A raised beach, coastal terrace, or perched coastline is a relatively flat, horizontal or gently inclined surface of marine origin, mostly an old abrasion platform which has been lifted out of the sphere of wave activity (sometimes called "tread"). Thus, it lies above or under the current sea level, depending on the time of its formation. It is bounded by a steeper ascending slope on the landward side and a steeper descending slope on the seaward side (sometimes called "riser"). Due to its generally flat shape it is often used for anthropogenic structures such as settlements and infrastructure.
Around the world, a combination of tectonic coastal uplift and Quaternary sea-level fluctuations has resulted in the formation of marine terrace sequences, most of which were formed during separate interglacial highstands that can be correlated to marine isotope stages (MIS).
A marine terrace commonly retains a shoreline angle or inner edge, the slope inflection between the marine abrasion platform and the associated paleo sea-cliff. The shoreline angle represents the maximum shoreline of a transgression and therefore a paleo-sea level.
The platform of a marine terrace usually has a gradient between 1°–5° depending on the former tidal range with, commonly, a linear to concave profile. The width is quite variable, reaching up to 1,000 metres (3,300 ft), and seems to differ between the northern and southern hemispheres. The cliff faces that delimit the platform can vary in steepness depending on the relative roles of marine and subaerial processes. At the intersection of the former shore (wave-cut/abrasion-) platform and the rising cliff face the platform commonly retains a shoreline angle or inner edge (notch) that indicates the location of the shoreline at the time of maximum sea ingression and therefore a paleo-sea level. Sub-horizontal platforms usually terminate in a low tide cliff, and it is believed that the occurrence of these platforms depends on tidal activity. Marine terraces can extend for several tens of kilometers parallel to the coast.
Older terraces are covered by marine and/or alluvial or colluvial materials while the uppermost terrace levels usually are less well preserved. While marine terraces in areas of relatively rapid uplift rates (> 1 mm/year) can often be correlated to individual interglacial periods or stages, those in areas of slower uplift rates may have a polycyclic origin with stages of returning sea levels following periods of exposure to weathering.
Marine terraces can be covered by a wide variety of soils with complex histories and different ages. In protected areas, allochtonous sandy parent materials from tsunami deposits may be found. Common soil types found on marine terraces include planosols and solonetz.
The formation of marine terraces is controlled by changes in environmental conditions and by tectonic activity during recent geological times. Changes in climatic conditions have led to eustatic sea-level oscillations and isostatic movements of the Earth's crust, especially with the changes between glacial and interglacial periods.
Processes of eustasy lead to glacioeustatic sea level fluctuations due to changes of the water volume in the oceans and hence to regressions and transgressions of the shoreline. At times of maximum glacial extent during the last glacial period, the sea level was about 100 metres (330 ft) lower compared to today. Eustatic sea level changes can also be caused by changes in the void volume of the oceans, either through sedimento-eustasy or tectono-eustasy.
Processes of isostasy involve the uplift of continental crusts along with their shorelines. Today, the process of glacial isostatic adjustment mainly applies to Pleistocene glaciated areas. In Scandinavia, for instance, the present rate of uplift reaches up to 10 millimetres (0.39 in)/year.
In general, eustatic marine terraces were formed during separate sea level highstands of interglacial stages and can be correlated to marine oxygene isotopic stages (MIS). Glacioisostatic marine terraces were mainly created during stillstands of the isostatic uplift. When eustasy was the main factor for the formation of marine terraces, derived sea level fluctuations can indicate former climate changes. This conclusion has to be treated with care, as isostatic adjustments and tectonic activities can be extensively overcompensated by a eustatic sea level rise. Thus, in areas of both eustatic and isostatic or tectonic influences, the course of the relative sea level curve can be complicated. Hence, most of today's marine terrace sequences were formed by a combination of tectonic coastal uplift and Quaternary sea level fluctuations.
Jerky tectonic uplifts can also lead to marked terrace steps while smooth relative sea level changes may not result in obvious terraces, and their formations are often not referred to as marine terraces.
