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Barns Batch Spinney
Barns Batch Spinney () is a 0.06-hectare geological Site of Special Scientific Interest near the village of Dundry, North Somerset, notified in 1987. The English Nature citation says that Barns Batch Spinney is important because of the exposures which it provides of the lower part of the classic Inferior Oolite limestone sequence of the Dundry area. It shows rocks lying stratigraphically below the Middle and Upper Inferior Oolite Limestones seen at Dundry Main Road South Quarry. The geology at this site provides a section spanning the division of the Middle Jurassic known as the Aalenian and Bajocian Stages and a sequence of rocks placed in the subdivision known as the discites zone, named after the characteristic fossil ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttle . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hectare
The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100- metre sides (1 hm2), or 10,000 m2, and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre is about and one hectare contains about . In 1795, when the metric system was introduced, the ''are'' was defined as 100 square metres, or one square decametre, and the hectare (" hecto-" + "are") was thus 100 ''ares'' or km2 (10,000 square metres). When the metric system was further rationalised in 1960, resulting in the International System of Units (), the ''are'' was not included as a recognised unit. The hectare, however, remains as a non-SI unit accepted for use with the SI and whose use is "expected to continue indefinitely". Though the dekare/decare daa (1,000 m2) and are (100 m2) are not officially "accepted for use", they are still used in some contexts. Description The hectare (), although not a unit of SI, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aalenian
The Aalenian () is a subdivision of the Middle Jurassic Epoch/ Series of the geologic timescale that extends from about 174.1 Ma to about 170.3 Ma (million years ago). It was preceded by the Toarcian and succeeded by the Bajocian. Stratigraphic definitions The Aalenian takes its name from the town of Aalen, some 70 km east of Stuttgart in Germany. The town lies at the northeastern end of the Swabian Jura. The name Aalenian was introduced in scientific literature by Swiss geologist Karl Mayer-Eymar in 1864. The base of the Aalenian is defined as the place in the stratigraphic column where the ammonite genus '' Leioceras'' first appears. The global reference profile (GSSP) is located 500 meters north of the village of Fuentelsaz in the Spanish province of Guadalajara.Cresta ''et al.'' (2001) The top of the Aalenian (the base of the Bajocian) is at the first appearance of ammonite genus '' Hyperlioceras''. In the Tethys domain, the Aalenian contains four ammonite biozo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mendip Hills
The Mendip Hills (commonly called the Mendips) is a range of limestone hills to the south of Bristol and Bath in Somerset, England. Running from Weston-super-Mare and the Bristol Channel in the west to the Frome valley in the east, the hills overlook the Somerset Levels to the south and the Chew Valley and other tributaries of the Avon to the north. The hills give their name to the local government district of Mendip, which administers most of the area. The higher, western part of the hills, covering has been designated an Area of Outstanding Natural Beauty (AONB), which gives it a level of protection comparable to a national park. The hills are largely formed from Carboniferous Limestone, which is quarried at several sites. Ash–maple woodland, calcareous grassland and mesotrophic grassland which can be found across the Mendip Hills provide nationally important semi-natural habitats. With their temperate climate these support a range of flora and fauna including birds, bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bath And North East Somerset
Bath and North East Somerset (B&NES) is a unitary authority district in England. Bath and North East Somerset Council was created on 1 April 1996 following the abolition of the county of Avon. It is part of the ceremonial county of Somerset. The unitary authority provides a single tier of local government with responsibility for almost all local government functions within the district, including local planning and building control, local roads, council housing, environmental health, markets and fairs, refuse collection, recycling, cemeteries, crematoria, leisure services, parks, and tourism. It is also responsible for education, social services, libraries, main roads, public transport, trading standards, waste disposal and strategic planning, although fire, police and ambulance services are provided jointly with other authorities through the Avon Fire and Rescue Service, Avon and Somerset Constabulary and the South Western Ambulance Service. Its administrative headquar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperlioceras Discites
