters may merge into a linear alignment and are commonly found along extensional structures such as fractures, fissures and graben. Pit craters usually lack an elevated rim as well as the ejecta deposits and lava flows that are associated with impact craters.Okubo, Chris, and Stephen Martel.
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A possible tectonic factor is the north–south extensional Upper Rhine Graben to the north. The Alps continue fairly smoothly into the following related Alpine mountain ranges: the Apennines to the southwest, the Dinarides to the southeast and the Carpathians to the northeast. In the east the Alps are bounded by the Viennese Basin and the Pannonian Basin, where east–west stretching of the crust takes place.
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Diabase and intruded rhyolites have also been identified in the sediments. All of the Salton Buttes, except for Mullet Island, have developed on a lineament, a linear feature with a conspicuous magnetic anomaly. The volcanoes seem to share a common feeder dyke. This dyke may be connected to deep-seated extensional processes along a transform fault that links the San Andreas Fault to the Gulf of California.
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In fluid dynamics, Kerr–Dold vortex is an exact solution of Navier–Stokes equations, which represents steady periodic vortices superposed on the stagnation point flow (or extensional flow). The solution was discovered by Oliver S. Kerr and John W. Dold in 1994Kerr, Oliver S., and J. W. Dold. "Periodic steady vortices in a stagnation-point flow." Journal of Fluid Mechanics 276 (1994): 307–325.
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The Alps were formed because the continents of Europe and Africa collided. It is thought that because the collision was irregular, the initial contact between the two continents resulted in the formation of dilational (extensional) structures in the foreland basin to the north of the Alps.Sengor, A.M.C. 1976. "Collision of irregular continental margins: Implications for foreland deformation of Alpine-type orogens", Geology, 4, 779–782.
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The ophiolite formed in the Late Cretaceous and consists of a basal metamorphic sole (150–200 m), peridotite tectonic (8–12 km), igneous peridotite and gabbro (0.5–6.5 km), sheeted dikes (1–1.5 km), and lavas (0.5–2.0 km). The Batinah complex containing continental margin sediments came from beneath the ophiolite during late-stage extensional faulting and then slid into the ophiolite late in the emplacement history.
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The central and southern part of the Apennines has been characterised by extensional tectonics since the Pliocene epoch (i.e. about the last 5 million years), with most of the active faults being normal in type and NW-SE trending. The extension is due to the back-arc basin in the Tyrrhenian Sea opening faster than the continental collision of the African Plate and the Eurasian Plate.
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The back-arc deformation may be either extensional or compressional. The overriding plate will shorten when its motion is directed towards the trench, resulting in a compression of the back- arc region. This type of deformation is associated with a shallow dipping subducted slab. Inversely, an overriding plate moving away from the trench will result in extension, and a back-arc basin will form.
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Tributary streams ran more-or-less in line with the Sierras, therefore not having their gradients increased. Thus their rate of valley cutting was not significantly affected. The results were hanging valleys and cascading waterfalls where the tributaries met the main streams. Additional uplift occurred when major faults developed to the east, especially the creation of Owens Valley from Basin and Range-associated extensional forces.
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The second, is associated with the formation of the West Antarctic Rift System between East and West Antarctica, which began in the Eocene and lasted into the late Oligocene era. This extensional phase was responsible for the formations of the basins on the continental shelf, including the Adare Basin. There has been considerable debate over the kinematic history of the West Antarctic Rift System.
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Often in mathematics, when one defines an equivalence relation on a set, one immediately forms the quotient set (turning equivalence into equality). In contrast, setoids may be used when a difference between identity and equivalence must be maintained, often with an interpretation of intensional equality (the equality on the original set) and extensional equality (the equivalence relation, or the equality on the quotient set).
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Cedar Breaks National Monument, Utah. Between the Rocky Mountains and the coast ranges is an area dominated by extensional forces. The extension of this region has occurred both regionally and locally in events beginning in the Jurassic; however, most extension was localized until the mid Miocene. These local events occurred in the Jurassic, late Cretaceous, and one spanning from the Eocene until the Oligocene.
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Divisio and partitio are classical terms for definitions. A partitio is simply an intensional definition. A divisio is not an extensional definition, but an exhaustive list of subsets of a set, in the sense that every member of the "divided" set is a member of one of the subsets. An extreme form of divisio lists all sets whose only member is a member of the "divided" set.
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The terrain of Guinevere Planitia is, although seemingly flat, full of extensional tectonic structures.Complex ridge terrain in Guinevere Planitia consists of embayed remnants of material that have undergone extensive deformation. Lineated materials contain one dominant orientation of tectonic features, and complexly lineated materials contain two or more tectonic fabrics. Ridge terrain includes the oldest materials found in this region and are often referred to as tessera.
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A graben is a tectonic feature associated with normal faulting. The footwall is raised while the hanging wall is lowered, creating a depression. The graben are thought to have formed from extensional stresses due to uplift and contraction of the volcanic deposits that filled the crater. Uplift is possible by isostatic rebound in response to the formation of the crater or from the volcanic material being deposited.
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The Southern Rocky Mountain Trench was created mainly by Cenozoic-aged extension (normal faulting). What little strike-slip movement that is found in the southern trench is not considered significant. The extensional faulting was nonetheless substantial, having extended as deep as . The southern trench also differs from the northern trench in that it is more sinuous and is asymmetrical in cross-section (perpendicular to its length).
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At the beginning of the first phase, these faults and folds made an impact on the tessera terrain, but later on it made an impact on the intratessera volcanic plains. On second phase, all the thrust faults and fold belts experienced a perpendicular extension. Furthermore, the last phase occurred when the extensional events continuously carried out the deformed structures from the plateau and affecting the volcanic units.
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Some also suggested this landform caused by the combined effect of shearing and extension or thrusting from crustal shortening. Starting from Permian, Junggar Basin was formed to initiate the foreland basin cycle. There presented extensional shearing and continuous deposition of non-marine foreland basin-fill till Triassic. Since the level of the trapped lake in the basin was rising, finer deposits covered widespread the basin with denudation.
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Z3 was developed in the Research in Software Engineering (RiSE) group at Microsoft Research and is targeted at solving problems that arise in software verification and software analysis. Z3 supports arithmetic, fixed- size bit-vectors, extensional arrays, datatypes, uninterpreted functions, and quantifiers. Its main applications are extended static checking, test case generation, and predicate abstraction. In 2015, it received the Programming Languages Software Award from ACM SIGPLAN.
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In the Late Tertiary, compressional forces ceased and extensional forces began. This led to the development of the Basin and Range province beginning 20–17 million years ago. The age of the Teton fault is somewhat controversial. Most estimates range between 2 and 13 million years old with a consensus that most of the movement on the fault occurred within the last 2 million years.
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Devana Chasma is a weak extensional rift zone on Venus, with a length of 4000 km, a width of 150–250 km, and a depth reaching 5 km. Most of the faults are facing north–south. The rift is located in Beta Regio, a 3000 km rise created by volcanic activity. Mantle plumes rising from the bottom are the reason behind the formation of the rift zone.
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About 1575–1562 Ma ago the Progine Zone was intruded by mafic magma during the same time spans as Rapakivi granites intruded more easterly domains in Fennoscandia. Later 1224–1215 and ca. 1204 Ma ago the progine zone was subject to extensional tectonics perhaps being a back-arc basin. The Protogine Zone obtained its final configuration during the Sveconorwegian orogeny 1130–950 Ma ago.
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The maximum temperature of around 180 K was reached at the depth of about 3 km. After the end of formation, the subsurface layer cooled, while the interior of Umbriel heated due to decay of radioactive elements present in its rocks. The cooling near-surface layer contracted, while the interior expanded. This caused strong extensional stresses in the moon's crust, which may have led to cracking.
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File:Volcanic Arc System.png Forearc basins form in subduction zones as sedimentary material is scraped off the subducting oceanic plate, forming an accretionary prism between the subducting oceanic lithosphere and the overriding continental plate. Between this wedge and the associated volcanic arc is a zone of depression in the sea floor. Extensional faulting due to relative motion between the accretionary prism and the volcanic arc may occur.
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Before the development of the silicon microcantilever, gold foil or tungsten wires were used as AFM sensors. A range of designs of quartz crystal resonators have been used, the most famous is the above- mentioned qPlus sensor. A new development which is getting attention is the KolibriSensor, using a length extensional quartz resonator, with a very high resonant frequency (~1 MHz) allowing very fast operation.
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They are common in extensional terrains, where heating takes place via deep circulation along faults, such as in the Western US and Turkey. Water passes through a heat exchanger in a Rankine cycle binary plant. The water vaporizes an organic working fluid that drives a turbine. These binary plants originated in the Soviet Union in the late 1960s and predominate in new US plants.
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As becomes clear, intensional definitions are best used when something has a clearly defined set of properties, and they work well for terms that have too many referents to list in an extensional definition. It is impossible to give an extensional definition for a term with an infinite set of referents, but an intensional one can often be stated concisely – there are infinitely many even numbers, impossible to list, but the term "even numbers" can be defined easily by saying that even numbers are integer multiples of two. Definition by genus and difference, in which something is defined by first stating the broad category it belongs to and then distinguished by specific properties, is a type of intensional definition. As the name might suggest, this is the type of definition used in Linnaean taxonomy to categorize living things, but is by no means restricted to biology.
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Some large layered complexes are not related to mantle plumes, or example, the Skaergaard intrusion in Greenland. Here, the large magma volumes which are created by mid-ocean ridge spreading allow the accumulation of large volumes of cumulate rocks. The problem of creating space for such intrusions is easily explained by the extensional tectonics in operation; extensional or listric faults operating at depth can provide a triangular space for keel-shaped or boat-shaped intrusions such as the Great Dyke of Zimbabwe, or the Narndee-Windimurra Complex of Western Australia. It is also possible that what we see as a cratonic margin today were created by the action of a plume event initiating a continental rifting episode; therefore the tectonic setting of most large layered complexes must be carefully weighed in terms of geochemistry and the nature of the host sequence, and in some cases a mixed mechanism cause is possible.
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Similarly, the thick succession of Mesoproterozoic strata consisting of the Belt-Purcell supergroup followed the same sequence of events leading to the structural culmination seen in the southern end of the Purcell anticlinorium. Evolution of the Lewis overthrust. The Lewis thrust is cut by two major extensional fault systems, the Flathead fault and the Rocky Mountain trench fault system. Both of which are late Eocene to Miocene in age.
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Transfer zones such as relay ramps can affect drainage within basins which in return can produce thickness trends. Understanding the drainage network in these extensional setting allows geologist to better identify lateral and vertical depositional facies. The Kaiso-Tonya, Butiaba-Wanseko, and the Pakwach transfer zones in the Albertine graben all contain hydrocarbons. The Kaiso- Tonya is a full graben style transfer zone much like conjugate convergent collateral types.
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Drazin, P. G., & Riley, N. (2006). The Navier–Stokes equations: a classification of flows and exact solutions (No. 334). Cambridge University Press.. These steady solutions exist as a result of a balance between vortex stretching by the extensional flow and viscous dissipation, which are similar to Burgers vortex. These vortices were observed experimentally in a four-roll mill apparatus by Lagnado and L. Gary LealLagnado, R. R., & Leal, L. I. (1990).
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Basin rift system initiated at the onset of north-south extension between the Australian and Antarctic plates in the late Jurassic. Growing extensional structures were filled with ~5000 meters of continental and fluvio-lacustrine sediments that comprise the Crayfish Group. In the Aptian the basin experienced widespread thermal subsidence where ~4000 meters of fluvial and lacustrine sediments of the Eumeralla Formation were deposited in the progressively widening sag basin.
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Krawczuk (2002)Krawczuk, M., 2002. Application of spectral beam finite element with a crack and iterative search technique for damage detection. Finite Elements in Analysis and Design 9–10, 991–1004. used an extensional spring at the damage location, with its flexibility determined using the stress intensity factors KI. Approximate methods to model the crack are by Chondros et al. (1998),Chondros, T., Dimarogonas, A., Yao, J., 1998.
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Lustrin A is an insoluble protein used in the production of a nacreous layer in bivalve molluscs. It contributes to the properties of the nacreous layer, imparting resistance to cracking and elasticity. This is accomplished by its structure; it consists of many spring-like units which can expand when the shell is under extensional pressure. Its structure is similar to that of proteins involved in silica deposition in diatoms.
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The Stewartry Group is a geological group, a stratigraphic unit of mainly breccias and sandstones of Permian age that are found in Southern Scotland. The sequence sits unconformably either on rocks of lower Paleozoic age or Carboniferous strata. The upper boundary of this unit is everywhere erosional. Rocks of the Stewartry Group form the fill of a series of extensional basins trending NW-SE to N-S across the Southern Uplands.
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This zone has thought to have been formed by the bending of the lithosphere resulting from subduction processes (causing gravity sliding and faulting). The PTZ represents the transitional zone between the extensional and compressional environments along the Manila Trench. This region increases in compressional strength as it approaches the accretionary prism of the trench. The PTZ also displays blind thrust faults and folds (essentially buried folds and faults).
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This is the basis for the position advanced by Chile and Argentina for their territorial claims. The Scotia Arc is the island arc system that links the mountains of the Antarctic Peninsula to those of Tierra del Fuego. There are various volcanoes in the islands around the Antarctic Peninsula. This volcanism is related to extensional tectonics in Bransfield Rift to the west and Larsen Rift to the east.
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The Taranaki Basin is an onshore-offshore Cretaceous rift basin on the West Coast of New Zealand. Development of rifting was the result of extensional stresses during the breakup of Gondwanaland. The basin later underwent fore- arc and intra-arc basin development, due to the subduction of the Pacific Plate under the Australian Plate at the Hikurangi Subduction System. The basin covers approximately 100,000 km2 of which the majority is offshore.
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These units are covered in a vast ice sheet, known as the West Antarctic Ice Sheet. Two major extensional events have affected the West Antarctic Rift System. This led to the formation of a series of continuous, north-south trending basins stretching from the Transantarctic mountains out into the Ross Sea embayment. The first is associated with the breakup of the supercontinent, Gondwana (Gondwanaland), during the Jurassic or Cretaceous.
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In mathematics, a setoid (X, ~) is a set (or type) X equipped with an equivalence relation ~. A Setoid may also be called E-set, Bishop set, or extensional set.Alexandre Buisse, Peter Dybjer, "The Interpretation of Intuitionistic Type Theory in Locally Cartesian Closed Categories - an Intuitionistic Perspective", Electronic Notes in Theoretical Computer Science 218 (2008) 21–32. Setoids are studied especially in proof theory and in type- theoretic foundations of mathematics.
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A number of geologists consider Cura-Mallín Basin, the sedimentary basin where the formation deposited, an extensional basin that developed on the western fringes of the much larger Neuquén Basin, while others consider it a back-arc basin. In the Upper Miocene the sedimentary basin was inverted.Radic, 2010 Relative to other nearby sedimentary basins of Miocene and Oligocene age Cura-Mallín Basin has been more researched.Franzese et al.
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The CaBER is a capillary breakup rheometer. A small quantity of material is placed between plates, which are rapidly stretched to a fixed level of strain. The midpoint diameter is monitored as a function of time as the fluid filament necks and breaks up under the combined forces of surface tension, gravity, and viscoelasticity. The extensional viscosity can be extracted from the data as a function of strain and strain rate.
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They were recognized as fragments of oceanic lithosphere, and dykes were viewed as the result of extensional tectonics at mid-ocean ridges. The plutonic rocks found in ophiolites were understood as remnants of former magma chambers. In 1973, Akiho Miyashiro revolutionized common conceptions of ophiolites and proposed an island arc origin for the famous Troodos Ophiolite in Cyprus, arguing that numerous lavas and dykes in the ophiolite had calc-alkaline chemistries.
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What is justice? Aside from being immutable, timeless, changeless, and one over many, the Forms also provide definitions and the standard against which all instances are measured. In the dialogues Socrates regularly asks for the meaning – in the sense of intensional definitions – of a general term (e. g. justice, truth, beauty), and criticizes those who instead give him particular, extensional examples, rather than the quality shared by all examples.
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A tectonic phase or deformation phase is in structural geology and petrology a phase in which tectonic movement or metamorphism took place. Tectonic phases can be extensional or compressional in nature. When numerous subsequent compressional tectonic phases share the same geodynamic cause (usually some plate tectonic mechanism) this is called an orogeny. During an orogeny tectonic phases lead to mountain building, which causes deformation and metamorphism of rocks.
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Syncline next to Nordenskjöld Lake in Torres del Paine National Park. The syncline formed during the Andean orogeny. The early development of the Andean orogeny in southernmost South America affected also the Antarctic Peninsula. In southern Patagonia at the onset of the Andean orogeny in the Jurassic, extensional tectonics created the Rocas Verdes Basin, a back-arc basin whose southeastern extension survives as the Weddell Sea in Antarctica.
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Map of plate motions in the Mediterranean region. The Gulf of Corinth (GoC) is located in the eastern region and is undergoing fast extension. The North Anatolian Fault (NAF) and East Anatolian Fault (EAF) are currently strike- slipping. Adapted from Armijo, 1999 The Gulf of Corinth basin, or Corinth rift, is an active extensional marine sedimentary basin thought to have started deforming during the late Miocene – Pleistocene epoch.
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Many volcanoes produce deformational structures as they grow. The flanks of volcanoes commonly exhibit shallow gravity slumps, faults and associated folds. Large volcanoes grow not only by adding erupted material to their flanks, but also by spreading laterally at their bases, particularly if they rest on weak or ductile materials. As a volcano grows in size and weight, the stress field underneath the volcano changes from compressional to extensional.
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This event was followed by low-angle extensional faulting along the East Antarctic plate. No uplift occurred during this initial phase of faulting due to counteracting erosional events. Shortly after, during the Mid Cretaceous (100 Ma), the West Antarctic Rift System began to form. Certain models show that the rapid rifting and intense thermal forces are due to a shallow (50 km depth) lithosphere-asthenosphere boundary under the Transantarctic Mountains.
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The two possible answers share a number of assumptions. First, it is assumed that the space of all possible events can be easily enumerated, providing an extensional definition of outcomes: {BB, BG, GB, GG}. This notation indicates that there are four possible combinations of children, labeling boys B and girls G, and using the first letter to represent the older child. Second, it is assumed that these outcomes are equally probable.
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Formed behind a subduction zone and involves process that creates an extensional regime oriented perpendicular to the subduction zone. First proposed by Karig (1971), shows the WPB as forming by back-arc spreading behind the Oki-Daito Ridge starting the Eocene. Crustal extension within the plate took place successively in the eastern portion of the plate to form the other inter-arc basins. Supporters include: Lewis et al.
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When a strike-slip fault is offset along strike such that the resulting bend in the fault hinders easy movement, e.g. a right stepping bend on a sinistral (left-lateral) fault, this will cause local shortening or transpression. Examples include the 'Big Bend' region of the San Andreas fault,Rust, D. 1998. Contractional and extensional structures in the transpressive ‘Big Bend’ of the San Andreas fault, southern California.
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Best argues that the principle of extensional self-defense mirrors the penal code statues known as the "necessity defense," which can be invoked when a defendant believes that the illegal act was necessary to avoid imminent and great harm. He also argues that is not just a theory, but policy in some African countries where governments hire armed soldiers to protect endangered wildlife from poachers who wish to sell their body parts in international markets: > "Pacifists cannot stop poachers, but bullets can, and while many measures > must be taken to protect endangered species, right now armed soldiers are > the best protection rhinos and elephants have against murderous, weapon- > wielding poachers." In testimony to the Senate in 2005, Jerry Vlasak stated that he regarded violence against Huntingdon Life Sciences as an example of extensional self- defense.Miller, John J. "In the name of the animals: America faces a new kind of terrorism", National Review, July 3, 2006.
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Many of these basins, including the Kutai, have formed in a back arc extensional setting, driven by passive or active subduction rollback. The mid Miocene episode of inversion in the Kutai can be linked to collision of continental fragments from the South China Sea with NW Borneo. The Pliocene inversion episode is contemporaneous with the collision of Australia with the Banda arc, with structural connections provided by strike- slip fault systems through Sulawesi.
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Laguna del Maule is located within a segment known as the Transitional Southern Volcanic Zone, west of the Peru–Chile Trench. Volcanoes in this segment are typically located on basement blocks that have been uplifted between extensional basins. The Laguna del Maule lake lies on the crest of the Andes, within a depression with a diameter of . The lake has a depth of and covers a surface of ; the surface is at an altitude of .
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The geometry of the Karoo Triple Junction, which is the bulging upward of land surface, might be formed due to extensional tectonics. Cracking and jointing are induced, hence lines of weaknesses are developed in the region. In the Thune section of the Okavango dyke swarm, the texture of the rocks show evidence of deformation caused by tensional strain. Planar foliations are found in rock grains which are perpendicular to the dyke plane.
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Zones of thickened crust, such as those formed during continent-continent collision tend to spread laterally; this spreading occurs even when the collisional event is still in progress. After the collision has finished the zone of thickened crust generally undergoes gravitational collapse, often with the formation of very large extensional faults. Large-scale Devonian extension, for example, followed immediately after the end of the Caledonian orogeny particularly in East Greenland and western Norway.
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During this time the Central Atlantic magmatic province (CAMP), with an estimated the largest igneous province in Earth's history, was formed to the present southwest of the Danish-Swedish realm. In the Skåne area, the Central Skåne Volcanic Province was active during the time of deposition of the Rya Formation, commencing around the Sinemurian- Pliensbachian boundary. The earliest magmatism was partly emplaced into and across pre-existing extensional basin structures.Bryan & Ferrari, 2013, p.
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A detachment province of Oligocene-Miocene age is located both onshore and within the offshore continental shelf. Primarily made up of listric down-to-the-basin growth faults, the system is overlain by up to five kilometers of deltaic sediments. Subsidence of these sediments is often due to simple gravitational failure or deeper extensional faulting associated with salt withdrawal. The abundance of sandstone in the area makes Louisiana a prime petroleum reservoir.
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500px NVPM are the result of rifting when a continent breaks up to form an ocean, producing transitional crust without volcanism. Extension causes a number of events to occur. First is lithospheric thinning, which allows asthenospheric upwelling; heating further erodes the lithosphere, furthering the thinning process. The extensional forces also cause listric faults and continentward dipping reflectors that help identify NVPM and distinguish them from VPM, characterized by seaward-dipping seismic reflectors.
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The fluidic layer contains the channels for the aqueous solution to travel through. Many devices have a cross slot where two opposing laminar streams converge. This creates planar extensional flow with a point where velocity becomes zero, which is known as the fluid stagnation point. Upon analyzing a fluid with beads, DNA, or other very small particles under a microscope, the trajectories of the particles and the stagnation point can be determined.
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Décollements in extensional settings are accompanied by tectonic denudation and high cooling rates. They can form by several methods: # The megalandslide model predicts extension with normal faults near the original fault source and shortening further away from the source. # The in situ model predicts numerous normal faults overlying one large décollement. # The rooted, low angle normal fault model predicts that the décollement is created when two thin sheets of rock decouple at depth.
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Models suggest that impacts accompanying accretion caused heating of Tethys's outer layer, reaching a maximum temperature of around 155 K at a depth of about 29 km. After the end of formation due to thermal conduction, the subsurface layer cooled and the interior heated up. The cooling near-surface layer contracted and the interior expanded. This caused strong extensional stresses in Tethys's crust reaching estimates of 5.7 MPa, which likely led to cracking.
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The Austrian constitution uses the term "supreme executive organ" multiple times but provides neither an intensional nor an extensional definition. Article 19 of the Federal Constitutional Law contains what appears to be a taxative enumeration of supreme executive organs, but this list is universally dismissed as specious and useless. The defining characteristics of supreme executive organs and the consequences of membership to the class have been established by case law and academic scholarship.
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The Weymouth Anticline has a west–east trending axis and plunges to the east. Strata beneath the Upper Triassic halite are unfolded indicating that the salt is acting as a decollement. The anticline is a result of inversion along the Abbotsbury–Ridgeway Fault, although it has been suggested that it developed by the tightening of an earlier rollover anticline, formed during an earlier extensional phase, due to the soft-linked nature of the faulting.
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Most sedimentation in the Adare Basin took place after the second extensional event. Sedimentation offshore Antarctica is primarily driven by pelagic settling, down-slope gravity flows, and across-slope current flows driven by the Antarctic Circumpolar Current. The continental slope in the Adare Basin is very steep and sinuous, causing turbidite channels to be common. Several Antarctic deep water currents are also responsible for depositing large amounts of sediment into the basin.
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High-grade (bonanza) gold ore, brecciated quartz-adularia rhyolite. Native gold (Au) occurs in this rock as colloform bands, partially replaces breccia clasts, and is also disseminated in the matrix. Published research indicates that Sleeper Mine rocks represent an ancient epithermal gold deposit (hot springs gold deposit), formed by volcanism during Basin & Range extensional tectonics.Geology and geochemistry of the Sleeper Gold Mine , USGS Open File Report 89-476, 1989 Sleeper Mine, Humboldt County, Nevada.
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The 2009 Samoa earthquake and tsunami took place on 29 September 2009 in the southern Pacific Ocean adjacent to the Kermadec-Tonga subduction zone. The submarine earthquake occurred in an extensional environment and had a moment magnitude of 8.1 and a maximum Mercalli intensity of VI (Strong). It was the largest earthquake of 2009. A tsunami was generated which caused substantial damage and loss of life in Samoa, American Samoa, and Tonga.