Marine terraces often result from marine erosion along rocky coast lines in temperate regions due to wave attack and sediment carried in the waves. Erosion also takes place in connection with weathering and cavitation. The speed of erosion is highly dependent on the shoreline material (hardness of rock), the bathymetry, and the bedrock properties and can be between only a few millimeters per year for granitic rocks and more than 10 metres (33 ft) per year for volcanic ejecta. The retreat of the sea cliff generates a shore (wave-cut/abrasion-) platform through the process of abrasion. A relative change of the sea level leads to regressions or transgressions and eventually forms another terrace (marine-cut terrace) at a different altitude while notches in the cliff face indicate short stillstands.
It is believed that the terrace gradient increases with tidal range and decreases with rock resistance. In addition, the relationship between terrace width and the strength of the rock is inverse, and higher rates of uplift and subsidence as well as a higher slope of the hinterland increases the number of terraces formed during a certain time.
Furthermore, shore platforms are formed by denudation and marine-built terraces arise from accumulations of materials removed by shore erosion. Thus a marine terrace can be formed by both erosion and accumulation. However, there is an ongoing debate about the roles of wave erosion and weathering in the formation of shore platforms.
Reef flats or uplifted coral reefs are another kind of marine terrace found in intertropical regions. They are a result of biological activity, shoreline advance and accumulation of reef materials.
While a terrace sequence can date back hundreds of thousands of years, its degradation is a rather fast process. On the one hand a deeper transgression of cliffs into the shoreline may completely destroy previous terraces; on the other hand older terraces might be decayed or covered by deposits, colluvia or alluvial fans. Erosion and backwearing of slopes caused by incisive streams play another important role in this degradation process.
The total displacement of the shoreline relative to the age of the associated interglacial stage allows calculation of a mean uplift rate or the calculation of eustatic level at a particular time if the uplift is known.
In order to estimate vertical uplift, the eustatic position of the considered paleo sea levels relative to the present one must be known as precisely as possible. Our chronology relies principally on relative dating based on geomorphologic criteria but in all cases we associated the shoreline angle of the marine terraces with numerical ages. The best-represented terrace worldwide is the one correlated to the last interglacial maximum (MISS 5e) (Hearty and Kindler, 1995; Johnson and Libbey, 1997, Pedoja et al., 2006 a, b, c). Age of MISS 5e is arbitrarily fixed to range from 130 to 116 ka (Kukla et al., 2002) but is demonstrated to range from 134 to 113 ka in Hawaii and Barbados (Muhs et al., 2002) with a peak from 128 to 116 ka on tectonically stable coastlines (Muhs, 2002). Older marine terraces well represented in worldwide sequences are those related to MIS 9 (~303–339 ka) and 11 (~362–423 ka) (Imbrie et al., 1984). Compilations show that sea level was 3 ± 3 meters higher during MISS 5e, MIS 9 and 11 than during the present one and −1 ± 1 m to the present one during MIS 7 (Hearty and Kindler, 1995, Zazo, 1999). Consequently, MIS 7 (~180-240 ka; Imbrie et al., 1984) marine terraces are less pronounced and sometimes absent (Zazo, 1999). When the elevations of these terraces are higher than the uncertainties in paleo-eustatic sea level mentioned for the Holocene and Late Pleistocene, these uncertainties have no effect on overall interpretation.
Sequence can also occurs where the accumulation of ice sheets have depressed the land so that when the ice sheets melts the land readjusts with time thus raising the height of the beaches (glacio-isostatic rebound)and in places where co-seismic uplift occur. In the latter case, the terrace are not correlated with sea level highstand even if co-seismic terrace are known only for the Holocene.
For exact interpretations of the morphology extensive datings, surveying and mapping of marine terraces is applied. This includes stereoscopic aerial photographic interpretation (ca. 1 : 10,000 – 25,000), on-site inspections with topographic maps (ca. 1 : 10,000) and analysis of eroded and accumulated material. Moreover, the exact altitude can be determined with an aneroid barometer or preferably with a levelling instrument mounted on a tripod. It should be measured with the accuracy of 1 cm (0.39 in) and at about every 50–100 metres (160–330 ft), depending on the topography. In remote areas technics of photogrammetry and tacheometry can be applied.
Different methods for dating and correlation of marine terraces can be used and combined.
