And the dolomite cemented the sediment particles in place, forming concretions.
|
|
These concretions were then exhumed by erosion to be exposed on the seabed today.
|
|
Instead of looking for hints of bone, he wondered if he should look for concretions.
|
|
Concretions occur when rock forms around an organic nucleus, which can be bone, Lyson said.
|
|
After seeking help from doctors, they discovered concretions underneath her eyelids, which caused massive discomfort and discharge.
|
|
These are actually sandstone concretions, but to the unknowing eye they can be quite the surreal sight.
|
|
There, he had learned to spot certain rocks called concretions that held fossils captive, like pearls in oysters.
|
|
The spherules are iron-heavy "concretions formed by action of mineral-laden water inside rocks," according to NASA.
|
|
Normal sedimentary concretions, he said, form at low temperatures, but they're comprised of dull and not shiny iron.
|
|
Scientists have already found hematite concretions on Mars, in the form of "blueberries" discovered by the Opportunity rover.
|
|
"There are many problems with [the MER] hypothesis, the most important of which include their nearly perfectly spherical shape (unlike highly irregular normal concretions), their uniform size range (never larger than about 7 mm, whereas normal concretions can reach huge size), their uniform distribution across a huge volume and area of rock (many concretions tend to be concentrated at chemical reaction fronts), their failure to clump together, other than a couple of loose doublets and single triplet, and their unusual mineralogy," Burt wrote to Gizmodo.
|
|
Rhinoliths are stone-like concretions formed by the gradual buildup of salts around things not normally found in the nose.
|
|
In addition to Milito's discovery of the concretion, Lyson's colleagues in South Africa searched for concretions rather than bone as well.
|
|
Dr. Robaei found "multiple darkly pigmented subconjunctival concretions" inside Lynch's eyelids, "some eroding through the conjunctival surface," according to the case study.
|
|
James Schuyler's diaries and diaristic poems, Aram Saroyan's minimalist concretions, and Ted Berrigan's affectionate takedowns of his friends all come to mind.
|
|
The underside of the woman's eyelids had multiple "darkly pigmented concretions," which means the mascara had accumulated into hard masses, like tiny rocks.
|
|
Patients suffering from the concretions typically present with a variety of symptoms, including nasal obstruction, headaches, facial pain and discharge from the nose.
|
|
Egg-shaped rocks called concretions that over time formed concentrically around some kind of nucleus - in this case mammal skulls - provided a bonanza.
|
|
INCREDIBLE BLACKBEARD DISCOVERY: STUNNING FIND ON BUCCANEER&aposS SHIP REVEALS PIRATE READING HABITS Over 200 concretions have been located at the wreck site.
|
|
Concretions occur when an iron object corrodes in water, causing a reaction that forms sand and other nearby items into a dense layer around the object.
|
|
Some of these are in the form of "concretions", round nodules of minerals that form when water flows through the ground and can dissolve minerals and redeposit them elsewhere.
|
|
The sediments in the seabed contained microbes, which consumed methane for energy and eventually changed the chemical composition of the sediments to create concretions of a rock called dolomite.
|
|
Image: Diva Amon and Craig Smith, University of Hawai'i at Mānoa There is, however, one alluring aspect of the CCZ: vast beds of metallic, potato-sized rock concretions, called manganese nodules.
|
|
"When we find cannons, we're quite excited because, if we're allowed to excavate around them, there will be 'concretions' of items near the cannon from when the ship sank," he said.
|
|
"The concretions got embedded in the conjunctiva and it went deeper into the subconjunctiva layer, but you could still see it, sort of like a tattoo," said Dr. Rebecca Taylor, clinical spokesperson for the AAO and an ophthalmologist in Nashville.
|
|
Manganese nodules, potato-sized concretions of rock and metal that form under crushing pressures on the pitch-black abyssal plains, are chock full of nickel, copper, and cobalt, in addition to the rare-earth oxides that form the core of nearly all modern technology.
|
|
Concretions on Bowling Ball Beach (Mendocino County, California) weathered out of steeply tilted Cenozoic mudstone. Concretions in Torysh, Western Kazakhstan. Concretions with lens shape from island in Vltava river, Prague, Czech Republic. Marlstone aggregate concretion, Sault Ste.
|
|
In the Connecticut River Valley, these concretions are often called "claystones" because the concretions are harder than the clay enclosing them. In local brickyards, they were called "clay-dogs" either because of their animal-like forms or the concretions were nuisances in molding bricks.Gratacap, L.P., 1884. Opinions Upon Clay Stones and Concretions. The American Naturalist, 18(9), pp.882-892.
|
|
The pyrite concretions typically are about 30 cm (1 foot) in diameter. Also, included within these calcite concretions are smaller calcite concretions, which have been engulfed by the growth of the larger concretions. The host rock, which contained these spherical boulders, consists of well-sorted, medium-grained, highly porous, and friable sandstone. Being only weakly indurated by small amounts of iron oxide, sometimes seen as Liesegang rings (banding) at Rock City, it is considerably softer and very much more easily eroded than the calcite concretions.
|
|
The much smaller septarian concretions found in the Kimmeridge Clay exposed in cliffs along the Wessex coast of England are more typical examples of septarian concretions.
|
|
Unlike the Moeraki boulders, some of these concretions contain the bones of mosasaurs and plesiosaurs. Similar large spherical concretions have been found in many other countries.
|
|
The large spherical boulders in Rock City are giant calcite-cemented concretions, typically called "cannonball concretions" because of their shape. They range in diameter from 3 to 6 meters (10 to 20 feet) with the average diameter being 3.6 meters (12 feet). These concretions lie 2 to 8 meters (6.6 to 26 feet) apart. Similar giant calcite-cemented concretions have also been found in a quartzite quarry within Lincoln County and in exposures of the similar age sandstones in Utah and Wyoming.
|
|
Concretions are usually similar in color to the rock in which they are found. Concretions occur in a wide variety of shapes, including spheres, disks, tubes, and grape-like or soap bubble-like aggregates.
|
|
Samples of small rock concretions found at McConnells Mill State Park in Pennsylvania. Concretions vary in shape, hardness and size, ranging from objects that require a magnifying lens to be clearly visible to huge bodies three meters in diameter and weighing several thousand pounds. The giant, red concretions occurring in Theodore Roosevelt National Park, in North Dakota, are almost in diameter. Spheroidal concretions, as large as in diameter, have been found eroding out of the Qasr El Sagha Formation within the Faiyum depression of Egypt.
|
|
Concretions: Concretions are formed when decaying organisms change the chemistry of their immediate surroundings in a manner that is conducive to minerals precipitating out of solution. These minerals accumulate in a mass roughly shaped like the region of altered chemistry. Sometimes the is egg-shaped. Most egg-shaped concretions have uniform interiors, however some form through the accumulation of mineral in layers.
|
|
Smaller but otherwise very similar septarian concretions are found within exposures of sedimentary rocks elsewhere in New Zealand. Similar septarian concretions have been found in the Kimmeridge Clay and Oxford Clay of England, and at many other locations worldwide.Scotchman, I.C., 1991, The geochemistry of concretions from the Kimmeridge Clay Formation of southern and eastern England, Sedimentology. v. 38, p. 79-106.
|
|
Wellington: GP Books. The Moeraki Boulders and Koutu Boulders of New Zealand are examples of septarian concretions, which are also cannonball concretions. Large spherical rocks, which are found on the shore of Lake Huron near Kettle Point, Ontario, and locally known as "kettles", are typical cannonball concretions. Cannonball concretions have also been reported from Van Mijenfjorden, Spitsbergen; near Haines Junction, Yukon Territory, Canada; Jameson Land, East Greenland; near Mecevici, Ozimici, and Zavidovici in Bosnia-Herzegovina; in Alaska in the Kenai Peninsula Captain Cook State Park on north of Cook Inlet beach and on Kodiak Island northeast of Fossil Beach; Reports of cannonball concretions have also come from Bandeng and Zhanlong hills near Gongxi Town, Hunan Province, China.
|
|
Struvite is a common mineral found in enteroliths (intestinal concretions) in horses.
|
|
Concretions vary considerably in their compositions, shapes, sizes and modes of origin.
|
|
Virtually identical spherical boulders, called Koutu Boulders, are found on the beaches, in the cliffs, and beneath the surface inland of the shore of Hokianga Harbour, North Island, New Zealand, between Koutu and Kauwhare points. Like the Moeraki Boulders, the Koutu Boulders are large, reaching in diameter, and almost spherical. Similar boulder-size concretions, known as Katiki Boulders, are also found on the north-facing shore of Shag Point some south of where the Moeraki Boulders are found. These concretions occur as both spherical cannonball concretions and flat, disk-shaped or oval concretions.
|
|
Concretions are formed from mineral precipitation around some kind of nucleus while a nodule is a replacement body. Descriptions dating from the 18th century attest to the fact that concretions have long been regarded as geological curiosities. Because of the variety of unusual shapes, sizes and compositions, concretions have been interpreted to be dinosaur eggs, animal and plant fossils (called pseudofossils), extraterrestrial debris or human artifacts.
|
|
Cannonball concretions are large spherical concretions, which resemble cannonballs. These are found along the Cannonball River within Morton and Sioux Counties, North Dakota, and can reach in diameter. They were created by early cementation of sand and silt by calcite. Similar cannonball concretions, which are as much as in diameter, are found associated with sandstone outcrops of the Frontier Formation in northeast Utah and central Wyoming.
|
|
Conjunctival concretions can be single, also multiple, less confluent. There is no difference between the site of the occurrence on the upper and lower eyelid, nor right or left eye. The vast majority of concretions are in the conjunctival surface rather than deep. There is no difference in age for predilection or incidence of concretions, due to the causes of conjunctivitis, aging, and even congenital factor.
|
|
Concretions on Bowling Ball Beach, south of 300px Bowling Ball Beach is a part of Schooner Gulch State Beach, in Mendocino County, California, in the United States. It is named for the spherical sandstone concretions found there at low tide.
|
|
These concretions range in size from a few millimeters to as much as in length and in thickness. Most of these concretions are oblate spheroids. Other "pop rocks" are small polycuboidal pyrite concretions, which are as much as in diameter.Hattin, D.E., 1982, Stratigraphy and depositional environment of the Smoky Hill Chalk Member, Niobrara Chalk (Upper Cretaceous) of the type area, western Kansas: Kansas Geological Survey Bulletin 225:1-108.
|
|
This can result in the precipitation of a certain chemical species producing colouring and staining of the rock, or the formation of concretions. Concretions are roughly concentric bodies with a different composition from the host rock. Their formation can be the result of localized precipitation due to small differences in composition or porosity of the host rock, such as around fossils, inside burrows or around plant roots.For concretions, see Collinson et al.
|
|
It is characterized by the presence of concretions along the hair shafts, clinically observed as yellow, and rarely as red or black nodules. These concretions derive from bacterial colonization along the hair shaft containing dried apocrine sweat with a cementing substance generated by the bacteria.
|
|
Concretions are often exposed at the surface by subsequent erosion that removes the weaker, uncemented material.
|
|
Ward,Ward, H.K., 1938, Concretions of Rock City. Mineralogist, v. 6, p. 23-24. and Swineford.
|
|
Elongate concretions form parallel to sedimentary strata and have been studied extensively due to the inferred influence of phreatic (saturated) zone groundwater flow direction on the orientation of the axis of elongation.Johnson, M.R., 1989, Paleogeographic significance of oriented calcareous concretions in the Triassic Katberg Formation, South Africa: Journal of Sedimentary Petrology, v. 59, p. 1008-1010.McBride, E.F., M.D. Picard, and K.L. Milliken, 2003, Calcite- Cemented Concretions in Cretaceous Sandstone, Wyoming and Utah, U.S.A.: Journal of Sedimentary Research. v.
|
|
Moqui Marbles, hematite, goethite concretions, from the Navajo Sandstone of southeast Utah. The "W" cube at the top is one cubic centimeter in size. Moqui Marbles, also called Moqui balls or "Moki marbles", are iron oxide concretions which can be found eroding in great abundance out of outcrops of the Navajo Sandstone within south-central and southeastern Utah. These concretions range in shape from spheres to discs, buttons, spiked balls, cylindrical forms, and other odd shapes.
|
|
Sheldon, J.M.A., 1900. Concretions from the Champlain clays of the Connecticut Valley. University Press, Boston. pp.74.
|
|
The crystallized barite at this location occurs in several closely spaced bands of calcite-cemented septarian concretions.
|
|
The sand comprising it accumulated within a river channel, which is part of the Dakota Sandstone, which accumulated within a low-lying coastal plain. Differential cementation and later erosion of cross-bedding inherited from the riverine sand, in which these concretions occur, created the "ornamentation", which these concretions exhibit.
|
|
Mosaic shows spherules, some partly embedded, spread over (smaller) soil grains on the Martian surface. Concretions are found in a variety of rocks, but are particularly common in shales, siltstones, and sandstones. They often outwardly resemble fossils or rocks that look as if they do not belong to the stratum in which they were found. Occasionally, concretions contain a fossil, either as its nucleus or as a component that was incorporated during its growth but concretions are not fossils themselves.
|
|
A spectacular example of boulder septarian concretions, which are as much as in diameter, are the Moeraki Boulders. These concretions are found eroding out of Paleocene mudstone of the Moeraki Formation exposed along the coast near Moeraki, South Island, New Zealand. They are composed of calcite- cemented mud with septarian veins of calcite and rare late-stage quartz and ferrous dolomite.Boles, J. R., C. A. Landis, and P. Dale, 1985, The Moeraki Boulders; anatomy of some septarian concretions, Journal of Sedimentary Petrology, vol.
|
|
Instead, all of these iron sulfide concretions were created by the precipitation of iron sulfides within anoxic marine calcareous ooze after it had accumulated and before it had lithified into chalk. Marleka fairy stone from Stensö in Sweden. Iron sulfide concretions, such as the Kansas Pop rocks, consisting of either pyrite and marcasite, are nonmagnetic (Hobbs and Hafner 1999). On the other hand, iron sulfide concretions, which either are composed of or contain either pyrrhotite or smythite, will be magnetic to varying degrees.
|
|
Tarr, W.A., 1935. Concretions in the Champlain formation of the Connecticut River Valley. Bulletin of the Geological Society of America, 46(10), pp.1493-1534. Similar disc-shaped calcium carbonate concretions have also been found in the Harricana River valley in the Abitibi- Témiscamingue administrative region of Quebec, and in Östergötland county, Sweden.
|
|
Conjunctival concretions can be seen easily by everting the eyelid. The projecting concretions can be removed if they are causing concerning symptoms. Removal can be performed by an eye doctor. Sometimes just a needle or a scalpel is used to remove the concretion under local light anesthesia of the conjunctiva in adults.
|
|
In the upper part, intercalations of black shale with gypsum flakes and abundant pyritic micritical concretions appear, some with ammonites.
|
|
Other concretions, which formed as a result of microbial sulfate reduction, consist of a mixture of calcite, barite, and pyrite.
|
|
Warkentin, B.P., 1967. Carbonate content of concretions in varved sediments. Canadian Journal of Earth Sciences, 4(2), pp.333-333.
|
|
After the formation of the concretions, differential erosion of the considerably softer sandstone surrounding them exposed as free-standing boulders.
|
|
A slice of a typical carbonate-rich septarian nodule. Septarian concretions (or septarian nodules) are carbonate-rich concretions containing angular cavities or cracks (septaria; ', from the Latin "partition, separating element", referring to the cracks / cavities separating polygonal blocks of hardened materials). Cracks are highly variable in shape and volume, as well as the degree of shrinkage they indicate. Although it has commonly been assumed that concretions grew incrementally from the inside outwards, the fact that radially oriented cracks taper towards the margins of septarian concretions is taken as evidence that in these cases the periphery was stiffer while the inside was softer, presumably due to a gradient in the amount of CaCO3 precipitate progressively cementing the mud porosity from outside to inside.
|
|
Detailed studies have demonstrated that concretions form after sediments are buried but before the sediment is fully lithified during diagenesis. They typically form when a mineral precipitates and cements sediment around a nucleus, which is often organic, such as a leaf, tooth, piece of shell or fossil. For this reason, fossil collectors commonly break open concretions in their search for fossil animal and plant specimens. Some of the most unusual concretion nuclei, are World War II military shells, bombs, and shrapnel, which are found inside siderite concretions found in an English coastal salt marsh.
|
|
Lyson and his colleagues subsequently hunted for fossils embedded in concretions and made unprecedented finds dating to the rise of mammals.
|
|
The cave is covered in concretions, and "organ pipes" are calcareous formations which reproduce the sound of an organ when touched.
|
|
These are found rarely in large septarian concretions in the Huron Shale in north-central Ohio near Milan, in Huron County.
|
|
The arthropods in the upper member of the Barstow Formation are preserved in concretions. The concretions are calcareous and range from 0.125 cm3 to 125 cm3. The fossils are typically three-dimensional and, on occasion, exhibit internal anatomy. Due to the preservation of soft-tissue, the Barstow Formation has been identified as a Konservat-Lagerstätte deposit.
|
|
Schistomerus is an extinct genus of predaceous diving beetle that is known from one species, Schistomerus californense, which inhabited Lake Barstow during the middle Miocene. It is the most common beetle found in the concretions from the Barstow Formation. The specimens are typically preserved in three dimensions. All ontogenetic stages of the beetle are present in the concretions.
|
|
Heritage Science 2015 3(4). Retrieved from heritagesciencejournal.com Underwater archaeologists have utilized X-rays to see what is beneath layers of concretions.
|
|
Castellana’s speleological complex is unique among other cave systems thanks to its three peculiarities: the Grave, the White Cave and the concretions.
|
|
Concretions form within layers of sedimentary strata that have already been deposited. They usually form early in the burial history of the sediment, before the rest of the sediment is hardened into rock. This concretionary cement often makes the concretion harder and more resistant to weathering than the host stratum. There is an important distinction to draw between concretions and nodules.
|
|
A model of Dinocochlea with Natural History Museum research scientist Paul Taylor as a scale. Hiatus concretions at the base of the Menuha Formation (Upper Cretaceous), the Negev, southern Israel. Hiatus concretion encrusted by bryozoans (thin, branching forms) and an edrioasteroid; Kope Formation (Upper Ordovician), northern Kentucky. Hiatus concretions are distinguished by their stratigraphic history of exhumation, exposure and reburial.
|
|
Villamil, 2012, p.164 The formation contains concretions and a high diversity of ammonites;Villamil, 2012, p.181 Wrightoceras munieri, Vascoceras cf. constrictum, Vascoceras cf.