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North-south rifting with the breakup of Pangea in the Triassic segmented the Ringkobing-Fyn High into a narrow graben. Sedimentation occurred in fault-bound alluvial fan deposits with occasional small marine transgressions, such as the Muschekalk Sea in the mid- Triassic in the Ringkobing-Fyn High. Triassic outcrops are only found on southern shore of Bornholm. Extensional faulting occurred throughout the Mesozoic, but overall, conditions remained the same into the Cretaceous.
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This side is called the "Tyrrhenian Extensional Zone." The mountains of Italy are of paradoxical provenience, having to derive from both compression and extension: > "The paradox of how contraction and extension can occur simultaneously in > convergent mountain belts remains a fundamental and largely unresolved > problem in continental dynamics." Both the folded and the fault-block systems include parallel mountain chains. In the folded system anticlines erode into the highest and longest massifs of the Apennines.
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The oldest rocks exposed at the surface in Iraq are part of the Cambrian and Ordovician age Khabour Quartzite Formation. Very little research and as of 1997 no boreholes have managed to reach underlying Precambrian rock. Most likely deeper basement rocks are part of the Afro- Arabian Plate formed into a craton in the Proterozoic. Northeastern Iraq has a thinned quasicontinental crust due to Neo-Tethys extensional faulting and plastic deformation of rocks.
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L-teconite mylonite formed from coarse-grained sandstone protolith, Glengarry Basin, Australia. This photograph illustrates a pronounced and prominent stretching lineation plunging steeply to the north, as a rake upon the main shear foliation parallel with the protractor. Stretching lineations may form in any faulting regime when conditions are such that rocks deform ductiley, including extensional, compressional, transpressional, and transtensional. Stretching lineations are formed by shearing of rocks during asymmetric deformation of a rock mass.
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The Sierra de Tejeda is in the central section of the Betic Range of Southern Spain. This part of the Betic cordilla has folds verging southwards from the Burdigalian age. The folds are cut by WSW-directed faults caused by extensional detachments in the Sierra de Tejeda anticline, and the fault surfaces are in turn cut by later NNW-directed faults from the Tortonian age. The most common rock in the Sierra Tejeda is limestone.
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This development is believed to have come about 40 million years ago as the extensional forces that caused the uplift of the Rockies began to cause the crust to thin and crack. Near-vertical faults formed almost uniformly throughout the region, most trending northwest to southeast. The blocks then broke up, some dropping and creating valleys like the Flathead and the Swan. In all, the whole process took around 100 million years.
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Xinjiang paleocraton was pulled apart for a continental rifting episode to form extensional basins in Late Cambrian. The continuous divergence of the continental crust during late Cambrian to Ordovician shaped the West Junggar Ocean. The West Junggar Ocean presented as the present Tangbale and Honguleleng ophiolites from intra-plate volcanism, and then this volcanism shut in mid-upper Ordovician. The Ordovician first ocean basin indicated that eastern Junggar was over passive margin.
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Suppose we have a language without modal adverbs like "necessarily". Such a language would be extensional, in the way that two predicates which are true about the same objects are interchangeable again without altering the truth-value. Thus, there is no assurance that two terms that are interchangeable without the truth-value changing are interchangeable because of meaning, and not because of chance. For example, "creature with a heart" and "creature with kidneys" share extension.
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Epicratonic Basins of Peri-Tethyan Platforms (Vol. 179). Éditions du Muséum. Triassic, Jurassic and Cretaceous strata are confined within basins controlled by the extensional structures of the Mesozoic rift. The Jurassic basins can be grouped into two main provinces located on either side of an emerged Massif Ancien: west, where the basin was open to the Early Atlantic, being related to its passive margin, and east with several epicontinental troughs connected to the Tethys Ocean.
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Lifted fault-block geology Tilted fault-block formation in the Teton Range Belasitsa, Rila - Rhodope massif, Bulgaria Fault-block mountains often result from rifting, an indicator of extensional tectonics. These can be small or form extensive rift valley systems, such as the East African Rift zone. Death Valley in California is a smaller example. There are two main types of block mountains; uplifted blocks between two faults and tilted blocks mainly controlled by one fault.
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Transtension is the state in which a rock mass or area of the Earth's crust experiences both extensive and transtensive shear. As such, transtensional regions are characterised by both extensional structures (normal faults, grabens) and wrench structures (strike-slip faults). In general, many tectonic regimes that were previously defined as simple strike-slip shear zones are actually transtensional. It is unlikely that a deforming body will experience 'pure' extension or 'pure' strike-slip.
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The intersecting of material and tectonic structures are the defined characteristic of tessera, but the sets are not always seen in the images. Due to the heavy tectonic deformation, it contains both contractional features of ridges and extensional features of graben and fractures. The boundaries of tessera shows embayment by other materials of other units. By this cross-cutting relationship, it provides evidence of tessera being the oldest unit within the strata.
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This is an iron-rich sediment resembling laterites and indicating extensive erosion of the massif (after its renewed uplift) under subtropical climatic conditions. In the Middle Eocene (Lutetian) a new distensional period started that reached its climax during the Oligocene. The stretching of the crust caused extensional grabens to form. Examples are the roughly N-S- to NNW-SSE- striking asymmetric graben structures of the Bresse, Cher, Limagne, Plaine du Forez and the Roanne graben.
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Indirect evidence is found in the shared characteristics of the field with other Quaternary volcanic fields linked to extensional faulting found throughout the province. This includes intraplate geochemical signatures in the magmas, and the presence of mantle and crustal xenoliths.Lynch, D. J., T. E. Musselman, J. T. Gutmann, and P. J. Patchett, Isotopic evidence for the origin of Cenozoic volcanic rocks in the Pinacate volcanic field, northwestern México, Lithos, 29, 295-302, 1993.
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IDEAS is a formal, higher-order, 4D (see four dimensionalism) ontology. It is extensional (see Extension (metaphysics)), using physical existence as its criterion for identity. In practical terms, this means the ontology is well suited to managing change over time and identifying elements with a degree of precision that is not possible using names alone. The ontology is being built using the BORO Method which has proven useful for the multi-disciplinary team working on IDEAS.
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The Yukon's crystalline basement is overlain by thick sedimentary strata deposited in extensional and/or rift basin environments. These basement rocks are not exposed anywhere in the Yukon, and the thickness of the surpracrustal sediments makes surveying using aeromagnetics, a technique used for inferring basement character in NWT, difficult. Hence, the character of the underlying crystalline basement of the Wernecke range is not well-known. Estimates for the age of the basement rock ranges from Archean to early Proterozoic.
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Journal of the Geological Society, 150, 515-527. It has been proposed that the Hoy sandstones are the lateral equivalents of the Eday Group, the thickness and associated facies changes being caused by active extensional faulting during deposition. The presence of lavas within the Eday Flagstone Formation has been used to lend support to this idea, but differences in the chemistry between these lavas and those on Hoy mean that such a correlation remains uncertain.Odling, N.W.A. 2000.
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The Moab Fault, near Moab, Utah, United States, is an extensional fault that runs approximately NW-SE, passing to the west of the Arches National Park. It is about long and has a maximum displacement of about . The fault connects with the Tenmile Graben in the north and extends through the Moab-Spanish Valley to the south. The fault outcrop has a well-defined fault zone bordered by a damage zone of minor faults and fractures.
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Tectonic extension occurs at the points where the fault forms stepovers, although the extensional structures are still relatively immature. The Cahuilla Basin, also known as the Salton Sink, is part of the trough that is occupied by the Gulf of California. The basin structure is surrounded by various crystalline rocks that were formed from the Precambrian era forwards to the Tertiary period. About of sediment fill the basin from the Miocene, testifying to rapid tectonic subsidence.
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While the East African rift system is experiencing profound extension the transfer zones that link major extensional faults do not experience this extension. Transfer zones within the East African rift are most commonly in the overlapping stage but every stage has been observed. Here, transfer zones are generally high areas with complex internal fault geometries. These general high areas generally are conjugate divergent type zones and have been observed in the Tanganyika rift and Albertine rift of Uganda.
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The grabens have also repeatedly been flooded by the Mediterranean, examples being the graben near Ampurdan and grabens in the Roussillon containing a Pliocene fauna. These extensional structures most likely owe their existence to renewed movements on Variscan fractures. The very young volcanic area near Olot probably has a similar cause. Ossoue glacier and Pic Montferrat in the Vignemale massif During the Quaternary, the Pyrenees experienced several glaciations, but of far less intensity than for example in the Alps.
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In areas of high crustal stretching, individual extensional faults may become rotated to too low a dip to remain active and a new set of faults may be generated. Large displacements may juxtapose syntectonic sediments against metamorphic rocks of the mid to lower crust and such structures are called detachment faults. In some cases the detachments are folded such that the metamorphic rocks are exposed within antiformal closures and these are known as metamorphic core complexes.
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Raditladi Basin topography Raditladi Basin is a large peak ring impact crater on Mercury with a diameter of 263 km. Inside its peak ring there is a system of concentric extensional troughs (graben), which are rare surface features on Mercury. The floor of Raditladi is partially covered by relatively light smooth plains, which are thought to be a product of the effusive volcanism. The troughs may also have resulted from volcanic processes under the floor of Raditladi.
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They range from porphyritic alkaline rhyolite to alkaline aplite to porphyritic alkaline granite. In map view, the igneous bodies of the Climax Stock form a roughly circular structure. In cross-section view, each intrusion has an inverted bowl shape. Published studies on the origin of the Climax Molybdenum Deposit and other Climax-type moly deposits have concluded that they form principally in incipient extensional tectonic settings well inland from shallow-angle subduction zones that have recently ceased.
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Within language we find instances of combined categories, such as tall man or small elephant. Combining categories was a problem for extensional semantics, where the semantics of a word such as red is to be defined as the set of objects having this property. This does not apply as well to modifiers such as small; a small mouse is very different from a small elephant. These combinations pose a lesser problem in terms of prototype theory.
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Rhine Graben (blue shades) between Basel and Frankfurt with adjoining mountain ranges (green to brown); colour-coding according to digital elevation model The extension induced by the formation of the Alps was sufficient to thin the crust and provide suitable dilational conduits for magmatic and volcanic activity to occur. This resulted in the emplacement of mafic dykes, which follow the general structural trend of the extensional faults. In addition, isolated volcanoes such as the Kaiserstuhl were formed.
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The Rocas Verdes ophiolites () are a series of greenschists and other rocks constituting ophiolites in Magallanes Region, southernmost Chile. The Rocas Verdes ophiolites represent the continental-oceanic crust that existed in a back-arc basin in the Mesozoic Era as result of extensional tectonics. This back-arc basin then evolved into the Magallanes foreland basin in the Cenozoic Era within the context of the wider Andean orogeny. The main Rocas Verdes ophiolites are the Sarmiento and Tortuga complexes.
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Rachmaninoff is a peak-ring impact crater on Mercury. This basin, first imaged in its entirety during MESSENGERs third Mercury flyby, was quickly identified as a feature of high scientific interest, because of its fresh appearance, its distinctively colored interior plains, and the extensional troughs on its floor. The morphology of Rachmaninoff is similar to that of Raditladi, which is one of the youngest impact basins on Mercury. The age of Raditladi is estimated at one billion years.
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Formally, α,β ∈ Dt, and α=0 or β=1. Extensional Identity occurs when an expression α is identical with a prior mentioned expression β, which makes α given. #They brought some beer (β), but they didn't drink [the beer]Given (α) because it was warm. A hypernym α of another item β is when the meaning of α includes β as a subcategory, making item α given: X: I brought carrots (β) to the picnic.
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An analysis of the propagation speed indicates that the rupture propagated at a normal velocity along the original segment, but increased in velocity to above the S-wave velocity after the jump across the extensional stepover and continued at that speed until propagation stopped. This makes the Kunlun earthquake the best documented example of a supershear earthquake. It has been suggested that the unusually wide zone of co-seismic deformation is a direct result of the supershear rupture propagation.
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An intensional definition, also called a connotative definition, specifies the necessary and sufficient conditions for a thing to be a member of a specific set. Any definition that attempts to set out the essence of something, such as that by genus and differentia, is an intensional definition. An extensional definition, also called a denotative definition, of a concept or term specifies its extension. It is a list naming every object that is a member of a specific set.
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KnowRob is an extensional project of RoboEarth. It is a knowledge processing system that combines knowledge representation and reasoning methods with techniques for acquiring knowledge and for grounding the knowledge in a physical system and can serve as a common semantic framework for integrating information from different sources. ' is a large-scale computational system that learns from publicly available Internet resources, computer simulations, and real-life robot trials. It accumulates everything robotics into a comprehensive and interconnected knowledge base.
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Bonanza gold ore from the Sleeper Mine, in brecciated quartz-adularia rhyolite. The Sleeper Gold Mine was a high-grade gold mine operated by AMAX Gold from 1986 until 1996, producing 1.66 million ounces of gold and 2.3 million ounces of silver. It is located about 25 miles northwest of Winnemucca in Humboldt County, Nevada. Sleeper Gold Project of Paramount Gold This was an epithermal (hot springs) gold deposit, formed by volcanism during Basin and Range extensional tectonics.
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Due to the similarities between Earth and Venus, it is suggested that they have a similar lithospheric elastic thickness of ~30 km. East African Rift is the only rift that can be compared to Devana Chasma.Solomon, S.C. (1985) The elastic lithosphere: Some relationships among flexure, depth of faulting lithosphere thickness and thermal gradient, Lunar Planet. w. 799-600. Both rifts have fault segments length around ~100 km, which makes them stronger than any extensional system on Earth.
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Rheometry (from the Greek ῥέος – rheos, n, meaning "stream") generically refers to the experimental techniques used to determine the rheological properties of materials, that is the qualitative and quantitative relationships between stresses and strains and their derivatives. The techniques used are experimental. Rheometry investigates materials in relatively simple flows like steady shear flow, small amplitude oscillatory shear, and extensional flow. The choice of the adequate experimental technique depends on the rheological property which has to be determined.
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Rebollar, C. J., A. Reyes, and M. Reichle, Estudio del enjambre de San Quintín, Baja California, México, ocurrido durante 1975, Geofís, Int., 21 (4), 331-358, 1982. The ten volcanic complexes of San Quintín are all aligned N-S to NW-SE, parallel to an offshore fault, the Santillán and Barrera line, and the main escarpment of the Gulf of California. The cones are therefore related to faulting, but no direct evidence for extensional faulting has been found.
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As mentioned above, the pre-rift stratigraphy of the central Gulf of Mexico basin, which now lies beneath nearly 20 kilometers of sediment deposited during the Jurassic through the Holocene, is made up primarily of extensional graben formations filled with "red beds," basalt flows, and diabase dikes and sills deposited and intruded during the break-up of Pangaea and the explosion of the Central Atlantic Magmatic Plume. Red beds, also referred to as non-marine clastic sequences, which are often red in color, have been found in wells drilled in the Gulf of Mexico which penetrated the Late-Triassic and Early-Jurassic strata, filling the extensional graben features. The Gulf of Mexico basin red beds are specifically named the Eagle Mills formation, located directly beneath the salt, evaporite and marine sediments deposited during the Jurassic, and often found with the diabase dikes and basalt flows mentioned above. Basement rocks in the northeastern region of the Gulf of Mexico basin are fragments of the African plate which remained behind during the breakup of Pangaea and date back to the late Precambrian through the Cambrian.
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In practice, not all polymers are suitable for fiber spinning or drawing. This is particularly an issue in extensional-thinning polymers, where capillary failure or necking can cause separation of the melt before solidification. Draw resonance is the most common issue that can occur during drawing of the polymer melt, regardless of polymer suitability. Resonance occurs when the rate of mass flow is not constant between the spinneret and fiber take up roller, despite being constant at each of those individual components.
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He examined the crustal structures of many locations in China and investigated sources of seismic waves. He studied the geodynamics of the extensional basins in North China and their connection to the 1976 Tangshan earthquake. In the 1990s, Zeng organized the first Sino- American joint project to investigate the crust and upper mantle of the Tibetan Plateau and the collision process of the Indian Plate with the Eurasian Plate. He was conferred the State Science and Technology Progress Award (Third Class) in 1997.
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Inside the crater walls, the floor of the crater is filled by lava plains, similar to the maria of the Moon. These plains are superposed by explosive vents associated with pyroclastic material. Outside the walls, material ejected in the impact which created the basin extends for , and concentric rings surround the crater. In the center of the basin is a region containing numerous radial troughs that appear to be extensional faults, with a crater, Apollodorus, located near the center of the pattern.
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This uplift has occurred because of the isostatic response associated with the formation of an extensional basin. As a consequence, the highest mountains exist immediately adjacent to the margin of the basin, and become increasingly low outwards. The boundaries between the hill ranges and the Rhine Graben are defined by major, normal fault zones. The northern section of the Rhine Plain is equally framed by somewhat lower mountain ranges, the Palatinate Forest on the western and the Odenwald on the eastern side.
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He contributed materially to the development of the follow-up TOPO-EUROPE Project, which addresses the neotectonic and topographic evolution of Europe. Ziegler published widely in international journals and in thematic volumes on processes controlling extensional and compressional intraplate tectonics and on the evolution of the lithosphere. His publications found wide recognition and contributed enormously to narrowing the gap between academia and the industry. His work changed the way geologists look at depositional systems and tectonic processes controlling the evolution of sedimentary basins.
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The earthquake was a result of movement on a moderately dipping thrust fault, interpreted to represent reactivation of one the extensional faults associated with the Timiskaming Graben. It had an epicentre approximately northeast of Témiscaming, Quebec. It occurred at 1:03 a.m. ET, the earthquake was felt over a wide swath of North America, extending west to Fort William (now Thunder Bay), east to Fredericton, New Brunswick, north to James Bay and south as far as Kentucky and West Virginia.
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This portion of Egypt is adjacent to the African and Arabian tectonic plates. The Red Sea divides the two and splits, with one branch turning north along the Gulf of Aqaba into the Dead Sea Transform system, and the main trend continuing along the Gulf of Suez. While the earthquake activity in the Gulf of Aqaba is characterized by left-lateral strike-slip faulting, the Gulf of Suez is primarily influenced by extensional tectonics, with increasing extension from north to south.
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This extensional deformation is associated with a steeply dipping slab. The extreme cases of these two types of back-arc deformation can be found in Chile and at the Marianas arc. The shallow dipping slab subducting beneath Chile at an angle of about 10–15° causes a compressional stress on the back-arc region behind the Andes. On the other extreme, the slab going down into the mantle at the Marianas subduction zone is so steep it is nearly vertical.
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The Delfin Basin (delfín is Spanish for "dolphin") is a pair of interconnected submarine depressions located on the seabed of the northern Gulf of California.Delgado-Granados et al, in SPE by the Geological Society of America, Map p.145 The northernmost of these is called the Upper Delfin Basin while the southernmost is called the Lower Delfin Basin. Both of these features are areas of subsidence caused by extensional forces imparted by a spreading center associated with the East Pacific Rise.
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The Variscan orogeny is the oldest event for which there is evidence in Dorset, forming a major series of thrust faults in Carboniferous and older rocks. These thrusts trend west–east, dip moderately towards the south and have controlled later basin development and subsequent phases of inversion. During the Permo-Triassic the area was affected by a phase of rifting that reactivated the older thrusts in extension. These extensional faults were themselves reactivated during further rifting in Jurassic to early Cretaceous times.
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The earthquake had an estimated magnitude of 7.0–7.5 , recalculated as 6.7 . The calculated epicentre lies about 4 km west-northwest of San Benedetto dei Marsi. Surface ruptures that were mapped at the time show that parts of both the MHF and SBMGF moved during the earthquake. Focal mechanisms calculated using the limited instrumental data available for the earthquake suggest strike-slip faulting, but this is at odds with the known geological structure and the mechanism is thought to be purely extensional.
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Map of Libya The Sirte Basin is a late Mesozoic and Cenozoic triple junction continental rift (extensional basin) along northern Africa that was initiated during the late Jurassic Period. It borders a relatively stable Paleozoic craton and cratonic sag basins along its southern margins. The province extends offshore into the Mediterranean Sea, with the northern boundary drawn at the 2,000 meter (m) bathymetric contour. It borders in the north on the Gulf of Sidra and extends south into northern Chad.
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Early work established that a key factor was to make a series of clear metaphysical choices to provide a solid (metaphysical) foundation. A key choice was for an extensional (and hence, four-dimensional) ontology which provided neat Criterion of identity. Using this top ontology as a basis, a systematic process for re-engineering legacy systems was developed. From a software engineering perspective, a key feature of this process was the identification of common general patterns, under which the legacy system was subsumed.
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Alba Mons, at the northern end of the Tharsis plateau, is 1500 km in diameter, and stands 6 km above the surrounding plains. In comparison, Mauna Loa is a meager 120 km wide and stands 9 km above the sea floor. The load of Tharsis has had both regional and global influences. Extensional features radiating from Tharsis include graben several kilometers wide, and hundreds of meters deep, as well as enormous troughs and rifts up to 600 km wide and several kilometers deep.
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Business Objects Reference Ontology is an upper ontology designed for developing ontological or semantic models for large complex operational applications that consists of a top ontology as well as a process for constructing the ontology. It is built upon a series of clear metaphysical choices to provide a solid (metaphysical) foundation. A key choice was for an extensional (and hence, four-dimensional) ontology which provides it a simple criteria of identity. Elements of it have appeared in a number of standards.
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Ghost craters on the planet Mercury have tectonic features such as graben and wrinkle ridges. These features were formed by extensional and contractional forces originating in tectonic processes such as uplift and global contraction. The combination of graben and wrinkle ridges inside ghost craters found on Mercury has not been observed on any of the other terrestrial planets. A simple cartoon cross-section of what a ghost crater might look like, with wrinkle ridges on either edges and graben located within.
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This resulted in the creation of a broad shield volcano. Subsequent volcanic activity created a complex edifice of trachyte and trachybasalt that formerly overlain the central part of the basaltic shield. Magmatism at Maitland continued until about 4.6 million years ago when the volcano went extinct. Volcanic activity at Maitland Volcano was consistent with extensional stresses across the northern Canadian Cordillera that began around 10 million years ago as a result of new plate motions between the Pacific and North American plates.
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This second model describes the upwelling of a mantle flow (plume) that accommodates the formation of crustal thickening by magmatic underplating and volcanic activities associated with the thin lithosphere. Planetary scientists that support this model identify two categories of extensional structures: long- narrow graben, referred to as a ribbons, and more widely spaced graben. The sequence of formation for these structures is still debatable. Some group of scientists believed that the ribbons were formed first, followed later on by the wide spaced graben.
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In some cases, the heated groundwater may rise along extensional faults related to rifting in the Northern Cordilleran Volcanic Province. The Lakelse Hot Springs near Lakelse Lake Provincial Park in northern British Columbia is interpreted to be one such example. With a temperature of , the springs are the hottest in Canada. It is also possible the magma associated with the Nass Valley eruption 250 years ago to the north rose along the same north trending fault lines fueling the Lakelse Hot Springs.
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However, unambiguous extensional features (very rare on the planet as a whole) are not seen in the Discovery quadrangle; only compressional scarps occur. Thus, core segregation occurred relatively early (before formation of a solid lithosphere) and was followed by cooling and contraction, the last phases of which probably contributed to the formation of arcuate scarps that predated the end of heavy bombardment. Rotational breaking by solar torques is another process likely to have occurred early in Mercurian history.Goldreich, P. & Soter, S. (1966).
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Sicily lies on part of the complex convergent boundary where the African Plate is subducting beneath the Eurasian Plate. This subduction zone is responsible for the formation of the stratovolcano Mount Etna and considerable seismic activity. Most damaging earthquakes however, occur on the Siculo-Calabrian rift zone. This zone of extensional faulting runs for about , forming three main segments through Calabria, along the east coast of Sicily and immediately offshore, and finally forming the southeastern margin of the Hyblaean Plateau.
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Break-up of a leaky transform into multiple smaller transforms. A leaky transform fault is a transform fault with volcanic activity along a significant portion of its length producing new crust. In addition to the regular strike-slip motion observed at transform boundaries, an oblique extensional component is present, resulting in motion of the plates that is not parallel to the plate boundary. This opens the fault, allowing melt to break through and cool on the ocean floor, producing new crust.
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205-223, page 205, archived here by Internet Archive on 26 October 2004 Those terranes which are the full thickness of the lithosphere are called microplates. Continent-sized blocks are called variously microcontinents, continental ribbons, H-blocks, extensional allochthons and outer highs. page 189 Because most stresses relate to the tectonic activity of moving plates, most motion between blocks is horizontal, that is parallel to the Earth's crust by strike-slip faults. However vertical movement of blocks produces much more dramatic results.
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The hotspot drifted from the Pacific Plate to the Nazca Plate approximately 1.2 million years ago and a seamount chain began to develop on the Nazca Plate. As the hotspot continued to migrate, rifting of the Nazca Plate developed along its track. This boundary is now known as Dietz Deep Volcanic Ridge, which extends to the northeast and grows at a velocity of 39 mm/year. The Dietz Deep Ridge terminates at the Dietz Deep Basin, an extensional feature with high elevational relief.
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NFB is the product of the asymmetric back-arc opening about a hinge point at 11°S, 165°E around which the Vanuatu chain has rotated 28° clockwise during the last 6 Ma, or 6–7.5°/Ma. This rotation has also caused rifting in the northern part of the NFB. Vanuatu can be divided into a southern and a northern tectonic blocks separate from the western NFB block. These blocks are separated by an extensional zone east of the islands chain.