The morphostratigraphic approach focuses especially in regions of marine regression on the altitude as the most important criterion to distinguish coast lines of different ages. Moreover, individual marine terraces can be correlated based on their size and continuity. Also paleo-soils as well as glacial, fluvial, eolian and periglacial landforms and sediments may be used to find correlations between terraces. On New Zealand's North Island, for instance, tephra and loess were used to date and correlate marine terraces. At the terminus advance of former glaciers marine terraces can be correlated by their size, as their width decreases with age due to the slowly thawing glaciers along the coast line.
The lithostratigraphic approach uses typical sequences of sediment and rock strata to prove sea level fluctuations on the basis of an alternation of terrestrial and marine sediments or littoral and shallow marine sediments. Those strata show typical layers of transgressive and regressive patterns. However, an unconformity in the sediment sequence might make this analysis difficult.
The biostratigraphic approach uses remains of organisms which can indicate the age of a marine terrace. For that often mollusc shells, foraminifera or pollen are used. Especially Mollusca can show specific properties depending on their depth of sedimentation. Thus they can be used to estimate former water depths.
There are various methods for the direct dating of marine terraces and their related materials including 14C radiocarbon dating, which is the most common one. E.g. this method has been used on the North Island of New Zealand to date several marine terraces. It utilizes terrestrial biogenic materials in coastal sediments such as mollusc shells analyzing the 14C isotope. In some cases dating based on the 230Th/234U ratio was applied though in case of detrital contamination or low uranium concentrations a high resolution dating was found to be difficult. In a study in southern Italy paleomagnetism was used to carry out paleomagnetic datings and luminescence dating (OSL) was used in different studies on the San Andreas Fault and on the Quaternary Eupcheon Fault in South Korea. In the last decennia, the dating of marine terraces has been enhanced since the arrival of terrestrial cosmogenic nuclides method, and particularly through the use of 10Be and 26Al cosmogenic isotopes produced in-situ. These isotopes record the duration of surface exposure to cosmic rays. and this exposure age reflects the age of abandonment of a marine terrace by the sea.
In order to calculate the eustatic sea level for each dated terrace it is assumed that the eustatic sea-level position corresponding to at least one marine terrace is known and that the uplift rate has remained essentially constant in each section.
Marine terraces play an important role in the research on tectonics and earthquakes. They may show patterns and rates of tectonic uplift and thus may be used to estimate the tectonic activity in a certain region. In some cases the exposed secondary landforms can be correlated with known seismic events such as the 1855 Wairarapa earthquake on the Wairarapa Fault near Wellington, New Zealand which produced a 2.7-metre (8 ft 10 in) uplift. This figure can be estimated from the vertical offset between raised shorelines in the area.
Furthermore, with the knowledge of eustatic sea level fluctuations the speed of isostatic uplift can be estimated and eventually the change of relative sea levels for certain regions can be reconstructed. Thus marine terraces also provide information for the research on climate change and trends in future sea level changes.
When analyzing the morphology of marine terraces it must be considered, that both eustasy and isostasy can have an influence on the formation process. This way can be assessed, whether there were changes in sea level or whether tectonic activities took place.
Raised beaches are found in a wide variety of coast and geodynamical background such as subduction on the pacific coast of South America (Pedoja et al., 2006), of North America, passive margin of the Atlantic coast of South America (Rostami et al., 2000), collision context on the Pacific coast of Kamchatka (Pedoja et al., 2006), Papua New Guinea, New Zealand, Japan (Ota and Yamaguchi, 2004), passive margin of the South China sea coast (Pedoja et al., in press), on west-facing Atlantic coasts, such as Donegal Bay, County Cork and County Kerry in Ireland; Bude, Widemouth Bay, Crackington Haven, Tintagel, Perranporth and St Ives in Cornwall, the Vale of Glamorgan, Gower Peninsula, Pembrokeshire and Cardigan Bay in Wales, the Isle of Jura and Isle of Arran in Scotland, Finistère in Brittany and Galicia in Northern Spain and at Squally Point in Eatonville, Nova Scotia within the Cape Chignecto Provincial Park.
Other important sites include various coasts of New Zealand, e.g. Turakirae Head near Wellington being one of the world's best and most thoroughly studied examples. Also along the Cook Strait in New Zealand there is a well-defined sequence of uplifted marine terraces from the late Quaternary at Tongue Point. It features a well preserved lower terrace from the last interglacial, a widely eroded higher terrace from the penultimate interglacial and another still higher terrace, which is nearly completely decayed. Furthermore, on New Zealand's North Island at the eastern Bay of Plenty a sequence of seven marine terraces has been studied.