|
|
The fountain in Place Crousillat has existed since the 16th century. During the 20th century, limestone concretions and vegetation developed, giving the familiar mushroom aspect.
|
|
It is lithologically represented by brownish-gray clays with jarosite tarnish and inter-layers of gray, fine-grained sandstones, and by marlaceous and sideritic concretions.
|
|
Conjunctival concretions are generally asymptomatic. Common symptoms include eye discomfort, eye irritation, and foreign body sensation. Sometimes, the larger, harder or multiple concretions make the rubbing off of the superficial layers of the conjunctiva or eyelids to cause conjunctival abrasion, especially prominent when upon blinking. In severe cases, dysfunction or inflammation of the Meibomian (Meibomianitis, an inflammation of the tarsal glands) glands may occur.
|
|
At this outcrop, it consists of massive thick beds of micaceous quartzite. It contains coarse pebbles of quartz and feldspar, flat pebbles of fine-grained black graywacke, and egg-shaped concretions up to in diameter. These cobble-size concretions are readily eroded by weathering to leave rust- stained depressions or cavities in the metaconglomerate.Stose, GW, and AJ Stose (1949) Ocoee Series of the Southern Appalachians.
|
|
These boulders consist of well-sorted, medium- grained sandstone, which is tightly cemented by calcite. The sandstone consists of more than 95 percent quartz sand. About 20 percent of the original sandstone, mostly feldspar grains, has been replaced by the calcite. Pyrite, which is now oxidized to goethite, occurs within the calcite cement of these concretions as microscopic crystals and very small, knobby concretions.
|
|
Disc concretions composed of calcium carbonate are often found eroding out of exposures of interlaminated silt and clay, varved, proglacial lake deposits. For example, great numbers of strikingly symmetrical concretions have been found eroding out of outcrops of Quaternary proglacial lake sediments along and in the gravels of the Connecticut River and its tributaries in Massachuset and Vermont. Depending the specific source of these concretions, they vary in an infinite variety of forms that include disc- shapes; crescent-shapes; watch-shapes; cylindrical or club-shapes; botryoidal masses; and animal-like forms. They can vary in length from to over and often exhibit concentric grooves on their surfaces.
|
|
Concretions, spherical or ovoid-shaped nodules found in some sedimentary strata, were once thought to be dinosaur eggs, and are often mistaken for fossils as well.
|
|
It joins the Missouri in Lake Oahe near Cannon Ball. The cannonball concretions found in the vicinity of this river are the source of its name.
|
|
Polymetallic nodules are concretions of manganese and iron (and other metals) found on the ocean floor. They are sometimes called manganese nodules, after their principal component.
|
|
The Lea Park Formation is composed of dark shale with minor siltstone. Calcite veins and ironstone concretions, as well as bentonite beds are found throughout the formation.
|
|
Tullimonstrum gregarium in a concretion from the Mazon Creek lagerstätten. The Mazon Creek fossil beds are a conservation ' found near Morris, in Grundy County, Illinois. The fossils are preserved in ironstone concretions, formed approximately in the mid-Pennsylvanian epoch of the Carboniferous period. These concretions frequently preserve both hard and soft tissues of animal and plant materials, as well as many soft-bodied organisms that do not normally fossilize.
|
|
Bearpaw shale being excavated to recover ammonites for ammolite production. The formation was deposited in the Bearpaw Sea, which was part of the Western Interior Seaway that advanced and then retreated across the region during Campanian time. It is composed primarily of dark grey shales, claystones, silty claystones and siltstones, with subordinate silty sandstones. It also includes bedded and nodular concretions (both calcareous and ironstone concretions) and thin beds of bentonite.
|
|
His name is also associated with "Desmarres' dacryoliths", defined as concretions consisting of Nocardia species, located in the lacrimal ducts. Mondofacto Dictionary He died in Neuilly-sur-Seine.
|
|
Researchers from the University of Utah have explored the similarities between the blueberries and spherical concretions discovered within “Jurassic Navajo Sandstone” in southern Utah. They have concluded Mars must have had previous ground water activity to form the blueberries. However, they do note the spherules are more spherical in the Martian sample due to the lack of “joints, fractures, faults, or other preferential fluid paths,” unlike the Utah sample. A team of researchers from Japan studied the spherules found in Utah as well as spherules that were later discovered in Mongolia, in the Gobi. They found evidence that the concretions found in these locations are first formed as “spherical calcite concretions” in sandstone.
|
|
Spherical concretions are present in the subsoil and underneath are tuffaceous material of varying degrees of disintegration and weathering. Tuffaceous material is exposed by extensive erosion in some places.
|
|
This species is known from a handful of good quality fossils preserved inside siderite concretions. Fossils of this species have been found in the Carboniferous sediments of United Kingdom.
|
|
These layered concretions can be even harder to recognize than those with uniform interiors because the layers can resemble egg white and yolk. The yellow of the false yolk comes from minerals like limonite, siderite, and sulfur. Concretions also generally lack distinct shells, although sometimes they can appear to have them if their outside surfaces have been case- hardened. Since their interiors are softer, erosion can separate the two, creating eggshell pseudofossils.
|
|
Additionally, in bulls, the secretion contains high amounts of fructose and citric acid. Concretions may be present in the secretory end pieces as well as parts of the duct system.
|
|
Landes,Landes, K.K., 1935, Scenic Kansas, Geological Survey of Kansas Bulletin, n. 36, 55 p. Shaffer,Shaffer, H.L., 1937, Concretions in the Dakota Sandstone, Compass, v. 17, p. 87-90.
|
|
Alloyed coal bands and lenses and iron oxide concretions have been observed in the shale. The shale is quarried in many western suburbs of Sydney for brick and miscellaneous ceramic manufacture.
|
|
It has many kettle lakes, some of which are 100 to deep. Kettle Point, Ontario, Canada, has rock concretions locally named 'kettles', but there are no kettle lakes in this region.
|
|
Some beds are up to 50 feet thick in the state. Prairie fires periodically light lignite on fire, including one fire that burned near Medora from 1951 until 1977, or over at 30 locations over a 7000-acre area close to Amidon. It is widely used as a road material and as ornamentation for gardens. Iron oxide, calcium carbonate and silica concretions frequently form nodules and concretions in the west, including siderite ironstone and petrified logs.
|
|
Kansas pop rocks are concretions of either iron sulfide, i.e. pyrite and marcasite, or in some cases jarosite, which are found in outcrops of the Smoky Hill Chalk Member of the Niobrara Formation within Gove County, Kansas. They are typically associated with thin layers of altered volcanic ash, called bentonite, that occur within the chalk comprising the Smoky Hill Chalk Member. A few of these concretions enclose, at least in part, large flattened valves of inoceramid bivalves.
|
|
These concretions are called "pop rocks" because they explode if thrown in a fire. Also, when they are either cut or hammered, they produce sparks and a burning sulfur smell. Contrary to what has been published on the Internet, none of the iron sulfide concretions, which are found in the Smoky Hill Chalk Member were created by either the replacement of fossils or by metamorphic processes. In fact, metamorphic rocks are completely absent from the Smoky Hill Chalk Member.
|
|
University of California Publications in Geological Sciences, Vol. 93. University of California Press, Berkeley. The formation is also renowned for the fossiliferous concretions in its upper member, which contain three- dimensionally preserved arthropods.
|
|
The upper of the Cleveland Shale contains abundant nodules of phosphate, nodules and bands (extremely thin beds) of pyrite, bands of calcisiltite, and lamination. Almost no concretions are found in the upper part.
|
|
The second feature contained seven concretions. Five of these were elongated, and one was prismatic. These were found in maroon mud, but were grey bodied. Indicating they originated in a different sedimentary environment.
|
|
The Mazon Creek fossils are found in the Upper Carboniferous Francis Creek Shale; the type locality is the Mazon River (or Mazon Creek), a tributary of the Illinois River near Morris, Grundy County, Illinois. The 25 to 30 meters of shale were formed approximately , during the Pennsylvanian period. The fossiliferous concretions are usually found within the thickest deposits of Francis Creek. The concretions occur in localized deposits within the silty to sandy mudstones, in the lower four metres of the formation.
|
|
Depending on the environmental conditions present at the time of their formation, concretions can be created by either concentric or pervasive growth. In concentric growth, the concretion grows as successive layers of mineral precipitate around a central core. This process results in roughly spherical concretions that grow with time. In the case of pervasive growth, cementation of the host sediments, by infilling of its pore space by precipitated minerals, occurs simultaneously throughout the volume of the area, which in time becomes a concretion.
|
|
In its type locality, the Collón Curá Formation is characterized by homogeneous greyish- yellow well-consolidated massive vitrocrystalline tuffs without visible sedimentary structures, but with calcareous concretions. The tuffaceous sediments contain pieces of white pumice with a vesicular character up to in size. The volcanic crystals in the tuff comprise andesine, hornblende and hypersthene in an argillaceous matrix. The concretions in the formation can reach up to in size and result from secondary diagenesis replacing the primary porosity of the sediments.
|
|
In the past, the origin of the spherical boulders found at Rock City had been erroneously interpreted as glacial boulders, corals, concretionary masses of limestone, and normal erosional remnants of sandstone. Shaffer was the first person to recognize them as calcite-cemented concretions. From a detailed examination of the mineralogy of these concretions and the carbon and oxygen isotopes of the calcite cement comprising them, McBride and others concluded that they formed as the result of diffusion of calcium through and precipitation of calcite within the sandstone containing them after being deeply buried. The carbon and calcium comprising these concretions came either from marine limestone, shells, anhydrite, or some combination of these in addition to bicarbonate derived from oxidized methane from strata outside of, but hydrologically connected to, the Dakota Sandstone.
|
|
The Hondita Formation is characterised by a sequence of sandy limestones and shales with calcareous concretions up to in diameter.Acosta & Ulloa, 2002, p.24 The formation has provided fossils of Acanthoceras sp., Rhynchostreon sp.
|
|
In Scandinavia, they are known as "marlekor" ("fairy stones").Kindle, E.M., 1923. Range and distribution of certain types of Canadian Pleistocene concretions. Bulletin of the Geological Society of America, 34(3), pp.609-648.
|
|
Hudson, J.D., M.L. Coleman, B.A. Barreiro and N.T.J. Hollingworth, 2001, Septarian concretions from the Oxford Clay (Jurassic, England, UK): involvement of original marine and multiple external pore fluids, Sedimentology. v. 48, p. 507-531.
|
|
Unusual concretions, composed of calcite, can be found near this river. These are known as "kettles" because they resemble the bottom of a large kettle. The river has been identified as a key biodiversity area.
|
|
The most significant deposit consists of various localities of the Late Carboniferous Francis Creek Shale of the Carbondale Formation at Mazon Creek, Illinois, which are composed of shales and coal seams yielding oblong concretions. Within most concretions is a mold of an animal and sometimes a plant that is usually marine in origin. When an insect is partly or wholly replaced by minerals, usually completely articulated and with three- dimensional fidelity, is called mineral replication. This is also called petrifaction, as in petrified wood.
|
|
Hiatus concretions are also often significantly bored by worms and bivalves.Wilson, M.A., and Taylor, P.D., 2001, Palaeoecology of hard substrate faunas from the Cretaceous Qahlah Formation of the Oman Mountains: Palaeontology. v. 44, pp. 21-41.
|
|
It consists of sands with sandstone concretions, layers of silts, clays and marls. Age of the formation, according to a crude 1962 estimate, is Valanginian(?) - Hauterivian - Barremian. Its thickness varies greatly, reaching 746 m in Teguldet borehole.
|
|
They are found throughout the fossil record but are most common during periods in which calcite sea conditions prevailed, such as the Ordovician, Jurassic and Cretaceous.Zaton, M., 2010, Hiatus concretions: Geology Today. v. 26, pp. 186–189.
|
|
Chan, M.A., B.B. Beitler, W.T. Parry, J. Ormo, and G. Komatsu, 2005. Red Rock and Red Planet Diagenesis: Comparison of Earth and Mars Concretions PDF version, 3.4 MB : GSA Today, v. 15, n. 8, pp. 4–10.
|
|
The lower boundary of a zone in which plinthite occurs generally is diffuse or gradual, but it may be abrupt at a lithologic discontinuity. Generally, plinthite forms in a soil horizon that is saturated with water for some time during the year. Initially, iron is normally segregated in the form of soft, more or less clayey, red or dark red redox concretions. These concretions are not considered plinthite unless there has been enough segregation of iron to permit their irreversible hardening on exposure to repeated wetting and drying.
|
|
Each Müller vesicle is spherical, about 7 µm across (in Loxodes), and is bounded by a membrane. It contains a Müller body, which comprises mineral concretions in an organic matrix bounded by a membrane, that is suspended in a vacuole by a stalk. The stalk is about 0.3–0.4 µm thick, and contains microtubules that connect the Müller body with the adjacent kinety, which is believed to help transmit the sensory signal to the rest of the cell. The mineral concretions are mostly salts of strontium in the genus Remanella, but barium in Loxodes.
|
|
At some places one finds hard beds of laterite. At other places it is decomposed and reorganised. Locally, the ferruginous rock is called kankar. The calcareous concretions, commonly used as the sources of lime, are known as ghutin.
|
|
Giroud López, 2014, p.168 The formation contains concretions and a high diversity of fossils. The formation was deposited in a transgressional and regressional epicontinental marine environment at the edge of the Paleo-Tethys Ocean.Janvier & Villarroel, 1998, p.
|
|
This structure is commonly found in silt to fine sand. It is typically interbedded with bioturbated mudstone. It commonly contains concretions of abundant mica and plant detritus in the tops of many laminae. This helps indicate a shape sorting.
|
|
The Hulcross Formation consists of dark grey to black shales and mudstones that were deposited in marine environments. The sediments coarsen upward and thin beds of siltstone and platy sandstone are present in the uppermost part. Sideritic ironstone concretions are common.
|
|
They appear in nodular patches, concentrated along bedding planes, protruding from weathered cliffsides, randomly distributed over mudhills or perched on soft pedestals. Small hematite concretions or Martian spherules have been observed by the Opportunity rover in the Eagle Crater on Mars.
|
|
Institute of Geological & Nuclear Sciences, Information Series no. 1, (Lower Hutt, New Zealand)Thyne, G.D., and J.R. Boles, 1989, Isotopic evidence for origin of the Moeraki septarian concretions, New Zealand, Journal of Sedimentary Petrology. v. 59, n. 2, p. 272-279.
|
|
Features that suggest this include cross-bedded sediments, the presence of many small spherical pebbles that appear to be concretions, vugs inside rocks, and the presence of large amounts of magnesium sulfate and other sulfate-rich minerals such as jarosite.
|
|
Forsskaolea is a small genus of 6 species of perennial herbs in the nettle family with non-stinging hairs and dot-like concretions of mineral matter on their green parts. The genus was named in honor of Swedish botanist Peter Forsskål.
|
|
Unweathered sections of the Gogo Formation are made of siltstone, shale and calcarenite with numerous limestone concretions. These concretions are resistant to weathering, producing extensive nodule fields on the ground in areas where the surrounding rock has eroded away. The Gogo sediments represent deep, hypoxic seafloor deposits in the vicinity of a large tropical reef composed primarily of algae and stromatoporoids during the Frasnian faunal stage of the Late Devonian. Associated stratigraphic units which comprise this ancient reef system are the Windjana Formation (the actual reef structures), Pillara Limestone (reef platform) and the Sadler Formation (fore-reef deposits).
|
|
They are commonly composed of a carbonate mineral such as calcite; an amorphous or microcrystalline form of silica such as chert, flint, or jasper; or an iron oxide or hydroxide such as goethite and hematite. They can also be composed of other minerals that include dolomite, ankerite, siderite, pyrite, marcasite, barite and gypsum. Although concretions often consist of a single dominant mineral, other minerals can be present depending on the environmental conditions which created them. For example, carbonate concretions, which form in response to the reduction of sulfates by bacteria, often contain minor percentages of pyrite.
|
|
The larger boulders, in diameter, are estimated to have taken 4 to 5.5 million years to grow while of marine mud accumulated on the seafloor above them. After the concretions formed, large cracks known as septaria formed in them. Brown calcite, yellow calcite, and small amounts of dolomite and quartz progressively filled these cracks when a drop in sea level allowed fresh groundwater to flow through the mudstone enclosing them.Pearson, M.J., and C.S. Nelson, 2005, Organic geochemistry and stable isotope composition of New Zealand carbonate concretions and calcite fracture fills , New Zealand Journal of Geology & Geophysics. v.
|
|
This is especially true of manganese nodules. Manganese and phosphorite nodules form on the seafloor and are syndepositional in origin. Thus, technically speaking, they are concretions instead of nodules. Chert and flint nodules are often found in beds of limestone and chalk.
|
|
The Clearwater Formation consists of primarily of black and green shale, with some interbedded grey and green sandstone and siltstone, and ironstone concretions. To the southeast of Cold Lake it includes massive hydrocarbon-bearing, glauconitic salt-and-pepper sandstones with interbedded shales.
|
|
102, p.228-229 The concretions from the Barstow Formation preserve both allochthonous arthropod communities and rare autochthonous arthropod communities. Over 21 orders of arthropods have been recorded. The fossil assemblage is dominated by Diptera (Dasyhelea australis antiqua), Coleoptera (Schistomerus californese), and Anostraca (Archaebranchinecta barstowensis).
|
|
The Alberta Group is composed of silty shale for the most part. Two thick shale deposits (Blackstone Formation and Wapiabi Formation) are present above and below a sandstone sequence (the Cardium Formation). Sideritic concretions and thin argillaceous limestone beds are present within the shale stacks.
|
|
There are also some instances of cone-in-cone occurring within coals. Often the cone-in-cone will be found as features of calcite layers within a shale,Carstens, H. 1985. Early diagenetic cone-in-cone-structures in pyrite concretions. Journal of Sedimentary Petrology.
|
|
As the ammonites died, they sank to the bottom and were buried by layers of bentonitic mud that eventually became shale. Many gem-quality ammonites are found within siderite concretions. These sediments preserved the aragonite of the shells, preventing it from converting to calcite.
|
|
Real egg fossils should preserve eggshell structures like pores, mammillae, and prismatic or continuous layers, which are not present in concretions. Any given concretion is unlikely to be exactly the same size as any other, so associations of egg-like objects of different sizes are probably not real eggs at all. Concretions can also be far larger than any real egg so an apparently unnaturally large "egg" has probably been misidentified. Insect trace fossils: Sometimes the living or breeding chambers of an insect burrow are so perfectly egg-shaped that even a paleontologist can mistake a natural cast of these chambers for a fossil egg.