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Faulted southeastern side of Svyatoy Nos peninsula, Lake Baikal – active faulting shown by faceted spurs. Artificial rendering of the Albertine Rift showing four of its rift lakes A rift lake is a lake formed as a result of subsidence related to movement on faults within a rift zone, an area of extensional tectonics in the continental crust. They are often found within rift valleys and may be very deep. Rift lakes may be bounded by large steep cliffs along the fault margins.
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Moctezuma volcanic field is a volcanic field in Sonora, Mexico. The towns of Moctezuma, La Junta, Casa Grande, San Clemente de Terapa, Tepache, El Llano and Divisaderos lie in the area. Volcanic activity in Mexico encompasses both oceanic and continental types of volcanic activity. Geographically, volcanism in Mexico is often subdivided into a Californian, Eastern Alcalic, Sierra Madre Occidental and Trans-Mexican Volcanic Belt, with the addition of a fifth proposed in 2007, which is known as the Northern Mexico Extensional Province.
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Between the upper slope of the trench and Calabria are a number of small fore-arc basins that developed through extensional listric faulting during the Tortonian. These basins subsequently subsided between the late Pliocene and Quaternary and are now infilled with mélange. The Aeolian Islands north of Calabria and Sicily represent the volcanic arc of the convergent system. The volcanism associated with these islands occurs at the northeast closure of the downgoing slab and began approximately during the late Pliocene to early Pleistocene (1.5–1.7 Ma).
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The slogan is 'points come later': this brings discussion full circle on this page. The point of view is written up in Peter Johnstone's Stone Spaces, which has been called by a leader in the field of computer science 'a treatise on extensionality'. The extensional is treated in mathematics as ambient—it is not something about which mathematicians really expect to have a theory. Perhaps this is why topos theory has been treated as an oddity; it goes beyond what the traditionally geometric way of thinking allows.
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Late Carboniferous paleogeography (about 320 Ma) with the Paleo-Tethys indicated The effects of this orogenic episode in Iran can be traced from the Late Devonian. Due to the scarcity of magmatism, metamorphism, and folding related to this episode, the role of the Hercynian orogeny in Iran is controversial; the Hercynian in Iran is largely represented by extensional rather than compressional tectonics (e.g., Sanandaj–Sirjan). Iranian microplates east and northeast of the Zagros were detached from Gondwana in the Carboniferous during this orogenic phase.
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The APVC is located in the southern Altiplano-Puna plateau, a surface plateau wide and long at an altitude of , and lies east of the volcanic front of the Andes. Deformational belts limit it in the east. The Altiplano itself forms a block that has been geologically stable since the Eocene; below the Atacama area conversely recent extensional dynamics and a weakened crust exist. The Puna has a higher average elevation than the Altiplano, and some individual volcanic centres reach altitudes of more than .
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On extensional duplexes, normal faults will accommodate the vertical motion, creating negative relief. Similarly, left stepping at a dextral fault generates contractional bends; shortening the step overs which is displayed by local reverse faults, push-up zones, and folds. On contractional duplex structures, thrust faults will accommodate vertical displacement rather than being folded, as the uplifting process is more energy efficient. Strike slip duplexes are passive structures; they form as a response to displacement of the bounding fault rather than by the stresses from plate motion.
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Through this research Dr. Mosher has discovered that the active tectonic environment is primarily made of breccia, sandstone and siltstone turbidity-current generated debris fans and that faulting, sedimentation and volcanism are merely a small part of plate boundaries. Another of her research projects focused on the partitioning of different types of strain during formation of ductile non-coaxial shear zones in both extensional and contractional environments, including the development of corrugations in metamorphic core complexes and the formation of rods and mullions in thrust nappes.
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500px During the Late Jurassic-Early Cretaceous, tectonic extensional forces created a shallow angle east-dipping detachment fault. This fault cut from what is now the Flemish Cap margin in Nova Scotia, eastern Canada to the Galicia margin, which is located west of the Iberian Peninsula. This fault penetrated the upper portion of the continental crust and merged into the transition between brittle upper and plastic lower crust. In time, displacement along this detachment fault decreased to zero at a point under the Galicia margin.
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In late Miocene to Pliocene, the slab detachment of Burma-microplate beneath the Shan-Thai block induced in a mantle window into the slab and resulted in alkaline and calk- alkaline volcanism along the Myanmar Central Belt. In the late Miocene (10 million years ago), the Myanmar Central Belt underwent a major regional plate kinematic reorganization transition. The tectonic regimes transform from northwest-southeast extensional force to basin inversion and was followed by a major uplift event caused by east-west compression during Plio-Pleistocene period.
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One of the most significant extensional structures in Himachal Pradesh is the Kaurik-Chango Fault Zone. This is interpreted to be seismically active from the presence of thermal springs and gypsum deposits and from studies of soft-sediment deformation structures thought to be seismites. These seismites have been used to suggest eight earlier earthquakes of magnitude greater than 6 in the Sumdo area affecting these Late Pleistocene to Holocene sediments. The estimated recurrence interval for earthquakes along this fault zone is about 10,000 years.
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Characteristic minerals include andalusite, biotite and cordierite. The metamorphic prograde sequence of the Buchan zone series is: biotite - cordierite - andalusite - sillimanite Buchan metamorphism occurs often in extensional settings, for example at rift basins. In contact metamorphism (metamorphism caused by high temperatures at low pressure in the vicinity of an igneous intrusion) a local contact aureole of zones is formed around a heat source. In rocks in subduction zones, that are transported to great depths in relatively low temperatures, rare types of metamorphic zones can develop.
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The Consag Basin is a submarine depression in the far northern part of the Gulf of California associated with the East Pacific Rise. It lies south of the Wagner Basin with which it is closely linked. The depression is a result of subsidence caused by the extensional forces probably imparted by the same spreading center which has produced the Wagner Basin. Both basins are bounded on their eastern side by the Wagner Fault, a primarily normal (vertical motion) fault which dips approximately 60 degrees to the northwest.
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There are four major phases in this orogenic event. First phase known as the Bretonian reflected in changes in the sediment input and the reactivation of a south plunging subduction zone. The second phase, the Sudetian, was of volcanic event and extrusive metamorphic and igneous rocks with uplift and mild folding of grabens in the vicinity which lead to inversion. The Asturian tectonic phase created fragmentation of the Variscans and its foreland due to the complex fault system of conjugate shear faults and secondary extensional faults.
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The St. George and Navarin extensional basins formed in the Bering Strait and filled with sediments. For much of the Cenozoic, Alaska experienced very cold conditions, preserved by fossils in the 5000 foot thick terrestrial sediments of the Chickaloon Formation in the Cook Inlet. By 10 to 13 million years ago, mountain glaciers had formed. A steady supply of moisture from the Pacific Ocean supported coastal glaciers beginning five million years ago, recorded by the glacial mudstone of the Yakataga Formation along the Gulf of Alaska.
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Warm mantle material wells up, melting the crust and often causing volcanoes to emerge in the rift basin. Extensional basins may appear to be caused by a graben, or depressed block of land, sinking between parallel normal faults that dip towards the center of the graben from both sides. In fact, they are usually made of linked asymmetrical half-grabens. Faults with antithetic slope directions linked in to a controlling fault, or periodic changes of dip in the controlling faults, give the impression of full graben symmetry.
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Large lava flow fields are described as flood-type lava that can be seen in fluctus fields. These are regions flooded with many low- viscosity volcanic flows from a single source that covers the area in a continuous flow field. Some flows may be radially distributed around a volcano of coronae as an apron, be fan-shaped, or sub-parallel in their orientation. Large flow fields may be sourced from large volcanoes, calderas, rift structures, or shield volcano fields and they are often associated with extensional environments.
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In the supra-subduction zone, spreading is not controlled like in mid-ocean ridge settings, as the extension is mainly facilitated by slab rollback that creates space independently of the availability of magma. Therefore, the fastest spreading rates are caused by the most rapid rollback and thus favours a magmatic spreading as in many cases the mantle may not be able to keep up with the spreading. Therefore, there is unusually thinned crust, large low angle extensional faults are common and lots of crustal rotation.
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The rift system may have been the result of extensional forces behind the continental collision of the Grenville Orogeny to the east which in part overlaps the timing of the rift development. Later compressive forces from the Grenville Orogeny likely played a major role in the rift's failure and closure. Had the rifting process continued, the eventual result would have been sundering of the North American craton and creation of a sea. The Midcontinent Rift appears to have progressed almost to the point where the ocean intruded.
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The central and southern part of the Apennines has been characterised by extensional tectonics since the Pliocene epoch (i.e. about the last five million years), with most of the active faults being normal in type and NW-SE trending. The extension is due to the back-arc basin in the Tyrrhenian Sea opening faster than the African Plate is colliding with the Eurasian Plate. To the northeast of the Apennine chain, the foreland is in contrast affected by W-E trending strike-slip to oblique-slip faults.
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This type of terrain is composed of long ridges and valleys, greater than 100 km long, that are cross cut by minor extensional fractures that run perpendicular to the fold axes of the ridges. This likely formed due to unidirectional contraction. Lava Flow Terrain is named such due to its resemblance to Pahoehoe flows found on Earth, with long curving ridges. It is thought that this terrain may be formed due to displacement and deformation due to movement of the material beneath these crustal pieces.
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At the south end of IBM, there is almost no convergence between the Caroline Plate and the Philippine Sea Plate. The IBM arc is not experiencing trench ‘roll-back’, that is, the migration of the oceanic trench towards the ocean. The trench is moving towards Eurasia, although a strongly extensional regime is maintained in the IBM arc system because of rapid PH-EU convergence. The nearly vertical orientation of the subducted plate beneath southern IBM exerts a strong “sea-anchor” force that strongly resists its lateral motion.
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The earliest known structures that affected the rocks of the Lake District are folds in the Skiddaw Group that are thought to be a result of slumping. It has also been proposed that there were active extensional faults during deposition of the group, consistent with the presence of two distinct sequences. In this model, the Causey Pike Fault is one of the early faults, which was reactivated during the Acadian Orogeny as a thrust. The eruption of the Borrowdale Volcanic Group was accompanied by volcano-tectonic faulting.
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During the Carboniferous period, the Lake District massif initially formed an emergent high. The north-dipping Maryport Fault formed on its northern margin as part of the regional Early Carboniferous extensional event, possibly reactivating an Acadian thrust structure. It was reactivated during the Variscan Orogeny as a reverse fault, leading to inversion of the Solway Basin to the north. The Lake District Boundary Fault on the western margin may also have been active at this time, possibly reactivating an Ordovician volcano-tectonic fault in part.
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This eruption, the largest known within the Cascade Volcanic Arc in a million years, destroyed Mazama's summit, reducing its approximate height by about . Much of the edifice fell into the volcano's partially emptied neck and magma chamber, creating a caldera. The region's volcanic activity results from the subduction of the offshore oceanic plate, and is influenced by local extensional faulting. Mazama is dormant, but the US Geological Survey says eruptions on a smaller scale are likely, which would pose a threat to its surroundings.
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While some differences can be explained by which volcanic zone a volcano belongs to, there are significant differences inside volcanic zones and even between neighbouring volcanoes. Despite being a type location for calc-alkalic and subduction volcanism, the Andean Volcanic Belt has a large range of volcano- tectonic settings, such as rift systems and extensional zones, transpressional faults, subduction of mid-ocean ridges and seamount chains apart from a large range of crustal thicknesses and magma ascent paths, and different amount of crustal assimilations.
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Constructions, and the entities they construct, are organized into a ramified type theory incorporating a simple type theory. The semantics is tailored to the hardest case, as constituted by hyperintensional contexts, and generalized from there to intensional and extensional contexts. The underlying logic is a Frege-style function/argument one, treating functions, rather than relations or sets, as primitive, together with a Church-style logic, centred on the operations of functional abstraction and application. Key constraints informing TIL approach to semantic analysis are compositionality and anti-contextualism.
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In the Late Jurassic, the third rifting event took place in response to the North Sea doming event. Major extensional faulting and rifting began approximately 157-155 Ma allowing for the Zechstein evaporites to form a detachment between basement rocks and upper stratigraphy largely influencing the natural gas and oil formation seen across the North German Basin. Organic-rich mudstones from the Kimmeridge Clay Formation is the source of the majority of the North German Basin's hydrocarbons which was restricted from migrating upward by the Zechstein salt.
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Extensional basins occur in the central and east parts of the fold belt. Oceanic subduction (or underthrusting) is evidenced for the western and central parts by slivers of ophiolite and blueschist metamorphism. These are known as Coolac serpentinite, and Honeysuckle Beds east of Tumut; The Kiandra Beds north of Batlow and the Tumut Pond Serpentinite Belt on the west side of Talbingo Dam. The Narooma Terrane migrated 2500 km westwards on the moving Pacific plate and became attached to the Adaminaby Superterrane in Silurian times.
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One important form of the extensional definition is ostensive definition. This gives the meaning of a term by pointing, in the case of an individual, to the thing itself, or in the case of a class, to examples of the right kind. For example, one can explain who Alice (an individual) is, by pointing her out to another; or what a rabbit (a class) is, by pointing at several and expecting another to understand. The process of ostensive definition itself was critically appraised by Ludwig Wittgenstein.
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The subducting oceanic crust is thought to split from the continental margin to aid subduction. In the event that the rate of trench retreat is greater than that of the island arc complex's progression, trench rollback will take place, and by consequence, extension of the overriding plate will occur to allow the island arc complex to match the trench retreat's speed. The extension, a back-arc basin, generates oceanic crust: ophiolites. Finally, when the oceanic lithosphere is entirely subducted, the island arc complex's extensional regime becomes compressional.
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4 Throughout the earlier periods of the Paleozoic, the intracratonic basin went through an extensional tectonic phase, which ended with a regional Carboniferous unconformity, representing the Hercynian orogenic compressional stage.Stewart, 2016, p.2420 From the Early Permian onwards, the basin experienced back-arc extension on the edge of Gondwana, leading to the formation of the regional Khuff Formation with anhydrite and halite deposition. This tectonic regime gradually transitioned into a passive margin setting with the opening of the Neo-Tethys in the Early Triassic.
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The principal feature of the eastern portion of the zone is the Blanco Ridge, a 150 km right lateral-moving fault that is responsible for the largest earthquakes in the region. The ridge itself varies between 3.5 and 7 km wide, and peaks between 600 and 1000 m above the seafloor. The ridge likely formed through extensive shearing and subsequent serpentinization from the intrusion of seawater. The Gorda Depression, a 10 km wide extensional basin, connects the eastern end of the Blanco Ridge to the Gorda Ridge.
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Production of REE around the world A rare-earth element-iron-lead-zinc (REE-Fe-Pb-Zn) system was formed from extensional rifting with upwelling of mantle, and therefore magma fractionation. There were multiple rifting events resulting in the deposition of iron minerals and the occurrence rare earth element was closely related to the iron and carbonatite dykes. The REE-Fe-Pb-Zn system occurs in an alternating volcanic and sedimentary succession. Apart from REE, LREE (light rare earth elements) are also found in carbonatite dykes.
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The tholeiitic dykes are made up of diabase and titanium-rich basalt, in contrast the calc-alkaline dykes are made up of andesite and rhyolite. The dyke swarms intrude the southern part of the Río de la Plata Craton, much the same way the Uruguayan dyke swarms intrude the northeastern part of the craton. The calc-alkaline dykes intruded in a period of transtensional tectonics during the Transamazonian orogeny, while the tholeiitic dykes intruded during the period of extensional tectonics that succeeded the orogeny.
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There are excellent examples in the Southwestern United States, including Arizona and Baja California. The more than 25 metamorphic core complexes in this region were formed during crustal extension during the mid-Cenozoic era. Block faulting of this nature is common in extensional settings and has been found to be an important part of physical geological models from sites around the globe, including Europe and China. Due to the availability and applicability of the systems, interest in core complexes and rotational extension systems remains high.
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The Magallanes Basin (predominantly used in Chile) or Austral Basin (mainly used in Argentina) is a major sedimentary basin in southern Patagonia. The basin covers a surface of about and has a NNW-SSE oriented shape. The basin is bounded to the west by the Andes mountains and is separated from the Malvinas Basin to the east by the Río Chico-Dungeness High. The basin evolved from being an extensional back-arc basin in the Mesozoic to being a compressional foreland basin in the Cenozoic.
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During the Pliocene–Quaternary the Western Cordillera was subject to extensional tectonics. A related fault system was active and gave rise to the Tucle horst and Tatio graben; it is also linked to Sol de Mañana in Bolivia and controls the position of several vents in El Tatio. Within the Tatio graben, a series of ignimbrites was emplaced. The first was the 10.5–9.3 million years old Rio Salado ignimbrite, which forms a thick layer; this might imply that the source of this ignimbrite was close to El Tatio.
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The central Apennines is one of the most seismically active areas in Italy. The Apennines mountain belt were formed in the Miocene to Pliocene as a result of the ongoing subduction of the Adriatic Plate beneath the Eurasian Plate, forming a fold and thrust belt. During the Quaternary, thrust tectonics gave way to extensional tectonics, with the development of a zone of normal faulting running along the crest of the mountain range. The extension is a result of either subduction rollback or the opening of the Tyrrhenian Sea.
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Three suites of intrusive and volcanic rocks are found in the Kutai Basin, and have been used to constrain the Tertiary stratigraphy . The felsic Nyaan volcanics, dated to 48-50 Ma may be related to the extensional tectonics that initiated basin formation. In some locations, the Nyaan volcanics and equivalents are at the base of the Tertiary sedimentary succession, while at other locations bedded tuffs, agglomerates and reworked pyroclastics are part of the late Eocene succession. The Sintang Intrusive suite are mafic to felsic and have a fine crystalline nature which indicates high level emplacement.
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A CaBER in use in a research laboratory The CaBER (Capillary Breakup Extensional Rheometer) is the only commercially available instrument based on capillary breakup. Based on the experimental work of Entov, Bazilevsky and co-workers, the CaBER was developed by McKinley and co-workers at MIT in collaboration with the Cambridge Polymer Group in the early 2000s. Currently, it is manufactured by Thermo Scientific with the commercial name HAAKE CaBER 1. The CaBER experiments employ a liquid bridge configuration and can be thought as a quantitative version of a "thumb & forefinger" test.
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The second quantitative information that can be extracted is the apparent extensional viscosity. Despite the great potential of the CaBER, this technique also presents a number of experimental challenges, mainly related to the susceptibility to solvent evaporation and the creation of a statically-unstable bridge of very low visco-elastic fluids, for which the fluid filament often happens to break already during the stretch phase. Different modifications of the commercial instrument have been presented to overcome these issues. Amongst others: the use of surrounding media different than air and the Slow Retraction Method (SRM).
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Republic Graben geologic map, Washington The Republic Graben, named after the town of Republic, Washington, is one of a number of Eocene extensional basins in what is now the Okanogan Highlands. Having been down dropped it preserves a thick section of volcanic and minor volcaniclastic rocks (Sanpoil Volcanics, mainly rhyodacite) as well as fossiliferous lacustrine deposits. The volcanic rocks represent the eruptive cover of the widespread Eocene granitic intrusions in the region, and formerly must have been much more widespread. Base and precious metal deposits are widespread in the graben.
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As granite formed, secondary rocks were only affected by slight contact metamorphism. The rest of the molten rock with its ore-containing fluids formed pegmatite, as well as veins of ore and minerals – the basis of the medieval mining industry and early industrialisation of this region. During the Upper Carboniferous and Lower Permian (Rotliegendes) large quantities of rock debris were deposited in intramontane basins and onto the foreland of the mountain range. These basins were formed by extensional tectonics which were accompanied by an intermediate to acidic volcanism.
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Helena lies within the northern part of the Intermountain Seismic Belt (ISB). This area of relatively intense seismicity runs roughly north-south from northwestern Arizona, through Utah, Idaho, and Wyoming, before dying out in northwestern Montana. It shows a marked deflection to the northwest near Helena, where it intersects with the Lewis and Clark fault zone, a zone of older WNW-trending faults. The ISB is characterized by normal faulting of late Quaternary age, indicating active extensional tectonics, as recognized throughout the Basin and Range province to the south.
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The cooling near-surface layer contracted, while the interior expanded. This caused strong extensional stresses in the moon's crust leading to cracking. The present-day system of canyons may be a result of this process, which lasted for about 200 million years, implying that any endogenous activity from this cause ceased billions of years ago. The initial accretional heating together with continued decay of radioactive elements were probably strong enough to melt the ice if some antifreeze like ammonia (in the form of ammonia hydrate) or some salt was present.
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Back arc basins form behind a volcanic arc and are associated with extensional tectonics and high heat flow, often being home to seafloor spreading centers. These spreading centers are like mid ocean ridges, though the magma composition of back arc basins is generally more varied and contains a higher water content than mid ocean ridge magmas. Back arc basins are often characterized by thin, hot lithosphere. Opening of back arc basins are still being studied but it is possible that movement of hot asthenosphere into lithosphere causes extension.
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The 1984 type theory was extensional while the type theory presented in the book by Nordström et al. in 1990, which was heavily influenced by his later ideas, intensional, and more amenable to being implemented on a computer. Martin-Löf's intuitionistic type theory developed the notion of dependent types and directly influenced the development of the calculus of constructions and the logical framework LF. A number of popular computer-based proof systems are based on type theory, for example NuPRL, LEGO, Coq, ALF, Agda, Twelf, Epigram, and Idris.
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USGS ShakeMap for the event The mainshock and the primary aftershock occurred on the previously mapped Roseau Fault, a , northeast-dipping normal fault that forms the western portion of the northwest-trending Les Saintes channel graben within the overriding North American Plate. Late 1990s bathymetric studies showed that it had vertical fault scarps approaching . The type of slip was primarily extensional, but included a small amount of left-lateral slip, and may have contributed to hydrological/volcanic effects that were observed on the island of Dominica, where a flooded fumarole drained twice.
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In fact, only single rules over extensional predicate symbols can be easily rewritten as an equivalent conjunctive query. The problem of deciding whether for a given Datalog program there is an equivalent nonrecursive program (corresponding to a positive relational algebra query, or, equivalently, a formula of positive existential first-order logic, or, as a special case, a conjunctive query) is known as the Datalog boundedness problem and is undecidable.Gerd G. Hillebrand, Paris C. Kanellakis, Harry G. Mairson, Moshe Y. Vardi: Undecidable Boundedness Problems for Datalog Programs. J. Log. Program.
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Among the Uranian satellites, Ariel appears to have the youngest surface with the fewest impact craters and Umbriel's the oldest. Miranda has fault canyons deep, terraced layers, and a chaotic variation in surface ages and features. Miranda's past geologic activity is thought to have been driven by tidal heating at a time when its orbit was more eccentric than currently, probably as a result of a former 3:1 orbital resonance with Umbriel. Extensional processes associated with upwelling diapirs are the likely origin of Miranda's 'racetrack'-like coronae.
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The epicenter of the 1920 earthquake lay within the inner zone of the Northern Apennines, which has been affected by extensional tectonics since the Late Miocene to Pliocene epochs. This extension is a result of the same process that opened the Tyrrhenian Sea during the same period, the rollback of the subducting Adriatic Plate. The continuing extension has resulted in a series of northwest- southeast trending normal faults bounding basins filled by the Pliocene to recent sediments. Near Garfagnana, there are two such basins, the Serchio and Magra grabens.
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When a strike-slip fault is offset along strike such as to create a gap i.e. a left-stepping bend on a sinistral fault, a zone of extension or transtension is generated. Such bends are known as releasing bends or extensional stepovers and often form pull-apart basins or rhombochasms. Examples of active pull-apart basins include the Dead Sea, formed at a left- stepping offset of the sinistral sense Dead Sea Transform system, and the Sea of Marmara, formed at a right-stepping offset on the dextral sense North Anatolian Fault system.
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The production of large quantities of magma, variously attributed to mantle plumes or to extensional tectonics, further pushed sea levels up, so that large areas of the continental crust were covered with shallow seas. The Tethys Sea connecting the tropical oceans east to west also helped to warm the global climate. Warm-adapted plant fossils are known from localities as far north as Alaska and Greenland, while dinosaur fossils have been found within 15 degrees of the Cretaceous south pole. Nonetheless, there is evidence of Antarctic marine glaciation in the Turonian Age.
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Intensity map for the Kos earthquake The earthquake's epicentre was located just southwest of the small island of Kara Ada on the northern side of the Gulf of Gökova. The gulf is a result of extensional tectonics related to ongoing subduction of the African Plate beneath the Aegean Sea Plate, and is currently expanding in a north-south direction on a set of west-east trending normal faults. The current opening rate is estimated to be at least 1.1 mm per year. The earthquake had an estimated magnitude of 6.6 on the moment magnitude scale.
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Being part of the Transdanubian Range, the Úrkút Manganese Ore was linked to the environmental evolution of the southern passive margin of the rifting Tethys Ocean.Galácz, A., Horváth, F., & Voros, A. (1985). Sedimentary and structural evolution of the Bakony Mountains (Transdanubian Central Range, Hungary): palaeogeographic implications. Acta Geologica Hungarica, 28(1-2), 85-100. After Hettangian drowning and Sinemurian-Pliensbachian extensional tectonics and subsidence, along with pelagic sedimentation and submarine topography, a pronounced horst developed over the local sea, with a depth on the Pliensbachian-Toarcian Basin of 600 m.Galácz, A. (1988).
