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Aust Cliff SSSI
Aust Cliff () is a 5.3 hectare geological Site of Special Scientific Interest adjacent to the Severn Estuary, near the village of Aust, South Gloucestershire, notified in 1954. The Severn Bridge crosses the cliff. Its SSSI designation is due to the presence of fossil beds. The site is famous for its Rhaetic bone bed, and is also the most productive locality in Britain for Triassic insects. The lower part of the cliff is a red mudstone, with bands of nodules of pinkish-white alabaster. Above the red mudstone is green mudstone, followed by the Rhaetic bone bed at the base of a band of black shale. Above the shale are cream-coloured limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ... beds. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cliff
In geography and geology, a cliff is an area of rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by the processes of weathering and erosion, with the effect of gravity. Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually composed of rock that is resistant to weathering and erosion. The sedimentary rocks that are most likely to form cliffs include sandstone, limestone, chalk, and dolomite. Igneous rocks such as granite and basalt also often form cliffs. An escarpment (or scarp) is a type of cliff formed by the movement of a geologic fault, a landslide, or sometimes by rock slides or falling rocks which change the differential erosion of the rock layers. Most cliffs have some form of scree slope at their base. In arid areas or under high cliffs, they are generally exposed jumbles of fallen rock. In areas of higher moisture, a soil slope may obscure the talus. Many cliffs also fea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mudstone
Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from '' shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology.'' New York, New York, W. H. Freeman, 2nd ed, 529 pp. The term ''mudstone'' is also used to describe carbonate rocks (limestone or dolomite) that are composed predominantly of carbonate mud. However, in most contexts, the term refers to siliciclastic mudstone, composed mostly of silicate minerals. The NASA Curiosity rover has found deposits of mudstone on Mars that contain organic substances such as propane, benzene and toluene. Definition There is not a single definition of mudstone that has gained general acceptance,Boggs 2006, p.143 though there is wide agreement that mudstones are fine-grained sedimentary rocks, composed mostly of silicate grains with a grain size less than . Individual grains this size are too small to be disting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Gloucestershire
Gloucestershire is one of the most geologically and scenically diverse counties in England, with rocks from the Precambrian through to the Jurassic represented. These varying rock-types are responsible for the three major areas of the county, each with its own distinctive scenery and land-use - the Forest of Dean in the west, bordering Wales, the Cotswolds in the east, and in between, the Severn Vale. Forest of Dean The Forest of Dean, situated between the rivers Severn and Wye, is formed of a raised basin of Palaeozoic rocks folded in the Variscan Orogeny, similar to the South Wales Coalfield to the west. Underlain by great thicknesses of the Old Red Sandstone, the basin is filled with Carboniferous limestones, sandstones and coal measures - all of which have contributed to the industrial history of the region. Sometimes called ‘the prettiest coalfield in Britain’, the Forest's main coal output was in the 18th, 19th and early 20th centuries, although for hundreds of year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sites Of Special Scientific Interest Notified In 1954
Site most often refers to: * Archaeological site * Campsite, a place used for overnight stay in an outdoor area * Construction site * Location, a point or an area on the Earth's surface or elsewhere * Website, a set of related web pages, typically with a common domain name It may also refer to: * Site, a National Register of Historic Places property type * SITE (originally known as ''Sculpture in the Environment''), an American architecture and design firm * Site (mathematics), a category C together with a Grothendieck topology on C * ''The Site'', a 1990s TV series that aired on MSNBC * SITE Intelligence Group, a for-profit organization tracking jihadist and white supremacist organizations * SITE Institute, a terrorism-tracking organization, precursor to the SITE Intelligence Group * Sindh Industrial and Trading Estate, a company in Sindh, Pakistan * SITE Centers, American commercial real estate company * SITE Town, a densely populated town in Karachi, Pakistan * S.I.T.E Indust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sites Of Special Scientific Interest In Avon