|
|
Irritator mounted as attacking an anhanguerid, both from the Romualdo Formation, National Museum of Brazil Thalassodromeus is known from the Romualdo Formation, which dates to the Albian stage of the Early Cretaceous period (about 110 million years ago). The formation is part of the Santana Group and, at the time Thalassodromeus was described, was thought to be a member of what was then considered the Santana Formation. The Romualdo Formation is a Lagerstätte (a sedimentary deposit that preserves fossils in excellent condition) consisting of lagoonal limestone concretions embedded in shales, and overlies the Crato Formation. It is well known for preserving fossils three-dimensionally in calcareous concretions, including many pterosaur fossils.
|
|
As time went by, the downwards extension of a stalactite and the progressive growth of the below stalagmite led to the formation of a column. Besides this elementary forms, there is a great number of other concretions such as calcite flowstones, curtains, (which are due to the flowing of water), corals, calcite crystals, (which formed underwater), cave pearls, formed of concentric layers as calcite crystallizes on a nucleus such as a microscopic grain of rock, and the eccentric concretions, which defy gravity. As regards eccentric stalactites, they normally have a small size and break the force of gravity. Unlike other stalactites, they grow multidirectionally in capricious ways, i.e.
|
|
The Pacho Formation (, Kslp) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation consisting of alternating siltstones and shales with siderite concretions dates to the Middle Cretaceous period; Late Albian to Cenomanian epochs and has an approximate thickness of .
|
|
This Black Shale level is composed at the base with greenish, organic-rich, pyritiferous clayey marlstone, with several enrichments such as sulfides and barite. Pyrite concretions and thin layers of phosphate and chert are found in the Shale and the lower Limestone.Grasselly, G., & Klivényi, É. (1960).
|
|
Forsyth, P.J., and G. Coates, 1992, The Moeraki boulders. Institute of Geological & Nuclear Sciences, Information Series no. 1, (Lower Hutt, New Zealand)Thyne, G.D., and J.R. Boles, 1989, Isotopic evidence for origin of the Moeraki septarian concretions, New Zealand, Journal of Sedimentary Petrology. v. 59, n.
|
|
Ledges State Park is a state park of Iowa, USA, located approximately south of the city of Boone. The park contains a sandstone gorge carved by Pea's Creek, a tributary of the Des Moines River. The gorge is deep in places, with concretions jutting from the cliffs.
|
|
Reid, W. T. (1952) Clastic limestone in the Upper Eagle Ford Shale, Dallas County, Texas: Field and Laboratory, v. 20, p. 111–122. The remainder of the Arcadia Park in the Dallas area is shale with concretions. Sandstones are found within the Arcadia Park north of Dallas.
|
|
The Maastricht Formation consists of soft, sandy shallow marine limestone (in Limburg locally called "mergel"), in fact chalk and calcareous arenite. These lithologies locally alternate with thin bands of marl or clay. The lower parts of the formation contain flint concretions. The upper parts can have shellrich layers.
|
|
The shales interfinger with sandstones and in certain parts coal beds are found. In the eastern domain around the Doros crater, dark iron-oxide cements occur in the upper conglomerate horizons.Wanke, 2000, p.21 In virtually all lithological units, bones of the amphibious reptile Mesosaurus tenuidens can be encountered in concretions.
|
|
The Upper Bedoulian Formation is a geological formation in the Murcia Region, Spain whose strata date back to the Early Cretaceous (late Barremian to early Aptian stage). The marls were deposited in an open marine environment. The lower unit ( thick) is marly with iron concretions and septaria.Upper Bedoulian Formation at Fossilworks.
|
|
The formation is present in the Northern Territory, Queensland, South Australia, and New South Wales. It is a sedimentary unit, principally made up of mudstone and siltstone, with calcareous concretions. Its maximum thickness is 600 metres. Its age is somewhere from Aptian to Albian, that is between 125 and 101 Mya.
|
|
Bell, W.T., 1901, The remarkable concretions of Ottawa County, Kansas, American Journal of Science, 4th Series, v. 11, p. 315-316. Later, these boulders were either noted or described by Gould,Gould, C.N., 1901, The Dakota Cretaceous of Kansas and Nebraska, Kansas Academy of Science, v. 17, p. 122-178.
|
|
Fossilized bones at the site had already been found since the 13th century. In 1710 David Siegmund Büttner published his book "Rudera diluvii testes i.e. Zeichen und Zeugen der Sündfluth" (Signs and witnesses of the flood). In 1818 Freiherr Friedrich von Schlotheim (1765-1832) found a human skull covered by lime concretions.
|
|
Insects preserved this way are often, but not always, preserved as concretions, or within nodules of minerals that formed around the insect as its nucleus. Such deposits generally form where the sediments and water are laden with minerals, and where there is also quick mineralization of the carcass by coats of bacteria.
|
|
The vault is located some thirty metres above the ground. It then goes to the second room that looks much like the previous one with the presence of concretions and basins . This last room is closed on a crack up to two metres above the ground. There is a significant colony of bats.
|
|
The formation comprises marine shales and limestones. The thick Jagua Vieja Member consists of black shales and horizontally laminated marly micritic to biomicritic limestones. The latter contains calcareous concretions which the fossils are found in.Iturralde Vinent & Norell, 1996 The formation overlies the San Cayetano Formation and is overlain by the Guasasa Formation.
|
|
Menilite Menilite Menilite is a greyish-brown form of the mineraloid opal.Menilite on Mindat.org It is also known as liver opal or leberopal (German), due to its color. It is called menilite because it was first described from Ménilmontant (Paris), France, where it occurs as concretions within bituminous Early Oligocene Menilite Shales.
|
|
They range from pea-size to baseball-size. They were created by the precipitation of iron, which was dissolved in groundwater.Chan, M.A. and W.T. Parry, 2002, 'Mysteries of Sandstone Colors and Concretions in Colorado Plateau Canyon Country PDF version, 468 KB : Utah Geological Survey Public Information Series. n. 77, pp. 1–19.
|
|
Ranney 2012, p.110 This exposed the Navajo Sandstone, the surface rock found throughout the Horseshoe Bend area, which also forms the entire depth of the canyon walls of the Grand Canyon at Horseshoe Bend. This sandstone is notable for its crossbedding and iron concretions. The Rincon on Lake Powell in southern Utah.
|
|
Many mechanisms have also been proposed to explain the formation of the very characteristic internal cracks (or cavities) pattern called septa. It includes the desiccation of clay-rich, gel-rich, or organic-rich, cores leading to the shrinkage of the concretion's softer center. Some theories suggest the expansion of gases (CO2, CH4) produced by the decay of organic matter. Less satisfying theories even consider the shrinkage of the concretion interior by sediment compaction or its brittle fracturing by earthquakes.Pratt, B.R., 2001, "Septarian concretions: internal cracking caused by synsedimentary earthquakes": Sedimentology, v. 48, p. 189-213.McBride, E.F., M.D. Picard, and K.L. Milliken, 2003, Calcite-Cemented Concretions in Cretaceous Sandstone, Wyoming and Utah, U.S.A.: Journal of Sedimentary Research. v. 73, n. 3, p. 462-483.
|
|
The gravel components of stonelayers may be compositionally variable, and while many are lithic clasts, often of quartzose composition, others may be metallic nodules and concretions of iron and manganese oxides, human artifacts, snail and clam shells (in highly calcareous soils), precious and semi-precious stones, or some combination thereof (Aleva 1983, 1987; Johnson 2002).
|
|
Conversely, > his pictorial world is such a seism, his painting crashing down in such hot > lava, telluric blazes, stellar fusions, Amazonian humus, and Pompeian > concretions that one wonders if Thibaut de Reimpré might not be hostage to > uncontrollable forces. Yet he is not. He is the master of these forces - > their shepherd and their diviner.
|
|
These were formed in the coastal sea in the Late Jurassic period. The conglomerates exhibit cracks of different types. These conglomerates are geologically unusual for three reasons. Firstly, the Valley of Rocks conglomerates include quartzite and pink granite, in addition to the typical Crimea sandstone, compacted clay, limestone, milky white quartz and brown siderite concretions.
|
|
These blueberries were found to be composed almost entirely of the mineral hematite. It was decided that the spectra signal spotted from orbit by Mars Odyssey was produced by these spherules. After further study it was decided that the blueberries were concretions formed in the ground by water.Bell, J (ed.) The Martian Surface. 2008.
|
|
The Blood Reserve Formation consists of hard, cliff-forming, fine- to medium-grained sandstones. They range in colour from light grey to grey-buff on fresh surfaces, and weather to buff, yellow and greenish. They are cemented by calcite and argillaceous minerals. Cross- bedding and irregular calcite concretions are common in the middle and upper portions.
|
|
New York: McGraw-Hill, 2003: 1843–1878. is also recommended. Rubbing whilst washing may help to disrupt the biofilm, hence increasing the accessibility of antiseptics to the bacteria. Patients who shave the affected area only once will generally experience a recurrence of the infection, since, the bacteria begin to develop the concretions once again as the hair grows back.
|
|
There is a rhodochrosite ore, composed of laminated gray, green, brown, and black sections, and is associated with a diagenetic origin.Polgari, M., Biro, L., Pal-Molnar, E., Dobosi, G., Bajnoczi, B., Nemeth, T., ... & Vigh, T. (2013). Rhodochrosite-Bearing Concretions from a Jurassic Manganese Ore Mineralization–Urkut, Hungary. Carpathian Journal of Earth and Environmental Sciences, 8(4), 139-146.
|
|
Observations at the site have led scientists to believe that the area was flooded with water a number of times and was subjected to evaporation and desiccation. In the process sulfates were deposited. After sulfates cemented the sediments, hematite concretions grew by precipitation from groundwater. Some sulfates formed into large crystals which later dissolved to leave vugs.
|
|
Kazakhstan created the Ustyurt Nature Reserve (223,300 hectares) in July, 1984 in the south of Mangystausky district in Eralievsky region. It preserves rare fauna and flora such as the Ustyurt Mountain sheep and the Saiga antelope. Among its features are Sherkala Mountain and the concretions found in the Torysh ('Valley of Balls') near the town of Shetpe.
|
|
The entrance to the cave The Grotte de Rosée (Cave of Rosée) is located near Éhein in the municipality of Engis, in Belgium. It has been classified as Wallonia's patrimoine immobilier exceptionnel de la Région wallonne ('exceptional heritage of Wallonia'), and can be visited only by accredited scientists. It houses a set of concretions which is unique in Belgium.
|
|
It also occurs in low-temperature clay- ironstone concretions. It was first described in 1861 for an occurrence in the San José Mine, Oruro City, Cercado Province, Oruro Department, Bolivia, and named for French chemist Charles-Adolphe Wurtz. It has widespread distribution. In Europe it is reported from Příbram, Czech Republic; Hesse, Germany; and Liskeard, Cornwall, England.
|
|
However, almost all species of shelled mollusks are capable of producing pearls (technically "calcareous concretions") of lesser shine or less spherical shape. Although these may also be legitimately referred to as "pearls" by gemological labs and also under U.S. Federal Trade Commission rules, and are formed in the same way, most of them have no value except as curiosities.
|
|
Observations at the site have led scientists to believe that the area was flooded with water a number of times and was subjected to evaporation and desiccation. In the process sulfates were deposited. After sulfates cemented the sediments, hematite concretions grew by precipitation from groundwater. Some sulfates formed into large crystals which later dissolved to leave vugs.
|
|
Over time, these concretions weathered from what was overlying rock, and then became concentrated on the surface as a lag deposit. The concentration of spherules in bedrock could have produced the observed blueberry covering from the weathering of as little as one meter of rock.Squyres, S. et al. 2004. The Opportunity Rover's Athena Science Investigation at Meridiani Planum, Mars.
|
|
Observations at the site have led scientists to believe that the area was flooded with water a number of times and was subjected to evaporation and desiccation. In the process sulfates were deposited. After sulfates cemented the sediments, hematite concretions grew by precipitation from groundwater. Some sulfates formed into large crystals which later dissolved to leave vugs.
|
|
The Eagle Sandstone, originally the Eagle Formation, is a geological formation in Montana whose strata date back to the Late Cretaceous. It is a light to brownish gray to pale yellow-orange, fine-grained sandstone. It contains areas of crossbedding and local shale members. It contains large (up to 15 feet in diameter) sandy calcareous concretions.
|
|
The formation is very fossiliferous with common macro-fossils, such as ammonites, gastropods, and bivalves found both in concretions and bedding planes, along with common petrified wood, woody material, and leaf and seed fossils. In addition to these are marine microfossils, including foraminifera and microgastropods. There are also rare vertebrate remains, including fish, pterosaurs, a dinosaur and marine turtles.
|
|
The process or processes that created septaria within Moeraki Boulders, and in other septarian concretions, remain an unresolved matter for which a number of possible explanations have been proposed. These cracks radiate and thin outward from the centre of the typical boulder and are typically filled with an outer (early stage) layer of brown calcite and an inner (late stage) layer of yellow calcite spar, which often, but not always, completely fills the cracks. Rare Moeraki Boulders have a very thin innermost (latest stage) layer of dolomite and quartz covering the yellow calcite spar. The composition of the Moeraki Boulders and the septaria that they contain are typical of, often virtually identical to, septarian concretions that have been found in exposures of sedimentary rocks in New Zealand and elsewhere.
|
|
Many Pierre Shale ammonites, and indeed many ammonites throughout earth history, are found inside concretions. An iridescent ammonite from Madagascar Other fossils, such as many found in Madagascar and Alberta, Canada display iridescence. These iridescent ammonites are often of gem quality (ammolite) when polished. In no case would this iridescence have been visible during the animal's life; additional shell layers covered it.
|
|
Weathering has caused heavy leaching and bleaching in some regions of the Bulldog Shale, including those around Coober Pedy, so that the rocks are white or multicolored. These horizons contain rich opal deposits. Horizons without this bleaching are primarily composed of organic-rich shale. Gypsum, in addition to carbonate limestone concretions rich in fossils are common in these unbleached shaly horizons.
|
|
The infection is diagnosed by close examination of the hair shafts where brown to yellow material called concretions are seen. There is usually an associated rancid odour. A microscopic examination can confirm the diagnosis, but this is rarely needed. Some patients with excessive sweating present the so-called corynebacterial triad, that is, the simultaneous presence of trichobacteriosis axillaris, erythrasma, and pitted keratolysis.
|
|
Today, shell- marl/calcareous ravine forests such as those at Crow's Nest are not common anywhere in the mid-Atlantic region. These plant communities are rare to this coastal plain ecosystem. There are two nutrient-rich plant communities associated with lime sands and localized shell concretions at Crow's Nest. One can be broadly classified as Basic Mesic Forests (G2, globally imperiled).
|
|
To the local Anishinabek, the rare stones were thunderbird eggs. The concretions are now protected, but are often found on nearby properties. "Kettle" concretion at Kettle Point, Ontario, defaced by graffiti. Just off shore, below the Kettle Point formation, is a layer of the Hamilton Group of shales and limestones which contains a large amount of light-coloured, high-quality chert.
|
|
These were inferred to be large, rough-textured gastroliths. The presence of only a few large and rough gastroliths in birds and in other non-avian dinosaurs usually indicates a mainly carnivorous diet, suggesting that B. guoi may have had a raptorial ecology. However, these structures were later found to be mineral concretions which formed after the animal had already died.
|
|
Shroba, R.R., and Carrara, P.E., 1996, Surficial geologic map of the Rocky Flats environmental technology site and vicinity, Jefferson and Boulder Counties, Colorado: U.S. Geological Survey Miscellaneous Investigations Series Map, I 2526. Nodular ironstone concretions occur in the mudstones that contain plant remains. Some of the material in the sandstones originated from silicic volcanoes far to the west.Wilson, M. 2002.
|
|
"A number of straightforward geological processes can yield round shapes," says Hap McSween. These include accretion under water, meteor impacts, or volcanic eruptions. The principal investigator, Steve Squyres, indicates they could alternately be concretions, or accumulated material, formed by minerals coming out of solution as water diffused through rock. Mosaic shows some spherules partly embedded, spread over the (smaller) soil grains.
|
|
Journal of the Palaeontological Society of India. 20:170-177. Various types of other fossils, i.e. jellyfish, sponges, worm trails, and bivalves have been reported from the Bass Formation. Critical examinations of these reported fossils have concluded that the fossil sponges are inorganic silica concretions; the jellyfish are either gas escape structures or algal colonies; and the worm trails are inorganic sedimentary structures.
|
|
The valley is covered is with of ice, overburden, rock falls, and tundra vegetation. Placer gold finds are covered by iron oxide in the form of dark organic matter. Gold was also discovered in gravel in ironstone concretions. Other minerals found in placer gold are arsenopyrite, large amount of pyrite, galena, chalcopyrite, ilmenite, rutile, garnet, cerussite and sometimes also magnetite.
|
|
Eurhinosaurus lived in open ocean, which was far away from the coastline. Eurhinosaurus was not like other ichthyosaurus and marine reptiles of the early Toarcian which showed a distinct provinciality. They had wide paleobiogeographic distribution in Western Europe. Fossils of Eurhinosaurus were found in the limestone and wackestone concretions in England, the Benelux, France, Switzerland and in southern and northern Germany.
|
|
Marie, Michigan. A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular shapes also occur. The word 'concretion' is derived from the Latin con meaning 'together' and crescere meaning 'to grow'.
|
|
35, p. 1705-1712. and the types of geological features that influence flow. Elongate concretions are well known in the Kimmeridge Clay formation of northwest Europe. In outcrops, where they have acquired the name "doggers", they are typically only a few metres across, but in the subsurface they can be seen to penetrate up to tens of metres of along-hole dimension.
|
|
The Houthem Formation consists of maximally 30 metres of light grey to light yellow calcareous arenites. The arenite can contain calcareous concretions, fossils and hardgrounds with shell fragments. At other places lenses of boundstone occur, formed by red algae. The hardgrounds make it possible to subdivide the formation into three members: the Geleen Member, the Bunde Member and the Geulhem Member.
|
|
It also occurs in masses. Color ranges from yellow to dark brown or black, the latter being due to the presence of manganese. Siderite is commonly found in hydrothermal veins, and is associated with barite, fluorite, galena, and others. It is also a common diagenetic mineral in shales and sandstones, where it sometimes forms concretions, which can encase three-dimensionally preserved fossils.
