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Corallian Limestone
The Corallian Group or Corallian Limestone is a geologic group in England. It is predominantly a coralliferous sedimentary rock, laid down in the Oxfordian stage of the Jurassic. It is a hard variety of "coral rag". Building stones from this geological structure tend to be irregular in shape. It is often found close to seams of Portland Limestone (e.g. Abbotsbury in Dorset, England). It is a younger limestone than its near-neighbour, the Oolitic, as found in the Cotswolds, in Gloucestershire. It is laterally equivalent to and interfingers with units of the Ancholme Group. A ridge of Corallian Limestone rises above the Vale of Avon and the Thames Valley in its Oxfordshire stretch. The Oxfordshire Corallian ridge is an escarpment holding back the hanging valley that is the Vale of White Horse and its hardness forced the River Thames to take a wide northern detour, to cut through the low ridge at Oxford. High points along the ridge are Cumnor Hurst and Wytham Hill. The outcrop kno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bran Point
Bran Point is a small headland on the Dorset coast in southern England, about halfway between the small villages of Ringstead to the east and Osmington Mills to the west. There is a picturesque cliff-top path between the two villages via Bran Point. The name derives from the brown colouring of the rock forming the cliffs of the headland, caused in part by residual oil deposits.Watson, D. F.; Hindle, A. D. and Farrimond P. (2000) "Organic geochemistry of petroleum seepages within the Jurassic Bencliff Grit, Osmington Mills, Dorset, UK" ''Petroleum Geoscience'' 6(4): pp. 289-297 The geology of the area is particularly interesting. The coastline in the area is formed from rocks and shingle with exposed cliffs behind. The Middle White Oolite of the Osmington Oolite more visible to the west has descended to beach level here. At the middle of the cliff, there is nodular rubble consisting of calcitized sponge spicules. Higher in the cliff are reddish brown beds containing ''Trigonia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stanford Formation
The Stanford Formation is a geologic formation in England. It preserves fossils dating back to the Oxfordian stage of the Middle Jurassic period, around 160 million years ago. See also * List of fossiliferous stratigraphic units in England See also * Lists of fossiliferous stratigraphic units in Europe * Lists of fossiliferous stratigraphic units in the United Kingdom References * {{DEFAULTSORT:Fossiliferous stratigraphic units in England England England is a Countri ... References * Jurassic England Jurassic System of Europe Oxfordian Stage {{England-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and is the only boundary between geological periods to remain formally undefined. By the beginning of the Jurassi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxfordian (stage)
The Oxfordian is, in the ICS' geologic timescale, the earliest age of the Late Jurassic Epoch, or the lowest stage of the Upper Jurassic Series. It spans the time between 163.5 ± 1.0 Ma and 157.3 ± 1.0 Ma (million years ago). The Oxfordian is preceded by the Callovian and is followed by the Kimmeridgian. Stratigraphic definitions The Oxfordian Stage was called "Clunch Clay and Shale" by William Smith (1815–1816); in 1818 W. Buckland described them under the unwieldy title "Oxford, Forest or Fen Clay". The term Oxfordian was introduced by Alcide d'Orbigny in 1844. The name is derived from the English city of Oxford, where the beds are well developed, but they crop out almost continuously from Dorset to the coast of Yorkshire, generally forming low, broad valleys. They are well exposed at Weymouth, Oxford, Bedford, Peterborough, and in the cliffs at Scarborough, Red Cliff and Gristhorpe Bay. Rocks of this age are found also in Uig and Skye. The base of the Oxfordian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedimentary
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles to settle in place. The particles that form a sedimentary rock are called sediment, and may be composed of geological detritus (minerals) or biological detritus (organic matter). The geological detritus originated from weathering and erosion of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes. The geological detritus is transported to the place of deposition by water, wind, ice or mass movement, which are called agents of denudation. Biological detritus was formed by bodies and parts (mainly shells) of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies ( marine snow). Sedimentation may also occur as dissolved minerals precipitate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Group (geology)