__NOTOC__ This is a list of the Sites of Special Scientific Interest (SSSIs) in the former county of Avon, England, United Kingdom. In England the body responsible for designating SSSIs is Natural England, which chooses a site because of its fauna, flora, geological or physiographical features. Although the county of Avon no longer exists, Natural England still uses its former borders to mark one of its Areas of Search. As of 2006, there are 86 sites designated in this Area of Search, of which 38 have been designated due to their biological interest, 39 due to their geological interest, and 9 for both. Natural England took over the role of designating and managing SSSIs from English Nature in October 2006 when it was formed from the amalgamation of English Nature, parts of the Countryside Agency and the Rural Development Service. The English counties were revised under the 1974 reorganisation of local government. Until the 2010s, Natural England, which maintains the database ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimorphodon2DB
''Dimorphodon'' was a genus of medium-sized pterosaur from the early Jurassic Period. It was named by paleontologist Richard Owen in 1859. ''Dimorphodon'' means "two-form tooth", derived from the Greek (') meaning "two", (') meaning "shape" and (') meaning "tooth", referring to the fact that it had two distinct types of teeth in its jaws – which is comparatively rare among reptiles. ''Dimorphodon'' inhabited Europe. Description The body structure of ''Dimorphodon'' displays many "primitive" characteristics, such as, according to Owen, a very small brain-pan and proportionally short wings. The first phalanx in its flight finger is only slightly longer than its lower arm. The neck was short but strong and flexible and may have had a membranous pouch on the underside. The vertebrae had pneumatic foramina, openings through which the air sacs could reach the hollow interior. ''Dimorphodon'' had an adult body length of long, with a 1.45 metre (4.6 ft) wingspan. The tai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimorphodon
''Dimorphodon'' was a genus of medium-sized pterosaur from the early Jurassic Period. It was named by paleontologist Richard Owen in 1859. ''Dimorphodon'' means "two-form tooth", derived from the Greek (') meaning "two", (') meaning "shape" and (') meaning "tooth", referring to the fact that it had two distinct types of teeth in its jaws – which is comparatively rare among reptiles. ''Dimorphodon'' inhabited Europe. Description The body structure of ''Dimorphodon'' displays many "primitive" characteristics, such as, according to Owen, a very small brain-pan and proportionally short wings. The first phalanx in its flight finger is only slightly longer than its lower arm. The neck was short but strong and flexible and may have had a membranous pouch on the underside. The vertebrae had pneumatic foramina, openings through which the air sacs could reach the hollow interior. ''Dimorphodon'' had an adult body length of long, with a 1.45 metre (4.6 ft) wingspan. The tai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterosaur
Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 to 66 million years ago). Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger. There were two major types of pterosaurs. Basal pterosaurs (also called 'non-pterodactyloid pterosaurs' or 'rhamphorhynchoids') were smaller animals with fully toothed jaws and, typically, long tails. Their wide wing membranes probably included and connected the hind legs. On the ground, they would have had an awkward sprawling posture, but the anatomy of their joints and strong claws would have made them effective climbers, and some may have even lived in trees. Basal pterosaurs were insectiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as the accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life. About 20% to 25% of sedimentary rock is carbonate rock, and most of this is limestone. The remaining carbonate rock is mostly dolomite, a closely related rock, which contains a high percentage of the mineral dolomite, . ''Magnesian limestone'' is an obsolete and poorly-defined term used variously for dolomite, for limes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite.Blatt, Harvey and Robert J. Tracy (1996) ''Petrology: Igneous, Sedimentary and Metamorphic'', 2nd ed., Freeman, pp. 281–292 Shale is characterized by its tendency to split into thin layers ( laminae) less than one centimeter in thickness. This property is called '' fissility''. Shale is the most common sedimentary rock. The term ''shale'' is sometimes applied more broadly, as essentially a synonym for mudrock, rather than in the more narrow sense of clay-rich fissile mudrock. Texture Shale typically exhibits varying degrees of fissility. Because of the parallel orientation of clay mineral flakes in shale, it breaks into thin layers, often splintery and usually parallel to the otherwise indistinguishable bedding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alabaster
Alabaster is a mineral or rock that is soft, often used for carving, and is processed for plaster powder. Archaeologists and the stone processing industry use the word differently from geologists. The former use it in a wider sense that includes varieties of two different minerals: the fine-grained massive type of gypsum and the fine-grained banded type of calcite.''More about alabaster and travertine'', brief guide explaining the different use of these words by geologists, archaeologists, and those in the stone trade. Oxford University Museum of Natural History, 2012/ref> Geologists define alabaster only as the gypsum type. Chemically, gypsum is a Water of crystallization, hydrous sulfur, sulfate of calcium, while calcite is a carbonate of calcium. The two types of alabaster have similar properties. They are usually lightly colored, translucent, and soft stones. They have been used throughout history primarily for carving decorative artifacts."Grove": R. W. Sanderson and Francis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of archo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