|
|
Boles, J. R., C. A. Landis, and P. Dale, 1985, The Moeraki Boulders; anatomy of some septarian concretions, Journal of Sedimentary Petrology, vol. 55, n. 3, p. 398-406.Fordyce, E., and P. Maxwell, 2003, Canterbury Basin Paleontology and Stratigraphy, Geological Society of New Zealand Annual Field Conference 2003 Field Trip 8, Miscellaneous Publication 116B, Geological Society of New Zealand, Dunedin, New Zealand.
|
|
The eastern side of Cavite consists of Carmona clay loam with streaks of Carmona clay loam steep phase and Carmona sandy clay loam. This type of soil is granular with tuffaceaous material and concretions. It is hard and compact when dry, sticky and plastic when wet. This type of soil is planted to rice with irrigation or sugarcane without irrigation.
|
|
Cambridge University Press. Over time, these concretions weathered from what was overlying rock, and then became concentrated on the surface as a lag deposit. The concentration of spherules in bedrock could have produced the observed blueberry covering from the weathering of as little as one meter of rock.Squyres, S. et al. 2004. "The Opportunity Rover’s Athena Science Investigation at Meridiani Planum, Mars".
|
|
In the process sulfates were deposited. After sulfates cemented the sediments, hematite concretions grew by precipitation from groundwater. Some sulfates formed into large crystals which later dissolved to leave vugs. Several lines of evidence point toward an arid climate in the past billion years or so, but a climate supporting water, at least for a time, in the distant past.
|
|
Concretion in the palpebral conjunctiva, is called conjunctival concretion, that is a (or a cluster of) small, hard, yellowish-white calcified matter, superficially buried beneath the palpebral conjunctiva. Most of concretions in the eye form in the palpebral conjunctiva, which is a clear membrane to surround the inside of the eyelid; fewer can be located in the cornea and retina.
|
|
The eastern side of Cavite consists of Carmona clay loam with streaks of Carmona clay loam steep phase and Carmona sandy clay loam. This type of soil is granular with tuffaceous material and concretions. It is hard and compact when dry, sticky and plastic when wet. This type of soil is planted with rice with irrigation or sugarcane without irrigation.
|
|
Layer 3 has even stronger humidified sand, as well as gypsum concretions. The stratigraphic sequence suggests that the shelter was inhabited during a much wetter period than today. The Tashwinat Mummy was found on the eastern side of a 160 by 80 cm. excavation, under the lowest layer of coals, where the sandstone floor showed a deliberate round excavation of about 25 cm.
|
|
The Hornillos Formation, deposited in the Algarrobal Basin,Abad, 1982, p. 5 comprises sandstones, limestones, conglomerates, and caliches, intercalated with lavas and andesitic breccias and various volcanic rocks. Between these last is a conspicuous layer of rhyo-dactitic lithic tuff, which reaches up to in thickness. Bones of indeterminate titanosaurs appear in a marly limestone stratum of thick with decimeter-sized calcareous concretions.
|
|
In 2018, Davidson and Everhart documented the events leading up to the disappearance of these fossils, and suggested that a photo and drawing of Waterhouse's workshop from 1869 appear to show concretions on the floor that may have been the unprepared girdles of Elasmosaurus. They also noted that conceptual sketches of the Palaeozoic Museum show that the model Elasmosaurus was originally envisioned with a long "tail", though later updated with a long neck. Davidson and Everhart concluded that the girdle fossils were most likely destroyed in Hawkins' workshop. Hawkins' workshop in Central Park; the rounded shapes in the lower center left may be concretions that contained the now missing girdle fossils of the holotype Fossils that may have belonged to the holotype were found by the American geologist Benjamin Franklin Mudge in 1871, but have probably been lost since.
|
|
These red "clinker" beds are often more resistant to erosion than the silty sandstone, so they appear on the higher parts of bluffs, and buttes on either side of the valleys of the Tongue River basin are often capped by beds of this baked and fused rock that are five to twenty feet thick. Besides the beds of reddish "clinker" larger concretions can be found that appear at first glance to be similar to melted glass or even pieces of volcanic rock. Although of a different appearance than the clinker these odd-looking concretions are also formed by the burning coal beds, with the difference in appearance being due to the difference in content of the material in the overlying bed that was heated to very high temperatures. The reddish "clinker" is crushed and used to surface roads throughout the Tongue River basin.
|
|
One notable exception occurs in the Calder Valley near Gawthorpe Hall, where as a result of the absence of the Tim Bobbin Rock which usually separates the King and Fulledge Thin mines, the Padiham Thick mine is up to 5.3 metres thick. Coal extracted from the Arley, Upper and Lower Mountain mines was used to produce high grade metallurgical coke which was in high demand for industry, whereas coal from the Union/Upper Foot mines had a high sulphur content making it unsuitable for making coke. The Union mine is contaminated with in-seam concretions known locally as coal balls or bobbers, spherical concretions, composed of limestone measuring from 0.1 to 1.0 metre in diameter that posed hazards for mining. They were largely responsible for the closure of Bank Hall Colliery, the area's largest and deepest pit.
|
|
The Muzo Formation is a generally calcareous sequence, however to the north of the Ibacapí Fault, it is observed to be weathered, and its calcareous composition is not recognized. To the north of Pauna, it has a siliceous character. In general, it is composed of dark gray calcareous claystones with intercalated sandstone lenses and limestone concretions. The formation commonly contains pyrite and calcite veins.
|
|
Siltstones can be distinguished from claystone away from the laboratory by chewing a small sample; claystone feels smooth while siltstone feels gritty. Siltstones differ significantly from sandstones due to their smaller pores and a higher propensity for containing a significant clay fraction. Although often mistaken for a shale, siltstone lacks the laminations and fissility along horizontal lines which are typical of shale. Siltstones may contain concretions.
|
|
Kettle Point is the site of a rare outcrop of an Upper Devonian shale called the Kettle Point Formation. This rock layer is exposed at the tip of the point near the shore of Lake Huron. A fragmentary fossil Dunkleosteus, named D. amblyodoratus or 'blunt spear', was found there. Spherical or ovoid concretions of rock, locally called "kettles", weather out of the shale along the shoreline.
|
|
Septarian calcite concretions and calcite geodes are numerous, and the shale forms the less steep canyon walls covered by talus slopes. A prominent band of jointed white sandstone about thick marks the middle of this formation. Lavender, gray and white shales lie below this sandstone, while an orange shale lies between this sandstone and the Trujillo Formation above. The Quartermaster and Tecovas Formations make up Capital Peak.
|
|
Several different facies are present in the Ntawere Formation, reconstructing a floodplain environment. The coarsest facies are trough cross-bedded conglomeratic sandstone full of mineral concretions. These coarse deposits formed in ancient channels such as riverbeds. Another type of facies involves thick beds of mudstone interbedding with thinner layers of fine-grained sandstone, indicating alternating low- and high-energy water flow within the channels.
|
|
The Edmonton Group consists of fine-grained sandstones, calcareous sandstones, siltstones, sandy shales and mudstones, bentonitic sandstones and shales, bentonite beds, ironstone concretions, carbonaceous shales and coal seams. Hard sandstones commonly cap mesas, buttes and plateaus where erosion has formed badlands topography, as is the case for much of the Horseshoe Canyon Formation and the Scollard Formation. Coarse-grained sediments are rare in the Edmonton Group.
|
|
Pawnee Rock was another Dakota Sandstone landmark in the region. There are concretions at Rock City in Ottawa County and Mushroom Rock State Park in Ellsworth County. These are cemented by calcium carbonate. The Greenhorn Limestone region, Blue Hills or Kearney Hills, in the central region is made up of thin—usually less than —chalky limestone beds alternating with thicker beds of blue-gray chalky shale.
|
|
Strontianite is an uncommon low-temperature hydrothermal mineral formed in veins in limestone, marl, and chalk, and in geodes and concretions. It occurs rarely in hydrothermal metallic veins but is common in carbonatites. It most likely crystallises at or near 100 °C. Its occurrence in open vugs and veins suggests crystallisation at very low pressures, probably at most equal to the hydrostatic pressure of the ground water.
|
|
The Belle Fourche Shale of northeastern Wyoming has about 400 to 800 feet of noncalcareous shale between the siliceous Mowry Shale below and the calcareous Greenhorn Formation above. It contains large ironstone concretions in the lower 50 feet of the formation. Bentonite beds are present throughout the shale. Of the shale that extends into Alberta, the formation primarily consists of shale, siltstone, and sandstone.
|
|
Donax is a genus of small, edible saltwater clams, marine bivalve molluscs. The genus is sometimes known as bean clams or wedge shells; however, Donax species have numerous different common names in different parts of the world. In the southeastern US they are known as "coquina", a word that is also used for the hard limestone concretions of their shells and those of other marine organisms.
|
|
They formed by the early cementation of sand by calcite. Somewhat weathered and eroded giant cannonball concretions, as large as in diameter, occur in abundance at "Rock City" in Ottawa County, Kansas. Large and spherical boulders are also found along Koekohe beach near Moeraki on the east coast of the South Island of New Zealand.Dann, C., and Peat, N. (1989) Dunedin, North and South Otago.
|
|
Koroit is close to the town of Yowah which also produces a similar type of opal. The Koroit opal field is known for the very distinctive type of boulder opal that is found in its mines. In Queensland boulder opal is found within a 300 km wide belt of sedimentary rocks in the Winton Formation. Here opal is found as a kernel in small concretions.
|
|
The Adamantina Formation, which is Turonian to Santonian in age, was deposited in semi-arid conditions around 95 million years ago. Morrinhosuchus was found in an outcrop of reddish sandstone with carbonate nodules, concretions, and areas of intense bioturbation. The Adamantina Formation is part of the larger Bauru Basin, from which several other notosuchians have been found. These include Sphagesaurus, Mariliasuchus, Adamantinasuchus, Armadillosuchus, and Baurusuchus.
|
|
The Muzo Formation is a generally calcareous sequence, while to the north of the Ibacapí Fault it is observed to be weathered and its calcareous composition is not recognized. To the north of Pauna the formation has a siliceous character. In general it is composed of dark gray calcareous claystones with lenses and limestone concretions. Additionally, it is common to find pyrite and calcite veins.
|
|
To the south of the area, this unit presents similar characteristics. A stratigraphic column along the La Palma-Yacopí road, shows that this unit is composed of a black marl with a solid appearance with black calcareous claystone intercalations.Acosta and Ulloa, 2001 In the upper part, intercalations of black shale with gypsum flakes and abundant pyritic micritical concretions appear, some with ammonites.Reyes et al.
|
|
It then precipitated further down and formed a particular type of soil horizon, which contains concretions of calcium carbonate. The Kaiserstuhl loess soils are used for intensive farming, as they offer good aeration, high water storage capacities and good mechanical qualities. Besides, as a result of farming deep narrow ravine-like paths developed. As the loess developed over time it is, furthermore, significant for flood control.
|
|
Mondofacto Dictionary definition of orbicularis oculi muscle With Alexios Trantas (1867–1960), the "Horner-Trantas spots" are named, being defined as small whitish-yellow chalky concretions of the conjunctiva around the corneal limbusWho Named It Horner- Trantas spots He was the author of numerous articles on ophthalmic medicine, published in Carl Wilhelm von Zehender's Klinische Monatsblatt für Augenheilkunde. He is credited with performing the first Z-plasty for correction of ectropion.
|
|
A gallery of thirty metres, covered in concentric circles and ovals, about eight metres above the ground, leads to a first room that leads to two lanes of forty metres in length, at different levels, leading to a large room in which there are two columns of stalagmites. A narrow conduit leads to a third room containing concretions and eccentrics. At this level, progress is blocked by a narrow conduit.
|
|
Mushroom Rock State Park, located in the Smoky Hills region of north-central Kansas, is noted for its mushroom rock formations. These rocks are the remains of beach sands and sediments of the Cretaceous Period, the interval of geologic time from about 144 to 66 million years ago. Sandstone and sedimentary rock is held together by natural cement. The concretions that make up Mushroom Rocks are cemented calcium carbonate.
|
|
The description of this specimen claimed that it was plausible, but uncertain, that Bohaiornis was ecologically similar to birds of prey. However, these rocks were later found to be mineral concretions, probably formed from the same mineral as the fossil specimen. Thus, they are not indicative of diet. Bohaiornithids had foot proportions which were between those expected of arboreal and terrestrial birds, but their long claws make terrestrial habits unlikely.
|
|
They are found where submarine erosion has concentrated early diagenetic concretions as lag surfaces by washing away surrounding fine- grained sediments. Their significance for stratigraphy, sedimentology and paleontology was first noted by Voigt who referred to them as Hiatus- Konkretionen.Voigt, E., 1968, Uber-Hiatus-Konkretion (dargestellt an Beispielen aus dem Lias): Geologische Rundschau. v. 58, pp. 281–296 "Hiatus" refers to the break in sedimentation that allowed this erosion and exposure.
|
|
Bromwich, p. 112 Another threat was posed by vegetation penetrating the stone lid of the channel. As well as obstructing the flow of the water, dangling roots introduced algae and bacteria that decomposed in a process called biolithogenesis, producing concretions within the conduit. It required constant maintenance by circitores, workers responsible for the aqueduct's upkeep, who crawled along the conduit scrubbing the walls clean and removing any vegetation.
|
|
Off the mainland coast of New Zealand, shelf-edge instability is enhanced in some locations by cold seeps of methane- rich fluids that likewise support chemosynthetic faunas and carbonate concretions. Dominant animals are tube worms of the family Siboglinidae and bivalves of families Vesicomyidae and Mytilidae (Bathymodiolus). Many of its species appear to be endemic. Deep bottom trawling has severely damaged cold seep communities and those ecosystems are threatened.
|
|
Hatchettite occurs in the coal measures of Belgium and elsewhere, occupying in some cases the interior of hollow concretions of iron-ore, but more generally the cavities of fossil shells or crevices in the rocks. It is of yellow colour, and translucent, but darkens and becomes opaque on exposure. It has no odour, is greasy to the touch, and has a slightly glistening lustre. Its hardness is that of soft wax.
|
|
A Stagnosol in the World Reference Base for Soil Resources (WRB) is soil with strong mottling of the soil profile due to redox processes caused by stagnating surface water. Stagnosol (Ah-Bg1-Bgc-Bg2) Stagnosols are periodically wet and mottled in the topsoil and subsoil, with or without concretions and/or bleaching. The topsoil can also be completely bleached (albic horizon). A common name in many national classification systems for most Stagnosols is pseudogley.
|
|
In the Ozarks, sphalerite is often found near faults in Paleozoic limestone and dolomite. In addition to copper, there are numerous iron minerals, but few with economic deposits. Two small pig iron furnaces operated in the 1800s and a tiny open pit mine in the 1960s, near Rosston, Arkansas extracting only a few hundred tons. The largest production overall was 120,000 tons produced from the Wilcox Group where weathering of bedded siderite produced limonite concretions.
|
|
Plants in this family have simple, opposite, decussated leaves with entire (or sometimes toothed, lobed, or spiny) margins, and without stipules. The leaves may contain cystoliths, calcium carbonate concretions, seen as streaks on the surface. The flowers are perfect, zygomorphic to nearly actinomorphic, and arranged in an inflorescence that is either a spike, raceme, or cyme. Typically, a colorful bract subtends each flower; in some species, the bract is large and showy.
|
|
The Boonton Formation is composed of reddish-brown to reddish-purple fine grained sandstone, as well as red, gray, purple, and black siltstone and mudstone. Siltstone and mudstone layers can be calcareous and feature dolomitic concretions. A well known fossil fish bed is known to exist in a carbonate rich siltstone near the top of the formation. Additionally, cross-bedded conglomerate layers interfinger with beds of the formation, usually bearing clasts of gneiss and granite.
|
|
R. Soc. Vict., 53, 1-125. These include the underlying Silurian rock known as the Fyansford formation above which is the 15 m thick darker Beaumaris Sandstone, overlain by yellowish Red Bluff Sandstone, as outcrops in the cliffs, ferruginised, with hard ironstone in the upper sections, extending to the platform, and as small reefs parallel to the coastline. A thin calcareous sandstone is overlain by fine sandy marl and sandstone with calcareous concretions.
|
|
Bad Sobernheim is also known as the discovery site for a number of fossils. Named after its main discovery site, a sand quarry in the outlying centre of Steinhardt, are Steinhardter Erbsen, or "Steinhardt Peas", sandstone concretions containing fossils, mostly plants.Mineralienatlas - Steinhardt (Zugriff Juni 2014) These ball-shaped sandstones contain plant and animal remnants that are roughly 30,000,000 years old, from the Oligocene. Wrapping the fossils inside one of these "peas" is baryte.
|
|
Gaspéite, a very rare nickel carbonate mineral, with the formula , is named for the place it was first described, in the Gaspé Peninsula, Québec, Canada. Gaspéite is the nickel rich member of the calcite group. A solid solution series exists between all members of this group with divalent cations readily exchanged within the common crystal structure. It forms massive to reniform papillary aggregates in fractures, botryoidal concretions in laterite or fracture infill.
|
|
It is well known for preserving fossils three-dimensionally in limestone concretions, including many pterosaur fossils. In addition to muscle fibres of pterosaurs and dinosaurs, fish preserving gills, digestive tracts, and hearts have been found there. The formation is interpreted as a coastal lagoon with irregular freshwater influence that contended with cycles of transgressing and regressing sea levels. The climate of the formation was tropical and largely corresponded to today's Brazilian climate.
|
|
The Pierre Shale is a geologic formation or series in the Upper Cretaceous which occurs east of the Rocky Mountains in the Great Plains, from Pembina Valley in CanadaCanadian Fossil Discovery Centre. to New Mexico. The Pierre Shale was described by Meek and Hayden in 1862 in the Proceedings of the Academy of Sciences (Philadelphia). They described it as a dark-gray shale, fossiliferous, with veins and seams of gypsum, and concretions of iron oxide.
|
|
It is in these concretions that the remains of Gracilisuchus and other tetrapods have been found. Unlike other Carnian (Late Triassic) formations, there are no dinosaur remains in the Chañares Formation. This has led researchers to assign a Middle Triassic age to the Chañares. Owing to shared faunal components, correlations with the Dinodontosaurus Assemblage Zone of the Santa María Formation in Brazil have been used to assign a Ladinian age to the Chañares.
|
|
The helical burrows - a generally accepted feature of the Tropidostoma Assemblage Zone - are vertical, spiralling tubes measuring just under 1 m in length. The burrows are found infilled with either fine sandstone or siltstone with calcareous concretions. The burrows were likely infilled during single flood events, suddenly trapping and burying the Diictodon pairs inside alive. This provides an explanation for the near perfect preservation of the Diictodon pairs found in the burrow casts.
