A cuspate foreland in Chicago, stabilised by vegetation Cuspate forelands, also known as cuspate barriers or nesses in Britain, are geographical features found on coastlines and lakeshores that are created primarily by longshore drift.Craig-Smith, S. J., Cuspate Forelands. In: M. L. Schwartz, ed. 2005. Encyclopedia of Coastal Science.
|
|
There are different management issues with regard to cuspate forelands depending on their formation. If a cuspate foreland has formed from deposition, it may be vulnerable if human interference alters the transport of sediments from the shoreline. However, if the cuspate foreland is a relic of a past feature that has eroded, human interference with longshore sediment movement will not have a significant impact on the cuspate foreland. For a cuspate foreland to be maintained, the input of sediment must be greater than output of sediment.
|
|
Longshore drift is usually the main process in the formation of a cuspate foreland The debate involving how cuspate forelands form is ongoing.McNinch, J. E., and Luettich, R. A., 2000. Physical processes around a cuspate foreland: implications to the evolution and long-term maintenance of a cape-associated shoal. Continental Shelf Research.
|
|
As well as forming along coastlines, cuspate forelands can also form along lake shores, although less is known about this type of cuspate foreland. This type of cuspate foreland includes Point Pelee along the shoreline of Lake Erie, and those found along the shoreline of Lake Victoria in Australia. There are two theories with regard to the formation of Point Pelee. Firstly, it is thought that Point Pelee has formed from depositional processes.
|
|
In some areas, such as along the North Carolina coastline, a series of cuspate forelands may form at least 100 km apart. In areas that have a large amount of shingle, such as the cuspate foreland at Dungeness, it is also common for a fresh water table to be present.
|
|
As sand erodes from the sandbank, it is pushed towards the coastline, contributing to the formation of the cuspate foreland as the sandbank migrates along the coast. This often occurs in the opposite direction to longshore drift. In the case of a cuspate foreland that has formed close to an island, it is possible for it to extend right up to the island, forming a tombolo. Depending on the physical conditions such as storms, the feature can alternate between a cuspate foreland and a tombolo.
|
|
Once formed, cuspate forelands can remain where they are and continue to develop as sediment accumulates, or alternatively they may migrate down the coast as one side of the foreland erodes and the other side accretes. Cuspate Forelands that move are typical of those that are formed on open coastlines. The direction of migration is often indicated by a series of successive beach ridges on the advancing side of the foreland where there is less wave energy. The movement of cuspate forelands is commonly explained by longshore drift acting as the main process.
|
|
Activities such as coastal development or engineering must be regulated for sediment to continue moving towards the foreland where it can be deposited. Development along cuspate forelands is risky due to erosion and the vulnerability to storms and sea level rise. As sea levels rise, cuspate forelands are likely to be at risk as they could move inland. At Point Pelee, approximately 1,900 hectares of former agricultural land on the cuspate foreland is now under water as a result of wind erosion and compaction of organic soils on the foreland.
|
|
However, there have been observed cases where two cuspate forelands on the same shoreline have migrated in opposite directions, showing that longshore drift does not always provide a sufficient explanation for their migration. If there is an offshore sandbank present, the position of the cuspate foreland is usually related to its position. If there is a change in the position of the sandbank, the position of the cuspate foreland typically follows. Not only does the sandbank act like an island since it causes waves to refract around it, but it also provides a source of sediment.
|
|
This cuspate foreland has formed as a result of the merging of SW waves from the English Channel, and waves from the east from the Strait of Dover. Another example is the cuspate foreland found between Awatere River and White Bluffs in Marlborough, New Zealand.Pickrill, R. A., 1977. Coastal processes, beach morphology, and sediments along the north-east coast of the South Island, New Zealand.
|
|
This gap in knowledge provides the opportunity for further research. It is likely that Point Pelee is migrating westwards since accretion is occurring on the western side, and erosion is occurring on the eastern side. Lake Victoria in Australia also has a number of cuspate forelands. Point Scott is a cuspate foreland along this lakeshore that has formed from the gradual accumulation of sand and gravel.