Along many coasts of mainland and islands around the Pacific, marine terraces are typical coastal features. An especially prominent marine terraced coastline can be found north of Santa Cruz, near Davenport, California, where terraces probably have been raised by repeated slip earthquakes on the San Andreas Fault. Hans Jenny (pedologist) famously researched the pygmy forests of the Mendocino and Sonoma county marine terraces. The marine terrace's "ecological staircase" of Salt Point State Park is also bound by the San Andreas Fault.
Along the coasts of South America marine terraces are present, where the highest ones are situated where plate margins lie above subducted oceanic ridges and the highest and most rapid rates of uplift occur. At Cape Laundi, Sumba Island, Indonesia an ancient patch reef can be found at 475 m (1,558 ft) above sea level as part of a sequence of coral reef terraces with eleven terraces being wider than 100 m (330 ft). The coral marine terraces at Huon Peninsula, New Guinea, which extend over 80 km (50 mi) and rise over 600 m (2,000 ft) above present sea level are currently on UNESCO’s tentative list for world heritage sites under the name Houn Terraces - Stairway to the Past.
Other considerable examples include marine terraces rising up to 360 m (1,180 ft) on some Philippine Islands and along the Mediterranean Coast of North Africa, especially in Tunisia, rising up to 400 m (1,300 ft).
Uplift can also be registered through tidal notch sequences. Notches are often portrayed as lying at sea level; however notch types actually form a continuum from wave notches formed in quiet conditions at sea level to surf notches formed in more turbulent conditions and as much as 2 m (6.6 ft) above sea level (Pirazzoli et al., 1996 in Rust and Kershaw, 2000). As stated above, there was at least one higher sea level during the Holocene, so that some notches may not contain a tectonic component in their formation.
Brandy Cove or Welsh Bae gîl is a very small beach in the Gower Peninsula, south Wales, that is much less accessible than Caswell Bay immediately to the east. It is set at the end of a valley from Bishopston village. It is reachable by footpath from Bishopston or from Caswell Bay over some steep cliffs. The bay gets its name from stories of smugglers using the bay to unload their illegal tobacco and alcohol goods during the eighteenth century.
The sandy stretches of the beach are only exposed at low tide. It is a Pleistocene raised beach where the surrounding geography shows evidence that the sea level was once thirty feet higher than it is today.
The beach has a couple of legends of the supernatural associated with it. One is about a witch who lived in the caves near the beach. The other story is connected to a chilling real life murder that took place near the beach in 1919. Nearby villagers claimed that they could hear screams coming from the caves near the beach at night.Brøggerhalvøya
Brøggerhalvøya is a peninsula in Oscar II Land on the west coast of the island of Spitsbergen in Svalbard, Norway. It is 20 kilometers (12 mi) long and 10 kilometers (6.2 mi) wide and borders Kongsfjorden to the north and Forlandsundet to the west. Ny-Ålesund, the worlds northernmost permanent settlement, is located on the peninsula, which is named for Waldemar Christopher Brøgger.The Norwegian Polar Institute placed reindeer on the peninsula in 1978. Their grazing had a negative impact on the frail but biologically rich area, reducing the biodiversity.The peninsula has a similar geology to Ny-Ålesund, Carboniferous and Permian, but is unaffected by coal wastes, which made the peninsula act as a control area. Melting ice since the last glacial period has resulted in the preservation of a superb raised beach sequence. Today, glaciers across the Peninsula have continued to experience a long-term decline in volume of ice and length since monitoring experiments began in the 1960s, a result of warming in the 20th century.Bunter (geology)
Bunter Pebble Beds are sandstone deposits containing rounded pebbles. They can be found in Warwickshire, Cheshire, Staffordshire, Nottinghamshire, Yorkshire, Devon and Dorset in England. They are thought to be alluvial deposits and, judging from the rounding of the mainly quartzite pebbles, to have resulted from prolonged transportation in a large and turbulent river, resulting in powerful abrasion. The deposits in the English Midlands are thought to have been transported in this way northwards from Brittany, France. This supposed river has been called the "Budleighensis", after the Devon village of Budleigh Salterton, a site where such deposits were discovered. The depositions took place in the lower Triassic period. Some newer conglomerates, e.g. near Ryton in Warwickshire, are thought to have arisen during the Ice Age by reworking and southward transportation of older deposits by ice flows.