|
|
Near Bermuda Argyrotheca is mostly found on the underside of leaf-shaped corals, like Agaricia, Mycetophyllia or Montastrea or in between branches of corals, such as Porites, Mussa and Madracis, up to about 75 m. Further down, sponges like Agelas and Plakorthis, and concretions dominante as substrate. A. cuneata in deeper waters near Brazil is commonly found attached to shell fragments like those of bivalves. Elsewhere undersea caves provide shelter in shallow water.
|
|
The shales are essentially fine-grained, very thin sandstones that include lime concretions and balls of consolidated mud. The limestone appears as solid gray-blue beds, a few inches to a few feet thick, and as lenses of limestone conglomerate. Most of the limestone lenses are less than long, but two were traced for nearly and one for . Viewed as a whole, the Kayenta is readily distinguished from the geologic formations above and below it.
|
|
Manganese nodule The Southern Ocean probably contains large, and possibly giant, oil and gas fields on the continental margin. Placer deposits, accumulation of valuable minerals such as gold, formed by gravity separation during sedimentary processes are also expected to exist in the Southern Ocean. Manganese nodules are expected to exist in the Southern Ocean. Manganese nodules are rock concretions on the sea bottom formed of concentric layers of iron and manganese hydroxides around a core.
|
|
Plinthite is firm or very firm when the soil moisture content is near field capacity and hard when the moisture content is below the permanent wilting point. Plinthite concretions are coherent enough to be separated readily from the surrounding soil. Plinthite commonly occurs within and above reticulately mottled horizons. The part of the iron-rich body that is not plinthite normally stains the fingers when rubbed while wet, but the plinthite center does not.
|
|
In the Clovis group of rocks the Mössbauer spectrometer (MB) detected goethite, that forms only in the presence of water, iron in the oxidized form Fe3+, carbonate-rich rocks, which means that regions of the planet once harbored water. The Opportunity rover was directed to a site that had displayed large amounts of hematite from orbit. Hematite often forms from water. The rover indeed found layered rocks and marble- or blueberry-like hematite concretions.
|
|
The Turkey Ridge is commonly mapped in the Mahantango Formation, or included in the Montebello Formation (Dmot), and only the Shamokin correlates with the Marcellus on adjacent map sheets. In extreme eastern Pennsylvania, the Broadhead Creek member, a dark gray silty shale with dark gray shaly limestone concretions, appears above the Stony Hollow and Union Springs, in a layer up to thick. Illustration of a Cephalopod (Goniatites vanuxemi) fossil from the Marcellus Formation.
|
|
Associated minerals include quartz, chalcedony, pyrite, pyrrhotite, sphalerite, galena, chalcopyrite and calcite.. Evenkite was the last part of the geode to form. It is believed to have resulted from thermal cracking of the organic matter (manly marine plants) that where trapped in the septarian concretions during the Jurassic burial, as the buried sediments were subjected to high pressure and temperatures. The French Alps region received a lot of geological uplift after the Jurassic burial.
|
|
The age and location indicate a possible Northern Pacific origin for the genus. M. starri lived and was preserved in strata deposited at depths of , placing them in the lower sublittoral zone. The specimens were preserved in concretions found as loose float cobbles along the Strait of Juan de Fuca shoreline and collected at sites B6133 and B6136. However the individual cobble matrices match sediments found in the upper Pysht and lower Clallam Formations.
|
|
Boulder opal consists of concretions and fracture fillings in a dark siliceous ironstone matrix. It is found sporadically in western Queensland, from Kynuna in the north, to Yowah and Koroit in the south. Its largest quantities are found around Jundah and Quilpie in South West Queensland. Australia also has opalized fossil remains, including dinosaur bones in New South WalesFirst dinosaur named in NSW in nearly a century after chance discovery ABC News, 5 December 2018.
|
|
This caused concretions containing plant material to form and preserve as rounded lumps of stone. Coalification was thus prevented, and the peat was preserved and eventually became a coal ball. The majority of coal balls are found in bituminous and anthracite coal seams, in locations where the peat was not compressed sufficiently to render the material into coal. Marie Stopes and David Watson analysed coal ball samples and decided that coal balls formed in situ.
|
|
The fossils of the Gogo Formation display three-dimensional soft-tissue preservation of tissues as fragile as nerves and embryos with umbilical cords. Over fifty species of fish have been described from the formation, and arthropods (including phylocarids and eurypterids) are similarly well-preserved. Nautiloids, goniatites and tentaculids are also known from the formation, but their soft tissue is not preserved. The calcareous concretions formed around objects from the shallow reef areas which sank into the deep anoxic basins.
|
|
Phytoliths are composed mainly of noncrystalline silicon dioxide, and about 4% to 9% of their mass is water. Carbon, nitrogen, and other major nutrient elements comprise less than 5%, and commonly less than 1%, of phytolith material by mass. These elements are present in the living cells in which the silica concretions form, so traces are retained in the phytoliths. Such immobilised elements, in particular carbon, are valuable in that they permit radiometric dating in reconstructing past vegetation patterns.
|
|
The gelatinous substance of the disk is translucent milky-blue in color, while the gastro- vascular space, gonads, radial and circular muscles of the subumbrella and the entodermal cores of the tentacles are purplish-pink. The outer parts of the veil-like folds of the palps are amber-brown, while the parts adjacent to the mouth are pink. The concretions of the 8 sense-organs are reddish-brown. The planulae are yellow, but the ephyra is pink.
|
|
Across the range of the outcrop, the limonite weathers out in a variety of shades and patterns as seen the collage on the right. This coloration varies from barely visible to one, two, or more shaded zones. The exposed stone often weathers out a parting seam, also seen in the collage, used split the limestone into thinner slabs for flagging. Limonite is often concentrated along the parting seam, sometimes to the point of forming small nodules or concretions.
|
|
There the Cretaceous succession includes Barremian and Aptian–Cenomanian limestones and marly limestones with abundant concretions of black chert. The Upper Jurassic succession begins with thin-bedded Kimmeridgian–Oxfordian cherty limestones, marls, sandstones and clays, which are identified in the lower part of Krubera Cave. Above lies the thick Tithonian succession of thick-bedded limestones with marly and sandy varieties. Sandy limestones are particularly abundant through the upper 1,000 m sections of deep caves of the Ortobalagan Valley.
|
|
The cave contains many large stalactites and stalagmites, many of exceptional beauty. A feature of the stalagmites is their "dish-pile" appearance, formed by water dropping from up to above and depositing calcium carbonate over a wide area. The enormous hall is high, long and wide. A steep path with atmospheric electric lighting allows the visitor to spend about 45 minutes in this underground space, with its rich calcite concretions, the highest of which is no less than high.
|
|
Sediments of certain abyssal plains contain abundant mineral resources, notably polymetallic nodules. These potato-sized concretions of manganese, iron, nickel, cobalt, and copper, distributed on the seafloor at depths of greater than 4000 meters, are of significant commercial interest. The area of maximum commercial interest for polymetallic nodule mining (called the Pacific nodule province) lies in international waters of the Pacific Ocean, stretching from 118°–157°, and from 9°–16°N, an area of more than 3 million km².
|
|
In 2000, he collaborated with the Pioneers Museum in the desert community of Imperial Valley, California, to reproduce souvenir copies and large models of its local mountain, Mount Signal, and the unique "Sand Spike" sand concretions found at its base. In 2003, he created 120 topographical models of the states of Missouri and Kansas, which he donated and delivered himself to 120 small historical society museums in both states. Monoprints from The Shapes Project, 2005/05.
|
|
There are many caves, the most important step is the cave of El Kef Biadh whose access is via a series of wells or galleries, most of which come from mining. The first large room of m long and 267 metres deep shelters concretions and huge boulders; its walls are covered with bushes of Eccentric. The hall ends with a diaclases which opens on a well. It measures about 150 metres long and 50 metres wide.
|
|
Any difference in the measured data was then attributed to the material in the spherules. A large difference in the obtained "spectra" was found. "This is the fingerprint of hematite, so we conclude that the major iron-bearing mineral in the berries is hematite," said Daniel Rodionov, a rover science team collaborator from the University of Mainz, Germany. This discovery seems to strengthen the conclusion, that spherules are concretions, grown in wet condition with dissolved iron.
|
|
Over the next 10 million years, erosion shrank the island until it was almost an atoll. Then, just over a million years ago, Rurutu passed over the Arago hotspot, which lifted it roughly 150 meters. Steep sea cliffs of ancient coral lifted by the event -- called makatea -- now largely encircle the island. These are riddled with caves filled with concretions -- indeed, Rurutu is largely unique among islands in French Polynesia in that its historic inhabitants were cave-dwelling.
|
|
Most are formed from the cemented infillings of burrow systems in siliciclastic or carbonate sediments. A distinctive feature of hiatus concretions separating them from other types is that they were often encrusted by marine organisms including bryozoans, echinoderms and tube worms in the Paleozoic Wilson, M.A., 1985, Disturbance and ecologic succession in an Upper Ordovician cobble-dwelling hardground fauna: Science. v. 228, pp. 575-577. and bryozoans, oysters and tube worms in the Mesozoic and Cenozoic.
|
|
Over time, exposed structures will be eroded, broken up and scattered. The dynamic nature of the environment may make in-situ conservation infeasible, especially as exposed organics, such as the wood of a shipwreck, are likely to be consumed by marine organisms such as piddocks. In addition, underwater sites can be chemically active, with the result that iron can be leached from metal structures to form concretions. The original metal will then be left in a fragile state.
|
|
Plinthite (from the Greek plinthos, brick) is an iron-rich, humus-poor mixture of clay with quartz and other minerals. Plinthite is a redoximorphic feature in highly weathered soil. The product of pedogenesis, it commonly occurs as dark red redox concretions that usually form platy, polygonal, or reticulate patterns. Plinthite changes irreversibly to an ironstone hardpan or to irregular soil aggregates on exposure to repeated wetting and drying, especially if it is also exposed to heat from the sun.
|
|
Red Rock Coulee is a Provincial Natural Area in southeastern Alberta, Canada, south-southwest of the city of Medicine Hat and south of the hamlet of Seven Persons on Alberta Highway 887. The main feature of this natural landscape is the large spherical reddish boulders (concretions), some of which measure in diameter.. They are scattered across the badlands and coulees, and can be seen along the hiking trails, as well as from the viewpoint on Highway 887.
|
|
The town is located on the southern shore of Conception Bay on the Avalon Peninsula of the island of Newfoundland. It is approximately 20 kilometres (12 miles) southwest of the provincial capital of St. John's. As such, the town is part of the St. John's Metropolitan Area and most residents are employed in the nearby cities of St. John's or Mount Pearl. The town lies on a zone of Cambrian bedrock, primarily shale containing limestone concretions and manganese ores.
|
|
Petrified logs are also known from the site. The site was fluvial when its rocks were being deposited, with channel sands and muds, and concretions of calcite-cemented sandstone containing fossils. Following excavation and preparation of the majority of the fossils from the site, its sauropod species was given the name Paluxysaurus jonesi. Neck vertebrae The name Paluxysaurus was based on the specimen FWMSH 93B-10-18, a partial skull including an associated left maxilla, nasal, and teeth.
|
|
Bed of concretions in the Rock Point Formation near Youngsville, New Mexico The formation is up to 70 m thick and is mostly reddish-brown and grayish-red massive siltstone and fine sandstone beds. It is the uppermost portion of the Chinle Group wherever it is exposed. In the Chama basin, its base is placed at the first persistent sandstone bed above the mudstones of the Petrified Forest Formation. Its contact with the overlying Entrada Sandstone is sharp.
|
|
In addition, possible remains of Mangrove roots have been found encased in siderite concretions. Amber has been found at the site occurring in small droplets, generally less than 5 millimeters in size. Taphonomic analysis of the Ellisdale faunaParris, D.C., Grandstaff, B. S., Denton Jr., R. K., Gallagher, W. B., DeTample, C., Albright, S. S., Spamer, E., and D. Baird, 1986, Taphonomy of the Ellisdale Dinosaur Site, Cretaceous of New Jersey. Final Report on National Geographic Grant 3299-86.
|
|
Though sea levels changed during the deposition of the clay, the habitat was generally a lush forest – perhaps like in Indonesia or East Africa today – bordering a warm, shallow ocean. The London Clay is a stiff bluish clay which becomes brown when weathered. Nodular lumps of pyrite and crystals of selenite (sometimes called "waterstones") frequently exist in the clay, and large septarian concretions are also common. These have been used in the past for making cement.
|
|
Many fossils are known from the Nacimiento Formation, although bone is often altered into phosphatic concretions. Fossils belonging to a number of different organisms have been found here, including: plants (mostly dicotyledonous angiosperms),Anderson 1960 gastropods, freshwater bivalves,Hartman 1981 cartilaginous fish and bony fish, salamanders, turtles, champsosaurs, amphisbaenians, lizards, snakes, crocodilians,Sullivan and Lucas 1986 birds, and a variety of archaic mammals. Mammalian groups represented include multituberculates, didelphid marsupials, insectivorans, plesiadapiforms, carnivorans, taeniodonts, mesonychids, condylarths, and cimolestans.
|
|
The body came to rest on its left side with limbs outstretched. Pyrite was present in the rocks around the specimen, and may have formed from sulfur given off by the bacteria consuming the carcass. About 20% of the hadrosaur's bones were enveloped by calcareous concretions but every single bone not found in a concretion bore many closely spaced ovular conical depressions. These ranged in diameter from 2.1 to 5.8 mm and from 1.6 to 3.6 mm deep.
|
|
The artists who produced these paintings used techniques rarely found in other cave art. Many of the paintings appear to have been made only after the walls were scraped clear of debris and concretions, leaving a smoother and noticeably lighter area upon which the artists worked. Similarly, a three- dimensional quality and the suggestion of movement are achieved by incising or etching around the outlines of certain figures. The art is also exceptional for its time for including "scenes", e.g.
|
|
In 1850 ironstone was discovered by John Marley of Bolckow and Vaughan in the Eston Hills, outliers of the Cleveland Hills, leading to mining on a large scale and the rapid growth of nearby Middlesbrough. By the 1870s industry would be producing steel in vast amounts, and mining for coal, alum, jet, cement stone concretions, shale and potash from the hills, as well as employing sandstone and limestone quarries to gather raw materials. Many of the mines and quarries are still evident today.
|
|
At the base of the deposit, these sandstones are reddish brown, very micaceous and shaley, sometimes containing calcareous nodules, ferruginous concretions and vegetable wax; above, they are gray and quartziferous. This is the Aye formation, including spiriferida like Cyrtospirifer verneuili, Rhynchonellida as Rhynchonella pugnus and R. boloniensis, some Orthoceras, Orthis striatula or Atrypa reticularis Well- preserved feldspar and mica probably come from wind erosion under a semi-arid climate of mountains present in the Netherlands today and extending to Düsseldorf.
|
|
Calcium deposits on a waterfall at Bagni San Filippo Bagni San Filippo is an area in the municipality of Castiglione d'Orcia in the Province of Siena, Italy, not far from Monte Amiata. It is a small hot spring containing calcium carbonate deposits, which form white concretions and waterfalls. The name derives from that of St Philip Benizi, who was a prior of the Servite order, and who lived as a hermit here in the thirteenth century. The grotto is open to visitors.
|
|
These collapses, sinkholes, galleries, and concretions form a caving site which is part of the La Rochefoucauld karst.H. Coquand, 1858 The relief of the commune is that of a low plateau sloping gently towards the valley of the Tardoire, with an average altitude of 110 m. The highest point is at an altitude of 134 m to the south- west in the Braconne forest near Gros Fayant. The lowest point is 70 m located on the Tardoire opposite the town of La Rochette.
|
|
He suggests that partially developed conical surfaces are also possible as a result of pressure developed from overlying sediments under conditions where a unilateral release of horizontal pressure may become effective. He goes on to suggest that the current explanations of his time are inadequate to cover the structure and its formation. He even suggested that formation due to crystallization was not consistent.Shaub, B.M. (1937) Origin of Cone-In-Cone and its Bearing on the Origin of Concretions and Septaria.
|
|
The fossil impressions are preserved in micrite limestones, resulting in low quality preservation of fine details. Another series of species were described from compression fossils found in thin layers and concretions of micrite from the "insect bed" and older stratum of the Bembridge Marls. The marls are exposed at a number of locations along the north coast of the Isle of Wight in England. Part of the Bouldnor Formation, the marls have been dated to the Late Eocene in age.
|
|
The last paper he published, in the American Journal of Sciences, 1883, was "On the peculiar concretions in meteoric iron." Smith served as president of the American Association for the Advancement of Science (1872) and of the American Chemical Society (1877). Smith purchased a collection of meteorites that had belonged to Gerard Troost of Nashville, Tennessee, and extended it by collecting specimens from all over the world. He attempted to obtain specimens from as many different meteoric falls as possible.
|
|
With RPC, the gallstones found within the biliary system are made of calcium bilirubinate or pigmented calcium. Calcium bilirubinate stones are prevalent in Asia and very rare in Europe and the United States. They tend to be friable concretions of various shapes and sizes within the biliary tree, and their associated bile is often muddy in consistency and contains numerous fine particles of calcium bilirubinate as well. This differs greatly from cholesterol stones, which are common in Europe and the United States.
|
|
The formation overlies the Knorringfjellet Formation and is overlain by the Rurikfjellet Formation. The formation comprises the lower Oppdalsåta and upper Slottsmøya Members The sediments comprise mudstones, dolomites and shales deposited in an open to deep marine low oxygen environment. The Slottsmøya Member, which averages in thickness in the study area, consists of dark-grey to black silty mudstone, often weathering to paper shale, and discontinuous silty beds with local occurrences of red to yellowish sideritic concretions as well as siderite and dolomite interbeds.
|
|
This continuity in the mudstone was what allowed them to infer that each bonebed was actually a component of a single large "mega-bonebed". At its thinnest point the mudstone bed hosting the centrosaur fossils is 25 cm thick and it measures 1 m at its thickest. Eberth, Brinkman and Barkas observed siltstone, claystone, and abundant organic matter in the composition of the "brown-grey" mudstone. Ironstone concretions can be found scattered throughout the bed, but were most abundant where fossils were also common.
|
|
These variations likely coincided with the presence of small "sub- environments" commonly found between rivers like splays, ponds or creeks. After being deposited in their final resting places the carcasses were torn apart, had their bones trampled and chewed by scavengers. These processes left the abrasion and toothmarks seen on the bones preserved at H97-02. Chemical reactions between the decaying dinosaur flesh and floodwaters caused iron to precipitate out of the water and formed the ironstone concretions commonly found in the mudrock hosting the mega-bonebed.