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The Ugly duckling theorem is an argument showing that classification is not really possible without some sort of bias. More particularly, it assumes finitely many properties combinable by logical connectives, and finitely many objects; it asserts that any two different objects share the same number of (extensional) properties. The theorem is named after Hans Christian Andersen's 1843 story "The Ugly Duckling", because it shows that a duckling is just as similar to a swan as two duckling are to each other. It was proposed by Satosi Watanabe in 1969.
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Every well-founded set-like relation can be embedded into a well-founded set- like extensional relation. This implies the following variant of the Mostowski collapse lemma: every well-founded set-like relation is isomorphic to set- membership on a (non-unique, and not necessarily transitive) class. A mapping F such that F(x) = {F(y) : y R x} for all x in X can be defined for any well- founded set-like relation R on X by well-founded recursion. It provides a homomorphism of R onto a (non-unique, in general) transitive class.
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Examples of such basinal environments include backarc, forearc, passive margin, epicontinental, and extensional basins. Sedimentary basin analysis is largely conducted by two types of geologists who have slightly different goals and approaches. The petroleum geologist, whose ultimate goal is to determine the possible presence and extent of hydrocarbons and hydrocarbon-bearing rocks in a basin, and the academic geologist, who may be concerned with any or all facets of a basin's evolution. Petroleum industry basin analysis is often conducted on subterranean basins through the use of reflection seismology and data from well logging.
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The east-west oriented dextral strike-slip Oca Fault in the north is estimated to have been active since the Early Eocene with a total displacement of . The Bucaramanga- Santa Marta Fault was a Jurassic extensional rift fault, reactivated as oblique reverse fault in the Oligocene.Ayala, 2009, p.11 Petroleum exploration in the Cesar-Ranchería Basin commenced in 1916. The first exploitation of hydrocarbons was performed in 1921 and 1922 at Infantas in the Ranchería Basin and in 1938 the first well (El Paso-1) was drilled in the Cesar Basin.
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About 200 million years after this collision and the formation of Pangea, during the middle of the Mesozoic Era, the Atlantic Ocean floor started spreading and great extensional forces were experienced, resulting in faulting. Connecticut's Eastern border fault was created, a fault which begins in New Haven and stretches 130 miles up to Keene, New Hampshire. As a result, the land west of this fault was downset, creating a rift valley and causing the land to tilt an average of 15 to 25 degrees. The fault is currently inactive.
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The Southeast Bathurst Fault Zone is a north-south trending system of extensional faults forming a graben-like structure on southeastern Bathurst Island in the Canadian Arctic Archipelago. It lies within the Boothia Uplift and is one of several fault zones associated with the Canadian Arctic Rift System. The fault zone formed in the latest Cretaceous to early Tertiary when extension of the Boreal Rifting Episode penetrated the North American continent from the Canada Basin. The Southeast Bathurst Fault Zone was reactivated when the Eurekan Rifting Episode uplifted and compressed the region during the Eocene.
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The Orcadian Basin is a sedimentary basin of Devonian age that formed mainly as a result of extensional tectonics in northeastern Scotland after the end of the Caledonian orogeny. During part of its history, the basin was filled by a lake now known as Lake Orcadie. In that lacustrine environment, a sequence of finely bedded sedimentary rocks was deposited, containing well-preserved fish fossils, with alternating layers of mudstone and coarse siltstone to very fine sandstone. These flagstones split easily along the bedding and have been used as building material for thousands of years.
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Tagg is probably best known for his work in the field of music analysis. Using mainly pieces of popular music as analysis objects, he stresses the importance of non-notatable parameters of expression and of vernacular perception in understanding "how music communicates what to whom with what effect" in today's world. He has adapted Charles Seeger's notion of the museme to demonstrate how combinations of such units are used to create both syncritic (intensional) structures inside the extended present, and diatactical (extensional) ones over time.See chapters 11–12 in Philip Tagg, Music’s Meanings, 2013.
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West-east-trending valleys score the Phlegra Montes region with a strike that is coincident with the orientation of graben to the west of the mountains, suggesting that regional extensional tectonism affected this region of Mars. Graben along this trend are also present in Galaxias Chaos and into Utopia Planitia. In the Phlegra Montes, some of these graben have been interpreted to host glaciers that have since given way to flow-like landforms called lineated valley fills (LVF). This is not considered a typical way for such landforms to occur on Mars.
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In many spots in Scandinavia basaltic dikes are found with ages between 670 and 650 million years. These are interpreted as evidence that by that time, rifting had started that would form the Iapetus Ocean. In Newfoundland and Labrador, the Long Range dikes are also thought to have formed during the formation of the Iapetus Ocean. It has been proposed that both the Fen Complex in Norway and the Alnö Complex in Sweden formed as consequence to mild extensional tectonics in the ancient continent of Baltica that followed the opening of the Iapetus Ocean.
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Ground fractures that were deemed to be tectonic in nature were documented on about of the White Mountain Fault Zone from Silver Creek to Piute Creek. The cracks trended 350° and a maximum right-lateral slip of about was measured, though other vertical (downslope) or extensional movement was also seen, especially on the -thick surface of the Bishop Tuff in the Volcanic Tableland. There, the largest displacements were seen in the vicinity of Casa Diablo Mountain. The cracks were found primarily in loose sand, which made measurements difficult.
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Formation of the Taranaki Basin initiated in the Late Cretaceous, due to the separation of Australia and Zealandia during the breakup of Gondwanaland. This breakup caused the formation of the Tasman Sea, along with multiple extensional basins on the New Zealand subcontinent, including an intra-plate rift that formed the Taranaki Rift, which would develop into the Taranaki Basin. Syn-rift sediments were deposited within rift controlled grabens across the basin, and are separated from the basement rock by a regional unconformity. These sedimentary layers contain faulting that is indicative of extension during deposition.
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Photograph of the first oil well in Comodoro Rivadavia The Golfo San Jorge Basin () is a hydrocarbon-rich sedimentary basin located in eastern Patagonia, Argentina. The basin covers the entire San Jorge Gulf and an inland area west of it, having one half located in Santa Cruz Province and the other in Chubut Province. The northern boundary of the basin is the North Patagonian Massif while the Deseado Massif forms the southern boundary of the basin. The basin has largely developed under condition of extensional tectonics, including rifting.
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Orogenic cycle of rifting, subduction, and accretion During the Jurassic period, Pangea began to pull apart causing separation of North America from South America. This rifting produced a subduction zone where the Nazca Plate was subducting to the east under the South American Plate. Part of this subducting plate was the Baudo- Island Arc separated from the South American continent by the marginal Colombian Sea. The formation of the extensional back-arc basin associated with this subduction is the origin of the Middle Magdalena Basin in the late Jurassic.
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Starting about 3 million years ago and continuing at least through the late Pleistocene, extensional faulting of the Earth's crust led to eruption of small volcanoes in the Boring volcanic field. This field extended roughly from Portland and Tualatin on the west to Battle Ground, Washington, on the north to Sandy and Boring on the east. Two of these volcanoes, Mount Sylvania and Cook's Butte, are in the Tryon Creek watershed. The Mount Sylvania eruptions included ash plumes and lava flows that covered some of the Waverly Heights Formation and Columbia River basalts.
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The main rift or "syn-rift" stage describes the phase of active stretching and fault block rotation. Syn-rift subsidence results from the elastic/isostatic adjustment of the crust due to mechanical stretching of the lithosphere. The subsidence is counteracted by upwelling of the asthenosphere into the space created by the mechanical stretching and thermal upward displacement of the asthenosphere-lithosphere boundary, causing uplift of the rift zone. The fundamental architectural element in many extensional basins is the half-graben, formed within the hanging walls of major rift-bounding or intra-rift basin faults.
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Antarctica Relief map with highlighted Adare Basin and relevant locations labeled. The Adare Basin is a geologic structural basin located north-east of Cape Adare of Antarctica, for which its named, and north of the western Ross Sea. The Adare Basin is an extensional rift basin located along a seafloor spreading center that forms the failed arm of the Tertiary spreading ridge separating East and West Antarctica, known as the West Antarctic Rift System and similar in structure to the East Africa Rift System. Centrally located in the Adare Basin is the Adare Trough.
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Pulsating continents model In the pulsating continents model, differentiated, low density crust survives early global subduction events forming continental regions. These regions undergo compression due to heating from the surrounding mantle, forming the compressional features of tessera, such as fold and thrust belts, and basin dome terrain. After sufficient crustal thickening has occurred, new lithosphere is generated causing gravitational collapse, producing the extensional features of tessera, such as extensive grabens. During this collapse, decompression causes partial melting, producing the intratessera volcanism seen within the larger regions of tessera terrain.
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The Gulf of Corinth is an area of active extensional tectonics. The underlying cause of this extension has been attributed to rollback of the African Plate as it subducts northwards beneath the Aegean Plate. Other possible mechanisms include gravitational collapse of crust overthickened during the Paleogene to early Neogene or the affects of the continuing propagation of the North Anatolian Fault towards the southwest. The rift that formed the Gulf of Corinth is bounded by large normal faults that vary in their polarity (dip direction) along its length.
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The Sirte Basin province is considered to be a type locality of a continental rift (extensional) area and is referred to as part of the Tethyan rift system.Futyan (1996) According to the designation scheme of Bally and Snelson, it is classified as 1211; a cratonic basin located on earlier rifted grabens on a rigid lithosphere and not associated with formation of megasutures.A. Bally and S. Snelson (1980) p.9 Clifford terms it as an interior fracture basin near the tectonic plate margin, which characteristically has an axis at an angle to that margin.
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Altimetry data also demonstrates the potential correlation between bathymetric gradient and direction of propagation. #Ridge-hotspot interaction causes weakening of lithosphere allowing new rifts to form as magma upwells. #In terms of crack length, rift tips with longer cracks possess a higher propagation driving force due to stronger far-field extensional forces, which leads to the idea that longer segments always grow at the expense of shorter segments. #In the case of spreading ridges in the back-arc basin, propagation has been thought to be controlled by the volcanic arc.
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The Mount Taylor volcanic field is composed primarily of basalt (with 80% by volume) and straddles the extensional transition zone between the Colorado Plateau and the Rio Grande rift. The largest volcanic plug in the volcanic field is Cabezon Peak, which rises nearly 2,000 feet above the surrounding plain. According to Robert Julyan's The Place Names of New Mexico, the Navajos identify Cabezon Peak "as the head of a giant killed by the Twin War Gods" with the lava flow to the south of Grants believed to be the congealed blood of the giant.
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These were accompanied by postcaldera eruptions, but the postcaldera flows have been entirely eroded away except in the Timber and Brushy Mountains (), a small intrarift horst within the Rio Grande rift. The Latir volcanic field is the southern terminus of a southward migrating Tertiary magmatic locus that blanketed much of the southern Rocky Mountains with volcanic rock during the Eocene and Oligocene. It has been suggested that this migration of volcanic activity heated and weakened the lithosphere along its path to produce focuses for later extensional deformation of the eastern Cordillera.
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Major fault zones around the Tibetan Plateau showing location of Kunlun fault The earthquake rupture began on a relatively small strike-slip fault segment at the western end of the Kunlun fault in the region of the mountain Buka Daban Feng. The rupture propagated to the east via an extensional stepover before following the main strand of the Kunlun fault. The region of co-seismic deformation (i.e. that occurred during the earthquake) is unusually large, with significant faulting being observed up to 60 km from the main rupture trace.
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Antisthenes apparently distinguished "a general object that can be aligned with the meaning of the utterance” from “a particular object of extensional reference." This "suggests that he makes a distinction between sense and reference." p. 20 The principal basis of this claim is a quotation in Alexander of Aphrodisias's “Comments on Aristotle's 'Topics'” with a three- way distinction: # the semantic medium, δι' ὧν λέγουσι # an object external to the semantic medium, περὶ οὗ λέγουσιν # the direct indication of a thing, σημαίνειν … τὸ …Prince 2015, pp. 518–522 (Antisthenes' literary remains: t. 153B.1).
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Built up by countless generations of lava flows and ash, the Tharsis bulge contains some of the youngest lava flows on Mars, but the bulge itself is believed to be very ancient. Geologic evidence indicates that most of the mass of Tharsis was in place by the end of the Noachian Period, about 3.7 billion years ago (Gya). Tharsis is so massive that it has placed tremendous stresses on the planet's lithosphere, generating immense extensional fractures (grabens and rift valleys) that extend halfway around the planet.Carr, M.H (2007).
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Most of western Turkey lies in an area of extensional tectonics that extends into the Aegean Sea. The cause of the extension is thought to be the rollback of the subducting slab of the African Plate that dips northwards beneath the Aegean. The overall N–S extension has resulted in a series of NW–SE to W–E trending seismically active normal faults with associated rift basins. The Afyon–Akşehir Graben lies in the hanging-wall of the low-angle Sultandağı Fault and contains nearly 1 km of late Miocene to Quaternary sedimentary fill.
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The BORO approach is designed to be a simple, repeatable process for developing formal ontologies. The method takes an extensional approach to ontology development. The method aims to be grounded in physical reality so that if followed to the letter the method should consistently produce the same ontology given the same inputs. It can then be used for comparing multiple data-sources for semantic matches/mismatches and for re- engineering multiple legacy systems into a coherent whole (either as a new monolithic system, or as a method for designing federation of existing systems).
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Magmatic foliations and mafic enclaves usually indicate radially increasing strains normal to the pluton contact and extensional strains parallel to it. Magmatic fabrics will not record information of the stoping process as they are only formed near the end of the pluton emplacement. Furthermore, any magmatic fabrics that are recorded are likely to be affected by strain. Therefore, the causes of the magmatic fabrics may not be discernable, and at best can only give inferences to the mechanisms for emplacement of the pluton, or magma chamber internal mechanisms.
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The Kythira Strait, located within the Western Hellenic arc, is subject to submergence on account of normal faulting which results in "extensional deformation and rotation" between two major segments of the external arc. According to Papadopoulos and Kijko, the Western Hellenic arc has high seismic activity, resulting in deformations in the strait which are active. Here the "seismic slip" recorded is on the order of 0.3 cm/year. Also reported in the strait are earthquakes at shallow and intermediate depths, with surface-wave magnitudes of up to 8.0.
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Niger–Congo languages have a clear preference for open syllables of the type CV (Consonant Vowel). The typical word structure of Proto-Niger–Congo (though it has not been reconstructed) is thought to have been CVCV, a structure still attested in, for example, Bantu, Mande and Ijoid – in many other branches this structure has been reduced through phonological change. Verbs are composed of a root followed by one or more extensional suffixes. Nouns consist of a root originally preceded by a noun class prefix of (C)V- shape which is often eroded by phonological change.
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During the Late Cretaceous to Eocene, the area now occupied by the rift was a shallow sea depositing carbonates. This period was mainly quiet tectonically but the northern part of the gulf region was affected by periodic far-field effects of the Alpine orogeny. A series of WSW- ENE trending extensional basins were inverted, creating isolated uplifted and folded areas known as 'Syrian arc' structures. These structures were mainly active during the Late Santonian but there is evidence of further movements on the same structures at the end of the Cretaceous and during the Paleogene.
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In the context of plate tectonics, strike-slip movement of the Tintina Fault on the Tintina-Northern Rocky Mountain Trench is also related to strike-slip movement along the San Andreas Fault, the extension of the Basin and Range Province, and other extensional or strike-slip fault systems in western North America. The Tintina Fault is one of the two major fault zones paralleling the Northern Cordilleran Volcanic Province, the other being the Denali Fault in the Yukon, the U.S. state of Alaska and along the British Columbia Coast.
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This model describes that the mantle downwelling flow assisted the development of crustal thickening and shortening of the ductile crust because of compression and accretion of thin lithosphere. However, this model needs a lot amount of time of crustal thickening (1-4 billion years). There are also a few constraints for this model. The first one is that this model provides no explanation for the contractional structures and the second one is that the timing of the extensional structures does not correlate well with the known cross-cutting relationships.
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But for salva veritate to hold as a definition of something more than extensional agreement, i.e., cognitive synonymy, we need a notion of necessity and thus of analyticity. So, from the above example, it can be seen that in order for us to distinguish between analytic and synthetic we must appeal to synonymy; at the same time, we should also understand synonymy with interchangeability salva veritate. However, such a condition to understand synonymy is not enough so we not only argue that the terms should be interchangeable, but necessarily so.
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Under the north Peloponnese, there is a 5.5–10 km well defined seismogenic zone that deepens to 12 km under the northern shore of the gulf. This is responsible for major earthquakes like the Mw = 6.2 June 15, 1995 event, and a large number of small to moderate earthquakes. For instance, in the summer of 1993, 232 earthquakes were recorded Due to such active seismicity, many earthquakes activate new fault planes. It is hypothesized that extensional slip on E-W striking, 20°-40° north-dipping planes are caused by earthquakes beneath the northern shore.
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The Eurotas River occupies the floor of a rift valley, or graben, created by extensional forces acting over the Hellenic Plate in a northeast-southwest direction. The corresponding fault-block mountains are the Taygetus Massif on the west and the Parnon Massif on the east – both limestone ridges derived from a former sea bed. On the east side of Taygetus is the Sparta Fault, a normal fault, which strikes in a zig-zag path along the foot of the massif and dips toward the interior of the valley. The river is on the western side.
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This earthquake was caused by movement on a NW-SE trending normal fault according to moment tensor solutions. Although Italy lies in a tectonically complex region, the central part of the Apennines has been characterised by extensional tectonics since the Pliocene epoch (i.e. about the last 5 million years), with most of the active faults being normal in type and NW-SE trending. The extension is due to the back-arc basin in the Tyrrhenian Sea opening faster than the African Plate is colliding with the Eurasian Plate.
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Intuitionistic type theory (also known as constructive type theory, or Martin- Löf type theory) is a type theory and an alternative foundation of mathematics. Intuitionistic type theory was created by Per Martin-Löf, a Swedish mathematician and philosopher, who first published it in 1972. There are multiple versions of the type theory: Martin-Löf proposed both intensional and extensional variants of the theory and early impredicative versions, shown to be inconsistent by Girard's paradox, gave way to predicative versions. However, all versions keep the core design of constructive logic using dependent types.
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Paleostress evolution in the Moroccan African margin from Triassic to Present. Tectonophysics, 357(1-4), 187-205. This basins were fault-bounded basins, with variations of the sedimentary thicknesses and intra-formational breccias related to major blocks. The Magmatic Province of the Atlas influenced the deposition of the main strata, where the Terrestrial settings of some Formations (Including Azilal) was disposed over a series of cut extensional faults depicting a mosaic of horsts and grabens oriented to the East, North-East and East-West, with the Middle Atlas among the main areas of subsidence.
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McKinley's work focuses on understanding the rheology of complex fluids such as surfactants, gels and polymers, which are ubiquitous in foods and consumer products. His research interests include non-Newtonian fluid dynamics, microfluidics, extensional rheology, field-responsive materials, super- hydrophobicity and the wetting of nanostructured surfaces. McKinley served as director of MIT's program in polymer science & Technology (PPST) from 2004-2009. McKinley is also co-founder of Cambridge Polymer Group, a Boston- based company employing 20 people and specializing in bespoke instrumentation, materials consulting and orthopedic polymeric materials.
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Because it is the planet nearest the Sun, Mercury represents one extreme in possible cosmochemical models of planet formation. Even before the Mariner 10 mission, Mercury's high density and photometric properties suggested a large core, presumably iron, and a lithosphere of silicate materials. Evidence for an intrinsic dipolar magnetic field (Ness and others, 1974) reinforces interpretations favoring a large core. This core, which formed partly as a result of radiogenic heating, produced additional heating, leading to global expansion and the formation of extensional fractures in the lithosphere (Solomon, 1976, 1977).
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The spherules resemble the glassy chondrules (rounded granules) in carbonaceous chondrites, which are found in carbon-rich meteorites and lunar soils. Remarkably similar lithostratigraphic and chronostratigraphic structural sequences between these two cratons have been noted for the period between 3.5 and 2.7 billion years ago. Paleomagnetic data from two ultramafic complexes in the cratons showed that at the two cratons could have been part of the same supercontinent. Both the Pilbara and Kaapvaal cratons show extensional faults which were active about during felsic volcanism and coeval with the impact layers.
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Parts of central and eastern Idaho lie within the northern part of the Intermountain Seismic Belt (ISB). This area of relatively intense seismicity runs roughly north–south from northwestern Arizona, through Utah, Idaho, and Wyoming, before dying out in northwestern Montana. The ISB is characterized mainly by normal faulting of late Quaternary age, indicating active extensional tectonics, as recognized throughout the Basin and Range province to the south. Some historical earthquakes show evidence of strike- slip faulting such as the two largest earthquakes of the 1935 Helena earthquake sequence.
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SEDEX deposits form in sedimentary basins under a regional tectonic extensional environment, under the ocean where cold seawater (blue arrows) is mixed with basin water and through sinsedimentary faults flow towards the bottom of the basin, which are heated by the geothermal gradient, and later ascends by convective currents (red arrows). Model for the origin of the Red Sea sulfide deposits. Cold seawater (blue arrows) enters the seafloor via deep-seated fractures. As it descends, it heats up and leaches silicon, metals and other solutes from the seafloor basalts.
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Tectonic and magmatic features associated with the Mackenzie Large Igneous Province, including the rifting that created the Poseidon Ocean. Red star shows the initial Mackenzie plume zone relative to the lithosphere. The Poseidon Ocean was an ocean that existed during the Mesoproterozoic period (from 1.6 to 1.0 billion years ago) of the geologic timescale. It began to form when a hotspot collided with lithosphere that was already in an extensional regime that allowed rifting to occur at the onset of hotspot volcanism that created the Mackenzie Large Igneous Province.
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Solfatara Pozzuoli The Phlegraean Fields ( "burning fields") caldera is a nested structure with a diameter of around . It is composed of the older Campanian Ignimbrite caldera, the younger Neapolitan Yellow Tuff caldera and widely scattered sub-aerial and submarine vents from which the most recent eruptions have originated. The Fields sit upon a Pliocene - Quaternary Extensional domain with faults, that run North- East to South-West and North-West to South-East from the margin of the Apennine thrust belt. The sequence of deformation has been subdivided into three periods.
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During extensional time periods, large, gently-dipping normal faults, called detachment faults, can form due to relative separation of the two sides surrounding the fault. Typically, these faults can have an offset on the order of one to tens of kilometers. As the region continues to experience extensive pressures, there is an isostatic effect which moves ductile crust material underneath the fault complex. This fault system can shear the footwall, creating domal mountain ranges, which on a large scale can develop into formations known as metamorphic core complexes.
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Continental-continental divergent/constructive boundary In plate tectonics, a divergent boundary or divergent plate boundary (also known as a constructive boundary or an extensional boundary) is a linear feature that exists between two tectonic plates that are moving away from each other. Divergent boundaries within continents initially produce rifts, which eventually become rift valleys. Most active divergent plate boundaries occur between oceanic plates and exist as mid-oceanic ridges. Divergent boundaries also form volcanic islands, which occur when the plates move apart to produce gaps that molten lava rises to fill.
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It is an extinct volcano dating to the Neoproterozoic and is approximately 704 million years old (+/- 4 million years) as dated using the U-Pb zircon crystal geochronology method. It is a unit of the Robertson River Igneous Suite and is located within the Blue Ridge anticlinorium. This volcanic formation was a result of crustal extensional rifting of the eastern Laurentian margin of the supercontinent Rodinia. This was the beginning of a chain of events that ultimately gave birth to the precursor Atlantic, the Iapetus Ocean at 550 Ma during the Ediacaran–Cambrian transition.
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The Garlock Fault is believed to have developed to accommodate the strain between the extensional tectonics of the Great Basin crust and the right lateral strike-slip faulting of the Mojave Desert crust. Unlike most of the other faults in California, slip on the Garlock Fault is left-lateral; that is, the land on the other side of the fault moves to the left from the perspective of someone facing the fault. Thus, the terrain north of the fault is moving westward and that on the south is moving eastward.
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5 Both Camarillas and Galve are in the Galve Sub-basin, a section of the Aliaga Basin, in the Iberian Range. All these basins were formed during the Permian–Triassic, when the main faults were active, and they are filled with Mesozoic–Quaternary sediments. The Upper Permian to Upper Jurassic deposits at the site of the Camarillas Formation are all of continental origin. In a second extensional stage during the Late Jurassic to Early Cretaceous, the Atlantic and the Bay of Biscay opened, and the Iberian Peninsula rotated from left to right.
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Geologic map of South Sudan The geology of South Sudan is founded on Precambrian igneous and metamorphic rocks, that cover 40 percent of the country's surface and underlie other rock units. The region was affected by the Pan-African orogeny in the Neoproterozoic and extensional tectonics in the Mesozoic that deposited very thick oil-bearing sedimentary sequences in rift basins. Younger basalts, sandstones and sediments formed in the last 66 million years of the Cenozoic. The discovery of oil in 1975 was a major factor in the Second Sudanese Civil War, leading up to independence in 2011.
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The northward movement of India pushes the southeast Asia block away from the collision resulting in the clockwise rotation of Borneo forming a large extensional basin. In defining whether this model is correct it is important to understand if the strike slip faults of south China extend through the South China Sea as far as Borneo. Three major faults are known to traverse Indochina and South China are the Three Pagodas, Mae Ping and the Red River Fault, but not where they continue off the coast. It is not confirmed how far they cut into the South China Sea.
