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Keuper Marl
Keuper marl is a former and now deprecated term for multiple layers of mudstone and siltstone of Triassic age which occur beneath parts of the English Midlands and neighbouring areas e.g. Cheshire, Nottinghamshire, Devon, eastern Worcestershire and northern Yorkshire. Typically red, or occasionally green or grey, these strata are generally featureless and contain few fossils. In basin formations, thick halite-bearing layers, or rock salt deposits, are sometimes present at the base of the marl. In modern nomenclature, Keuper marl is included within the Mercia Mudstone Group The Mercia Mudstone Group is an early Triassic lithostratigraphic group (a sequence of rock strata) which is widespread in Britain, especially in the English Midlands – the name is derived from the ancient kingdom of Mercia which corresponds to t .... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keuper
The Keuper is a lithostratigraphic unit (a sequence of rock strata) in the subsurface of large parts of west and central Europe. The Keuper consists of dolomite, shales or claystones and evaporites that were deposited during the Middle and Late Triassic epochs (about ). The Keuper lies on top of the Muschelkalk and under the predominantly Lower Jurassic Lias or other Early Jurassic strata. The Keuper together with the Muschelkalk and the Buntsandstein form the Germanic Trias Group, a characteristic sequence of rock strata that gave the Triassic its name. "Muschelkalk (geology)", Britannica Online Encyclopedia, October 2010, webpage: EB-39 Exposure The Upper Triassic is well exposed in Swabia, Franconia, Alsace and Lorraine and Luxembourg; it extends from Basel on the east side of the Rhine into Hanover, and through England into Scotland and north-east Ireland; it appears flanking the central plateau of France and in the Pyrenees and Sardinia. The Keuper sequence is li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marl
Marl is an earthy material rich in carbonate minerals, clays, and silt. When hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae. Marl makes up the lower part of the cliffs of Dover, and the Channel Tunnel follows these marl layers between France and the United Kingdom. Marl is also a common sediment in post-glacial lakes, such as the marl ponds of the northeastern United States. Marl has been used as a soil conditioner and neutralizing agent for acid soil and in the manufacture of cement. Description Marl or marlstone is a carbonate-rich mud or mudstone which contains variable amounts of clays and silt. The term was originally loosely applied to a variety of materials, most of which occur as loose, earthy deposits consisting chiefly of an intimate mixture of clay and calcium carbonate, formed under freshwater conditions. These typically contain 35–65% clay and 65–35% carbonate. The ... [...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 distingui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siltstone
Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, pp.381-382 Although its permeability and porosity is relatively low, siltstone is sometimes a tight gas reservoir rock, an unconventional reservoir for natural gas that requires hydraulic fracturing for economic gas production. Siltstone was prized in ancient Egypt for manufacturing statuary and cosmetic palettes. The siltstone quarried at Wadi Hammamat was a hard, fine-grained siltstone that resisted flaking and was almost ideal for such uses. Description There is not complete agreement on the definition of siltstone. One definition is that siltstone is mudrock (clastic sedimentary rock containing at least 50% clay and silt) in which at least 2/3 of the clay and silt fraction is composed of silt-sized particles. Silt is define ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic
The Triassic ( ) is a geologic period and system (stratigraphy), system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Year#Abbreviations yr and ya, Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic, 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 vert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English Midlands
The Midlands (also referred to as Central England) are a part of England that broadly correspond to the Kingdom of Mercia of the Early Middle Ages, bordered by Wales, Northern England and Southern England. The Midlands were important in the Industrial Revolution of the 18th and 19th centuries. They are split into the West Midlands and East Midlands. The region's biggest city, Birmingham often considered the social, cultural, financial and commercial centre of the Midlands, is the second-largest city and metropolitan area in the United Kingdom. Symbolism A saltire (diagonal cross) may have been used as a symbol of Mercia as early as the reign of Offa. By the 13th century, the saltire had become the attributed arms of the Kingdom of Mercia. The arms are blazoned ''Azure, a saltire Or'', meaning a gold (or yellow) saltire on a blue field. The saltire is used as both a flag and a coat of arms. As a flag, it is flown from Tamworth Castle, the ancient seat of the Mercian Kings, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheshire
Cheshire ( ) is a ceremonial and historic county in North West England, bordered by Wales to the west, Merseyside and Greater Manchester to the north, Derbyshire to the east, and Staffordshire and Shropshire to the south. Cheshire's county town is the cathedral city of Chester, while its largest town by population is Warrington. Other towns in the county include Alsager, Congleton, Crewe, Ellesmere Port, Frodsham, Knutsford, Macclesfield, Middlewich, Nantwich, Neston, Northwich, Poynton, Runcorn, Sandbach, Widnes, Wilmslow, and Winsford. Cheshire is split into the administrative districts of Cheshire West and Chester, Cheshire East, Halton, and Warrington. The county covers and has a population of around 1.1 million as of 2021. It is mostly rural, with a number of towns and villages supporting the agricultural and chemical industries; it is primarily known for producing chemicals, Cheshire cheese, salt, and silk. It has also had an impact on popular culture, producing not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nottinghamshire
Nottinghamshire (; abbreviated Notts.) is a landlocked county in the East Midlands region of England, bordering South Yorkshire to the north-west, Lincolnshire to the east, Leicestershire to the south, and Derbyshire to the west. The traditional county town is Nottingham, though the county council is based at County Hall in West Bridgford in the borough of Rushcliffe, at a site facing Nottingham over the River Trent. The districts of Nottinghamshire are Ashfield, Bassetlaw, Broxtowe, Gedling, Mansfield, Newark and Sherwood, and Rushcliffe. The City of Nottingham was administratively part of Nottinghamshire between 1974 and 1998, but is now a unitary authority, remaining part of Nottinghamshire for ceremonial purposes. The county saw a minor change in its coverage as Finningley was moved from the county into South Yorkshire and is part of the City of Doncaster. This is also where the now-closed Doncaster Sheffield Airport is located (formerly Robin Hood Airport). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devon
Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devon is a coastal county with cliffs and sandy beaches. Home to the largest open space in southern England, Dartmoor (), the county is predominately rural and has a relatively low population density for an English county. The county is bordered by Somerset to the north east, Dorset to the east, and Cornwall to the west. The county is split into the non-metropolitan districts of East Devon, Mid Devon, North Devon, South Hams, Teignbridge, Torridge, West Devon, Exeter, and the unitary authority areas of Plymouth, and Torbay. Combined as a ceremonial county, Devon's area is and its population is about 1.2 million. Devon derives its name from Dumnonia (the shift from ''m'' to ''v'' is a typical Celtic consonant shift) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Worcestershire
Worcestershire ( , ; written abbreviation: Worcs) is a county in the West Midlands of England. The area that is now Worcestershire was absorbed into the unified Kingdom of England in 927, at which time it was constituted as a county (see History of Worcestershire). Over the centuries the county borders have been modified, but it was not until 1844 that substantial changes were made. Worcestershire was abolished as part of local government reforms in 1974, with its northern area becoming part of the West Midlands and the rest part of the county of Hereford and Worcester. In 1998 the county of Hereford and Worcester was abolished and Worcestershire was reconstituted, again without the West Midlands area. Location The county borders Herefordshire to the west, Shropshire to the north-west, Staffordshire only just to the north, West Midlands to the north and north-east, Warwickshire to the east and Gloucestershire to the south. The western border with Herefordshire includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yorkshire
Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other English counties, functions have been undertaken over time by its subdivisions, which have also been subject to periodic reform. Throughout these changes, Yorkshire has continued to be recognised as a geographic territory and cultural region. The name is familiar and well understood across the United Kingdom and is in common use in the media and the military, and also features in the titles of current areas of civil administration such as North Yorkshire, South Yorkshire, West Yorkshire and the East Riding of Yorkshire. Within the borders of the historic county of Yorkshire are large stretches of countryside, including the Yorkshire Dales, North York Moors and Peak District national parks. Yorkshire has been nicknamed "God's Own Country" or "God's Own County" by its i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halite
Halite (), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride ( Na Cl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pink, red, orange, yellow or gray depending on inclusion of other materials, impurities, and structural or isotopic abnormalities in the crystals. It commonly occurs with other evaporite deposit minerals such as several of the sulfates, halides, and borates. The name ''halite'' is derived from the Ancient Greek word for "salt", ἅλς (''háls''). Occurrence Halite dominantly occurs within sedimentary rocks where it has formed from the evaporation of seawater or salty lake water. Vast beds of sedimentary evaporite minerals, including halite, can result from the drying up of enclosed lakes and restricted seas. Such salt beds may be hundreds of meters thick and underlie broad areas. Halite occurs at the surface today in playas in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