The pebbles, also called cobbles, which can be used as gravel, as ballast or as cobblestones, are mainly milky-white quartzite but can vary in colour and composition, including some that are hard, reddish-coloured sandstone. The sandstone in which these pebbles are deposited can be used for building or as an aggregate for cement or concrete.
The name "Bunter" derives from the German term "Buntsandstein", "bunt" meaning "variegated" or "colourful", referring to the colour of the sandstone deposit, which varies from reddish to greenish. This sandstone is widespread across central Europe, notably in the Black Forest and Odenwald region of Germany, as well as the Vosges Mountains in northeastern France.
The sandstone can be hard enough for building, yet easy enough to "work", resulting in bridges, castles, cathedrals and churches constructed of reddish sandstone, throughout the relevant areas of Europe (e.g. Germany, Luxembourg, Switzerland, Alsace in France, Denmark, Poland). The land under which these beds lie is generally very well drained, creating heathlike conditions. Because of the drainage, the soil tends to be of low fertility. A notable area in Britain that has these characteristics is Cannock Chase, a designated Area of Outstanding Natural Beauty (AONB).
The long shingle tombolo of Chesil Beach in Dorset and the raised beach of Portland, Dorset are partly composed of Bunter pebbles. As yet, no fully satisfactory and universally accepted geological explanation has been formulated to explain their precise origin and mode of transport, as each proposed theory has its difficulties.Emergent coastline
An emergent coastline is a stretch along the coast that has been exposed by the sea by a relative fall in sea levels by either isostasy or eustasy.Emergent coastline are the opposite of submergent coastlines, which have experienced a relative rise in sea levels.
The emergent coastline may have several specific landforms:
Raised beach or machair
Wave cut platform
Sea cave such as King's Cave, Isle of ArranThe Scottish Gaelic word machair or machar refers to a fertile low-lying raised beach found on some of the coastlines of Ireland and Scotland (especially the Outer Hebrides.
Hudson Bay, in Canada's north, is an example of an emergent coastline. It is still emerging by as much as 1 cm per year. Another example of emergent coastline is the Eastern Coastal Plains of the Indian Subcontinent.Geology of Northumberland
This article describes the geology of the historic county of Northumberland. It does not include that southeastern part of the historic county which has since 1974 formed a part of the metropolitan county of Tyne and WearThe geology of Northumberland in northeast England includes a mix of sedimentary, intrusive and extrusive igneous rocks from the Palaeozoic and Cenozoic eras. Devonian age volcanic rocks and a granite pluton form the Cheviot massif. The geology of the rest of the county is characterised largely by a thick sequence of sedimentary rocks of Carboniferous age. These are intruded by both Permian and Palaeogene dykes and sills and the whole is overlain by unconsolidated sediments from the last ice age and the post-glacial period. The Whin Sill makes a significant impact on Northumberland's character and the former working of the Northumberland Coalfield significantly influenced the development of the county's economy. The county's geology contributes to a series of significant landscape features around which the Northumberland National Park was designated.Huon Peninsula
Huon Peninsula is a large rugged peninsula on the island of New Guinea in Morobe Province, eastern Papua New Guinea. It is named after French explorer Jean-Michel Huon de Kermadec. The peninsula is dominated by the steep Saruwaged and Finisterre and Cromwell Mountains. The nearest large town is the Morobe provincial capital Lae to the south, while settlements on the north coast include the former German town of Finschhafen, the district capital of Wasu, Malalamai and Saidor with its World War II era Saidor Airport.