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The Niger Delta Basin is an extensional rift basin where rifting occurred from the Late Jurassic to the Late Cretaceous. Cretaceous fracture zones, expressed as trenches and ridges, control the tectonic framework of the delta and separate the margin into individual sub-basins, which form the boundary faults of the Cretaceous Benue- Abakaliki trough. The Niger Delta Basin is the youngest and most southern sub- basin (located at the southwest boundary) in the Benue-Abakaliki trough. The Benue-Abakaliki trough represents a failed arm of a rift triple junction associated with the opening of the South Atlantic.
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The Antarctic Plate is a tectonic plate containing the continent of Antarctica, the Kerguelen Plateau and extending outward under the surrounding oceans. After breakup from Gondwana (the southern part of the supercontinent Pangea), the Antarctic plate began moving the continent of Antarctica south to its present isolated location causing the continent to develop a much colder climate. The Antarctic Plate is bounded almost entirely by extensional mid- ocean ridge systems. The adjoining plates are the Nazca Plate, the South American Plate, the African Plate, the Somali Plate, the Indo-Australian Plate, the Pacific Plate, and, across a transform boundary, the Scotia Plate.
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The positive buoyancy of the continental slab—in opposition principally to ridge push—can then drive exhumation of the subducting crust at a rate and mode determined by plate geometry and the rheology of the crustal materials. The Norwegian Western Gneiss Region is the archetype for this exhumation mode, which has been termed 'eduction' or subduction inversion.Andersen, T. B., Jamtveit, B., Dewey, J. F., and Swensson, E., 1991, Subduction and eduction of continental crust: major mechanism during continent-continent collision and orogenic extensional collapse, a model based on the south Caledonides: Terra Nova, v. 3, p. 303-310.
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The Basin and Range Province extending across Nevada, into western Utah, and south into Mexico now consists of N-S normal faulting due to crustal extension. If these normal faults show any extension in late Eocene to early Miocene, this could be evidence the Sevier orogenic event collapsing after deactivation. Thickening of the crust due to Sevier and Laramide faulting is thought to have led to current Basin and Range extension throughout the Cenozoic.Livacarri, R.F., 1991, Role of crustal thickening and extensional collapse in the tectonic evolution of the Sevier-Laramide Orogeny, Western United States, Geology [Boulder], Vol.
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The resonance would have led to orbital eccentricity and tidal heating that may have warmed Tethys' interior enough to form the ocean. Subsequent freezing of the internal ocean after the moons escaped from the resonance may have generated the extensional stresses that created Ithaca Chasma. An alternative hypothesis is that it was formed at the same time as the large crater Odysseus which lies near a pole of the Ithaca Chasma. When the impact that created Odysseus occurred, the shockwave may have traveled through Tethys and produced a circumcircular fracture analogous to outer ring graben of multiring impact basins.
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The Kangaamiut dike swarm (old spelling: Kangâmiut) is a 2.04 billion year old dike swarm located in the Qeqqata region of western Greenland. The dikes cut Archean orthogneisses and are exposed along approximately of the coast and a similar distance up to the inland ice to the east, covering an area of about . To the north it is bounded by the paleoproterozoic Ikertooq shear zone (old spelling: Ikertôq) while to the south the boundary is gradational with a gradual reduction in the density of dikes. The dike swarm was intruded during a phase of extensional tectonics.
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Turkey is a seismically active area within the complex zone of collision between the Eurasian Plate and both the African and Arabian Plates. Much of the country lies on the Anatolian Plate, a small plate bounded by two major strike-slip fault zones, the North Anatolian Fault and East Anatolian Fault. The western part of the country is also affected by the zone of extensional tectonics in the Aegean Sea caused by the southward migration of the Hellenic arc. The easternmost part of Turkey lies on the western end of the Zagros fold and thrust belt, which is dominated by thrust tectonics.
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The Canadian Arctic Rift System is a branch of the Mid-Atlantic Ridge that extends into the North American continent. It is an incipient structure that diminishes in degree of development northwestward, bifurcates at the head of Baffin Bay and disappears into the Arctic Archipelago. The rift system is mainly an extensional structure, which has allowed Greenland and Canada to rotate apart and form intervening seaways. The segment extending from the Labrador Sea to Baffin Bay is sometimes referred to as the Labrador Sea–Baffin Bay rift system or the North Atlantic–Labrador Sea rift system.
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The TVF is predominantly composed of volcanic rocks that follow a high potassium calc-alkaline (HKCA) suite formed by post-collisional continent subduction of the Indian slab and regional extension (extensional tectonics). The rocks found in this region are basalt, dacite welded tuff, basaltic trachyandesite and trachyandesite.Jiang, C., Wan, J., Wang, Y., Wei, H., and Zhang, X (2006), Tectonic controls on the late Miocene-Holocene volcanic eruptions of the Tengchong volcanic field along the southeastern margin of the Tibetan plateau, Journal of Asian Earth Science, 2007, 275-389. These rocks where extruded out as lava flows and pyroclastic material.
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From the late Devonian to the end of the Permian ending in the Paleozoic era the Variscan Orogeny occurred. The super continents of Gondwanaland and Laurussia collided creating an extensive mountain range just east of the pre-existing Caledonian mountains and creating Pangea the super continent at the end of the Variscan phase. The collision of these plates plays an important role in the potential of hydrocarbons in the Southern North Sea basin. The start of this phase is the collapsing of the Caledonian orogeny and a general extensional regime which would cause a depression to fill with sediment.
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Additional uplift occurred when major faults developed to the east, especially the creation of Owens Valley from Basin and Range-associated extensional forces. Uplift of the Sierra accelerated again about two million years ago during the Pleistocene. The uplifting and increased erosion exposed granitic rocks in the area to surface pressures, resulting in exfoliation (responsible for the rounded shape of the many domes in the park) and mass wasting following the numerous fracture joint planes (cracks; especially vertical ones) in the now solidified plutons. Pleistocene glaciers further accelerated this process and the larger ones transported the resulting talus and till from valley floors.
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The breakup of Rodinia one of the oldest supercontinents, produced rifts between 900 million and 600 million years ago in the Neoproterozoic. These deep extensional basement faults filled with sediments, such as the Uinta rift basin and were often reactivated more recently in Earth history by orogenies. The Uinta Formation and Uncompahgre Formation are both examples of remnant Precambrian rift basin sediments. The end of the Neoproterozoic is not known from the rock record, indicating a period of long-running terrestrial erosion which produced by the Great Unconformity, from 1.1 billion to 510 million years ago.
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The TAO evolved through a series of extensional back-arcs separated by compressional events when the subducting oceanic plate got stuck in Gondwana's margin. As Gondwana was amalgamated in the Early Palaeozoic during the so-called Pan-African orogenies the TAO propagated along the southern (modern coordinates) Proto-Pacific/Iapetus margin of the supercontinent. The TAO ended with the Gondwanide orogeny. This and younger orogens covers most of the outboard margin of the TAO, and, likewise, the inboard margin is almost entirely covered by younger deposits and ice but remains exposed in Australia along the Torrens Hinge Line or Delamarian orogeny.
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Coronae are large, circular structures with concentric fractures around them that result from mantle upwelling followed by extensional collapse. Since many sequences of upwelling and collapse have been observed as structurally different coronae on Venus' surface, all coronae appear to share a sequence of heavy volcanism as a result of upwelling, topographic rise, tectonic deformation, subsidence due to gravitational collapse, and continued volcanism. Coronae on Venus differ in the location of topographic uplift, and have been characterized as such. Topographic uplift may occur in the depression, the rim, the outer rim, or a combination of these locations.
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The Makran accretionary wedge, north of the Murray ridge, developed in response to the subduction of the Gulf of Oman oceanic crust beneath Eurasia from about 14 Ma onwards. The southern boundary of the offshore Indus basin is marked by the Saurashtra Arch. It is a volcanic high which extends eastwards into onshore India, coinciding with large outcrop of Deccan volcanics. In the offshore, the arch is cut by steep vertical faults interpreted as extensional faults associated with strike-slip movement along an east-west-trending transform fault marking the northern edge of the Arabian Sea oceanic crust.
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The Exmouth Plateau is an elongate northeast striking extensional passive margin located in the Indian Ocean roughly 3,000 meters offshore from western and northwestern Western Australia. The plateau makes up the westernmost structural unit of the Northern Carnarvon Basin, which comprises the Exmouth, Barrow, Dampier, and Beagle Sub-basins, and the Rankin Platform. The Exmouth Plateau was once a part of the northern shore of eastern of Gondwanaland until it broke away during Late Jurassic to Early Cretaceous, leaving behind the oceanic crust of the Argo, Cuvier, and Gascoyne abyssal plains that now surround the distal margins of Exmouth Plateau.
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A large part of Kenya is underlain by Precambrian basement, while the Kenya rift basin (a typical extensional basin) hosts Tertiary volcanics that cover Mesozoic sediments (Recently these sediments have been considered for oil exploration). The sedimentary basins evolved along the Anza trough during the Late Paleozoic to Early Tertiary times through extension tectonics during the major Gondwanaland breakup. In the Miocene Period the region underwent intermittent uplift and subsidence along major boundary faults accompanied by the large outpouring of lava flows. The Anza trough intersects the modern rift valley in the area of Lake Turkana.
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Their surfaces are heavily cratered, though all of them (except Umbriel) show signs of endogenic resurfacing in the form of lineaments (canyons) and, in the case of Miranda, ovoid race-track like structures called coronae. Extensional processes associated with upwelling diapirs are likely responsible for the origin of the coronae. Ariel appears to have the youngest surface with the fewest impact craters, while Umbriel's appears oldest. A past 3:1 orbital resonance between Miranda and Umbriel and a past 4:1 resonance between Ariel and Titania are thought to be responsible for the heating that caused substantial endogenic activity on Miranda and Ariel.
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The regions immediately east of the Andes experience a series of changes resulting from the Andean orogeny. Parts of the Sunsás Orogen in Amazonian craton disappeared from the surface of earth being overridden by the Andes. The Sierras de Córdoba, where the effects of the ancient Pampean orogeny can be observed, owe their modern uplift and relief to the Andean orogeny in the Tertiary. Further south in southern Patagonia the onset of the Andean orogeny caused the Magallanes Basin to evolve from being an extensional back-arc basin in the Mesozoic to being a compressional foreland basin in the Cenozoic.
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The Trans-Mexican Volcanic Belt Volcanoes of Mexico are related to subduction of the Cocos and Rivera Plates to the east, which has produced large, explosive eruptions. Most active volcanoes in Mexico occur in the Trans-Mexican Volcanic Belt, which extends from west to east across central- southern Mexico. A few other active volcanoes in northern Mexico are related to extensional tectonics of the Basin and Range Province, which splits the Baja California peninsula from the mainland. Popocatépetl, lying in the eastern half of the Trans-Mexican Volcanic Belt, is the second-highest peak in Mexico after the Pico de Orizaba.
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The makeup and structure of the volcanoes in Antarctica change largely from the other places around the ring. In contrast, the Antarctic Plate is almost completely surrounded by extensional zones, with several mid-ocean ridges that encircle it, with only a small subduction zone at the tip of the Antarctic Peninsula, reaching eastward to the remote South Sandwich Islands. The most well-known volcano in Antarctica is Mount Erebus, which is also the world's southernmost active volcano. In many respects the geology of the Antarctic Peninsula is an extension of the Andes, hence the name sometimes used by geologists: "Antarctandes".
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These horsts and grabens extend from onshore areas northward into a complex offshore terrane that includes the Ionian Sea abyssal plain to the northeast. This plain is underlain by oceanic crust that is being subducted to the north and east beneath the Hellenic arc. The Pelagian province to the west, particularly the pull-apart basins of the Sabratah Basin and extending along the South Cyrenaica Fault Zone (SCFZ) and the Cyrenaica Platform to the east, is strongly influenced by extensional dextral strike-slip faulting. To the south, the Nubian Swell is the stable continental basement for this rifted basin.
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During the middle of the Miocene period Japan was affected by the opening of the Sea of Japan as a back-arc basin in response to continuing subduction of the Pacific Plate. This period of extensional tectonics caused the development of rift basins on the western side of Honshu, including the northern part of the Fossa Magna. When the back-arc spreading stopped during the late Miocene, the rifted area started to shorten and the basins became inverted. The western margin of the Nagano Basin, part of the Fossa Magna, is formed by an active reverse fault zone, the West Nagano Basin Fault.
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The terrane hosts a swarm of NEE-SSW oriented dykes that date to the Neoproterozoic. East of the SYSZ, the latitudinal Colonia Shear Zone (CSZ) separates the Palaeoproterozoic (2000±100 Ma) Piedra Alta Terrane to the north from the Tandilia Terrane to the south. A period of extensional tectonics in the Late Paleoproterozoic coincided with the formation and intrusion of the Piedra Alta mafic dike swarm and the rapakivi granites of Illescas Batholith. The 1790±5 Ma-old Late Palaeoproterozoic Piedra Alta mafic dike swarm was subsequently affected by the -wide Mesoproterozoic SYSZ and its eastern end bends along the dextral megashear zone.
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The epicentre of the earthquake lies within a zone of active extensional faulting, but close to the southern flank of Vesuvius. Analysis of focal mechanisms from the area around Vesuvius indicates that active faulting in the area involves NW–SE and NE–SW trending oblique-slip normal faults and E–W trending normal faults, part of the zone of active extension that extends the full length of the Apennines mountain chain, associated with continued opening of the Tyrrhenian Sea. An association between earthquakes in the central Apennines and eruptions of Vesuvius has been proposed, but is not yet proven.
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This would have led to orbital eccentricity and tidal heating that may have warmed Tethys' interior enough to form a subsurface ocean. Subsequent freezing of the ocean after the moons escaped from the resonance may have generated the extensional stresses that created the enormous graben system of Ithaca Chasma on Tethys. The satellite system of Uranus is notably different from those of Jupiter and Saturn in that it lacks precise resonances among the larger moons, while the majority of the larger moons of Jupiter (3 of the 4 largest) and of Saturn (6 of the 8 largest) are in mean-motion resonances.
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The end result is that the Northern Cordilleran Volcanic Province and the terrains of which the volcanic province occupies have moved northwards. In the context of plate tectonics, strip-slip movement of the Tintina Fault is also related to strike-slip movement along the San Andreas Fault and other extensional or strike-slip fault systems of western North America. To the west, the Denali Fault is the source of minor earthquakes that extend along the length of the fault. In contrast to the Tintina Fault, strike-slip movement along the Denali Fault has offset at least of the surface.
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Arc volcanism and extension occurred as the Neo-Tethys Ocean subducted under the southern margin of Laurasia during the Mesozoic. Uplift and compressional deformation took place as the Neotethys continued to close. Seismic surveys indicate that rifting began in the Western Black Sea in the Barremian and Aptian followed by the formation of oceanic crust 20 million years later in the Santonian. Since its initiation, compressional tectonic environments led to subsidence in the basin, interspersed with extensional phases resulting in large-scale volcanism and numerous orogenies, causing the uplift of the Greater Caucasus, Pontides, Southern Crimean Peninsula and Balkanides mountain ranges.
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The southern boundary is somewhat poorly defined, possibly because it corresponds to a shallow relic subduction zone, but runs roughly along the Jemez Lineament. Individual island arc terranes accreted to Laurentia during the Yavapai Orogeny include the Elves Chasm block in the Grand Canyon, Green Mountain, Dubois-Cochetopa, Irving Formation, Moppin-Gold Hill, and Ash Creek- Payson. The latter includes the Payson Ophiolite. Quartzite-rhyolite successions associated with extensional basins include the Vadito Group and Hondo Group in New Mexico and the Mazatzal Group in Arizona, deposited during the transition from the Yavapai to the Mazatzal orogens at 1700 Mya.
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The extensional basin in which the Mazatzal Group was deposited lasted about 30 Ma, from the Payson Ophiolite at 1730 Mya to the Mazatzal Peak Quartzite sometime after 1700 Mya. A number of regional orogenies fall within the time span of the Yavapai orogeny and are regarded as parts of the overall orogenic system. These include the Ivanpah orogeny (1710–1680 Mya) in the New York Mountains area; the Central Plains orogeny in the mid-continent; the Medicine Bow orogeny at 1708–1750 Mya that produced the Cheyenne belt, the Colorado province or Colorado orogeny at 1780–1700 Mya.
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The dykes of the complex consist of carbonatite and alkaline rocks such melilite and sövite. It has been proposed that both the Fen Complex in Southern Norway and the Alnö Complex formed as consequence to mild extensional tectonics in the ancient continent of Baltica following the opening of the Iapetus Ocean. Harry von Eckermann published a landmark study on the Alnö Complex in 1948 correctly claiming a magmatic origin of carbonatite, albeit his finds were only widely accepted after the Ol Doinyo Lengai eruption of carbonatite lava in the 1960s showed contemporary evidence on the existence of such magmas.
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This caused strong extensional stresses in the moon's crust reaching estimates of 30 MPa, which may have led to cracking. Some present-day scarps and canyons may be a result of this process, which lasted for about 200 million years. The initial accretional heating together with continued decay of radioactive elements and likely tidal heating may have led to melting of the ice if an antifreeze like ammonia (in the form of ammonia hydrate) or some salt was present. The melting may have led to the separation of ice from rocks and formation of a rocky core surrounded by an icy mantle.
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It is generally accepted that basin and range topography is the result of extension and thinning of the lithosphere, which is composed of crust and upper mantle. Extensional environments like the Basin and Range are characterized by listric normal faulting, or faults that level out with depth. Opposing normal faults link at depth producing a horst and graben geometry, where horst refers to the upthrown fault block and graben to the down dropped fault block. The average crustal thickness of the Basin and Range Province is approximately 30 – 35 km and is comparable to extended continental crust around the world.
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As with other neighboring parts of Antarctica the Weddell Sea shares a common geological history with southernmost South America. In southern Patagonia at the onset of the Andean orogeny in the Jurassic extensional tectonics created the Rocas Verdes Basin, a back-arc basin whose surviving southeastward extension forms the Weddell Sea. In the Late Cretaceous the tectonic regime of Rocas Verdes Basin changed leading to its transformation into a compressional foreland basin –the Magallanes Basin– in the Cenozoic. While this happened in South America the Weddell Sea part of the basin escaped compressional tectonics and remained an oceanic basin.
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A HP/UHP metamorphism caused by subduction at the Silurian/Devonian boundary was followed in the Devonian/Mississippian by polyphase dynamometamorphism due to crustal shortening. The latter developed a cross pattern in the resulting structures – the well known Variscan x. The intensive nappe-stacking during continental collision transported high-grade terranes in a southerly direction over less deformed units creating the impression of an inverted metamorphism – a feature so ubiquitous in the Massif Central. The last two deformational phases in the Pennsylvanian formed under extensional stresses and again produced a cross pattern in the resulting structures.
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Since then the basin has been deepened mainly through subsidence caused by extensional tectonics. In the northern part of the Baltic Sea basin, including the Gulf of Bothnia and the Bothnian Sea, the depression originated as a series of interconnected rifts that were not active enough to split the East European Craton. Subsidence in the southern parts was most pronounced during a period starting in the Late Ordovician and lasting to Middle Silurian. At this time the Baltic sea basin and the East European Craton were part of a continent and tectonic plate known as Baltica.
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Thick-skinned deformation refers to shortening that involves basement rocks rather than just the overlying cover. This type of geometry is typically found in the hinterland of a collisional zone. This style may also occur in the foreland where no effective decollement surface is present or where pre-existing extensional rift structures may be inverted.Butler, R. W. H., S. Mazzoli, S. Corrado, M. De Donatis, D. Di Bucci, R. Gambini, G. Naso, C. Nicolai, D. Scrocca, P. Shiner, and V. Zucconi, 2004, Applying thick-skinned tectonic models to the Apennine thrust belt of Italy—Limitations and implications, in K. R. McClay, ed.
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Royce is also perhaps the founder of the Harvard school of logic, Boolean algebra, and foundations of mathematics. His logic, philosophy of logic, and philosophy of mathematics were influenced by Charles Peirce and Alfred Kempe. Students who in turn learned logic at Royce's feet include Clarence Irving Lewis, who went on to pioneer modal logic, Edward Vermilye Huntington, the first to axiomatize Boolean algebra, and Henry M. Sheffer, known for his eponymous stroke. Many of Royce's writings on logic and mathematics are critical of the extensional logic of Principia Mathematica, by Bertrand Russell and Alfred North Whitehead, and can be read as an alternative to their approach.
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The Girón Formation (, Jg) is an extensive geological formation stretching across from the north in Teorama, Norte de Santander, across the Mesa de Los Santos and Chicamocha Canyon towards west of Nobsa, Boyacá in the northern part of the Altiplano Cundiboyacense in the south. The formation extends across the northern and central part of the Eastern Ranges of the Colombian Andes. The formation forms the basement in the Middle Magdalena Valley and is forming the Serranía de Los Cobardes. The Girón Formation consists of thickly bedded red sandstones, shales, siltstones and conglomerates deposited in a terrestrial alluvial and fluvial to fluvio-lacustrine environment in an extensional basin setting.
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The Barents Sea was originally formed from two major continental collisions: the Caledonian orogeny, in which the Baltica and Laurentia collided to form Laurasia, and a subsequent collision between Laurasia and Western Siberia. Most of its geological history is dominated by extensional tectonics, caused by the collapse of the Caledonian and Uralian orogenic belts and the break-up of Pangaea. These events created the major rift basins that dominate the Barents Shelf, along with various platforms and structural highs. The later geological history of the Barents Sea is dominated by Late Cenozoic uplift, particularly that caused by Quaternary glaciation, which has resulted in erosion and deposition of significant sediment.
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From around 550 Ma the beds of the Geosyncline began a series of intraplate extensional and contractional events. The beds began to buckle, fold, uplift and block fault, creating a range of mountains called the Delamerian Highlands, possibly up to in height.This mountain range may have been the southern extent of the Petermann Orogeny and part of a suspected Supermountain range that may have stretched more than through the newly forming Gondwana supercontinent. The uplifting was so violent that despite now being located in the center of a plate, the Flinders Seismic Zone of which Hallett Cove is part remains one of the most seismically active regions in Australia.
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A long strike slip fault follows a staircase-like trajectory consisting of interspaced fault planes that follow the main fault direction. These sub parallel stretches are isolated by offsets at first, but over long periods of time they can become connected by step overs in order to accommodate the strike slip displacement. In long stretches of strike-slip the fault plane can start to curve, giving rise to structures similar to step overs. Right lateral motion of a strike slip fault at a right step over (or overstep) gives rise to extensional bends characterised by zones of subsidence, local normal faults, and pull apart basins.
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The earthquake sequence occurred in an area of complex tectonics caused by the continuing collision between the Pacific Plate and the Australian Plate. In addition to the major plates, several smaller plates are recognised. The South Bismarck Plate is moving southeastward relative to the Pacific Plate (or another microplate) and its northern boundary in the Bismarck Sea is made up of segments that are alternately extensional and sinistral transform in type. At its eastern end, where it runs close to New Ireland, this boundary is formed by the Weitin Fault, although it is unclear whether that fault is just one of the structures that carries the plate motion.
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The earthquake occurred in the southern and central part of the Apennines, an earthquake-prone area where several large faults are present, and where extensional tectonics phenomena are common due to the collision of the African Plate with the Eurasian Plate. The earthquake was preceded by lighter earthquakes starting in February 1688 and by a series of foreshocks in the days before the main shock. It was followed by aftershocks lasting at least until December of that year. The magnitude of the main shock is reported as 6.98 ±0.12 by the Italian National Institute of Geophysics and Volcanology, while the Mercalli intensity is estimated as XI (Extreme).
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Abdizhamil started his literary way with a novel, his favorite genre. A soldier, who just was back from World War II, took a pen into hands and under the pressure of the flushing inspiration presented on the paper the impressions received in a bloody battle, in the struggle between life and death. The impressions were so great that on returning from the army, working tirelessly for four to five years, gave birth to the extensional novel "Kurland" (1950). Although the artistry was not at the quite proper level, this work was included into the literature because of its wealth of ideas and new images.
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In his article "Quantifying In" (1968), Kaplan discusses issues in intensional and indirect (Ungerade, or oblique) discourse, such as substitution failure, existential generalization failure, and the distinction between de re / de dicto propositional attitude attributions. Such issues were made salient primarily by W. V. Quine in his "Quantifiers and Propositional Attitudes" (1956). The phrase "quantifying in" comes from Quine's discussion of what he calls "relational" constructions of an existential statement. In such cases, a variable bound by an anterior variable-binding operator occurs within a non-extensional context such as that created by a 'that' clause, or, alternatively, by propositional attitude or modal operators.
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The basin includes five significant depocenters. The Inner Otway Basin, Torquay Sub-basin, Morum Sub- basin, Nelson Sub-basin, and Hunter Sub-basin formed as a result of two major, basin-wide rifting phases. At the onset of major north-south rifting in the late Jurassic several east-west trending extensional depocenters developed in the onshore part of the basin to define the Inner Otway Basin. Renewed rifting in the late Cretaceous was driven by a change in crustal extension style from north-south to northeast-southwest resulting in the structurally different, northwest-southeast trending Torquay, Morum, Nelson, and Hunter Sub-basins in the mid- and off-shore.
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The Perth Basin began forming in the Late Permian during the breakup of Gondwana, as the Australian continental plate began rifting away from the African and Indian continental plates. During the Permian, what is now the Perth Basin was the eastern half of a rift valley that formed as the continental plates were pulled apart. This pulling apart, which continued until the Jurassic, led to the central zone subsiding as a graben allowing the sea to enter with the subsequent deposition of transgressive marine sediments. The Perth Basin architecture is dominated by listric, extensional faulting that formed during sedimentation and controlled the distribution of the sediments.