|
|
Cuspate forelands can be separated into three distinct areas: the central nose or apex, and two marginal wings. The apex usually has ridges that run parallel to the converging shorelines. Cuspate forelands can extend up to 5 km from the shoreline, and an underwater shoal may extend much further, up to 15 km from the exposed apex. Located between the mainland and the foreland are often lagoons or marshy areas.
|
|
The Netherlands: Springer, pp. 354–355. Formed by accretion and progradation of sand and shingle, they extend outwards from the shoreline in a triangular shape. Some cuspate forelands may be stabilised by vegetation, while others may migrate down the shoreline. Because some cuspate forelands provide an important habitat for flora and fauna, effective management is required to reduce the impacts from both human activities and physical factors such as climate change and sea level rise.
|
|
In the case of a cuspate foreland, the prevailing wind and a powerful secondary wind in the opposite direction move shingle down the coastline from both directions to a place where the coastline changes, causing a foreland to develop. The majority of cuspate forelands are formed over a coastline that juts out into the sea at enough of an angle to allow the drifting beach material to 'spill over' as a result of long shore drift in both directions.
|
|
Stable cuspate forelands that are composed of shingle often have vegetation above the high tide line. As vegetation is established, mites and collembolans break down plant matter such as roots, resulting in the accumulation of organic matter. Plants also cause the soil to develop and water retention to increase, therefore providing a habitat where more plants can grow. Vegetation above the high tide line is common on cuspate forelands that are stable and composed of shingle.
|
|
An example of this type of cuspate foreland is the one found at Dungeness along the southern coast of Britain.Davis, R. A., and FitzGerald, D., 2004. Beaches and Coasts. Blackwell Publishing: Australia.
|
|
Accessed 8 April 2011. When there is an aquifer present under a cuspate foreland, regulation of water removal is required. At Dungeness, water restrictions have been put in place to maintain the aquifer level. The management of coastlines needs to take into account the natural processes that occur on cuspate forelands since many provide a habitat for birds. Alternative ways of managing coastal erosion is needed, such as the use of ‘soft’ defences instead of high impact defences such as sea walls.
|
|
Chevron folds, Ireland A fold can be shaped like a chevron, with planar limbs meeting at an angular axis, as cuspate with curved limbs, as circular with a curved axis, or as elliptical with unequal wavelength.
|
|
After the formation of the cuspate foreland into its distinctive triangular shape, it will start to be colonised by pioneer species that are hardy and tough enough to survive in the environment. These pioneer species secure the cuspate foreland and allow a greater amount of sediment to further secure it. Colonization and succession of vegetation is dependent on a number of factors. Firstly, if the shingle is too coarse, the amount of fine sediment that can remain between the spaces is reduced, and the likelihood that seeds will germinate and grow upwards is low.
|
|
Trenhaile, A. S., 2000. Point Pelee: a large cuspate foreland on Lake Erie. Canadian Geographer, 44(2), pp. 191–195. Alternatively, it is suggested that Point Pelee is a relic of a past feature that has eroded over time.
|
|
Some cuspate forelands naturally do not contain any vegetation due to a high level of disturbance from physical factors such as wave action. However, with the frequency of storms arising from climate change, the effect on forelands and their associated vegetation needs to be effectively managed.
|
|
American Midland Naturalist 53:88–114. found that the tooth morphology did vary with diet, and that herbivorous taxa tended to possess laterally compressed, sharp, cuspate teeth. Later research supported this, and found that this morphology, particularly in Iguana, may be used to shear plants.Montanucci, R. R. 1968.
|
|
Poleo Formation (tan sandstone beds at top) resting on Salitral and Shinarump Formations. West of Abiquiu, New Mexico. The Poleo Formation is a cliff- forming formation composed mostly of yellowish-gray fine to medium sandstone, but with up to 20% conglomerate. The sandstone shows cross bedding and cuspate ripples.
|
|
Cuspate forelands can form both along coastlines and along lakeshores. Those formed along coastlines can be in the lee of an offshore island, along a coastline that has no islands in the vicinity, or at a stream mouth where disposition occurs.Bird, E., 2008 Coastal geomorphology: an introduction. 2nd ed.