The area was the site of the Huon Peninsula campaign of World War II, in 1943-44 as Japanese troops retreating from Lae fought their way over the Finisterre Mountains to Madang on the north coast.Llanon
Llanon (also spelled Llan-non) is a village in Ceredigion, Wales. It adjoins the village of Llansantffraid on the coast of Cardigan Bay, 5 mi (8.0 km) north of Aberaeron and 11 miles (18 km) south of Aberystwyth on the A487 road. It is situated on a raised beach. The village is named after the church of Saint Non (llan-Non), the mother of Saint David. By tradition, St David was brought up in Llanon. The electoral ward which includes Llansantffraid had a population of 2,386 in 2011.Marine transgression
A marine transgression is a geologic event during which sea level rises relative to the land and the shoreline moves toward higher ground, resulting in flooding. Transgressions can be caused either by the land sinking or the ocean basins filling with water (or decreasing in capacity). Transgressions and regressions may be caused by tectonic events such as orogenies, severe climate change such as ice ages or isostatic adjustments following removal of ice or sediment load.
During the Cretaceous, seafloor spreading created a relatively shallow Atlantic basin at the expense of deeper Pacific basin. This reduced the world's ocean basin capacity and caused a rise in sea level worldwide. As a result of this sea level rise, the oceans transgressed completely across the central portion of North America and created the Western Interior Seaway from the Gulf of Mexico to the Arctic Ocean.
The opposite of transgression is regression, in which the sea level falls relative to the land and exposes former sea bottom. During the Pleistocene Ice Ages, so much water was removed from the oceans and stored on land as year-round glaciers that the ocean regressed 120 m, exposing the Bering land bridge between Alaska and Asia.Morston Cliff
SSSI NORFOLK GEOLOGICAL
Morston Cliff is a 1-hectare (2.5-acre) geological Site of Special Scientific Interest east of Wells-next-the-Sea in Norfolk. It is a Geological Conservation Review site. It is part of Blakeney National Nature Reserve, which is managed by the National Trust, and of the Norfolk Coast Area of Outstanding Natural Beauty.This key Pleistocene site has the only interglacial deposit of a raised beach in East Anglia. It is believed to be Ipswichian, dating to around 125,000 years ago, and is overlain by glacial deposits of the late Devensian Hunstanton Till.The Peddars Way and Norfolk Coast Path go through the site.Portland Raised Beach
Portland Raised Beach refers to two raised beaches located at Portland Bill, on the Isle of Portland, Dorset, England, and is part of the Jurassic Coast. The main one is known as the West Pleistocene Raised Beach; nearby is the East Pleistocene Raised Beach.They represent the significant fluctuations in sea level and climate change during the last Ice Age, and both largely consist of shelly and sandy pebble deposits. The cause of the two fluctuations was twofold: the growth of the ice, which absorbed large quantities of water, and the weight of the ice in the north that caused the landmass to tilt.Rothera Air Facility
Rothera Research Station is the BAS logistics centre for the Antarctic and home of well-equipped biological laboratories and facilities for a wide range of research. The station is situated on a rock and raised beach promontory at the southern extremity of Wormald Ice Piedmont, south-eastern Adelaide Island.
The station has a 900 metres (3,000 ft) crushed rock runway, with an associated hangar and bulk fuel storage facility, and a wharf for the discharge of cargo from supply ships. There is a transitory summer population of scientists and support staff who reach Rothera either by ship or through use of a de Havilland Canada Dash 7 aircraft flying from the Falkland Islands.
From its inception until the 1991/1992 summer season BAS Twin Otter aircraft used the skiway 1,000 feet (300 m) above the station on Wormald Ice Piedmont. With the commissioning of the gravel runway and hangar in 1991/1992 air operations became more reliable and access to Rothera was greatly improved through a direct airlink from the Falkland Islands. The Twin Otters mainly fly south of Rothera, via a network of fuel depots, most of which are manned. Heading south of Rothera, the first stop would be Fossil Bluff, then Sky Blu.
The Dash 7 will make approximately 20 flights a season to Stanley during the summer, bringing in scientists, support staff, food and equipment. When not tasked for these flights, the Dash can fly to Sky Blu in one hop, landing on the Blue Ice runway, significantly enhancing the range of the Twin Otters by depositing fuel and equipment in much larger quantities.Surf zone
As ocean surface waves come closer to shore they break, forming the foamy, bubbly surface called surf. The region of breaking waves defines the surf zone. After breaking in the surf zone, the waves (now reduced in height) continue to move in, and they run up onto the sloping front of the beach, forming an uprush of water called swash. The water then runs back again as backswash. The nearshore zone where wave water comes onto the beach is the surf zone. The water in the surf zone, or breaker zone, is shallow, usually between 5 and 10 m (16 and 33 ft) deep; this causes the waves to be unstable.Terrace (geology)
In geology, a terrace is a step-like landform. A terrace consists of a flat or gently sloping geomorphic surface, called a tread, that is typically bounded one side by a steeper ascending slope, which is called a "riser" or "scarp." The tread and the steeper descending slope (riser or scarp) together constitute the terrace. Terraces can also consist of a tread bounded on all sides by a descending riser or scarp. A narrow terrace is often called a bench.The sediments underlying the tread and riser of a terrace are also commonly, but incorrectly, called terraces, leading to confusion.