|
|
Two situations occur: with high silica input and constant clay background sedimentation thick chert layers form. On the other hand, when the silica input is constant and the clay signal varies rhythmically fairly thick clay bands interrupted by thin chert bands accumulate. By adding carbonates as a third component complicated successions can be created, because silica is not only incompatible with clays but also with carbonates. During diagenesis the silica within the carbonate-rich layers starts pinching and coagulates into ribbons, nodules and other irregular concretions.
|
|
This burrowing is called bioturbation by sedimentologists. It can be a valuable indicator of the biological and ecological environment that existed after the sediment was deposited. On the other hand, the burrowing activity of organisms can destroy other (primary) structures in the sediment, making a reconstruction more difficult. Chert concretions in chalk, Middle Lefkara Formation (upper Paleocene to middle Eocene), Cyprus Secondary structures can also form by diagenesis or the formation of a soil (pedogenesis) when a sediment is exposed above the water level.
|
|
The first scientifically documented fossils in North Dakota were collected during the Lewis and Clark expedition between 1804 and 1806 as they mapped the course of the Missouri River. The first fossil written about in the state were petrified wood preserved in sandstone concretions discovered at the Cannonball River. In 1833 a German named Alexander Philip Maximilian observed leaf impressions preserved in sandstone in the upper Missouri River area. He thought the plants were similar to modern phanerogammic plants still growing in the area.
|
|
There are many different ways insects can be fossilized and preserved including compressions and impressions, concretions, mineral replication, charcoalified (fusainized) remains, and their trace remains. Compressions and Impressions are the most extensive types of insect fossils, occurring in rocks from the Carboniferous to the Holocene. Impressions are like a cast or mold of a fossil insect, showing its form and even some relief, like pleating in the wings, but usually little or no color from the cuticle. Compressions preserve remains of the cuticle, so color distinguishes structure.
|
|
The holotype consists of a complete skull, a mandible, series of 19 dorsal, sacral and caudal vertebrae, ribs, both ilia and a partial femur, from a single individual. It was discovered and collected during a 2009 expedition in the Metangula Graben, under the supervision of Projecto PalNiassa. ML1620 came from an unnamed fossiliferous unit located near Tulo, a small village situated along the Metangula-Cóbue road. The fossil bed is composed of a grey mudstone with abundant septaria-like calcareous concretions, dating to the Late Permian.
|
|
The skull was discovered in October 1993 by speleologists of CARS (Centro Altamurano Ricerche Speleologiche) in the cave of Lamalunga in Altamura, Italy. While exploring the cave the researchers stumbled upon a deep karst sinkhole, formed by the action of running water on limestone. The sinkhole merges into a tunnel about long in which they found the Altamura Man incorporated into the calcium carbonate concretions that had formed by water dribbling down the cave walls. The finding was reported to researchers at the University of Bari.
|
|
The first Ediacaran fossils discovered were the disc-shaped Aspidella terranovica in 1868. Their discoverer, Scottish geologist Alexander Murray, found them useful aids for correlating the age of rocks around Newfoundland. However, since they lay below the "Primordial Strata" of the Cambrian that was then thought to contain the very first signs of animal life, a proposal four years after their discovery by Elkanah Billings that these simple forms represented fauna was dismissed by his peers. Instead, they were interpreted as gas escape structures or inorganic concretions.
|
|
The Moeraki Boulders are concretions created by the cementation of the Paleocene mudstone of the Moeraki Formation, from which they have been exhumed by coastal erosion. The main body of the boulders started forming in what was then marine mud, near the surface of the Paleocene sea floor. This is demonstrated by studies of their composition; specifically the magnesium and iron content, and stable isotopes of oxygen and carbon. Their spherical shape indicates that the source of calcium was mass diffusion, as opposed to fluid flow.
|
|
Whether wild or cultured, gem-quality pearls are almost always nacreous and iridescent, like the interior of the shell that produces them. However, almost all species of shelled mollusks are capable of producing pearls (technically "calcareous concretions") of lesser shine or less spherical shape. There is a lot of myth and legend surrounding some of these pearls. The Pearl of Lao Tzu for a long time thought to be the largest Pearl had its history fabricated by a conman by the name of Victor Barbish.
|
|
The distribution of bite marks corresponds inversely to the presence of flesh in the animal. For instance, lower limb bones sustained the most damage because there was the least amount of flesh shielding the bones at those locations. The concretions formed as the flesh chemically reacted to the seafloor on the largest parts of the animal where the scavenging mosasaur would be unable to fully wrap its jaws around the carcass. Bones pulled free from the carcass were buried in the mud and preserved in mudstone.
|
|
The following series of Muffe (Molds) literally presented the spontaneous reactions of the materials employed, enabling matter to 'come to life' in drippings and concretions which reproduced the effects and appearance of real mold. In some artworks of the same period which he called Gobbi (Hunchbacks), Burri focused on the painting’s spatial interaction, achieving another original outcome due to the incorporation of tree branches on the rear of the canvas which pushed two-dimensionality towards Three-dimensional space.Christov-Bakargiev, Carolyn (1997). "Alberto Burri, The Surface at Risk", in Tolomeo, Maria Grazia, Christov-Bakargiev, Carolyn.
|
|
Distribution of Durisols In the World Reference Base for Soil Resources (WRB), a Durisol is a soil of arid and semi-arid environments that contains cemented secondary silica (SiO2) in the upper metre of soil, either as concretions (durinodes – duric horizon) or als continuously cemented layer (duripan – hardpan (Australia) – dorbank (South Africa) – petroduric horizon). In the FAO/Unesco Soil Map of the World, the Durisols with petroduric horizon were indicated as duripan phase of other soils, e.g. of Xerosols and Yermosols. Durisols are developed mainly in alluvial and colluvial deposits of all texture classes.
|
|
The Ornatenton Formation is composed mainly of mudstone with some iron-oolith benches, glauconitic sandstones, and a horizon of carbonate concretions. It stretches from the Eastern Alps to the Rhine valley, and the facies area stretches into Switzerland where it is known as the 'argovian' facies. In southern Germany, the formation is underlain by the Variansmergel Formation and regionally overlapped by the Kandern or Impressamergel Formation, while in the Wutach area it is replaced by the Wutach Formation. Further east, in the French Alps, it dovetails with the Sengenthal Formation.
|
|
The name comes from the Moqui (or Moki), which some archeologists believe to be an ancient tribe in the Anasazi-Hopi area at an unknown time period. They are not attested historically, and the name has been used to simply refer to ancient peoples of the area and by white people to refer to Indians in general. They originated as an explanation for moqui marbles, strange geologic concretions in the Navajo Sandstone Formation. More likely, the name comes from a Hopi language word meaning "[the] dead", moki, being related to religious beliefs.
|
|
His other papers deal with gas-analysis, fire-damp, illuminating gas, the composition of hydrochloric acid and of ammonia, urinary and other morbid concretions, and the disinfecting powers of heat. His Elements of Experimental Chemistry (1799) enjoyed considerable vogue in its day,Henry's manual on chemistry and Parkes's manual on chemistry are mentioned by Charles Darwin as books that he studied before attending Cambridge. going through eleven editions in 30 years. He was one of the founders of the Mechanics' Institute that was to become the University of Manchester Institute of Science and Technology.
|
|
One of the "round rocks" found in Osceola Long thought to be a glacial remnant, these conglomerate rocks are found in the area of the Weaubleau structure. They are nearly perfectly round, and are referred to locally simply as, "geodes," "round rocks","Missouri rock balls" or "Weaubleau eggs". It has been suggested that the round rocks are chert concretions or nodules. The round rocks may have formed when the impact threw shale clasts of Northview Formation away from the center of the crater and subsequent silica-saturated waters precipitated silica around the shale clasts.
|
|
The river's name originates from the Algonquin word Nanikana, meaning "the main way" Environnement Québec, North Harricana River Aquatic Reserve (Online version) or "Biscuit River", depending on the source. Biscuit (or ànakonà in Algonquin, aanakonaa in Ojibwe, and aaihkunaau in East James Bay Cree) refers to bannock- like the unusual flat stones, sand, limestone and clay concretions, which are found in the river, called Pierres de fée or "fairy stones."Grand Quebec.com, Harricana River The Harricana River and its mouth at Hannah Bay is visible on the left.
|
|
Rhodochrosite concretions with fish and plant fossils are common on the strata, composed by Mn-bearing Calcite with traces of hydroxyl-apatite, kutnohorite, smectite, quartz, feldspar, barite, pyrite, and quartz-cristobalite. Mineralized sections do not contain fossils or traces of benthic fauna, and contain only rarely fish remnants, planktonic organisms as well as silicified, manganized, or coalified plant fragments.M. Polgári, M. Philippe, M. Szabó-Drubina, M. Tóth Manganese- impregnated wood from a Toarcian manganese ore deposit, Eplény Mine, Bakony Mts, Transdanubia, Hungary N. Jhb. Geol. Paläont. Monathefte, 3 (2005), pp.
|
|
Goethite is found all over the planet, usually in the form of concretions, stalactitic formations, oolites (a form consisting of tiny round grains cemented together), reniform (kidney shapes) or botryoidal (globular, like bunches of grapes) accumulations. It is also a very common pseudomorph. It is frequently encountered in the swampy areas at the head of spring waters ('bog iron'), on cave floors, and on the bottom of lakes and small creeks. The boxworks or gossan resulting from the oxidation of sulfide ore deposits is formed of goethite along with other iron oxides and quartz.
|
|
In the Tingutinguti stream section, the Indotrigonia africana Member exhibits several up to thick, poorly sorted, conglomeratic sandstone beds. They contain mud clasts, reworked concretions and/or accumulations of thick-shelled bivalves (mainly Indotrigonia africana and Seebachia janenschi), and exhibit megaripple surfaces. These conglomeratic sandstone layers are interpreted as storm deposits. In the Dwanika and Bolachikombe stream sections, and in a small tributary of the Bolachikombe creek, a discrete, up to thick conglomerate in the lower portion of the Indotrigonia africana Member displays evidence of a tsunami deposit.
|
|
In exceptional situations, microscopic features such as microtrichia on sclerites and wing membranes are even visible, but preservation of this scale also requires a matrix of exceptionally fine grain, such as in micritic muds and volcanic tuffs. Because arthropod sclerites are held together by membranes, which readily decompose, many fossil arthropods are known only by isolated sclerites. Far more desirable are complete fossils. Concretions are stones with a fossil at the core whose chemical composition differs from that of the surrounding matrix, usually formed as a result of mineral precipitation from decaying organisms.
|
|
There are two species of Anhanguera: A. blittersdorfi, the type species; and A. piscator. A. blittersdorfi is based on a complete skull from the Romualdo Formation calcareous concretions (Santana Group) of the Ceará and Pernambuco states of Brazil. The species A. piscator, known from a nearly-complete skeleton, was at one point proposed to belong to the genus Coloborhynchus,Veldmeijer, A. J. (2003). Preliminary description of a skull and wing of a Brazilian Cretaceous (Santana Formation; Aptian-Albian) pterosaur (Pterodactyloidea) in the collection of the AMNH. PalArch’s Journal of Vertebrate Palaeontology 0, 1-14.
|
|
Their origin and also that of certain so-called scarfs and blankets is from carbonates deposited by water trickling down a sloping and corrugated surface. Sixteen of these alabaster scarfs hang side by side in Hoveys Balcony, three white and fine as crape shawls, thirteen striated like agate with various shades of brown. Streams and true springs are absent, but there are hundreds of basins, varying from in diameter, and from to in depth. The water in them contains carbonate of lime, which often forms concretions, called pearls, eggs, and snowballs, according to their size.
|
|
The locality where Gracilisuchus was discovered is known as the Los Chañares locality, and is located at . It consists of badlands at the base of a latitudinal escarpment, with the exposed rocks being composed of feldspar and quartz grains, along with glass shards, embedded in a geology silica and clay. These rocks belong to the lower portion of the Chañares Formation, which locally overlies the Tarjados Formation and underlies the Los Rastros Formation. Starting about above the boundary between the Tarjados and Chañares Formations, brown concretions of carbonate are present throughout the rock.
|
|
It appears in some places that the sea floor was breached and sediments and fossils were trapped like those in the junction bed between West Bay and Eype. Most of Dorset was starved of sediment and condensed limestones collected. These limestone beds are often iron rich, lending them a rusty colour. One particular bed, exposed at Burton Cliff, contains large numbers of orange, discus-shaped concretions, which on closer inspection reveal themselves to be pieces of shell from a species of mussel, coated with a thin layer of iron-rich sediment.
|
|
These soils have thin layers and are less fertile. These soils are mainly found in Karnataka (Shimoga, Chikmaglur and Hassan districts), Andhra Pradesh (Rayalaseema),Telangana [ Whole Telanana] , eastern Tamil Nadu (espesically tiruvannamalai and cuddalore district), Orissa, Jharkhand (Chotanagpur), Uttar Pradesh (Bundelkhand), Madhya Pradesh (Balaghat and Chhindwara), Rajasthan (Banswara, Bhilwara, Bundi, Chittaurgarh, Kota and Ajmer districts), Meghalaya, Mizoram, Manipur and Nagaland. (b) Sandy Red Soil: These soils have formed by the disintegration of granite, grani gneiss, quartzite and sandstone. These are 1 friable soil with high content of secondary concretions of sesquioxide clays.
|
|
In March 1722 Rutty delivered the Gulstonian lectures at the College of Physicians on the anatomy and diseases of the urinary organs, and published them in 1726 as A Treatise of the Urinary Passages, with a dedication to Sir Hans Sloane. The work relates two distinctive cases: one in the practice of John Bamber, lithotomist to St. Bartholomew's Hospital, of calcified concretions in the caecum giving rise to symptoms resembling renal colic; and the other of double renal calculus in the daughter of Sir Hugh Myddelton, from a note by Francis Glisson.
|
|
Soil consequently encompasses a variety of regolith components identified at landing sites. Typical examples include: bedform armor, clasts, concretions, drift, dust, rocky fragments, and sand. The functional definition reinforces a recently proposed generic definition of soil on terrestrial bodies (including asteroids and satellites) as an unconsolidated and chemically weathered surficial layer of fine-grained mineral or organic material exceeding centimeter scale thickness, with or without coarse elements and cemented portions. Martian dust generally connotes even finer materials than Martian soil, the fraction which is less than 30 micrometres in diameter.
|
|
The bioturbated, tuffaceous, green mudstones and sometimes sandstones with small or medium-sized rounded pebbles are scattered throughout the formation, or more rarely concentrated into minor beds or seams of conglomerate. Large calcareous concretions, some rounded or with an irregular rootlike shape, generally with hollow centers are common at many places. The beds are highly foraminiferal, with pelagic types, often pure enough to form a foraminiferal ooze-like sediment. On the fresh surface of the rock platform, the formation is hard, and of a gray-black or dark olive-green color.
|
|
In Lancashire, especially in the Burnley area, peat concretions are known as coal balls or colloquially as Burnley bobbers. They are particularly common in the seams of the Upper Foot Mine and Lower Mountain Mine in East Lancashire but also in the mines in Todmorden Moor on the eastern edge of this coal field. Due to their hardness, they often caused damage to the mining equipment, as well as the picks, drums and cutting jibs in the coal mines in North East Lancashire. In the mines of Todmorden Moor the coal balls were common.
|
|
Design of a guard for a ballock-dagger with top mount of the scabbard, by Hans Holbein the Younger, A set of bollock daggers found on board the 16th century ship Mary Rose. The blades have either completely corroded or remain only in the form of concretions. A bollock dagger or ballock knife is a type of dagger with a distinctively shaped hilt, with two oval swellings at the guard resembling male testes ("bollocks"). The guard is often in one piece with the wooden grip, and reinforced on top with a shaped metal washer.
|
|
Because plant and animal material can be preserved underwater, archaeobotany and archaeozoology have roles in underwater archaeology. For example, for submerged terrestrial sites or inland water, identification of pollen samples from sedimentary or silt layers can provide information on the plants growing on surrounding land and hence on the nature of the landscape. Information about metal artifacts can be obtained through X-ray of concretions. Geology can provide insight into how the site evolved, including changes in sea-level, erosion by rivers and deposition by rivers or in the sea.
|
|
Commonly associated minerals include pyrite, pyrrhotite, galena, sphalerite, fluorite, dolomite, and calcite. As a primary mineral it forms nodules, concretions, and crystals in a variety of sedimentary rock, such as in the chalk layers found on both sides of the English Channel at Dover, Kent, England, and at Cap Blanc Nez, Pas de Calais, France, where it forms as sharp individual crystals and crystal groups, and nodules (similar to those shown here). As a secondary mineral it forms by chemical alteration of a primary mineral such as pyrrhotite or chalcopyrite.
|
|
The holotype was found on the Loma La Catalina, west of Villa de Leyva, Colombia in 2009. The fossil was discovered in a layer of calcareous claystone with abundant occurrences of ferruginous-calcareous nodules and concretions. The section belongs to the middle segment of the Paja Formation called "Arcillolitas abigarradas Member" and has been dated on the basis of ammonites to be Late Barremian to Early Aptian in age.Cadena, 2015a The turtle is the earliest recorded sandownid turtle in the world and the first of this family discovered in South America.
|
|
A small but spectacular basin, once full of drip water, is now adorned with crystals, which embellish its bottom and walls. Every corner of the cave is adorned with very white and translucent stalagmites. In front of the visitor takes place the final scene: two high and huge columns seem to support the vault of the last hall, embellished everywhere by white stalactites and coral concretions. This is the end and the most enchanting moment of the underground tour that remind the visitor of the power and of the gracefulness of the nature.
|
|
A horizontal layer of the soil, whose physical features, composition and age are distinct from those above and beneath, is referred to as a soil horizon. The naming of a horizon is based on the type of material of which it is composed. Those materials reflect the duration of specific processes of soil formation. They are labelled using a shorthand notation of letters and numbers which describe the horizon in terms of its colour, size, texture, structure, consistency, root quantity, pH, voids, boundary characteristics and presence of nodules or concretions.
|
|
Nevertheless, the size, spacing, and shape of the marks were similar to those of teeth from the mosasaur species Tylosaurus proriger. The distribution of bite marks corresponds inversely to the presence of flesh in the animal. For instance, lower limb bones sustained the most damage because there was the least amount of flesh shielding the bones at those locations. The largest parts of the animal would have been too large for the scavenging mosasaur to completely wrap its jaws around, and these are the areas around which the concretions formed.