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After termination of extensional faulting near the end of Albian time, the Jeanne d'Arc Basin and its surrounding margins subsided as a region. Consequently, the basin was buried beneath a northeastward-thickening wedge of mostly un-deformed Upper Cretaceous and Tertiary strata. Continued burial of the Egret Member source rock during this final episode of passive margin conditions resulted in heating and maturation of the source rock such that it gradually passed through the "oil window" over an increasingly large area of the basin. This burial process resulted in generation of large volumes of petroleum and migration into the overlying structural and stratigraphic traps.
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Gradual freezing of such an ocean, in combination with polar wander and the loading of Sputnik Planitia with ice, would also explain the extensional tectonic features seen across Pluto. Alternatively, if the accumulation of ice in a single cap (without an impact) created a positive gravity anomaly that reoriented Pluto prior to formation of a basin, the tidal bulge raised by Charon might then have maintained Pluto's orientation even if the positive anomaly later disappeared. The creation of the gravity anomaly is thought to require thinning the ice crust by ~90 km below Sputnik Planitia. However, the crust must be kept cool to maintain such variations in its thickness.
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Queen Charlotte, Denali and Tintina fault zones The volcanic history of the Northern Cordilleran Volcanic Province presents a record of volcanic activity in northwestern British Columbia, central Yukon and the U.S. state of easternmost Alaska. The volcanic activity lies in the northern part of the Western Cordillera of the Pacific Northwest region of North America. Extensional cracking of the North American Plate in this part of North America has existed for millions of years. Continuation of this continental rifting has fed scores of volcanoes throughout the Northern Cordilleran Volcanic Province over at least the past 20 million years (see Geology of the Pacific Northwest) and occasionally continued into geologically recent times.
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The Niger Delta Basin is located in the Gulf of Guinea on the west coast of Africa. Geologic map of the Niger Delta Basin and the Benue trough, and the oil fields in the region. The Niger Delta Basin, also referred to as the Niger Delta province, is an extensional rift basin located in the Niger Delta and the Gulf of Guinea on the passive continental margin near the western coast of Nigeria with suspected or proven access to Cameroon, Equatorial Guinea and São Tomé and Príncipe. This basin is very complex, and it carries high economic value as it contains a very productive petroleum system.
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A rift about long and wide, named the Alpha-Lada extensional belt, spans the northwestern edge of Lada Terra separating the relatively high lands of Lada Terra from the broad lowlands of Lavinia Planitia. The Lavinia Planitia basin is suspected to be an area of mantle downwelling, where there are less thermal stresses on the lithosphere. Because the nearby Lada Rise is speculated to be an area of mantle upwelling, models predict this could create a zone of weakness between these two convection cells which stretches the lithosphere, thus creating the rift zone. Associated with the rift zone are large lava flow fields and corona.
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The radar images from the Magellan missions revealed that the terrestrial style of plate tectonics is not active on Venus and the surface appears to be immobile at the present time. Despite these surface observations, there are numerous surface features that indicate an actively convecting interior. The Soviet Venera landings revealed that the surface of Venus is essentially basaltic in composition based on geochemical measurements and morphology of volcanic flows. The surface of Venus is dominated by patterns of basaltic volcanism, and by compressional and extensional tectonic deformation, such as the highly deformed tesserae terrain and the pancake like volcano-tectonic features known as coronae.
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The Canadian Arctic Rift System is a major North American geological structure extending from the Labrador Sea in the southeast through Davis Strait, Baffin Bay and the Arctic Archipelago in the northwest. It consists of a series of interconnected rifts that formed during the Paleozoic, Mesozoic and Cenozoic eras. Extensional stresses along the entire length of the rift system have resulted in a variety of tectonic features, including grabens, half-grabens, basins and faults. Development of the Canadian Arctic Rift System was accompanied by two plate tectonic episodes that originated on opposite sides of the North American Plate and were propagated toward each other.
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The epicenter area of the earthquake is covered by wind-blown sediments and there is no trace of a fault at the surface prior to the earthquake. The phenomenon was suspected to be an artificial earthquake allegedly caused by hydraulic fracking activity in the Central Kalahari Game Reserve. This speculation has been dismissed by the Botswana Geoscience Institute saying that the earthquake was natural, taking note that the earthquake was recorded at a depth of . Geophysical investigation of the epicenter region show that the earthquake is natural, related to deep mantle fluids moving up the crust and causing the extensional reactivation of an ancient thrust fault.
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According to Robert John Pankhurst, "The Ferrar Supregroup is well known as being representative of a Middle Jurassic (and partly later), Gondwana-wide continental flood basalts event which includes Tasmanian dolerites, the Karoo Supergroup of southern Africa and the Serra Geral basalts of central South America." These continental tholeiites are indicative of a large-scale extensional rift system and associated Middle Jurassic magmatic activity linked to the break-up of Gondwana 25 m.y. later, when East Antarctica separated from Africa, and the Mozambique Basin opened. Included in the supergroup are the Ferrar Dolerite sills and dykes, the Kirkpatrick Basalts, and the volcanogenic Carapace Sandstone and Mawson Formation.
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Four types of traps have been identified in offshore Indus: an extensional rollover anticline trend in the upper slope, drape structures over the Eocene carbonate banks and seamounts, stratigraphic traps formed by sands pinching out against the Murray Ridge and folds associated with the Murray Ridge shear faults and shale diapirs. Presence of seal may be an issue in some areas due to erosional channels. The source rock is questionable, as Sembar Formation, which is a proven source onshore, is too deep offshore and most likely overmature to charge the reservoirs. Paleocene-Eocene carbonates can be the potential source rocks in the offshore Indus basin.
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In general, pre-Triassic stratigraphy and rifting has been confirmed below the northern North Sea but is poorly known and little conclusive information exists about Devonian and Carboniferous extensional events. While precise dating and the spatial extent of the active stretching are uncertain, recent stratigraphic syntheses suggest syn-rift dates of no younger than Scythian, with a possible initiation during the late or even early Permian. The following middle Triassic to early Jurassic post- rift stage is considerable better known. Subsidence (approximately nine intervals) in the northern North Sea was accompanied by faulting, stepping down from both margins towards the present Viking Graben axis.
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The Adare Trough is a single, northwest-southeast trending, graben roughly 120 km long with high rifted flanks located centrally in the Adare Basin, 100 km northwest of Cape Adare. The flanks are roughly 40 km apart and are asymmetrical when compared to one another, with the East flank rising higher than the west by roughly 550 meters. The major uplift required to form the Adare trough marks the last major extensional phase of the Adare basin. Magnetic anomalies curve southwards from the Adare Trough towards the Ross Sea, indicating the Adare Trough is part of the extinct third arm of a West Antarctic Rift System ridge- ridge-ridge triple junction.
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The cleavage has an overall WSW-ENE trend, although regionally it is somewhat arcuate, being more SW-NE trending in the west and more west-east trending in the east. The main Acadian structures in the Skiddaw Group are a set of thrust faults, of which the Causey Pike Fault has the greatest extent, being recognised across the whole of the main outcrop of the group. This and other thrusts within the Skiddaw Group are thought to be reactivated extensional faults that were active during sedimentation. The Borrowdale Volcanic Group sequence was folded during the Acadian and some of the volcano-tectonic faults were reactivated.
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Some early studies (e.g., ) dated accretion as late as 42 Ma. A recent study suggests it may have been as early as 55 Ma. This date has added significance as it is also the start of a change in direction of the Pacific plate, as seen in the bend in the Hawaiian-Emperor seamount chain, and also a change in the Pacific Northwest from compressional to extensional tectonics.; ; ; . This may also be when the last of the Resurrection plate was subducted under British Columbia.. Initiation of the north-striking right-lateral Straight Creek Fault at ~48 Ma. likely resulted from strain accumulated during the accretion of Siletzia.
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Most sulfide brines will remain in concentration until they reach reducing conditions, a higher pH or lower temperatures. Ore fluids are generally linked to metal rich waters that have been heated within a sedimentary basin under the elevated thermal conditions typically in extensional tectonic settings. The redox conditions of the basin lithologies exert an important control on the redox state of the metal-transporting fluids and deposits can form from both oxidizing and reducing fluids. Metal-rich ore fluids tend to be by necessity comparatively sulfide deficient, so a substantial portion of the sulfide must be supplied from another source at the site of mineralization.
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Geologists call this region the Basin and Range Province. Extensional forces causes rock at depth to stretch like silly putty and rock closer to the surface to break along normal faults into downfallen basins called grabens; small mountain ranges known as horsts run parallel to each other on either side of the graben. Normally the number of horsts and grabens is limited, but in the Basin and Range region there are dozens of horst/graben structures, each roughly north-south trending. A succession of these extend from immediately east of the Sierra Nevada, through almost all of Nevada, and into western Utah and southern Idaho.
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These features can be several kilometers high (as opposed to hundreds of meters high for wrinkle ridges), and are thought to represent large lithosphere-scale thrust faults. Displacement ratios for these are ten times those of wrinkle ridges, with shortening estimated to be hundreds of meters to kilometers. Approximately half of the extensional features on Mars formed during the Noachian, and have changed very little since, indicating that tectonic activity peaked early on and decreased with time. Wrinkle ridge formation both around Tharsis and in the eastern hemisphere is thought to have peaked in the Hesperian, likely due to global contraction attributed to cooling of the planet.
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So how are the three seemingly irreconcilable principles above resolved? Davidson distinguishes causal relations, which are an extensional matter and not influenced by the way they are described, from law-like relations, which are intensional and dependent on the manner of description. There is no law of nature under which events fall when they are described according to the order in which they appeared on the television news. When the earthquake caused the Church of Santa Maria dalla Chiesa to collapse, there is surely some physical law(s) which explains what happened, but not under the description in terms of the event on Channel 7 at six p.m.
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Another axiom proposed in the late 1960s was Maurice Boffa's axiom of superuniversality, described by Aczel as the highpoint of research of its decade. Boffa's idea was to make foundation fail as badly as it can (or rather, as extensionality permits): Boffa's axiom implies that every extensional set-like relation is isomorphic to the elementhood predicate on a transitive class. A more recent approach to non- well-founded set theory, pioneered by M. Forti and F. Honsell in the 1980s, borrows from computer science the concept of a bisimulation. Bisimilar sets are considered indistinguishable and thus equal, which leads to a strengthening of the axiom of extensionality.
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The Greater India Basin model is therefore put forward to explain such observation, where the total amount of convergent has actually been dispersed into two separate stages of crustal thickening, i.e. the uplift of the microcontinent (Tibetan Plateau) and the Himalaya orogeny. The subduction and disappearance of the Great Indian Basin oceanic crust beneath the microcontinent reduces the measurable amount of total convergence expressed by crustal shortening at the surface. Paleomagnetic data suggests that the Indian continent had experienced a N-S extension with minimum extension rates of 40–67 mm/y during 118 and 68 Ma. Such extensional rate is comparable to typical records of intracontinental rifting.
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This is thought to be caused by the influence of the mid ocean ridge extensional stress regime. The morphology of the western portion also suggests that it was formed before the hot spot interacted with the Juan de Fuca ridge. The northwestern section of Brown Bear is dominated by a large (5 km diameter) rounded volcanic cone structure. The southern portion extends south of 46.1 degrees North Latitude, and consists of relatively small (1–2 km diameter) volcanic cones. 3\. Cobb Seamount (46° 44′ 0″ N, 130° 47′ 0″ W) The Cobb Seamount rises from a 2750 m basin to within 37 meters of the ocean surface.
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The Vosges is greatly similar to the corresponding range of the Black Forest on the other side of the Rhine: both lie within the same degrees of latitude, have similar geological formations, and are characterized by forests on their lower slopes, above which are open pastures and rounded summits of a rather uniform altitude. Both areas exhibit steeper slopes towards the Rhine River and a more gradual descent on the other side. This occurs because both the Vosges and the Black Forest were formed by isostatic uplift, in a response to the opening of the Rhine Graben. The Rhine Graben is a major extensional basin.
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The Western Limassol Forest Complex, an ophiolite assemblage on the island of Cyprus dated to the Late Cretaceous, is believed to have come from a leaky, left-lateral transform fault about wide. Structural deformation of dykes in the ophiolite complex indicate injection into a shearing environment; they trend N-S but are cut by E-W trending shear zones. These intrusions are likely syn-tectonic, as they both pass through and are cut by the shear zones. The Emerald Fracture Zone (EMZ), located on the boundary of the Antarctic and Pacific plates to the south of New Zealand, is an ideal location to study extensional transform faults.
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The trenchward migration of the spreading center is attributed to the subduction of the Phoenix Plate under the Antarctic Plate. Slab rollback and South Shetland Trench oceanward retreat have led to extensional forces acting on the leading edge of the overriding plate. The Bransfield Strait, the result of this extension, is presumed to be four million years old or less; magnetic anomalies created by the formation of new basaltic crust and aligned with the axis of the Bransfield Rift indicate that the newly formed oceanic crust in the Bransfield Strait is roughly 1.3 million years old. Unfortunately the deposition of sediments and extensive intrusions into the rift render computer modeling unreliable.
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The Caja del Rio plateau is a monogenetic volcanic field, which includes approximately 60 cinder cones, spatter cones, and basalt outflows. The volcanism can be explained by the field's location, which is very close to the intersection of the Rio Grande Rift and the Jemez Lineament. The Rio Grande Rift is a result of extensional, (or divergent) tectonic forces exerted upon the American Southwest. This feature runs southward from the vicinity of Leadville, Colorado, through the entire state of New Mexico, through the vicinity of El Paso, Texas, and into Chihuahua, Mexico. The Rift began forming approximately 30 million years ago during the late Oligocene Epoch.
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Main faults of the Siculo-Calabrian rift zone Sicily lies on part of the complex convergent boundary where the African Plate is subducting beneath the Eurasian Plate. This subduction zone is responsible for the formation of the stratovolcano Mount Etna. Most of the damaging earthquakes occur on the Siculo-Calabrian rift zone, a zone of extensional faulting which runs for about , forming three main segments through Calabria, along the east coast of Sicily and immediately offshore, and finally forming the southeastern margin of the Hyblean Plateau, a carbonate platform in southeastern Sicily. Faults in the Calabrian segment were responsible for the 1783 Calabrian earthquakes sequence.
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The Greek philosopher Antisthenes, a pupil of Socrates, apparently distinguished "a general object that can be aligned with the meaning of the utterance” from “a particular object of extensional reference". According to Susan Prince, this "suggests that he makes a distinction between sense and reference". p. 20. The principal basis of Prince's claim is a passage in Alexander of Aphrodisias' “Comments on Aristotle's 'Topics'” with a three-way distinction: # the semantic medium, δι' ὧν λέγουσι # an object external to the semantic medium, περὶ οὗ λέγουσιν # the direct indication of a thing, σημαίνειν ... τὸ ...Prince 2015, pp. 518–522 (Antisthenes' literary remains: t. 153B.1).
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Tectonic plates boundaries detailed-en Sunda Plate map-fr The Cenozoic plate tectonics of the Indonesian region have generated a complex assemblage of micro-continental blocks and marginal ocean basins surrounded by extensional margins, subduction zones and major transcurrent faults. The island of Borneo and the Kutai basin are located on the Sunda micro-plate, which is bounded to the north and west by the Eurasian plate, to the south by the Indo-Australian plate and to the west by the Philippine and Pacific oceanic plates. In the Cenozoic, the Indo-Australian plate has been moving north and subducting under Eurasia. The collision of the Indian continent with Eurasia halted subduction and uplifted the Himalayas.
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The volcanoes of the belt are diverse in terms of activity style, products, and morphology. While some differences can be explained by which volcanic zone a volcano belongs to, there are significant differences within volcanic zones and even between neighboring volcanoes. Despite being a type location for calc-alkalic and subduction volcanism, the Andean Volcanic Belt has a broad range of volcano-tectonic settings, as it has rift systems and extensional zones, transpressional faults, subduction of mid-ocean ridges and seamount chains as well as a large range of crustal thicknesses and magma ascent paths and different amounts of crustal assimilations. Romeral in Colombia is the northernmost active member of the Andean Volcanic Belt.
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Since no external forcing is exerted in these experiments, the fluid thread can spatially rearrange and select its own time scales. Quantitative observations about strain rate, along with an apparent extensional viscosity and the breakup time of the fluid, can be estimated from the evolution of the minimal diameter of the filament. Moreover, theoretical considerations based on the balance of the forces acting in the liquid filament, allow to derive information such as the extent of non- Newtonian behaviour and the relaxation time. The information obtained in capillary breakup experiments are a very effective tool in order to quantify heuristic concepts such as "stringiness" or "tackiness", which are commonly used as performance indices in several industrial operations.
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The Campbell Plateau is a roughly triangular, cratonic microcontinent which formed during the break-up of Gondwana around 80 Ma. Large parts of the plateau are made of Palaeozoic or older granites overlain by much younger shield volcanoes who form the Auckland and Campbell Islands. The Campbell Plateau is made of continental crust, but, as such, is unusually thin. The reason for this is debated, but there are two likely candidates: either an Early Cretaceous extensional events or the Late Cretaceous break-up between New Zealand and Antarctica. Cretaceous extension between the South Island and the Campbell Plateau created the Great South Basin in which 8 km of sediments have since accumulated.
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The Animikie Group sediments were deposited between 2,500 and 1,800 million years ago, in the Animikie Basin. Deposition of sediments began after the Algoman orogeny and continued through the Great Lakes tectonic zone rupture from 2,200 to 1,850 million years ago. The Animikie Group formations are in east-central and northeastern Minnesota, and the Thunder Bay District of Northern Ontario; they are geographically divided into the Gunflint Range, the Mesabi and Vermilion ranges, and the Cuyuna Range. The Animikie Basin was an extensional basin which developed over a basement consisting of the 2,750- to 2,600-million-year-old Superior province to the north and the 3,600-million-year-old Minnesota River Valley subprovince to the south.
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Peralkaline granites (A-Type granitoids) have very high concentrations of alkaline elements and very low concentrations of phosphorus; they are deposited at moderate depths in extensional zones, often as igneous ring complexes, or as pipes, massive bodies, and lenses. These fluids have very low viscosities and high element mobility, which allows for crystallization of large grains, despite a relatively short crystallization time upon emplacement; their large grain size is why these deposits are commonly referred to as pegmatites. Economically viable pegmatites are divided into Lithium-Cesium-Tantalum (LCT) and Niobium-Yttrium-Fluorine (NYF) types; NYF types are enriched in rare-earth minerals. Examples of rare-earth pegmatite deposits include Strange Lake in Canada, and Khaladean-Buregtey in Mongolia.
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Katz's theory, to take this example, is based on the fundamental idea that sense should not have to be defined in terms of, nor determine, referential or extensional properties but that it should be defined in terms of, and determined by, all and only the intensional properties of names. He illustrates the way a metalinguistic description theory can be successful against Kripkean counterexamples by citing, as one example, the case of "Jonah." Kripke’s Jonah case is very powerful because in this case the only information that we have about the Biblical character Jonah is just what the Bible tells us. Unless we are fundamentalist literalists, it is not controversial that all of this is false.
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The Ischigualasto-Villa Unión Basin () is a small sedimentary basin located in the Argentine Northwest, Argentina. It is located in the southwestern part of La Rioja Province and the northeastern part of San Juan Province. The basin borders the Sierras Pampeanas in the east, the western boundary of the basin is formed by the Valle Fértil Fault, bordering the Precordillera, and it is bound in the southeast by the El Alto Fault, separating the basin from the Marayes-El Carrizal Basin. The basin started forming in the Late Permian, with the break-up of Pangea, when extensional tectonics, including rifting, formed several basins in Gondwana; present-day South America, Africa, Antarctica, India and Australia.
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Iceland is located on the Mid-Atlantic Ridge, the extensional tectonic plate boundary between the North American Plate and the Eurasian Plate. It is also located over a deep-seated mantle plume known as the Iceland hotspot, which causes dynamic uplift of the Iceland Plateau, with associated volcanism and seismicity.Gudmundsson A (2000) Dynamics of volcanic systems in Iceland: example of tectonism and volcanism at juxtaposed hot spot and mid- ocean ridge systems. Annual Review of Earth and Planetary Sciences 28: 107–140 The line of the Mid-Atlantic Ridge is offset by two transform zones in Iceland, the South Iceland Seismic Zone (SISZ) in the south and the Tjornes Fracture Zone in the north.
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The pre-salt layer was formed in restricted basins in the South Atlantic due to the break-up of Gondwana and arid climates The pre-salt layer is a diachronous series of geological formations on the continental shelves of extensional basins formed after the break-up of Gondwana, characterised by the deposition of thick layers of evaporites, mostly salt. Some of the petroleum that was generated from sediments in the pre-salt layer, has not migrated upward (see salt dome) to the post-salt layers above. This is especially common off the coast of Africa and Brazil. The total oil reserves are thought to be a significant fraction of the world's reserves.
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All these volcanoes are considered part of the Central Volcanic Zone of the Andes, and lie east of the Peru-Chile Trench. Notable among them are Ampato and Coropuna for exceeding a height of , Huaynaputina and El Misti for their large eruptions and Ubinas and Sabancaya for their recent activity. These volcanoes are found in places where strike-slip faults which delimit the volcanic arc and strike along its length intersect additional faults formed by extensional tectonics. Such faults occur around Sabancaya as well and include the Huambo- Cabanaconde, the Huanca, the Ichupampa, the Pampa Sepina, Sepina, Solarpampa and Trigal faults; the volcanoes Ampato and Sabancaya are aligned on this fault, which may thus be responsible for their existence.
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Every set model of ZF is set-like and extensional. If the model is well-founded, then by the Mostowski collapse lemma it is isomorphic to a transitive model of ZF and such a transitive model is unique. Saying that the membership relation of some model of ZF is well- founded is stronger than saying that the axiom of regularity is true in the model. There exists a model M (assuming the consistency of ZF) whose domain has a subset A with no R-minimal element, but this set A is not a "set in the model" (A is not in the domain of the model, even though all of its members are).
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Due to the extensional regime shaping the region, the system is dominated by normal faulting, most of which is North-South striking and dipping around 60 degrees to the East. Though the system is mostly dip-slip, there are regions of strike-slip formed mylonites in the East providing evidence for past sinistral strike-slip motion. The general strike of the fault system is North-South, though the fault activity varies between the 3 regions of the AFZ. The Northern region encompasses the Salar del Carmen major fault which splits the region into a Western domain with large active faults striking N160 to N170 and an Eastern domain with mostly inactive faults overlain by Quaternary deposits.
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The broad region of Lada Terra contains massive coronae, rift zones, and volcanic plains as well as many other features that scientists use to attempt to piece together the history of this complex planet. The distinctive cross-cutting relationships found in the bedding of Lada Terra have been important in realizing relative ages of the extensional belts and coronae, as well as the complex tesserae features present planet-wide. In 1990 the Venus Radar Mapper revealed the largest outflow channel system on the planet located in the northern region of Lada Terra. Although Lada Terra is generally considered a highland of Venus, the topography is much lower-lying than its northern counterparts Ishtar Terra and Aphrodite Terra.
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There is local evidence of marine conditions affecting the basin during one of these periods as shown by the presence of scolecodonts (marine microfossils) in the Eday Marl Formation. This and other later marine incursions have been correlated with global sea level highstands previously recognised from the middle to upper Devonian sequences of New York State, including the Taghanic, Genundewa, Middlesex and Rhinestreet events. On the Orkney Islands, volcanic rocks are found within the lower part of the Eday Group. These form isolated exposures of varying chemistry, indicating a change in magma source from one with a strong influence from earlier subduction to the alkali basalts more normally associated with extensional tectonics.
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During this era the end of extensional tectonics had been well constrained in the southern North Sea basin; the extension occurred from the late Carboniferous to the Triassic. There had been some reactivation of Varsican basement faults due to the subsidence of the Sole Pit Basin and allowing basin tilts creating a peripheral graben system around the basin. Due to the reactivation of the basement faults it led to the beginning of halokinesis in the basin. The halokinesis allowed major uplift during the Mesozoic because of the presence of salt and the reactivation of basement faults; the thrusting permitted the sediment to thrust over the diapers and float on top of the Zechstein salt.
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When the MOIST (Moine and Outer Isles Seismic Traverse) deep seismic profile was acquired north of the Scottish mainland by the BIRPS group in 1981 a series of east-dipping fault zones were imaged, two of which were interpreted as potential continuations of the Moine Thrust. The presence of half graben basin in the hanging walls of these faults was interpreted to represent Devonian and Mesozoic extensional reactivation of the Caledonian thrust structures. Further deep profiles acquired in the same area, the DRUM and GRID lines confirmed these features. Onshore in Shetland the Wester Keolka Shear was proposed to represent the Moine Thrust, although more recent radiometric dating results suggest that this is unlikely to be the case.
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Tectonic and magmatic features associated with the Mackenzie Large Igneous Province. Red star shows the initial Mackenzie plume zone relative to the lithosphere; partial black circle is the estimate of the zone of plume influence on stress- field orientation; dark lines are dikes of the Mackenzie swarm; CRB indicates the Coppermine River basalts; M indicates the Muskox intrusion. At the beginning of the Mackenzie magmatic event, the Mackenzie hotspot collided with lithosphere that was already in an extensional regime that allowed rifting to occur. Passive rifting has been interpreted as the mechanism that produced the opening of the former Poseidon Ocean, the geometry of which would have been partly controlled by dike swarm geometry.