|
|
Cuspate forelands provide a habitat for various flora and fauna. If a foreland is relatively stable and experiences low wave impact, it may be possible for vegetation to grow. In the United Kingdom, 11 taxa of invertebrates are found on shingle habitats. Shingle beaches also provide a habitat for birds to breed, nest, and rest en route while migrating.
|
|
Kayak Point is a cuspate foreland on Port Susan, with a sandy beach that was derived from erosion of nearby bluffs. The park is largely undeveloped, with only dedicated solely to recreational uses. Kayak Point County Park features a sandy beach along Port Susan with picnic shelters and parking. The beach is interrupted by a boat launch and a pier.
|
|
Dungeness () is a headland on the coast of Kent, England, formed largely of a shingle beach in the form of a cuspate foreland. It shelters a large area of low-lying land, Romney Marsh. Dungeness spans Dungeness Nuclear Power Station, the hamlet of Dungeness, and an ecological site at the same location. It lies within the civil parish of Lydd.
|
|
A cuspate foreland can form in a strait or along a coastline that has no islands or shoals in the area. In this case, longshore drift as well as prevailing wind and waves bring sediment together from opposite directions. If there is a large angle between the waves and the shoreline, the sediment converges, accumulates, and forms beach ridges.Ashton, A., et al.
|
|
The two rivers were made to flow into the lagoon of Brondolo, which was to the south of the lagoon of Venice and connected to it. This lagoon, which did not have a direct access to the sea, was turned into a freshwater lake and, later, it became completely silted up. The sea shore in this area advanced into the sea, forming a cuspate foreland.
|
|
Sculpture Mountain () is a large dissected mountain between the Monument Nunataks and Sheehan Mesa. Named by the Northern Party of New Zealand Geological Survey Antarctic Expedition (NZGSAE), 1962–63, due to the cuspate embayment which has been sculptured into the feature. The mountain is at the end of the Mesa Range and was renamed from Sculpture Tableland to the feature's current name when its status as a mountain was confirmed.
|
|
Winterton Ness is an area of foreland on the North Norfolk coast of England. Winterton Ness is located to the north of the village of Winterton-on-Sea between in the north to to its south.JNCC website Technically it is a narrow cuspate foreland with a high obtuse angle between its two shorelines. A number of studies appear inconclusive as to the nature if erosion or, conversely, accretion of sediment in the area.
|
|
Journal of Vertebrate Paleontology. . Yanoconodon's name is composed of two elements: 'Yan' is taken from the Yan Mountains in the north of the Hebei Province near where the holotype of Yanoconodon was found; 'Conodon' is an often used as a mammalian taxonomic suffix meaning 'cuspate tooth'. Its species name, "allini," is derived from mammalian researcher Edgar Allin, who was notable for his research on the mammalian middle ear.Luo, Z., Chen, P., Li, G., & Chen, M. (2007).
|
|
There are generally 12 maxillary teeth. It has been established that Massetognathus with multi-cuspate post canines adapted to herbivory, moved the lower jaw posteriorly and dorsally during the power stroke of the occlusion. Massetognathus is the only cynodont from the Chañares Formation with clear adaptations for herbivory, with basined, labiolingually expanded upper and lower post-canines, ensuring a rudimentary dental occlusion, feeding on ground level vegetation or on the lower branches of taller plants and shrubs.
|
|
A cuspate foreland can form in the lee of an island. In this case, oncoming waves are diffracted around the island, protecting the coastline from the oncoming wave fronts. Sediments brought along the shoreline via longshore drift are then able to settle and accumulate in the lee of the island where there is less wave energy. This type of foreland has formed on the west shore of the North Island of New Zealand, in the lee of Kapiti Island.
|
|
Reasons can include: seawalls locking up sand dunes, coastal structures like ports and harbors that prevent longshore transport, dams and other river management structures. Continuous, long-term renourishment efforts, especially in cuspate-cape coastlines, can play a role in longshore transport inhibition and downdrift erosion. These activities interfere with the natural sediment flows either through dam construction (thereby reducing riverine sediment sources) or construction of littoral barriers such as jetties, or by deepening of inlets; thus preventing longshore transport of sediment.