|
|
The base of the Arapahoe Formation is marked by a discontinuous conglomerate, or where the conglomerate is absent, by sandstone beds that commonly contain large ironstone concretions. The conglomerate is composed principally of chert pebbles, but pebbles of granite, gneiss and schist are also present. Medium grey to brown claystone makes up the majority of the formation, with lesser amounts of light grey to light brown quartzose sandstone. The formation top is marked by a change from sandstone and claystone to the tuffaceous sediments of the overlying Denver Formation.
|
|
The concretions sometimes contain the remains of fish, whose bodies are often preserved complete in three-dimensions due to rapid encasement and the slow rate of decay in the oxygen-poor surroundings. By repeated baths in a dilute acid solution, the matrix is dissolved away via a process of acid etching to reveal delicate fish fossils, some retaining impressions of soft tissues. The discovery of Materpiscis, a placoderm preserved with an embryonic juvenile still attached by its umbilical cord, has revealed that at least some placoderms gave birth to live young."Aussie fish fossil gives birth to history" Accessed 29 May 2008.
|
|
Cannonball concretions in the North Unit Bisons and dog poo sign at the Painted Canyon Visitor Center Feral horses Both main units of the park have scenic drives, approximately 100 miles of foot and horse trails, wildlife viewing, and opportunities for back country hiking and camping. There are three developed campgrounds: Juniper Campground in the North Unit, Cottonwood Campground in the South Unit, and the Roundup Group Horse Campground in the South Unit. One of the most popular attractions is wildlife viewing. Among the local wildlife, bison may be more dangerous and visitors are advised to view them from a distance.
|
|
They include acid-resistant lab ceramics, refractory bricks and linings, filler in paint, electrical insulation, boilermaker's chalk, chromic-acid purification pots, and crucibles used in the manufacture polycrystalline-diamonds. Blocks of pyrophyllite are stilled quarried and sold as either "Wonderstone" or "African Stone" for sculpting. It can be easily carved with rasps and power tools and finished with a beautiful polish. The quarries are also the source of naturally grooved, spherical to disk-shaped, and sometimes intergrown concretions composed of either hematite, pyrite, or wollastonite, which are collected by gem, mineral, and rock collectors and subject of much folklore.
|
|
When first reported, Archaeomarasmius leggetti was the second extinct species of agaric fungus to be described, and it is the only species to be known from the New Jersey amber. Three species, Aureofungus yaniguaensis, Coprinites dominicana and Protomycena electra, have been described from the Miocene Dominican amber found in the Dominican Republic. The extinct Agaricomycetes species Quatsinoporites cranhamii, found in marine calcareous concretions on Vancouver Island, Canada, and dating to about 130–125 Mya, is probably in the Hymenochaetales or the Polyporales. In 2007, another agaric was reported, Palaeoagaracites antiquus, found in Early Cretaceous Burmese amber (about 100 Mya).
|
|
Geochemistry is the science that uses the principles of chemistry to explain the mechanisms behind major geological systems. The aspect of geochemistry is of importance for analogue sites when locations offer the possibility to test analysis instruments for future space missions (manned or robotic). Geochemical fidelity is also of importance for the development and test of equipment used for in-situ resource utilization. Examples for such analogue sites are terrestrial volcanoes that offer rocks similar to those found on the Moon or hematite concretions which can be found in Earth deserts and also on Mars (so-called "Blueberries").
|
|
The most impressive room is the Crystal Palace with its giant's kettles and domes, waterfalls stalactites, and stalagmites, the main candle being 2.8 m high with a diameter of 60 cm, snowy regions, and across space a shower of hyaline crystalline tubes, 5 cm diameter for heights ranging from 1 to 2 m and, fistulas, crystal wands all hollow and containing water. Other eccentric crystallization, formed by capillarity in the most diverse forms (draperies, hooks, buckles, screws, etc..). exist in large numbers, reminiscent of the corals or strange flowers. In the second room, there are also quirky and stalactites concretions like swords.
|
|
The Ichkeul cave is located in the Jebel Ichkeul, located about twenty kilometres from the city of Bizerte in the National Park Ichkeul covering an area of hectares including a lake of hectares. Limestone, dolomite, and marble rocks date from Triassic and Jurassic and are located above a collapsed ditch. The cave itself has a narrow entrance allowing access to a vast room with large cracks along the length of the walls and showing several cavities. The room is followed by a narrow corridor formed by the wall and giant calcitic concretions, which ends with a stack of 32 metres.
|
|
It is overlain by the Lealt Shale which consists of a lower and an upper grey shale (respectively the Kildonnan and Lonfearn members) separated by a thin band of algal limestone. The shale is overlain by the thicker Valtos Sandstone which contains concretions. It is found along the east coast northwards from Poll nam Parlan and around the northern end and down the eastern side of the Bay of Laig. This in turn is overlain by the bivalve-rich limestone and shale of the Duntulm Formation and lastly the dark shales and ostracod-bearing limestones of the Kilmaluag Formation.
|
|
The Cretaceous strata of James Ross Island also yielded the dinosaur genus Antarctopelta, which was the first dinosaur fossil to be found on Antarctica. Paleogene and Early Eocene marine sediments that outcrop on Seymour Island contain plant-rich horizons. The fossil plants are dominated by permineralized branches of conifers and compressions of angiosperm leaves, and are found within carbonate concretions. These Seymour Island region fossils date to about 51.5–49.5 and are dominated by leaves, cone scales, and leafy branches of Araucarian conifers, very similar in all respects to living Araucaria araucana (monkey puzzle) from Chile.
|
|
Gravel, sand and silt are the larger soil particles, and their mineralogy is often inherited from the parent material of the soil, but may include products of weathering (such as concretions of calcium carbonate or iron oxide), or residues of plant and animal life (such as silica phytoliths). Quartz is the most common mineral in the sand or silt fraction as it is resistant to chemical weathering, except under hot climate; other common minerals are feldspars, micas and ferromagnesian minerals such as pyroxenes, amphiboles and olivines, which are dissolved or transformed in clay under the combined influence of physico-chemical and biological processes.
|
|
Moonlight Head is a locality located on the Great Ocean Road in southwest of Victoria on the Southern Ocean. It is believed to be the headland seen by Matthew Flinders from the Investigator during a break in showery weather, on the night of 20 April 1802.Only Melbourne (citing Flinders 1814) It is notable for the vertical cliffs up to 50 metres high, which in some places overhang, and expose geological structures such as cross bedding, scour and fill channels and variable sizes of concretions. There is also a sea cave and a massive active landslip, which extends inland for 500 metres.
|
|
These objects used to be referred to as "calcareous concretions" by some gemologists, even though a malacologist would still consider them to be pearls. Valueless pearls of this type are sometimes found in edible mussels, edible oysters, escargot snails, and so on. The GIA and CIBJO now simply use the term 'pearl' (or, where appropriate, the more descriptive term 'non-nacreous pearl') when referring to such items and, under Federal Trade Commission rules, various mollusk pearls may be referred to as 'pearls', without qualification. A few species produce pearls that can be of interest as gemstones.
|
|
The Moeraki Boulders at sunrise The Moeraki Boulders are unusually large and spherical boulders lying along a stretch of Koekohe Beach on the wave-cut Otago coast of New Zealand between Moeraki and Hampden. They occur scattered either as isolated or clusters of boulders within a stretch of beach where they have been protected in a scientific reserve. The erosion by wave action of mudstone, comprising local bedrock and landslides, frequently exposes embedded isolated boulders. These boulders are grey-colored septarian concretions, which have been exhumed from the mudstone enclosing them and concentrated on the beach by coastal erosion.
|
|
The most fascinating feature of the Caves of Castellana are the concretions. This term is used to indicate the mineral deposits that covered the naked walls of a cave by crystallisation of the calcite carried in solution by infiltrating rain water, that had penetrated all the overhanging layers of the rock by a very slow seepage. When the water drips through the roof of an empty cavern, the calcite dissolved in it deposits on the roof and going downwards takes the shape of a stalactite. When the drop of water falls on the floor, the calcite takes the shape of a stalagmite.
|
|
Woodbine Formation located between Dallas and Fort Worth consists of marine and terrestrial fossils such as concretions and trace fossils, including the last known dinosaurs in this part of Texas. Directly east of the Woodbine is the Eagle Ford, where fossilized shark teeth, plesiosaurs, crabs, and small marine lizards called Coniasaurus can be found. The northwest quadrant of the I-20 and 408 loop is abundant in shark teeth. Directly east of 408 on Kiest Blvd is a large section of the Eagle Ford Shale outcropping beneath the Austin Chalk, where fossilized shark teeth are often found.
|
|
White-eye is white soil with lime nodules, which is non-stratified, geologically recent deposits of silty or loamy material, deposited by the wind and cemented together with calcium carbonate concretions. White soil deposits with lime nodules are found in the illuvial horizons of soils that formed on loess and loess-like loams. In the soil profile, the nodules stand out as bright spots with a clear and rounded shape. The size of spots is 1–2 cm in diameter, which is comparable to the size of an eye, and, more specifically, to that of the species of birds known as White-eye.
|
|
Several other sites also showed hematite, such as Aureum Chaos. Because terrestrial hematite is typically a mineral formed in aqueous environments or by aqueous alteration, this detection was scientifically interesting enough that the second of the two Mars Exploration Rovers was sent to a site in the Terra Meridiani region designated Meridiani Planum. In-situ investigations by the Opportunity rover showed a significant amount of hematite, much of it in the form of small spherules that were informally named "blueberries" by the science team. Analysis indicates that these spherules are apparently concretions formed from a water solution.
|
|
Some of the bollock daggers found on board the Mary Rose; for most of the daggers, only the handles have remained while the blades have either rusted away or have been preserved only as concretions. To defend against being boarded, Mary Rose carried large stocks of melee weapons, including pikes and bills; 150 of each kind were stocked on the ship according to the Anthony Roll, a figure confirmed roughly by the excavations. Swords and daggers were personal possessions and not listed in the inventories, but the remains of both have been found in great quantities, including the earliest dated example of a British basket-hilted sword.Childs (2007), p.
|
|
The inside of a large geode lined by amethyst crystals Geodes (derived from the Greek word "γεώδης" meaning "Earth-like") are geological secondary formations within sedimentary and volcanic rocks. Geodes are hollow, vaguely spherical rocks, in which masses of mineral matter (which may include crystals) are secluded. The crystals are formed by the filling of vesicles in volcanic and sub-volcanic rocks by minerals deposited from hydrothermal fluids; or by the dissolution of syn-genetic concretions and partial filling by the same, or other, minerals precipitated from water, groundwater or hydrothermal fluids. Geodized brachiopod fossil lined with calcite with a single crystal of sphalerite, from the Devonian of Wisconsin.
|
|
In 2006 a comprehensive underwater survey was undertaken to identify any potential remains from the wreck of the Bourgianen, a late 19th- century schooner wrecked at the mouth of the inlet in June 1900. The survey identified the presence of a section of timber wreckage and also identified a number features associated with this wreckage, including iron concretions and a possible swivel-gun. This schooner, which was of Italian origin and built in August 1899, was commanded by captain Narciso Antonio Barsello. The vessel was on-route from the port of Catania to Barcelona with a cargo of broad-beans and other perishable goods.
|
|
Self-portrait of Opportunity near Endeavour Crater on the surface of Mars (January 6, 2014). Cape Tribulation southern end, as seen in 2017 by Opportunity rover The Opportunity rover landed in a small crater, dubbed "Eagle", on the flat plains of Meridiani. The plains of the landing site were characterized by the presence of a large number of small spherules, spherical concretions that were tagged "blueberries" by the science team, which were found both loose on the surface, and also embedded in the rock. These proved to have a high concentration of the mineral hematite, and showed the signature of being formed in an aqueous environment.
|
|
At low tide there is an interesting walk from Ladies Bay along the base of the cliffs to St Helier's Bay. The rocky shoreline overlooks the Waitematā Harbour which itself occupies a drowned valley system cut in marine sediments of Miocene Age (15–25 million years ago). Generally, around Auckland these soft Miocene sediments are alternating Waitemata series sandstone and mudstone with more massive beds of sandstone sometimes with minor occurrences of limestone.Geological Map of New Zealand The concretions that can be easily seen, are formed by the action of ground water with dissolved minerals (mainly calcium carbonate of which limestone is made) percolating through the layers.
|
|
The Kellaways Formation is a geological formation of the Callovian Series from the Jurassic. It is found in the British Isles, immediately above the Great Oolite Series: below the Oxford Clay Formation and above the Cornbrash. It consists of two layers, the Kellaways Sand, a light green-grey clayish silt and sand with layers of sand concretions, overlying the Kellaways Clay, a dark grey plastic fissile clay. They were laid down during the Callovian, offshore from the London-Brabant Island, between 165 and 160 million years ago, in the latitude of the modern Mediterranean Sea, when the structure of Britain was still taking shape.
|
|
217-240 Jean-Claude Duplessy initially focused on the concretions of the caves and demonstrated that they were good recorders of the hydrological cycle and air temperature at the time they were formed. He obtained the first reconstructions of air temperatures and climatic conditions in the south of France for the last millennia and for the previous interglacial periodDuplessy J.C., Let al., « Continental climatic variations between 130,000 and 90,000 years B.P », Nature, 1970, 226, p. 631-633 Recently, this type of study has been resumed in Europe due to the development of new dating methods and the study of stalagmites seems open to a great future.
|
|
Geologists starting with Hünicken and Pensa have classified the Bajo de Véliz unit into three component members: from lowest to highest, the Cautana, Pallero, and Lomas members. The Cautana member (102 meters thick) contains clastic rock which grades upward from a coarse bed of polymictic conglomerate at the base, to an intercalated layer of sandstone and greenish-grey siltstone. This is overlaid by a caprock of arkosic or feldspar-rich sandstones and cut banks of greenish siltstone. The Pallero member (53 meters thick) contains clearly-banded and fine-grained material: sandstones, as well as green beds with numerous fossil remains, dropstones, disk-shaped concretions.
|
|
Rhomboteuthis lehmani from La Voulte-sur-Rhône Some soft parts of organisms are preserved as phosphatised concretions, in exceptional cases down to cellular details, e.g. retinal structures in the eyes of conchilyocaridi crustacea. Apart from Beecher's Trilobite Bed and the Hunsrück Slate, La Voulte-sur-Rhône is the only other locality where extensive pyritization of soft parts occurs. see page 41 However, pyritisation is not the only preservation pathway; several stages of mineralization (originally phosphate followed by calcite or gypsum, then pyrite and finally galena) are seen, each successive mineralization event degrades the detail preserved, with only gross morphological features preserved in the most advanced stages.
|
|
The exposed rocks, which consist of pyrite-rich shales with calcareous concretions, are part of the upper Alum Shale Member of the Whitby Mudstone Formation, which has been dated to about 182 million years ago, or the Toarcian stage of the Jurassic period. GSM 3166 was described by Edwin Tulley Newton, who loaned it from Rev. Purdon, in 1888. He described it as a species of Scaphognathus, S. purdoni, named after Purdon; he did not include it in the type species S. crassirostris due to differences in the curvature of the top of the skull, as well as the midline channel on the top of the skull.
|
|
These communities are rare in the coastal plain ecosystem. The principal rich forest associated with ravines down-cutting into lime sands and localized shell concretions is currently classified as the Northern Coastal Plain/Piedmont Basic Mesic Hardwood Forest and is found on two dry, very steep slopes facing Potomac Creek. More study is required for a better understanding of the environment and ecology at Crow's Nest. In the larger context of biodiversity protection in Virginia and the mid-Atlantic region, the factors which contribute to the unique character of this region and its important neotropical migrant populations include its size, large-patch community dynamics, its diversity of habitats, and the known or potential occurrence of rare ecosystems and biota.
|
|
The landscape of Wiehen Hills, in which the remains of Wiehenvenator have been found In 1998, geologist Friedrich Albat, prospecting for the Landschaftsverband Westfalen-Lippe Museum of Natural History, discovered the remains of a large theropod at the abandoned Pott quarry in the Wiehen Hills near Minden, Westphalia. The remains were discovered within the Ornatenton Formation, a geological formation composed mainly of mudstone, sandstones, and a horizon of carbonate concretions. The fragmentary theropod skeleton was excavated between October 1998 and October 2001, and was found alongside abundant marine invertebrates and fossil wood. At the time of their discovery, the bones were heavily weathered out of the surrounding sediments and are somewhat poorly preserved.
|
|
Iron and steel wrecks are subject to corrosion, which is most rapid in shallow sea water where the salinity induces galvanic corrosion, oxygen content is high and water movement replenishes the oxygen rapidly. In deeper water and in still water the corrosion rates can be greatly reduced. Corrosion rates of iron and steel are also reduced when concretions, solid layers of rust, or layers of marine organisms separate the metal from the ambient water, and encourage the development of a layer of relatively stable black oxide in the hypoxic layers. Ships that sink upright onto a sand bottom tend to settle into the sand to a similar level to that at which they would normally float at the surface.
|
|
The superficial formations and Mesozoic formations discharge large volumes of groundwater to the sea. Much of this discharge flows through karstic solution channels in the Tamala limestone, a calcareous and siliceous formation deposited in the middle to late Pleistocene (1,500,000-10,000 years ago). Many karst features of the Tamala Limestone, the result of karst processes and include subterranean drainage through caverns and tunnels, dolines and sinkholes, residual cone hills and circular depressions, limestone pillars and root concretions, can be linked directly to the Nambung River. Caves have evolved in relation to the movement of weakly acidic water groundwater that gradually dissolves calcium carbonate in the limestone, which can be locally redeposited within caves and cavities.
|
|
Devonian nodular limestone Concretionary nodular limestone at Jinshitan Coastal National Geopark, Dalian, China In sedimentology and geology, a nodule is a small, irregularly rounded knot, mass, or lump of a mineral or mineral aggregate that typically has a contrasting composition, such as a pyrite nodule in coal, a chert nodule in limestone, or a phosphorite nodule in marine shale, from the enclosing sediment or sedimentary rock. Normally, a nodule has a warty or knobby surface and exists as a discrete mass within the host strata. In general, they lack any internal structure except for the preserved remnants of original bedding or fossils. Nodules are closely related to concretions and sometimes these terms are used interchangeably.