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The central Apennines of Italy are dominated by extensional tectonics as a result of either roll-back associated with continuing subduction of the Adriatic Plate or northeastward movement of the Adriatic Plate relative to the Eurasian Plate. The epicentral area of the earthquake lies within the Fucino Basin, an area of active rifting with a Pliocene to recent fill of greater than 1 km of fluvial to lacustrine sediments. Since the Late Pliocene the subsidence has controlled by a set of NW-SE trending, SW-dipping normal faults, including the Marsican Hwy Fault (MHF) and the San Benedetto dei Marsi–Gioia dei Marsi Fault (SBMGF), which bound the northeast side of the basin.
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In the begin of the late Triassic, high volumes of sediments accumulate off of the shoreline of western Australia to the northern extend of the Exmouth Plateau by the Mungaroo Deltas. The Carnian (237-228 Ma) to Norian (228-209 Ma) aged fluviodeltaic sediments deposited were siliciclastic claystones and sandstones, and detritus which would late make up the coals found in Mungaroo Formation. As extensional rifting between Greater Indian and the Australian continued, magmatic intrusion along the westernmost section of the Exmouth Plateau caused further rifting to the outer margins. By the end of the Late Triassic (209-201 Ma) tectonic activity had relatively slowed down and less deltaic sediments were deposited compared to the Carnian and Norian.
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In at least one source,"From Aristotle to EA: a type theory for EA" a class is a set in which an individual member can be recognized in one or both of two ways: a) it is included in an extensional definition of the whole set (a list of set members) b) it matches an Intensional definition of one set member. By contrast, a "type" is an intensional definition; it is a description that is sufficiently generalized to fit every member of a set. Philosophers sometimes distinguish classes from types and kinds. We can talk about the class of human beings, just as we can talk about the type (or natural kind), human being, or humanity.
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On a broader scale, there was a change in absolute direction of the Pacific plate. (marked by the end of the bend in the Hawaiian-Emperor seamount chain), and a change in the convergence of the Kula plate with the North American plate.. As subduction waned so did the force that had clamped Siletzia against the continent, and the tectonic regime shifted from compressional to extensional.. Deposition of sand from the then proximal Idaho Batholith into the Tyee Formation in southern Oregon may have continued as late as 46.5 Ma,. but was interrupted when Siletzia rifted from the continent and began rotating away.As explained earlier, it appears the rotation was about a northern pole.
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Its chemical composition places it within the field of collisional or intraplate granites (Rapela et al. 1990), and has been interpreted as a product of partial melting of the crust due to changes in the thermal regime during regional uplift (Otamendi et al. 2002). Since the foundation of the Pampas, the Sierras has been involved in a series of extensional events in the Late Paleozoic (Gondwanan cycle), the latter accompanied by a large magmatism, volcanism, and finally the Cenozoic Andean orongenic cycle, which produced the present morphology. The brittle tectonic Andica is represented by reverse faults among which stand out in the hills of Cordoba those high peaks, the Giants, Copina and Cumbrecita.
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All the coastal lagoons of Lazio formed in the same way: an offshore Pliocene graben created by extensional forces in NE and SW directions behind a karst of Mesozoic limestone gradually filled by peaty and fluvial deposition in the Pleistocene. A barrier fringe of sand developed offshore enclosing first a lagoon, then a coastal marsh. The remnant chain of lagoons are brackish due to heavy inflow of fresh water from springs at the base of the porous Volscian Mountains and the intrusion of salt water from the marsh, much of which is still below sea level. The positions of the lakes are determined by local elevations and equilibrium between inflow and outflow.
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The coronae, which are unique to Miranda, initially defied easy explanation; one early hypothesis was that Miranda, at some time in its distant past, (prior to any of the current cratering) had been completely torn to pieces, perhaps by a massive impact, and then reassembled in a random jumble. The heavier core material fell through the crust, and the coronae formed as the water re-froze. However, the current favoured hypothesis is that they formed via extensional processes at the tops of diapirs, or upwellings of warm ice from within Miranda itself. The coronae are surrounded by rings of concentric faults with a similar low-crater count, suggesting they played a role in their formation.
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This oceanic crust likely formed during the middle Jurassic Period, roughly 170 million years ago, in an extensional regime within either a back- arc or a forearc basin. It was later accreted to the continental margin of Laurasia. Longitudinal sedimentary tapering of pre-orogenic sediments correlates strongly with curvature of the submarine frontal accretionary belt in the South China Sea margin, suggesting that pre-orogenic sediment thickness is the major control on the geometry of frontal structures. The preexisting South China Sea slope that lies obliquely in front of the advancing accretionary wedge has impeded the advancing of frontal folds resulting in a successive termination of folds against and along strike of the South China Sea slope.
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Individuals (instances) are the basic, "ground level" components of an ontology. The individuals in an ontology may include concrete objects such as people, animals, tables, automobiles, molecules, and planets, as well as abstract individuals such as numbers and words (although there are differences of opinion as to whether numbers and words are classes or individuals). Strictly speaking, an ontology need not include any individuals, but one of the general purposes of an ontology is to provide a means of classifying individuals, even if those individuals are not explicitly part of the ontology. In formal extensional ontologies, only the utterances of words and numbers are considered individuals – the numbers and names themselves are classes.
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A marine regression occurred and the fold and thrust belts of Malargüe (36°00 S), Chos Malal (37° S) and Agrio (38° S) started to develop in the Andes and did so in until Eocene times. This meant an advance of the orogenic deformation since the Late Cretaceous that caused the western part of Neuquén Basin to stack in the Malargüe and Agrio fold and thrust belts. In the Oligocene the western part of the fold and thrust belt was subject to a short period of extensional tectonics whose structures were inverted in the Miocene. After a period of quiescence the Agrio fold and thrust belt resumed limited activity in the Eocene and then again in the Late Miocene.
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The James Ross Island Volcanic Group is a stratigraphic unit of Cenozoic age distributed on James Ross Island and Vega Island of the James Ross Island group, the Tabarin and Trinity peninsulas of Graham Land and surrounding islands in the Prince Gustav and Antarctic sounds. The volcanic group consists predominantly of alkali basalts with minor hawaiites, benmoreites and mugearites. They are interpreted to have been deposited by volcanic eruptions in an extensional back-arc setting after subduction had ceased along the western margin of the Antarctic Peninsula. K–Ar dating of these rocks suggest that they were erupted from about 7 million years ago up until about a few hundred thousand years ago.
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Mount Jefferson Mount Jefferson shows normal magnetic polarity, suggesting that it formed less than 730,000 years ago. Created by the subduction of the oceanic Juan de Fuca tectonic plate under the continental North American tectonic plate in an area where the Earth's crust is thick, it is part of the Oregon High Cascades, which are influenced by the movement of the North American Plate and the extension of its continental crust. These extensional processes formed grabens, or valley-like depressions between parallel fault lines, at the eastern boundary of the central Cascades, including a deep formation. Jefferson does not lie in one of these grabens, but these tectonic processes continue, albeit at a less dramatic rate.
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Along the Pacific margin the convergence of tectonic plates lead to renewed subduction which produced the large rhyolitic provinces and plutonic belts of the Permian–Jurassic. By the end of the Paleozoic erosion had led to the formation of a peneplain in the eastern Sierras Pampeanas. Later tectonic movements split this surface into various levels with the highest level being Pampa de Achala. As the South Atlantic opened following the Paraná-Etendeka flood basalts, the Andean orogeny began the formation of the Andes, the product of volcanism and compressional forces along the Pacific margin, but also resulted in the development of extensional basins in South America and a passive margin along the Atlantic coast, processes still going on today.
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The Riverside Mountains are one of several ranges that constitute the Maria Fold and Thrust Belt (MFTB). The Maria Fold and Thrust Belt underwent generally thick-skinned (involving basement rocks) north–south-trending crustal shortening in the Cretaceous. The structures of the MFTB are exposed by to later generally east–west-trending large-scale crustal extension in the Miocene, through what is known to geologists as the Colorado River Extensional Corridor. This north–south shortening is anomalous, as crustal shortening in the rest of the North American Cordillera is oriented generally east–west because of the generally east–west compression that was due to the subduction of the Farallon plate under western North America.
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Passive margins are characterised by large prisms of sedimentary material deposited since the original break-up of a continent associated with formation of a new spreading centre. This wedge of material will tend to spread under gravity and, where an effective detachment layer is present such as salt, the extensional faulting that forms at the landward side will be balanced at the front of the wedge by a series of toe-thrusts. Examples include the outboard part of the Niger delta (with an overpressured mudstone detachment)Bilotti, F. & Shaw, J.H. 2005. Deep-water Niger Delta fold and thrust belt modeled as a critical taper wedge: The influence of elevated basal fluid pressure on structural styles.
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As with all large intrusive bodies, the method by which the batholith's plutons were emplaced is a matter of debate, due to the space problem of adding such large masses to the upper crust. Four main mechanisms have been proposed; stoping, diapirism, extensional faulting and uplift of the overlying country rock over a laccolithic sill with a relatively small vertical dyke feeder. Evidence for a stoping mechanism has been described locally from the margin of the Tregonning intrusion, where a series of intrusive sheets extend out from the roof zone of the intrusion into the country-rock. Although the Land's End pluton was once thought to have a diapiric origin, its emplacement is now interpreted to have been accommodated by fault movements during regional extension.
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Recently, the two built-ins `in/2` and `notin/2` have been extended to allow positive and negative table (also called extensional) constraints. Thanks to the employment of AR as the implementation language, the constraint solving part of B-Prolog is relatively small (3800 lines of Prolog code and 6000 lines of C code, including comments and spaces) but its performance is very competitive. The AR language is open to the user for implementing problem-specific propagators. For example, the following defines a propagator for maintaining arc consistency for the constraint `X+Y #= C`. Whenever an inner element `Ey` is excluded from the domain of `Y`, this propagator is triggered to exclude `Ex`, the counterpart of `Ey`, from the domain of `X`.
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However, the amount of shortening that has taken place on the thrust is not connected to Eocene extension due to the Rocky Mountain trench fault system and the Flathead fault having no influence positionally on the footwall and hanging wall cutoffs of the Lewis thrust. Instead, this transpression was replaced with transtension in the early Eocene involving east-west crustal extension and tectonic exhumation, which brought up mid-crustal metamorphic rocks to the surface to be exposed. Additionally, this transition from transpression to transtension resulted in rapid cooling of the metamorphic core complexes as they were exhumed and brought to the surface. Dextral transtension on intracontinental strike-slip faults in northeastern and southwestern British Columbia culminated with the mid Eocene extensional exhumation of midcrustal metamorphic core complexes.
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Vacuum systems usually consist of gauges, vapor jet and pumps, vapor traps and valves along with other extensional piping. A vessel that is operating under vacuum system may be any of these types such as processing tank, steam simulator, particle accelerator, or any other type of space that has an enclosed chamber to maintain the system in less than atmospheric gas pressure. Since a vacuum is created in an enclosed chamber, the consideration of being able to withstand external atmospheric pressure are the usual precaution for this type of design. Along with the effect of buckling or collapsing, the outer shell of vacuum chamber will be carefully evaluated and any sign of deterioration will be corrected by the increase of thickness of the shell itself.
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Fotla Corona The geodynamic surface of Venus is dominated by patterns of basaltic volcanism, and by compressional and extensional tectonic deformation, such as the highly deformed tesserae terrain and the concentrically-fractured coronae. On Venus, coronae are large (typically several hundred kilometres across), crown-like, volcanic features. Coronae were first identified in 1983, when the radar imaging equipment aboard the Venera 15 and Venera 16 spacecraft produced higher-resolution images of some features previously thought to be impact craters. It is believed that coronae are formed when plumes of rising hot material in the mantle push the crust upwards into a dome shape, which then collapses in the centre as the molten magma cools and leaks out at the sides, leaving a crown-like structure: the corona.
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The plume related Malani magmatism in the NW Indian shield is intraplate, anorogenic, A-type and is indicative of extensional tectonic environment in the region. There is a relationship between mantle plume related anorogenic magmatism and assembly of a supercontinent. In this research paper similarities between TAB of NW Indian shield, Seychelles, Madagascar, Nubian-Arabian shield central Iran and South China constituting Malani supercontinent in terms of bimodal anorogenic magmatism, ring structures, Strutian glaciation and subsequent desiccation are discussed. Paleomagnetic data also support the existence of Malani Supercontinent The TAB is unique in the geological evolution of the Indian shield as it marks a major period of anorogenic (A-type), ‘Within Plate’, high heat producing (HHP) magmatism represented by the Malani igneous suite of rocks (MIS).
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Beneath the sediments of the Gulf of Mexico basin, most of the pre-Triassic basement rocks are believed to be allochthonous thrust sheets sutured during the formation of Pangaea. However, it was during the break-up of the supercontinent that the foundation for the Gulf of Mexico sediments would be laid. Prior to the rifting which formed the Gulf of Mexico basin, extensional deformation in the Late-Triassic caused by the breakup up of Pangaea, and more specifically the rifting of the Atlantic Ocean, created basement graben formations which filled with terrestrial red bed sediments, and volcanic sediments from the eruption of the Central Atlantic Magmatic Plume. The plume erupted 60,000 cubic kilometers of flood basalts over ancestral North and South America, Africa and parts of Europe.
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There is little evidence of internal faulting in the basin, although fracture sets are well-developed and two stages of vein development have been observed. The northern margin of the basin is formed by a steep south-dipping fault that is interpreted to be mainly post-Devonian brittle structure that has formed close to the original basin edge. The southern margin is formed by the steep north-dipping Haukå Fault, which is interpreted to increase in displacement westwards, locally cutting out the alluvial fan deposits, although it is still regarded as being close to the original basin edge. The eastern margin is formed by a low-angle extensional fault, known as the Hornelen Detachment, part of the larger scale Nordfjord-Sogn Detachment (NSD).
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Critics of a purely tectonic hypothesis have also noted that although pit crater chains (central to the diking hypothesis) are generally aligned and coincident with graben, they are occasionally found to bifurcate and to cross coeval graben in a perpendicular direction in the vicinity of Noctis Labyrinthus. Some authors have also proposed that Noctis Labyrinthus' chasmata may have formed due to extensional faulting in weakened rocks composed of interlayered tuff and lava flows, known to produce pit crater chains parallel to graben. Other authors have suggested that phreatomagmatic processes were associated with the formation of the Noctis Labyrinthus chasmata. This hypothesis is not widely favored because chaos terrain morphology, proposed to form from this mechanism, is not found in the Noctis Labyrinthus fracture network.
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Typically, the gravity field over the outer swell is about 50 mGal (0.5 mm/s²) higher than expected from isostasy, while gravity over the trench is about 200 mGal (2 mm/s²) less than that expected from isostatic considerations. The bending of the plate is associated with tension in the upper 20 km, and shallow earthquakes, caused by tensional failure induced by the downward bending of the oceanic plate are common; about 20 extensional outer rise earthquakes with magnitude 5 or greater occur annually. Most tension axes are perpendicular to the trench, independent of the direction of relative motion between the two plates, indicating that failure is controlled by bending stresses in the plate. Plate bending also causes deeper (down to 50 km) earthquakes due to compression.
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From the Late Carboniferous to the Early Permian the New England orogen was dominated by an extensional setting related to a subduction to strike-slip transition. Subduction was re-initiated in the Permian and the granitic rocks of the New England Batholith were produced by a magmatic arc, indicating the presence of an active plate margin along most of the orogen. Permian to Cretaceous remains of this convergent margin, preserved as fragments in Zealandia (New Zealand, New Caledonia, and the Lord Howe Rise), were rifted off Australia during the Late Cretaceous to Early Tertiary break-up of eastern Gondwana and the opening of the Tasman Sea. The Cretaceous Junction Plate, located north of Australia, separated the eastern Tethys from Panthalassa.
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The basin started forming in the Early Jurassic, with the break-up of Pangea and the creation of the South Atlantic, when extensional tectonics, including rifting, formed several basins in eastern South America and southwestern Africa. The accommodation space in the Cañadón Asfalto Basin was filled by volcanic, fluvial and lacustrine deposits in various geologic formations, separated by unconformities related to transtensional and transpressional tectonic forces. The Cenozoic evolution of the basin is mainly influenced by the Andean orogeny, producing folding and faulting in the basin. The basin is of paleontological significance as it hosts several fossiliferous stratigraphic units providing many fossils of dinosaurs, turtles, mammals, plesiosaurs, pterosaurs, crocodylomorphs, fish, amphibians and flora in the Mesozoic and mammals, amphibians, fish and flora in the Cenozoic.
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The geodynamic movements are noted in the stratigraphy by regional unconformities. The predominantly extensional movement was overprinted by a compressional setting, active since the early Cenozoic. This compressional phase is noted in folds and compressional faults present in the basin.Di Pietro, 2016, p.23 The sedimentary infill of the Early and Middle Jurassic in the basin is characterized by fluvial and lacustrine sediments of the Las Leoneras, Cañadón Asfalto and Cañadón Calcáreo Formations covering the volcanic Lonco Trapial Formation, which comprises intermediate volcanic rocks sourced by magmas coming from the mantle. This succession is unconformably covered by lacustrine, fluvial and volcaniclastic rocks of the approximately 10 to 15 million year ranging Chubut Group comprising the older Los Adobes Formation and the younger Cerro Barcino Formation.
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Reconstruction of Bronze Age stilt houses on Lake Ohrid, near Peštani, North Macedonia The Ohrid and Prespa Lakes are the two largest in a north-south chain of tectonic basins (grabens) including the Korca basin, and Lake Ioannina in NW Greece, known as the Dessaret group. The transition from compressional to extensional tectonics in the central Balkan Mts occurred around 6 million years ago, with the oldest lake sediments being Pliocene, possibly 3-5 million years oldHoffmann et al. 2010 Evolution of ancient Lake Ohrid: a tectonic perspective. Biogeosciences, 7, 3377–3386, www.biogeosciences.net/7/3377/2010/doi:10.5194/bg-7-3377-2010/, Albrecht, Christian and Wilke, Thomas: Ancient Lake Ohrid: biodiversity and evolution; in Patterns and Processes of Speciation in Ancient Lakes, Developments in Hydrobiology, Springer Netherlands, 2009, pp 103 to 140. .
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The next tectonic event was the Great Lakes tectonic zone which began with compression caused by the collision of the Superior province and the Minnesota River Valley subprovince during the Algoman orogeny about 2,700 million years ago; it continued as a pulling apart (extensional) rift from 2,450 to 2,100 million years ago, followed by a second compression which deformed the rocks in the Lake Superior region during the Penokean orogeny which lasted from 1,900 to 1,850 million years ago. The first deposits occurred during the initial stages of extension of the Great Lakes tectonic zone in the continental crust. As the crust expanded it thinned, and magma was intruded through fissures in the thinned crust. Sedimentation stopped during this transitional period because the elevation was now above sea level.
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The earliest event recorded in the terrane is the intrusion of the protoliths to the Scourian gneisses at about 3.0-2.7 Ga. Blocks within the Lewisian complex were then juxtaposed by Inverian and Laxfordian deformation from about 2.4-1.7 Ga. At about 1200 Ma, the terrane was affected by extensional tectonics causing rifting and the deposition of the thick coarse clastic sequence of the Torridonian. This was interrupted by a tilting event of unknown origin that caused a hiatus of about 200 Ma, followed by further deposition. At the start of the Cambrian, there was a marine transgression and deposition of shallow marine sandstone and carbonates continuing into the Ordovician. In the Silurian the terrane became involved in the Caledonian continental collision, with the Highland Terrane being thrust over this segment of the Laurentian foreland.
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Since the downgoing slab is partly anchored in the viscous layers of the mantle, and therefore its lateral movement is significantly slower than the surface plate, then any motion of the overriding plate will cause extensional or compressional stress in the back-arc region depending on the direction of motion. In addition, mantle convection in the upper mantle wedge caused by the downward movement of the subducted slab causes stress in the upper plate and the high heat flow that characterizes back-arcs. The pulling effect of the slab as it goes down into the mantle causes a rollback motion of the trench, which also applies stress on the back- arc region of the upper plate. However, this last process has less of an impact on deformation compared to upper plate motion.
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In 1995, Michael J. Pruis and Kenneth L. Tanaka of the United States Geological Survey published an abstract for the 26th Lunar and Planetary Science Conference, identifying tectonic features in the Martian northern plains that were inconsistent with a plate tectonics- based model introduced in 1994 by Norman J. Sleep of Stanford University. The orientation of the Phlegra Montes was reported as consistent with Sleep's model, assuming that they were superposed by transform faults. However, Tanaka and Pruis did not identify any transform offset in this region. Due to the parallel nature of the Phlegra Dorsa ridges to the massifs, and the presence of perpendicular graben (extensional stresses), there is a strong implication of a localized east-west compressive stress in contradiction to the predictions made by Sleep's model.
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Basal contact of a lava flow section of the Fundy Basin About 250 million years ago during the early Triassic period, Atlantic Canada lay roughly in the middle of a giant continent called Pangaea. This supercontinent began to fracture 220 million years ago when the Earth's lithosphere was being pulled apart from extensional stress, creating a divergent plate boundary known as the Fundy Basin. The focus of the rifting began somewhere between where present-day eastern North America and northwestern Africa were joined. During the formation of the Fundy Basin, volcanic activity never stopped as shown by the going eruption of lava along the Mid-Atlantic Ridge; an underwater volcanic mountain range in the Atlantic Ocean formed as a result of continuous seafloor spreading between eastern North America and northwestern Africa.
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His initial fluid mechanics interests included hypersonic aerodynamics, creeping flow, sloshing and channel flows and leading to flows in porous media, ship hydrodynamics and models for flow separation. He moved on to free and moving boundary problems. He pioneered the study of diffusion-controlled moving boundary problems in the 1970s his involvement centring on models for phase changes and elastic contact problems all built around the paradigm of the Hele-Shaw free boundary problem. Other industrial collaboration has led to new ideas for lens design, fibre manufacture, extensional and surface-tension- driven flows and glass manufacture, fluidised-bed models, semiconductor device modelling and a range of other problems in mechanics and heat and mass transfer, especially scattering and ray theory, nonlinear wave propagation, nonlinear oscillations, nonlinear diffusion and impact in solids and liquids.
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Initially using the soul- swapping to create trans-extensional experiences with zoo animals, the hippies start using the machine to transfer souls with influential people, gaining wealth and power, and becoming the cult "Men of the Machine". In the present, this cult is led by Gordon Rimmer. In the days prior to Patrick's murder, Lydia Spring had figured out a connection between her family and Gordon and accosted him about it, but instead he abducted her, swapped her soul with that of a corgi, and planned to use Lydia to coerce Patrick into giving up his "other machine". Through clues left by Patrick, who is in fact Zachariah Webb travelling in time, Dirk and Todd find the machine and escape from Gordon by travelling back in time to just before Patrick's murder.
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Symposium held in Kirchberg/Wechsel, Austria, August 14–21, 1988. Since later in the 1990s, Ruy de Queiroz has been engaged, jointly with Dov Gabbay, in a program of providing a general account of the functional interpretation of classical and non-classical logics via the notion of labeled natural deduction. As a result, novel accounts of the functional interpretation of the existential quantifier, as well as the notion of propositional equality, were put forward, the latter allowing for a recasting of Richard Statman's notion of direct computation, and a novel approach to the dichotomy "intensional versus extensional" accounts of propositional equality via the Curry–Howard correspondence. Since the early 2000s, Ruy de Queiroz has been investigating, jointly with Anjolina de Oliveira, a geometric perspective of natural deduction based on a graph-based account of Kneale's symmetric natural deduction.
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The northernmost strand of the western fault set, the Ross Lake fault itself, is a vertical zone of horizontally-lineated mylonite that separates upper-amphibolite-facies rocks of the Cascades crystalline core from sub-greenschist-facies rocks to the east. Some dextral shear and 6–12 km of NE-side down normal slip occurred from 50(?) to post-45 Ma. At Elijah Ridge, the Ross Lake fault steps westward across a gently dipping extensional zone to the Gabriel Peak tectonic belt. This approximately 100 kilometer long, northeast-dipping mylonite zone is dominated by flattening, but kinematic indicators record dextral shear in the north and reverse shear farther south. This transpressional deformation occurred from 65 Ma (and earlier?) to 58 Ma when at least 7–24 km of dextral slip was probably transferred to the eastern faults by ENE-striking shear zones.
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B21 (Boston, MA): "excellent new book" and Frederick F Schmidt, Truth: A Primer, Westview Press: 1995. In the book, Kirkham proposes that the various theories of truth proposed through the centuries are really not all in competition with one another after all, because they are often intended to answer distinct questions about truth. For example, some have been intended only to provide the extensional necessary and sufficient conditions for truth, while others have been intended to provide a definition of truth, and still others are intended only to explain the linguistic and non-linguistic purposes of statements that predicate truth or falsity. According to MIT Press, this book is their all-time best-selling work in analytic philosophy and nearly half of all English-reading professional philosophers in the world own a personal copy of the book.
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The "quantifying in" idiom captures the notion that the variable-binding operator (for example, the existential quantifier 'something') reaches into, so to speak, the non- extensional context to bind the variable occurring within its scope. For example, (using a propositional attitude clause), if one quantifies into the statement "Ralph believes that Ortcutt is a spy," the result is (partly formalized): :(Ǝx) (Ralph believes that x is a spy) :["There is someone Ralph believes is a spy"] In short, Kaplan attempts (among other things) to provide an apparatus (in a Fregean vein) that allows one to quantify into such intensional contexts even if they exhibit the kind of substitution failure that Quine discusses. If successful, this shows that Quine is wrong in thinking that substitution failure implies existential generalization failure for (or inability to quantify into) the clauses that exhibit such substitution failure.