|
|
Baiotomeus russelli has been discovered in Alberta, Canada, in Cochrane 2 of the Paskapoo Formation, which has been dated to the lower Tiffanian stage of the Paleocene. Remains consist of nine upper premolars, (P4), which average nearly 2.5 mm in length. This is smaller than the teeth of other genus members; from front to back, approximately 45% less than B. douglassi and 40% less than B. lamberti. The rows of cusps also display a strong curvature and the cuspate anterolabial lobe is better developed.
|
|
Orford Ness is a cuspate foreland shingle spit on the Suffolk coast in Great Britain, linked to the mainland at Aldeburgh and stretching along the coast to Orford and down to North Weir Point, opposite Shingle Street. It is divided from the mainland by the River Alde, and was formed by longshore drift along the coast. The material of the spit comes from places further north, such as Dunwich. Near the middle point of its length, at the foreland point or 'Ness', once stood Orfordness Lighthouse, demolished in summer 2020 due to the encroaching sea.
|
|
Great Ganinick and Little Ganinick The islands of Great Ganinick and Little Ganinick (, place of wild garlic) (), are part of the GCR and are in an early stage of the linkage of two islands by a tombola. The sand bar is building from Little Ganinick, northwards, towards the larger island although the sand supply does not appear to be sufficient to link the two islands. On the north side of Great Ganinick a "cuspate" shaped beach is forming. Great Ganinick has the only known oak tree in the Eastern Islands.
|
|
The island is characterized by an irregular coastline of approximately , with numerous bays and inlets and a significant diversity of other coastal land forms, including spits, bluffs, dunes, lagoons, cuspate forelands, tombolos, tide flats, streams and tidal deltas, islands, and rocky outcrops. The high point is Toe Jam Hill. On the Kitsap Peninsula, Bremerton and Poulsbo lie across the Port Orchard channel to the west, and the city of Port Orchard lies across Rich Passage to the south. The island is quite hilly and is known for its popular Chilly Hilly bicycle ride every February.
|
|
Retrieved 11 Nov 2011 Previously used for logging, farming, and mining during the early 20th century, the islands are returning to a primitive state; evidence of human habitation is still present, albeit mostly obscured by the regenerating forests. The islands' coastlines possess varied geology, where precambrian sandstone has eroded into sea caves, and the resulting sand has formed sandspits, cuspate forelands, tombolos, barrier spits, and beaches. Ecologically, the islands contain some old growth, but primarily secondary Northern hardwood forest. There are elements of the oak, hickory, and hemlock hardwood forests of the eastern United States, but also features of the Boreal forest typical of Ontario.
|
|
In all there have been eight lighthouses at Dungeness: five main (or 'high') lights (of which the fifth is still fully operational today), and three subsidiary (or 'low') lights. The addition of a subsidiary light became necessary owing to the constant accretion of shingle on the east side of the spit (an ongoing problem on this cuspate foreland), which gradually leaves each lighthouse at an ever-increasing distance from the sea on that side. In the nineteenth and twentieth centuries Dungeness was used as an experimental station by Trinity House; in the 1860s it was the first of their lighthouses to be equipped with a fog horn and the first to be given a permanent (if short-lived) electric lamp.
|
|
Cape Banks is a headland in the Australian state of South Australia located in the gazetted locality of Carpenter Rocks at the south end of Bucks Bay and the north end of Bungaloo Bay on the state's south east coast about west south west of the city of Mount Gambier. The cape is described by one source as being "a rocky point, high, SSE of Cape Buffon" while another source describes it as ‘a cuspate foreland protruding seaward in lee of calcarenite rocks and reefs’. It was named by the Royal Navy officer, James Grant, on 3 December 1800. The navigation aid known as the Cape Banks Lighthouse is not located on the cape but on an unnamed headland located at the northern end of Lighhouse Bay which is the next bay to the north-west of Bucks Bay.
|
|