In geology, a group is a lithostratigraphic unit consisting of a series of related formations that have been classified together to form a group. Formations are the fundamental unit of stratigraphy. Groups may sometimes be combined into supergroups. Groups are useful for showing relationships between formations, and they are also useful for small-scale mapping or for studying the stratigraphy of large regions. Geologists exploring a new area have sometimes defined groups when they believe the strata within the groups can be divided into formations during subsequent investigations of the area. It is possible for only some of the strata making up a group to be divided into formations. An example of a group is the Glen Canyon Group, which includes (in ascending order) the Wingate Sandstone, the Moenave Formation, the Kayenta Formation, and the Navajo Sandstone. Each of the formations can be distinguished from its neighbor by its lithology, but all were deposited in the same va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Yorkshire
North Yorkshire is the largest ceremonial counties of England, ceremonial county (lieutenancy area) in England, covering an area of . Around 40% of the county is covered by National parks of the United Kingdom, national parks, including most of the Yorkshire Dales and the North York Moors. It is one of four counties in England to hold the name Yorkshire; the three other counties are the East Riding of Yorkshire, South Yorkshire and West Yorkshire. North Yorkshire may also refer to a non-metropolitan county, which covers most of the ceremonial county's area () and population (a mid-2016 estimate by the Office for National Statistics, ONS of 602,300), and is administered by North Yorkshire County Council. The non-metropolitan county does not include four areas of the ceremonial county: the City of York, Middlesbrough, Redcar and Cleveland and the southern part of the Borough of Stockton-on-Tees, which are all administered by Unitary authorities of England, unitary authorities. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford Clay Formation
The Oxford Clay (or Oxford Clay Formation) is a Jurassic marine sedimentary rock formation underlying much of southeast England, from as far west as Dorset and as far north as Yorkshire. The Oxford Clay Formation dates to the Jurassic, specifically, the Callovian and Oxfordian ages, and comprises two main facies. The lower facies comprises the Peterborough Member, a fossiliferous organic-rich mudstone. This facies and its rocks are commonly known as lower Oxford Clay. The upper facies comprises the middle Oxford Clay, the Stewartby Member, and the upper Oxford Clay, the Weymouth Member. The upper facies is a fossil poor assemblage of calcareous mudstones. Oxford Clay appears at the surface around Oxford, Peterborough and Weymouth and is exposed in many quarries around these areas. The top of the Lower Oxford Clay shows a lithological change, where fissile shale changes to grey mudstone. The Middle and Upper Oxford Clays differ slightly, as they are separated by an argilla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Faringdon Sand
The Faringdon Sand is a geologic formation in England. It preserves fossils dating back to the Cretaceous period. See also * List of fossiliferous stratigraphic units in England See also *Lists of fossiliferous stratigraphic units in Europe * Lists of fossiliferous stratigraphic units in the United Kingdom References * {{DEFAULTSORT:Fossiliferous stratigraphic units in England England England is a country ... References Cretaceous England Aptian Stage Lower Cretaceous Series of Europe {{England-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ampthill Clay
The Ampthill Clay is a Mesozoic geologic formation in southern England. Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the formation.Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607. Vertebrate paleofauna * ''Cryptosaurus eumerus'' "Femur.""Table 17.1," in Weishampel, et al. (2004). Page 367. See also * List of dinosaur-bearing rock formations ** List of stratigraphic units with few dinosaur genera This list of stratigraphic units with few non-avian dinosaur genera includes Mesozoic stratigraphic units of formation rank or higher that have produced dinosaur body fossils which have been referred to at most five genera. Since taxonomy freque ... Footnotes References * Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. . Oxfordian Stage {{UK-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kimmeridge Clay Formation
The Kimmeridge Clay is a sedimentary deposit of fossiliferous marine clay which is of Late Jurassic to lowermost Cretaceous age and occurs in southern and eastern England and in the North Sea. This rock formation is the major source rock for North Sea oil. The fossil fauna of the Kimmeridge Clay includes turtles, crocodiles, sauropods, plesiosaurs, pliosaurs and ichthyosaurs, as well as a number of invertebrate species. Description Kimmeridge Clay is named after the village of Kimmeridge on the Dorset coast of England, where it is well exposed and forms part of the Jurassic Coast World Heritage Site. Onshore, it is of Late Jurassic (Kimmeridgian) age and outcrops across England, in a band stretching from Dorset in the south-west, north-east to North Yorkshire. Offshore, it extends into the Lower Cretaceous (Berriasian Stage) and it is found throughout the Southern, Central and Northern North Sea. The foundations of the Humber Bridge on the southern (Barton) side of the bri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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