|
|
Geologically the district forms part of the vast Indo-Gangetic alluvial tract, of which the origin is attributed to a sag in the earth's crust, formed, in the upper eocene times, between the northwardly drifting Gondwanaland and the rising Himalayan belt, and gradually filled in by sediments so as to constitute a level plane with a very gentle seaward slope. The alluvium formation of the district, comprising sand, silt & clay with occasional gravel, is of the early quaternary to sub-recent age. The older alluvium called bhangar, forms slightly elevated terraces usually above the flood levels. It is rather dark in colour generally rich in concretions and nodules of impure calcium carbonate, locally known as kankar.
|
|
Cope had loaned these elements to the English sculptor Benjamin Waterhouse Hawkins to help prepare them out of their surrounding concretions. At the time, Hawkins was working on a "Paleozoic Museum" in New York's Central Park, where a reconstruction of Elasmosaurus was to appear, an American equivalent to his life-sized Crystal Palace Dinosaurs in London. In May 1871 much of the exhibit material in Hawkins' workshop was destroyed by vandals (working for the New York politician William M. "Boss" Tweed) and their fragments buried; it is possible that the girdle elements of Elasmosaurus were at the workshop and were likewise destroyed. Nothing was subsequently mentioned about their loss by Hawkins or Cope.
|
|
The Grotte de Rosée is classified, with the cave Lyell (named after Charles Lyell; both are in fact two parts of the same site), patrimoine immobilier exceptionnel de la Région wallonne (exceptional heritage of Wallonia), under "underground site exceptional," by order of 8 July 1977.Fiche de la Région wallonne It is accessible only to researchers due to the fragility of many concretions and because the opening to tourists and recreational cavers also would result in a change in the natural balance of the biotope, by changes in temperature and light, trampling of clay and nutrient that benefit some species, taking into account that the study of this fauna is still very little progress in this cave.
|
|
Map of Brazil with the type locality of Teyujagua paradoxa within the Paraná Basin. The holotype material, UNIPAMPA 653, was collected from an exposure in the Sanga do Cabral Formation in Southern Brazil, informally known as Bica São Tomé, located in the Paraná Basin. The locality is composed of five outcrops, with UNIPAMPA 653 being found roughly above the base of outcrop 5, in a layer rich in calcareous concretions. The specimen was collected by a team from the Paleobiology Laboratory of the Universidade Federal do Pampa (Unipampa) at the beginning of 2015, and later described in a study co-authored by Dr. Felipe L. Pinheiro and others and published in Scientific Reports (Nature Publishing Group) in early 2016.
|
|
The import and export of goods made with nacre are controlled in many countries under the International Convention of Trade in Endangered Species of Wild Fauna and Flora. A pearl is created in the mantle of a mollusk when an irritant particle is surrounded by layers of nacre. Although most bivalves can create pearls, oysters in the family Pteriidae and freshwater mussels in the families Unionidae and Margaritiferidae are the main source of commercially available pearls because the calcareous concretions produced by most other species have no lustre. Finding pearls inside oysters is a very chancy business as hundreds of shells may need to be pried open before a single pearl can be found.
|
|
There the Marcellus is separated from the overlying Skaneateles Formation, a more clastic and fossiliferous dark shale, by the thin Stafford or Mottville Limestone bed. In West Virginia, the Marcellus may be separated from the brown shales of the Mahantango by occasional sandstone beds and concretions, or it may lie directly below the younger Late Devonian Harrel Formation (or its lateral equivalents) because of a disconformity, which represents a gap in the geological record due to a period of erosion or non-deposition. In eastern Ohio the Hamilton Group also lies disconformably beneath the Rhinestreet Shale Member of the West Falls Formation, another transgressive black shale tongue with similar characteristics to the Marcellus.
|
|
Anvil rock in the Shawnee National Forest, Illinois A close view of a Liesegang ring present on a natural arch of sandstone, found at a beach near Khayelitsha, South Africa. Liesegang rings (concentric concretions) on east side of Saginaw Hill, Tucson Arizona The process by which Liesegang rings develop is not completely understood. Liesegang rings may form from the chemical segregation of iron oxides and other minerals during weathering. One popular mechanism suggested by geochemists is that Liesegang rings develop when there is a lack of convection (advection) and has to do with the inter-diffusion of reacting species such as oxygen and ferrous iron that precipitate in separate discrete bands which become spaced apart in a geometric pattern.
|
|
Acetylsalicylic acid is a weak acid, and very little of it is ionized in the stomach after oral administration. Acetylsalicylic acid is quickly absorbed through the cell membrane in the acidic conditions of the stomach. The increased pH and larger surface area of the small intestine causes aspirin to be absorbed more slowly there, as more of it is ionized. Owing to the formation of concretions, aspirin is absorbed much more slowly during overdose, and plasma concentrations can continue to rise for up to 24 hours after ingestion. About 50–80% of salicylate in the blood is bound to albumin protein, while the rest remains in the active, ionized state; protein binding is concentration-dependent.
|
|
Tetrapod fossils have been found only in the lower lithologic unit of the Chañares Formation, where they are preserved almost exclusively within carbonate concretions. Fossilized bone preserved in concretion shows some of the best form of preservation, with dark brown bone surfaces exhibiting virtually no evidence of macroscopic weathering. The fossil accumulations of the Chañares assemblage are considered to be the product of two different taphonomic pathways: attritional accumulation associated with natural deaths of individuals by predation, disease and old age, and mass mortality of animals associated with volcanic events. In the mass mortality event, there is a clear bias towards preservation of individuals representing smaller-sized to mid-sized taxa such as Massetognathus.
|
|
Hill 57 is a low-rise plateau located adjacent to the city limits of Great Falls, Montana, about north of 9th Avenue North/Northwest Bypass on Stuckey Road and abutting to the Valley View neighborhood. Hill 57 consists of rock belonging to the Colorado Group, a stratigraphic unit consisting largely of shale. Within this group is a subunit known as the Blackleaf Formation (or the Albian Formation), a shale with a small proportion of fine-to-medium grain sandstone. At the bottom of the Blackleaf Formation is another geologic subunit, the Flood Member, a sandstone consisting of layers (from top to bottom) of very hard calcareous sandstone, fissile sandstone with concretions of ironstone or stained limestone, and medium-hard light-colored sandstone.
|
|
Restoration of the head Irritator and Angaturama are known from the Romualdo Formation, whose rocks are dated to the Albian stage of the Early Cretaceous Period, about 110 million years ago. During this time, the Southern Atlantic Ocean was opening, forming the series of circum-Atlantic basins of southern Brazil and southwestern Africa, but the northeastern part of Brazil and West Africa were still connected. The Romualdo Formation is part of the Santana Group and, at the time Irritator was described, was thought to be a member of what was then considered the Santana Formation. The Romualdo Formation is a Lagerstätte (a sedimentary deposit that preserves fossils in excellent condition) consisting of limestone concretions embedded in shales, and overlies the Crato Formation.
|
|
The formation of cone-in-cone structures has been attributed to: #Volume increase inversion from aragonite to calcite in which expansion of conical aragonite pushed cones apart and allowed for clay to intrude # Burial-induced pressure solution and clay layers remaining as insoluble residues # Fracturing of crystalline mineral composites that form in over-pressured chambers, with fractures forming from a decrease in pore pressure # Formation during early diagenesis by expansive mineral growth (force of crystal growth), in which the cones are produced by the growth of cone-shaped aggregates of fibrous calcite, the clay layers originate as the crystals displace and disturb the original clay-rich sediment. # Gillman and MetzgerGillman, R.A., Metzger, W.J.. 1967. Cone-in-cone concretions from western New York. Journal of Sedimentary Petrology.
|
|
The specimen NHMUK PV R36634 was found in 2011 within a concretion in Saltwick Bay, which also belongs to the Alum Shale Member. It consists of a scapula, coracoid, and humerus; the head of the humerus was broken off during excavation as a result of the concretion being hammered open (which is the usual method for exposing ammonites preserved in concretions). Although it is impossible to refer this specimen to Parapsicephalus with confidence, its provenance and similarity to Dorygnathus were the basis of the tentative identification of the specimen as belonging to this genus. An additional possible specimen is a skull collected in 1994 from Altdorf, Bavaria, Germany, which bears great similarity to GSM 3166 and also preserves some additional elements.
|
|
In June, Turner gave three fossil vertebrae to the American scientist John LeConte, a member of the railway survey, to take back east to be identified. In December, LeConte delivered some of the vertebrae to the American paleontologist Edward Drinker Cope at the Academy of Natural Sciences of Philadelphia (ANSP, known since 2011 as the Academy of Natural Sciences of Drexel University). Recognizing them as the remains of a plesiosaur, larger than any he had seen in Europe, Cope wrote to Turner asking him to deliver the rest of the specimen, at the ANSP's expense. In December 1867 Turner and others from Fort Wallace returned to the site and recovered much of the vertebral column, as well as concretions that contained other bones; the material had a combined weight of .
|
|
As we have them, they consist of manuscripts of his lectures and notes of his students. They were published by Volcher Coiter (Nuremberg, 1575). Falloppio argued against Fracastoro's theory of fossils, as described as follows in Charles Lyell's Principles of Geology: > Falloppio of Padua conceived that petrified shells had been generated by > fermentation in the spots where they were found, or that they had in some > cases acquired their form from 'the tumultuous movements of terrestrial > exhalations.' Although a celebrated professor of anatomy, he taught that > certain tusks of elephants dug up in his time at Puglia were mere earthy > concretions, and, consistently with these principles, he even went so far as > to consider it not improbable, that the vases of Monte Testaceo at Rome were > natural impressions stamped in the soil.
|
|
Associated with these pipe-like features are objects that were described as "rusty scraps" and "strangely shaped stones". Analysis of the former by Liu Shaolin at a local smeltery reportedly found that they consist of 30 percent ferric oxide (oxidized iron) and large amounts of silicon dioxide and calcium oxide. Because any metallurgical analysis reports the composition of a material analyzed not in terms of the actual minerals comprising it, but only in terms of percentages of the oxides of the specific elements present, the calcium present in the analyzed material could have been in the form of calcite, a mineral that naturally forms concretions. According to news stories, the pipes were first discovered by a group of scientists from the United States who were seeking dinosaur fossils.
|
|
The dominant bedrock of the Young Creek valley is black shale, which is cut by many dikes and sills of light-colored granitic rock and is capped in the high mountains on both sides of the valley by conglomerate and sandstone. There are also a few beds of limestone and many limestone concretions. Except for a small area of sandstone near the big bend the numerous bedrock exposures along the creek are shale or the intruded dikes. The gravel deposits of Young Creek are of three classes—highbench gravels, which lie well above the stream levels and form in part the canyon wall; low-bench gravels, which adjoin the creek channel within the canyon; and flood-plain gravels, over which the stream flows in times of high water.
|
|
According to the former, the formations are the result of coral activity (but detail investigation shows no coral), while the latter explain the phenomenon with the prismatic weathering and desertification of the rocks, the formation of sand and limestone concretions, or lower Eocene bubbling reefs. Based on a petrographic and stable isotope geochemical study and field observations, evidence exists that these structures represent an exceptionally record of paleo-hydrocarbon seep system (low magnesium calcite cements are strongly depleted in heavy carbon isotope 13C). The pathways of fluid circulation are recorded as columns set in sands, which columns after recent sand removal gave desert-like landscape. The dynamic reconstruction of the origin of these structures, the processes of fluid migration and microbial mediation of hydrocarbon oxidation leading to carbonate precipitation have been studied by De Boever et al. (2009).
|
|
The north-eastern coast Early Iron Age hut circles are found throughout the island. One located near the North East coast contains within its bounds a cave to which walls have been artificially added; several hammerstones are located in the cave and surrounding vicinity, some with concretions of crushed shells stuck to them. The cave site is below a dramatic basalt shaft interrupting the general appearance of the cliffs, and is framed by two large boulders, one of which resembles an eagle; archaeologists have thus concluded that the site must have been regarded as special, possibly being used for hermitic purposes (being too remote and difficult to reach for ordinary domestic use), and have named the site the oracle cave. Loch nam Ban Mora Later in the Iron Age, the inhabitants of Eigg chose to fortify the island.
|
|
Nothing seemed capable of living there but a colony of bats, some flapping about on lazy wing, and others torpid; no process to be active, but the cold one of petrifaction, which, in nature's own confused method, had elaborated throughout the cavern, columns and pinnacles and cushions ... and concretions, some as fleecy as snow, others as crisp as hoar-frost, and others of an opal hue as transparent as crystal. All was rich, beautiful, and sparkling. It was a marvel to adventurers, but unfit for habitation; yet, in later years, this hole of the mountain was possessed by a Spanish goat-herd, who reached his solitude by the same threadlike but dangerous tracks as his goats. There might the recluse have lived till his bones fell among the petrifaction, but he was at length expelled from its gloomy precincts on account of his contraband iniquities.
|
|
In Moqui Canyon near Red Cone Spring nearly of Kayenta limestone conglomerate rests in a long meandering valley cut in Wingate. Likewise, the contact between the Kayenta and the Navajo in places seems to be gradational, but generally a thin jumbled mass of sandstone and shales, chunks of shale and limestone, mud balls, and concretions of lime and iron, lies at the base of the fine-grained, cross bedded Navajo. Mud cracks, a few ripple marks, and incipient drainage channels were observed in the topmost bed of the Kayenta on Red Rock Plateau; and in west Glen Canyon, wide sand- filled cracks appear at the horizon. These features indicate that, in places at least, the Wingate and Kayenta were exposed to erosion before their overlying geologic formations were deposited, are it may be that the range in thickness of the Kayenta thus in part (is) accounted for.
|
|
The Cottonwood is not a flinty limestone such as those seen higher on the surrounding hilltops; however, nodules, concretions, and trace fossils (filled-in burrows) of partly silicified material that weather more slowly than the rest of the member can give the limestone an appearance of containing flint. While the abundance of fusulinids remains a characteristic of the top of the Cottonwood through to Osage County, Oklahoma, south of Chase County, Kansas the member has lost its massive limestone characteristic and does not form the conspicuous outcrops seen farther north. In Greenwood County, Kansas, the unit appears as light- gray limestone crowded with horizontal thin leaves of platy algae, attaining a maximum observed thickness of 8 feet. The Cottonwood in southern Kansas and northern Oklahoma is an interbedded limestone and calcareous shale with a very diverse, abundant, and well-preserved fossil fauna, especially brachiopods, mollusks, and ammodiscid foraminifera (shelly facies).
|
|
More often, the size scale of the rock is larger than the object it resembles, such as a cliff profile resembling a human face. Well-meaning people with a new interest in fossils can pick up chert nodules, concretions or pebbles resembling bones, skulls, turtle shells, dinosaur eggs, etc., in both size and shape. In the late 1970s and early 1980s, Japanese researcher Chonosuke Okamura self-published a series of reports titled Original Report of the Okamura Fossil Laboratory, in which he described tiny inclusions in polished limestone from the Silurian period (425 mya) as being preserved fossil remains of tiny humans, gorillas, dogs, dragons, dinosaurs and other organisms, all of them only millimeters long, leading him to claim, "There have been no changes in the bodies of mankind since the Silurian period... except for a growth in stature from 3.5 mm to 1,700 mm." archived at Improbable Research.
|
|
In 1934, Salmon and co-author Horace N. Coryell published a report in The American Museum of Natural History detailing the fossil findings of Theron Wasson, Chief Geologist of the Pure Oil Company. It summarizes the stratigraphy of the Pierre formation south of Glendive, Montana where the fossils were obtained, along with a more detailed lithographic description of the member in which the fossils occur, and especially of the concretions in which they are found. There is also a list of fossils of this faunule, mostly Mollusca and a few new species. The species included in this list consist of eight Gastropoda, ten Caphalopoda, fifteen Pelecypoda (now referred to as Bivalvia, two Scaphopoda (or Tusk shells), and the two new species being ammonoid Cephalopoda, coming to a total of thirty-five species. A discussion of the classification and nomenclature of one of Meek’s species of Cephalopoda is also included.
|
|
The Shales With Beef Member is around 28–30 metres thick in the Lyme Regis- Charmouth region and predominantly consists of thinly bedded medium to dark grey mudstone, blocky calcareous pale-weathering mudstone and brown grey organic rich mudstones with frequent interbeds of fibrous calcite ("beef"), that are usually less than 10 centimetres thick. Several beds of nodular and tabular limestone are also present. It is the lowest unit of the formation and directly overlies the Blue Lias Formation, with the boundary being marked by a prominent bioturbated horizon. Notable persistent marker beds within the member include the laminated calcareous siltstone "Fish Bed", "Table Ledge", which consists of lens beds of limestones with mud content with nests of rhynchonellid brachiopods, the Devonshire Head and the Spittles limestones and the Birchi Nodules (which are septarian concretions) The upper boundary with the Black Ven Marl Member is marked by the prominent laterally persistent limestone Birchi Tabular Bed.
|
|
The first part of the book begins with 5 friends (Carneades the host and the Skeptic, Philoponus the Chymist, Themistius the Aristotelian, Eleutherius the impartial Judge, and an unnamed narrator) meeting in Carneades's garden and chatting about the constituents of mixed bodies. In part one, Carneades (Boyle) lays out four propositions to the gathering, which sets the foundation for the rest of the book. They are as follows: :Proposition I. :It seems not absurd to conceive that at the first production of mixt bodies, the universal matter whereof they among other parts of the universe consisted, was actually divided into little particles of several sizes and shapes variously moved. :Proposition II. :Neither is it impossible that of these minute particles divers of the smallest and neighboring ones were here and there associated into minute masses or clusters, and did by their coalitions constitute great store of such little primary concretions or masses as were not easily dissipable into such particles as composed them.
|
|
Martel, and Ed. Rahir, Les cavernes et les rivières souterraines de la Belgique étudiées spécialement dans leurs rapports avec l'hydrologie des calcaires et avec la question des eaux potables, Vol. II Les calcaires carbonifériens du bassin de Dinant et coup d'œil sur le bassin de Namur; H. Lamertin, Bruxelles, 1910. From west to east, there are five halls, connected via narrow passages: # is the deepest, 10m below the entrance, measuring 10m by 9m; # the Hall of the moon, 8m by 3m, a name given by Doudou, because of light entering through a joint in the ceiling; # the Hall of Nutons, 4m by 3m, part of which is the gallery containing stalactites, which rises toward the west and is obscured by concretions; # the Hall of the Cone, 14m by 3m, named for a cone on the ceiling; # the Grand Hall, 20m by 18m, and 4m high, with two oblique chimneys containing layers of sediment full of bones. These are most likely the remains of some sixty bears and fifty boars, which were collected there by water running through the cave.
|
|