Terraces are formed in various ways.Uig, Skye
The village of Uig (Scottish Gaelic: Ùige) lies at the head of the sheltered inlet of Uig Bay on the west coast of the Trotternish peninsula on the Isle of Skye, Scotland.Vasa Loch
Vasa Loch is a brackish lagoon in southwestern Shapinsay, Orkney Islands. (Ordnance, 2002) This water body has been shown on early maps of the island in a very similar shape and size to its current geometry, separated from the North Sea by a narrow strip of raised beach.(Masters, 1840) Vasa Loch is fed by small rivulets and upland springs that rise on the western part of the island's western spur. pH levels of the loch are strongly alkaline, in the range of 10.15. (Hogan, 2006)Watermill Cove
Watermill Cove is on the north–west coast of St Mary’s, Isles of Scilly.
It is a historic anchorage, still used today by passing yachts and other small vessels. At Tregear's Porth, there are the remains of an old quay, with the slipway still in use for small craft.
The cove is within an Area of Outstanding Beauty, is a Geological Conservation Review site and was designated a Site of Special Scientific Interest (SSSI) in 1996.
The 0.48-hectare (1.2-acre) site is notified for a succession of Quaternary exposures in the cliff and from sea level to the top of the cliff (oldest to youngest) the succession shows:
organic silts and sands
head deposits of the Late Devensian with microscopic remains of plants and pollen and dated to c. 30,000 years before present. The remains indicate an Arctic tundra climate
raised beach deposits, a storm beach of the Late Ipswichian interglacial 130,000 years ago and ended about 114,000 years ago.Wave-cut platform
A wave-cut platform, shore platform, coastal bench, or wave-cut cliff is the narrow flat area often found at the base of a sea cliff or along the shoreline of a lake, bay, or sea that was created by erosion. Wave-cut platforms are often most obvious at low tide when they become visible as huge areas of flat rock. Sometimes the landward side of the platform is covered by sand, forming the beach, and then the platform can only be identified at low tides or when storms move the sand.West Linga
West Linga is an uninhabited island located between Mainland and Whalsay in Shetland, Scotland.Wynd
A wynd () is typically a narrow lane between houses. The name is frequently encountered in towns and villages in Scotland and Northern England. The word derives from Old Norse venda ("to turn"), implying a turning off a main street, without implying that it is curved. In fact, most wynds are straight. In many places wynds link streets at different heights and thus are mostly thought of as being ways up or down hills.
There are many wynds in North Yorkshire and County Durham, such as "Bull Wynd" in Darlington and Lombards Wynd in Richmond, North Yorkshire.The Old Town of Edinburgh had many wynds, such as St. Mary's Wynd, Blackfriars Wynd and Niddry Wynd, until Victorian street improvements in the 19th century led to their being widened and renamed "streets".
Wynds feature prominently in the city centre of Aberdeen, a testament to the medieval street pattern in the city’s past. Before the levelling of St. Catherine’s Hill and the construction of Union Street, Back Wynd served as the main thoroughfare to and from The Green, the main point of entry into the city of Aberdeen in the early 1500s. Another medieval wynd still existing in the city centre, Correction Wynd, was built to link the top half of the city to its lower half.
In the East Neuk fishing village of Pittenweem in Fife, all walking connections between the shore and the raised beach—apart from the road down to the harbour—are wynds, namely: West Wynd, Calman's Wynd, Bruce's Wynd, School Wynd, Water Wynd and Cove Wynd.
On North Carolina’s Bald Head Island the main roads are referred to as wynds, such as North, South and West, Bald Head Wynd and Stede Bonnet Wynd and Edward Teach Wynd.