''Hyperlioceras'' is an extinct genus of cephalopod included in the ammonitid family Graphoceratidae that lived during the Bajocian stage of the Middle Jurassic. The type species is ''Hyperlioceras discites'' (Waagen, 18567) Morphology The shell of ''Hyperlioceras'' is very compressed and involute, with a tall persistent keel and a deep umbilicus. Biostratigraphic significance The International Commission on Stratigraphy (ICS) has defined the base of the Bajocian Stage of the Jurassic as the lowest occurrence of the genus ''Hyperlioceras'', at 170.3 ± 1.4 million years ago, which defines base of the ''Hyperlioceras discites'' Zone. This point also marks the end of the preceding Aalenian The Aalenian () is a subdivision of the Middle Jurassic Epoch/ Series of the geologic timescale that extends from about 174.1 Ma to about 170.3 Ma (million years ago). It was preceded by the Toarcian and succeeded by the Bajocian. Stratigraphic ... Stage. The upper boundary of the Bajocian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonite
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) than they are to shelled nautiloids such as the living ''Nautilus'' species. The earliest ammonites appeared during the Devonian, with the last species vanishing during the Cretaceous–Paleogene extinction event. Ammonites are excellent index fossils, and linking the rock layer in which a particular species or genus is found to specific geologic time periods is often possible. Their fossil shells usually take the form of planispirals, although some helically spiraled and nonspiraled forms (known as heteromorphs) have been found. The name "ammonite", from which the scientific term is derived, was inspired by the spiral shape of their fossilized shells, which somewhat resemble tightly coiled rams' horns. Pliny the Elder ( 79 AD n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bajocian
In the geologic timescale The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geoch ..., the Bajocian is an age (geology), age and stage (stratigraphy), stage in the Middle Jurassic. It lasted from approximately 170.3 annum, Ma to around 168.3 Ma (million years ago). The Bajocian Age succeeds the Aalenian Age and precedes the Bathonian Age. Stratigraphic definitions The Bajocian Stage takes its name from the Latin name (Bajocae) of the town of Bayeux, in the region of Normandy in France. The stage was named and introduced in scientific literature by French palaeontologist Alcide d'Orbigny in 1842. The base of the Bajocian stage is defined as the place in the stratigraphic column where fossils of the ammonite genus ''Hyperlioceras'' first appear. A global reference profile (a GSSP) for the ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Jurassic
The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations containing land animal fossils include the Forest Marble Formation in England, the Kilmaluag Formation in Scotland,British Geological Survey. 2011Stratigraphic framework for the Middle Jurassic strata of Great Britain and the adjoining continental shelf: research report RR/11/06 British Geological Survey, Keyworth, Nottingham. the Daohugou Beds in China, the Itat Formation in Russia, and the Isalo III Formation of western Madagascar. Paleogeography During the Middle Jurassic Epoch, Pangaea began to separate into Laurasia and Gondwana, and the Atlantic Ocean formed. Eastern Laurasia was tectonically active as the Cimmerian plate continued to collide with Laurasia's southern coast, completely closing the Paleo-Tethys Ocean. A subd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Site Of Special Scientific Interest
A Site of Special Scientific Interest (SSSI) in Great Britain or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland is a conservation designation denoting a protected area in the United Kingdom and Isle of Man. SSSI/ASSIs are the basic building block of site-based nature conservation legislation and most other legal nature/geological conservation designations in the United Kingdom are based upon them, including national nature reserves, Ramsar sites, Special Protection Areas, and Special Areas of Conservation. The acronym "SSSI" is often pronounced "triple-S I". Selection and conservation Sites notified for their biological interest are known as Biological SSSIs (or ASSIs), and those notified for geological or physiographic interest are Geological SSSIs (or ASSIs). Sites may be divided into management units, with some areas including units that are noted for both biological and geological interest. Biological Biological SSSI/ASSIs m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dundry Main Road South Quarry
Dundry Main Road South Quarry () is a 0.7 hectare geological Site of Special Scientific Interest near the village of East Dundry, North Somerset, notified in 1974. The quarry was cited in the 19th century by d'Orbigny as the English "type section" for the Inferior Oolite. Dundry has long been a famous palaeontological and stratigraphic locality. The type locality for many species of molluscs and brachiopods, as well as other lesser groups, it is renowned as one of the world's most fossiliferous exposures with well over two hundred species recorded. The Main Road Quarry exposes a fine section in the Middle and Upper Inferior Oolite, with the rocks lying stratigraphically below them visible at Barns Batch Spinney. The former characterised by a typically southern English-Normandy fauna, including the rich ammonite occurrences of the "Brown iron-shot", and the latter by contrasting faunas of Cotswold aspect. This contrast is direct evidence for movements of the Mendip Axis in Middl ... [...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 lime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