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The upper crust beneath the wide shoals of the Grand Banks region is composed of old Precambrian and Paleozoic strata that were moderately deformed by compression during the collisions of ancient continental plates during final assembly of the super-continent Pangea in Devonian to Carboniferous times. Later, these old 'basement' rocks were subjected to multiple episodes of stretching during the Mesozoic and the strain of that extension was expressed in growth of large rips in the rock fabric known as faults. The crust was thinned in areas of stretching and the synchronous growth of faults allowed those areas to subside; that is, to sink relative to surrounding areas, thereby creating rift basins. The Jeanne d'Arc Basin is one of these areas of rift subsidence that is bounded and transected by extensional faults which record the plate tectonic history of the North Atlantic region.
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Geological section from north to south of the Wealden Anticline, note the unsymmetrical lower Cretaceous/Jurassic sediments in the core of the anticline. The diagram has undergone extensive vertical exaggeration As a result of the Alpine orogeny the basin was squeezed between the basement to the north and the south, this resulted in the reactivation of the formerly normal faults into minor thrusts (as they had been during the Variscan Orogeny) and the formation of the Wealden Anticline. The region's two surface structural highs (areas of crust and rocks which are uplifted), the Wealden Anticline and the Channel High, are superimposed upon earlier, Mesozoic basins, (the Weald and Channel basins). This nearly exact superimposition of compressional features upon underlying formerly extensional features exemplifies perfectly the principles of structural inversion across a large and well defined geologic feature.
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Low-angle fault contact between Devonian sediments of the Kvamshesten Basin and mylonites of the underlying shear zone Lihesten near Hyllestad made of well-jointed Devonian conglomerates (part of the Solund Basin) in fault contact with mylonites of the detachment The Nordfjord—Sogn Detachment (NSD) is a major extensional shear zone up to 6 km in thickness, which extends about 120 km along strike from Nordfjord to Sognefjord, bringing Devonian continental coarse clastic sedimentary rocks into close contact with eclogite facies metamorphic rocks of the Western Gneiss Region. It formed towards the end of the Caledonian Orogeny and was mainly active during the Devonian. It has an estimated displacement of at least 70 km and possibly as much as 110 km. It was reactivated during the Mesozoic and may have influenced the development of fault structures in the North Sea rift basin.
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The Stratoni fault was identified as the fault responsible for the 1932 event because of evidence of surface ruptures recorded soon after the earthquake and from the pattern of isoseismals, which were elongated in a W-E to NW-SE orientation and similarly orientated volume of recently observed seismicity. From the observation of slickensides along exposed fault planes, the movement along the fault is dip-slip extensional with local areas of oblique slip with a component of sinistral (left-lateral) strike-slip. The extension direction is currently oriented north-south but, when the fault was formed, was oriented NNE-SSW, perpendicular to the fault trace, possibly due to subsequent clockwise rotation of the area. The earthquake was followed by three strong aftershocks (M=6.0, 5.7 & 6.2) in the period 26-29 September, and the largest (M6.3) on 11 May of the following year.
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The Big Maria Mountains are one of several ranges that constitute the Maria fold and thrust belt (MFTB). The MFTB underwent generally thick-skinned (involving basement rocks) north–south trending crustal shortening in the Cretaceous. The structures of the MFTB are exposed by to later generally east–west trending large-scale crustal extension in the Miocene, through what is known to geologists as the Colorado River Extensional Corridor This north–south shortening is anomalous, as crustal shortening in the rest of the North American Cordillera is oriented generally east–west because of the generally east–west compression that was due to the subduction of the Farallon plate under western North America. Also unlike the rest of the North American Cordillera, deformation in the MFTB involved rocks of the North American Craton, most notably the Grand Canyon sequence of sedimentary rocks.
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Located at 126°E, the AAD would thus mark the 40 km-long transition between Indian Ocean and Pacific MORBs (mid-ocean ridge basalts), a boundary that has been migrating westward during the past tens of million years. Between 102°E and the AAD, where the spreading rate is constant, the left-stepping transform faults suggest the presence of oblique extensional forces while the presence of a long, elevated ridge near the 96°E right-stepping transform suggests a compressional force is also active. Together these features indicate the two tectonic plate made a recent counter-clockwise change in relative motion. Between 88°E and 118°E there are nine transform faults offsetting the SEIR 21–135 km or an age of 0.5–3.6 Ma, accompanied by eight first-order segments (older than 5 Ma) and five east-migrating rifts.
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Immediately east of the early Andes foreland basins developed and their flexural subsidence caused the ingression of waters from the Atlantic all the way to the front of the orogen in the Maastrichtian. The Andes at the latitudes of 32–36° S experienced a sequence of uplift in the Cenozoic that started in the west and spread to the east. Beginning about 20 million years ago in the Miocene the Principal Cordillera (east of Santiago) began an uplift that lasted until about 8 million years ago. From the Eocene to the early Miocene, sediments accumulated in the Abanico Extensional Basin, a north-south elongated basin in Chile that spanned from 29° to 38° S. Tectonic inversion from 21 to 16 million years ago made the basin to collapse and the sediments to be incorporated to the Andean cordillera.
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If the plains of Elysium Planitia are being actively resurfaced, this casts earlier crater count-based age estimates into doubt across the entire region, with particular counts from the Athabasca Valles valley floor (comparing polygonized terrains to non-polygonized terrains) possibly misdated as nearly 40 times younger than they were initially estimated to be. The authors further argue that the progression of polygonal terrains to thermokarst terrains to pingo morphologies suggests (in analogy to terrestrial circumstances) an increasingly temperate climate into the late Amazonian. In 2009, Joyce Vetterlein and Gerald P. Roberts of the University of London in England reported on the presence of extensional faulting off southern Cerberus Fossae, cross-cutting morphologies attributed to both the outflow channel and to subsequent lava cover. The authors noted that these faults are likely the most recent geologic feature in the Cerberus Fossae and Athabasca Valles region.
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Intraplate volcanoes occur in many places of the Western United States, including along the Sierra Nevada, on the Colorado Plateau, the Basin and Range province and the Rio Grande Rift. Lunar Crater volcanic field lies within the Basin and Range province along with other volcanic fields, but in an unusually central position. Upwelling of asthenospheric mantle in response to the tectonic regime of the Basin and Range may be responsible for the eruptive activity there, although other processes have also been proposed such as mantle downwelling and compensating flow in the asthenosphere; older volcanism in the region is related to the subduction of the Farallon Plate. The Basin and Range province has had a complicated geological history and in the last 20 million years features extensional tectonics (tectonic processes involving a dilatation of the crust) represented by normal faults (faults where the downmoving blocks move in a way consistent with gravity).
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Modal logic is historically the earliest area in the study of intensional logic, originally motivated by formalizing "necessity" and "possibility" (recently, this original motivation belongs to alethic logic, just one of the many branches of modal logic). Modal logic can be regarded also as the most simple appearance of such studies: it extends extensional logic just with a few sentential functors: these are intensional, and they are interpreted (in the metarules of semantics) as quantifying over possible worlds. For example, the Necessity operator (the 'square') when applied to a sentence A says 'The sentence "('square')A" is true in world i if it is true in all worlds accessible from world i'. The corresponding Possibility operator (the 'diamond') when applied to A asserts that "('diamond')A" is true in world i iff A is true in some worlds (at least one) accessible to world i.
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He noted that the western piedmont of the range system appeared to slope gradually, while the eastern piedmont was bounded by an escarpment. Moore interpreted the massifs of the Phlegra Montes as block-faulted, in contradiction to the contemporary understanding that the mountains had formed in association with impact-related processes; Moore found no evidence of characteristic impact-related features in the vicinity of the ranges. He argued for an endogenic origin (rather than an exogenic, impact- based one) due to the alignment of the feature with Elysium, similar to the alignment of Claritas Fossae with the Tharsis Rise, analogizing the formation mechanism terrestrially to the African superswell or the Hawaiian hotspot. In 1986, J. Lynn Hall, Sean C. Solomon (Massachusetts Institute of Technology) and James W. Head (Brown University) modeled stresses in the Elysium Rise based on the distribution of extensional and compressional tectonic features seen on Viking imagery.
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Together with Alfred Tarski and Jan Łukasiewicz, he formed the troika, which made the University of Warsaw, during the interbellum, perhaps the most important research center in the world for formal logic. His main contribution was the construction of three nested formal systems, to which he gave the Greek-derived names of protothetic, ontology, and mereology. ("Calculus of names" is sometimes used instead of ontology, a term widely employed in metaphysics in a very different sense.) A good textbook presentation of these systems is that by Simons (1987), who compares and contrasts them with the variants of mereology, more popular nowadays, descending from the calculus of individuals of Leonard and Goodman. Simons clarifies something that is very difficult to determine by reading Leśniewski and his students, namely that Polish mereology is a first-order theory isomorphic to what is now called classical extensional mereology.
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The Kam Group is a 0.3–6 kilometre thick sequence that overlies banded iron formations of the Central Slave Cover Group. The contact between these two groups is not well preserved due to the intrusion of gabbro sills and moderate shearing. The Kam group is separated into a lower and upper group based on the existence of a thin felsic volcaniclastic layer (Ranney Chert) dated at 2722 Ma. The lower Kam group consists of the Chan Formation which contains flows of pillowed basalts intruded by a series of gabbroic sills and dikes that were produced in an extensional back-arc basin setting. Sedimentary rocks exposed in the northern part of the formation are between 2.84 and 2.80 Ga. The Upper Kam Group contains three formations deposited between 2772 and 2701 Ma. It is composed mainly of intermediate and basaltic volcanic rocks with thin intercalated rhyolite tuff layers and minor komatiite flows.
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Farther north it is less clearly defined, forming a large arch that swings westward through central Yukon. Volcanoes within the British Columbia portion of the Northern Cordilleran Volcanic Province are disposed along short, northerly trending en-echelon segments which, in the British Columbia portion of the volcanic province, are unmistakably involved with north-trending rift structures including synvolcanic grabens and half-grabens similar to the East African Rift, which extends from the Afar Triple Junction southward across eastern Africa. The Northern Cordilleran rift system formed as a result of the North American continent being stretched by extensional forces as the Pacific Plate slides northward along the Queen Charlotte Fault to the west, on its way to the Aleutian Trench, which extends along the southern coastline of Alaska and the adjacent waters of northeastern Siberia off the coast of Kamchatka Peninsula. As the continental crust stretches, the near-surface rocks fracture along steeply dipping cracks parallel to the rift known as faults.
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The Great Lakes tectonic zone (GLTZ) is bounded by South Dakota at its tip and heads northeast to south of Duluth, Minnesota, then heads east through northern Wisconsin, Marquette, Michigan, and then trends more northeasterly to skim the northernmost shores of lakes. Algoman orogeny added landmass to the Superior province by volcanic activity and continental collision along a boundary that stretches from present-day South Dakota, U.S., into the Lake Huron region near Sudbury, Ontario, Canada. It is long, and separates the older Archean gneissic terrane to the south from younger Late Archean greenstone-granite terrane to the north. The zone is characterized by active compression during the Algoman orogeny (about ), a pulling-apart (extensional) tectonics (2,450 to 2,100 million years ago), a second compression during the Penokean orogeny (1,900 to 1,850 million years ago), a second extension during Middle Proterozoic time (1,600 million years ago) and minor reactivation during Phanerozoic time (the past 500 million years).
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Sometime during the late Cretaceous period, the sea withdrew from the area that was to become the California coast in the region of Santa Barbara and Ventura, exposing the sediments that had accumulated during tens of millions of years underwater – the Espada and Jalama Formations – and they began to erode. In the early Eocene, the sea returned, resuming sediment deposition on the eroded surface, making an unconformity. The first unit deposited in the Eocene was the limestone Sierra Blanca Formation, although only north of the Santa Ynez Fault, and then the ancient sea deposited the Juncal Formation on top of the Sierra Blanca.Norris, 77-81 At this time, the crustal block on which these units were deposited was nearer to the present-day position of San Diego; it has twisted approximately 90 degrees clockwise during the last 15 million years, as part of a process of regional, extensional deformation associated with motion along the boundary of the Pacific and North American Plates.
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320px The Sandwick Fish Bed near 260px Thick fluvial sandstones of Givetian age exposed in the cliffs on the western coast of 260px 260px In common with the Devonian basins of Norway and East Greenland, the Orcadian Basin lies entirely within the area affected by crustal thickening during the Caledonian orogeny. The recognition of extensional faulting at various scales in these areas at the same time as deposition led to the suggestion that these basins reflect the gravitational collapse of this thickened zone. Other tectonic models have suggested that transtensional sinistral (left lateral) strike-slip movement on the Great Glen Fault, which passes through the centre of the basin, was the main cause of basin formation. The continuity of Middle Devonian facies belts across the trace of the fault zone, after accounting for subsequent reactivation of the Great Glen Fault in a dextral sense, has been used to argue against strike-slip activity during sedimentation.
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They then extended this study by superposing their data atop other models of stress created around the Tharsis Rise, whose globally influential stress field would have affected any compressional or extensional features created by the formation of Elysium. The north-south- oriented wrinkle ridges of the Phlegra Montes region were best-predicted by a superposed model that the researchers prepared involving Tharsis, Elysium, and Hecates Tholus (which is thought to predate the rise of Elysium Mons). In 1993, Kenneth L. Tanaka (United States Geological Survey) and Richard A. Schultz (University of Nevada, Reno) published a conference paper in which a series of parallel rises in the Thaumasia Plateau around the Coprates Rise and proposed based on its geomorphological indicators that the region was a fold and thrust belt. Similar parallel compressional features were observed in the vicinity of the Phlegra Montes, and the authors proposed that this region may also be a fold and thrust belt.
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Close-up of Verona Rupes, a large fault scarp on Miranda possibly high, taken by Voyager 2 in January 1986 Close-up of the ring of concentric fault scarps around Elsinore Corona The three coronae imaged on Miranda by Voyager 2 The fault scarps around Elsinore (top right) and the chevrons of Inverness Corona (bottom left) Due to Uranus's near-sideways orientation, only Miranda's southern hemisphere was visible to Voyager 2 when it arrived. The observed surface has patchwork regions of broken terrain, indicating intense geological activity in Miranda's past, and is criss-crossed by huge canyons, believed to be the result of extensional tectonics; as liquid water froze beneath the surface, it expanded, causing the surface ice to split, creating graben. The canyons are hundreds of kilometers long and tens of kilometers wide. Miranda also has the largest-known cliff in the Solar System, Verona Rupes, which has a height of .
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The Rio Grande Rift is a continental rift zone, which extends approximately 680 miles (~1,100 km) from central Colorado in the north to the state of Chihuahua, Mexico in the south. It is the product of extensional tectonic (or divergent) forces that formed a series of basins between the Colorado Plateau and the North American craton Thin continental crust, normal fault block topography, high regional elevation, and volcanism is found over the course of the rift. The history of movement along the rift has been divided into three separate stages: an initial stage during the late Eocene to early Oligocene, a second stage during the late Oligocene to late Miocene, and a third stage beginning in the late Miocene or early Pliocene and continuing to the recent past. Activity in the vicinity of the Caballos during the first stage included explosive rhyolitic eruptions from cauldrons located to the northwest, west, and southeast.
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Classes as non-objects, as useful fictions: Gödel 1944:131 observes that "Russell adduces two reasons against the extensional view of classes, namely the existence of (1) the null class, which cannot very well be a collection, and (2) the unit classes, which would have to be identical with their single elements." He suggests that Russell should have regarded these as fictitious, but not derive the further conclusion that all classes (such as the class-of-classes that define the numbers 2, 3, etc) are fictions. But Russell did not do this. After a detailed analysis in Appendix A: The Logical and Arithmetical Doctrines of Frege in his 1903, Russell concludes: :"The logical doctrine which is thus forced upon us is this: The subject of a proposition may be not a single term, but essentially many terms; this is the case with all propositions asserting numbers other than 0 and 1" (1903:516).
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The volcanic activity still relates to the subduction of the Nazca Plate beneath the South America Plate, however; one proposed mechanism is that a Miocene change in the subduction regimen led to the development of extensional tectonics and of faults that form the pathways for magma ascent, while other mechanisms envisage changes in mantle characteristics.alt=Payún Matrú is part of a group of volcanoes, with a string of volcanoes just to its south Other volcanic fields in the region are the Llancanelo volcanic field, the Nevado volcanic field and Salado Basin volcanic field; the first two lie north of Payún Matrú and the last south. These fields are subdivided on the basis of geochemical differences and consist of two stratovolcanoes (Payún Matrú itself and Nevado) and many monogenetic volcanoes. The volcanic field is part of the larger Payunia volcanic province, which covers an area of about in the Provinces of La Pampa, Mendoza and Neuquén and is also known as the Payenia or Andino- Cuyana volcanic province.
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A Mind Map on the Use of Information and Communication Technology (ICT) in Educational Assessment Information and communications technology (ICT) is an extensional term for information technology (IT) that stresses the role of unified communications and the integration of telecommunications (telephone lines and wireless signals) and computers, as well as necessary enterprise software, middleware, storage and audiovisual systems, that enable users to access, store, transmit, and manipulate information. The term ICT is also used to refer to the convergence of audiovisual and telephone networks with computer networks through a single cabling or link system. There are large economic incentives to merge the telephone network with the computer network system using a single unified system of cabling, signal distribution, and management. ICT is an umbrella term that includes any communication device, encompassing radio, television, cell phones, computer and network hardware, satellite systems and so on, as well as the various services and appliances with them such as video conferencing and distance learning.
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In 2005, Jeffrey C. Hanna and Roger J. Phillips of Washington University in St. Louis studied the mechanisms by which the outflow channel systems of the Athabasca and Mangala valles might have formed, given their apparent origination from fissures (respectively, Cerberus Fossae and Memnonia Fossae). They hypothesized that tectonic overpressure could feasibly offset the implausibly high porosities necessary to explain the modeled floodwater volumes seen in both regions, and numerically modeled the stress fields and displacements at depth of each source fossae. Models were made in the case that diking was involved in the release of the pressurized reservoir floodwaters, or in the case of gradual extensional tectonic activity. Also in 2005, Alfred McEwen and co-workers at the University of Arizona (in collaboration with others, including Matthew P. Golombek of the Jet Propulsion Laboratory, Devon Burr of the United States Geological Survey, and Philip Christensen of Arizona State University) reported their characterization of Zunil Crater - a large rayed crater in the neighborhood of the Athabasca Valles - and its associated secondary craters.
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In total, the areal extent of the debouched lava flows that formed the Athabasca Valles system have been mapped as covering a region reaching completely across Elysium Planitia to the south, indistinctly disappearing into the northern margin of Zephyria Planum and stretching across a wide swath of Cerberus Palus in the east-west sense, canvassing a region nearly as wide as the Elysium Rise. This flood lava unit is as large as Oregon and is of a greater areal extent than the largest of the large igneous provinces on Earth - the Deccan and Rajamundry Traps of southern India. A knobby terrain lies to the northwest of the debouchment of the Athabasca Valles and has been dated by crater counting to be the oldest extant geologic unit in the Athabasca Valles system, and is Noachian in age. Modern extensional near-source faulting associated with southern Cerberus Fossae has been found to postdate the formation of all features in the valley, and are likely the most geologically recent features of the Athabasca Valles system.
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Columbia began to fragment about 1.5–1.35 Ga, associated with continental rifting along the western margin of Laurentia (Belt-Purcell Supergroup), eastern India (Mahanadi and the Godavari), southern margin of Baltica (Telemark Supergroup), southeastern margin of Siberia (Riphean aulacogens), northwestern margin of South Africa (Kalahari Copper Belt), and northern margin of the North China Block (Zhaertai-Bayan Obo Belt). The fragmentation corresponded with widespread anorogenic magmatic activity, forming anorthosite-mangerite-charnockite- granite (AMCG) suites in North America, Baltica, Amazonia, and North China, and continued until the final breakup of the supercontinent at about 1.3–1.2 Ga, marked by the emplacement of the 1.27 Ga Mackenzie and 1.24 Ga Sudbury mafic dyke swarms in North America. Other dyke swarms associated with extensional tectonics and the break-up of Columbia include the Satakunta-Ulvö dyke swarm in Fennoscandia and the Galiwinku dyke swarm in Australia. An area around Georgetown in northern Queensland, Australia, has been suggested to consist of rocks that originally formed part of Nuna 1.7 billion years ago in what is now Northern Canada.
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Electronic Group:Dept. of Electricals and Electronics 3\. Mechanical Group: Dept. of Casting, Machinery and Mechanical Drafting In 1990 In February, Mr. Tian-Fu, Guan was inaugurated as a principal in the school 1990s In 1993 In February, Mr. Ming-Sin, Lian appeared in the inauguration of a principal in the school In 1994 In August, the augmentation of Extensional Program of Compulsory Education in the evening school In 1995 In August, the augmentation of the Practical Education Program In 1998 In September, the suspension of the Cooperative Education Program In 1999 In February, the completion of the Internet service In September, the practice of academically credit system commencing with the first-year students 2000s In 2000 In February, the school was reorganized into National Jui-Fang Industrial Vocational School due to the needs of provincial abridgment In August, Principle Ming-Sin, Lian was changed over the post to NKLCIVS, and the representative director of the Academic Affair was Mr. Jin-Cheng, Jhan In September, the suspension of the Dept.
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It formed due to extensional cracking, faulting, and rifting of the North American Plate as the Pacific Plate grinds and slides past the Queen Charlotte Fault, unlike subduction that produces the volcanoes in Japan, the Philippines, and Indonesia. The region has Canada's largest volcanoes, much larger than the minor stratovolcanoes found in the Canadian portion of the Cascade Volcanic Arc. Several eruptions are known to have occurred within the last 400 years. Mount Edziza is a huge volcanic complex that erupted several times in the past several thousand years and has formed several cinder cones and lava flows. The complex comprises the Mount Edziza Plateau, a large volcanic plateau (65 km long and 20 km wide) made of predominantly basaltic lava flows with four large stratovolcanoes built on top of the plateau. The associated lava domes and satellite cones were constructed over the past 7.5 million years during five magmatic cycles beginning with eruption of alkali basalts and ending with felsic and basaltic eruptions as late as 1,340 years ago.
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The first was model of reception of scientific ideas in peripheral countries along an active/passive axis. A passive reception is limited to local comments on the ideas, while in the active mode members of national disciplinary groups change their research programmes and attempt in some way to participate in the new paradigm. The second model (written with Mark Henderson) looks at the cognitive structure of ideas as they are received, envisioning four modes of receptions (thetic, antithetic, corrective, and extensional). All of the examples are drawn from the three sets of ideas. The second model was an outgrowth of his classic course, “Darwin, Freud, and Einstein,” which he has taught yearly at Harvard Summer school since 1993. An address to the Catalan History of Science Society in 1992 addressed approaches to the comparative history of science in small countries, and the Normal MacColl Lecture at Cambridge University in 2000, which was a synthesis of the receptions of Darwin, Einstein and Freud in Spain, viewed in comparative perspective.
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Lake Tahoe is the youngest of several extensional basins of the Walker Lane deformation zone that accommodates nearly per year of dextral shear between the Sierra Nevada-Great Valley Block and North America. Three principal faults form the Lake Tahoe basin: the West Tahoe Fault, aligned between Meyers and Tahoe City, and which is the local segment of the Sierra Nevada Fault, extending on shore north and south of these localities; the Stateline/North Tahoe Fault, starting in the middle of the lake and creating the relief that forms Stateline, NV; and the Incline Village Fault, which runs parallel to the Stateline/North Tahoe Fault offshore and into Incline Village. The West Tahoe Fault appears to be the most active and potentially hazardous fault in the basin. A study in Fallen Leaf Lake, just south of Lake Tahoe, used seafloor mapping techniques to image evidence for paleoearthquakes on the West Tahoe and revealed the last earthquake occurred between 4,100 and 4,500 years ago. Subsequent studies revealed submarine landslides in Fallen Leaf Lake and Lake Tahoe that are thought to have been triggered by earthquakes on the West Tahoe fault and the timing of these events suggests a recurrence interval of 3,000–4,000 years.
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Cross-section of the Pyrenees, the Tremp-Graus Basin is located at the left in the South Pyrenean Zone Regional cross-section from south (left) to north (right) showing the piggyback basin between the Montsec Thrust in the south and the Boixols Thrust in the north Upper Santonian limestones on top of the younger Maastrichtian Tremp Formation View from the south of the central part of the Tremp-Graus Basin with the Sant Corneli prominently in the background View from the north of the central part of the Tremp-Graus Basin with the Montsec in the background View from the west of the Tremp-Graus Basin with the Boixols Thrust and anticline in the background The Tremp Basin was formed in the northeastern corner of the Iberian Plate, a microplate that existed as a separate tectonic block between the Eurasian and African Plates since the Hercynian orogeny that formed the supercontinent Pangea. Progressive opening of the Atlantic Ocean between the Americas and at first Africa, later Iberia and finally Europe, caused large differential motions between these continents,Andeweg, 2002, Ch.1 p.1 with extensional tectonics starting in the Early Jurassic with the opening of the Neotethys ocean between southwestern Europe and Africa.Sibuet et al.
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