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Cambering (geology)
Cambering is a phenomenon typically seen at a valley crest or plateau margin whereby blocks of competent strata such as sandstone stretch, tilt or rotate with respect to underlying incompetent rock layers such as clay or mudstone. It results from the weaker underlying strata deforming under the weight of the strata above it. Cambering is associated with valley bulging and the development of gulls on the upper slopes. Valley bulging is the development of an anticlinal structure in the underlying weaker strata, the long axis of which is broadly coincident with the orientation of the valley. Valley bulging was first described in England within the upper Derwent catchment in Derbyshire and is also encountered within the Cotswolds. Gulls are fractures in competent strata that typically form parallel to a valley side in association with cambering. They occur on a range of scales with widths from millimetres to tens of metres. The gulls may be voids open to the sky or they may be pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Competence (geology)
In geology competence refers to the degree of resistance of rocks to deformation or flow. In mining 'competent rocks' are those in which an unsupported opening can be made. Characteristics Competent rocks are more commonly exposed at outcrops as they tend to form upland areas and high cliffs, or headlands where present on a coastline. Incompetent rocks tend to form lowlands and are often poorly exposed at the surface. During deformation competent beds tend to deform elastically by either buckling or faulting and fracturing. Incompetent beds tend to deform more plastically, although it is the ''competence contrast'' between different rocks that is most important in determining the types of structure that are formed. The relative competence of rocks may change with temperature, such as in metamorphosed limestones, which are relatively competent at low metamorphic grade, but become highly incompetent at high metamorphic grade. Most sedimentary and volcanic sequences show layering ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Quartz-bearing sandstone can be changed into quartzite through metamorphism, usually related to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay particles, but become hard, brittle and non–plastic upon drying or firing. Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impurities, such as a reddish or brownish colour from small amounts of iron oxide. Clay is the oldest known ceramic material. Prehistoric humans discovered the useful properties of clay and used it for making pottery. Some of the earliest pottery shards have been dated to around 14,000 BC, and clay tablets were the first known writing medium. Clay is used in many modern industrial processes, such as paper making, cement production, and chemical filtering. Between one-half and two-thirds of the world's population live or work in buildings made with clay, often ... [...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] |
Anticline
In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is the location where the curvature is greatest, and the limbs are the sides of the fold that dip away from the hinge. Anticlines can be recognized and differentiated from antiforms by a sequence of rock layers that become progressively older toward the center of the fold. Therefore, if age relationships between various rock strata are unknown, the term antiform should be used. The progressing age of the rock strata towards the core and uplifted center, are the trademark indications for evidence of anticlines on a geologic map. These formations occur because anticlinal ridges typically develop above thrust faults during crustal deformations. The uplifted core of the fold causes compression of strata that preferentially erodes to a deeper st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe by the North Sea to the east and the English Channel to the south. The country covers five-eighths of the island of Great Britain, which lies in the North Atlantic, and includes over 100 smaller islands, such as the Isles of Scilly and the Isle of Wight. The area now called England was first inhabited by modern humans during the Upper Paleolithic period, but takes its name from the Angles, a Germanic tribe deriving its name from the Anglia peninsula, who settled during the 5th and 6th centuries. England became a unified state in the 10th century and has had a significant cultural and legal impact on the wider world since the Age of Discovery, which began during the 15th century. The English language, the Anglican Church, and Engli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River Derwent, Derbyshire
The Derwent is a river in Derbyshire, England. It is long and is a tributary of the River Trent, which it joins south of Derby. Throughout its course, the river mostly flows through the Peak District and its foothills. Much of the river's route, with the exception of the city of Derby, is rural. However, the river has also seen many human uses, and between Matlock and Derby was one of the cradles of the Industrial Revolution. It is the site of the Derwent Valley Mills, the first industrial-scale cotton mills. Today it provides a water supply to several surrounding cities, and its steep-sided valley is an important communications corridor through the uplands of the Peak District. The scenery of the Derwent valley attracts many tourists. The upper reaches pass through the Peak District National Park, whilst the middle reaches around the old spa town of Matlock Bath offer souvenir shops and amusement arcades, together with attractions such as the Heights of Abraham and its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derbyshire
Derbyshire ( ) is a ceremonial county in the East Midlands, England. It includes much of the Peak District National Park, the southern end of the Pennine range of hills and part of the National Forest. It borders Greater Manchester to the north-west, West Yorkshire to the north, South Yorkshire to the north-east, Nottinghamshire to the east, Leicestershire to the south-east, Staffordshire to the west and south-west and Cheshire to the west. Kinder Scout, at , is the highest point and Trent Meadows, where the River Trent leaves Derbyshire, the lowest at . The north–south River Derwent is the longest river at . In 2003, the Ordnance Survey named Church Flatts Farm at Coton in the Elms, near Swadlincote, as Britain's furthest point from the sea. Derby is a unitary authority area, but remains part of the ceremonial county. The county was a lot larger than its present coverage, it once extended to the boundaries of the City of Sheffield district in South Yorkshire where it cov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cotswolds
The Cotswolds (, ) is a region in central-southwest England, along a range of rolling hills that rise from the meadows of the upper Thames to an escarpment above the Severn Valley and Evesham Vale. The area is defined by the bedrock of Jurassic limestone that creates a type of grassland habitat rare in the UK and that is quarried for the golden-coloured Cotswold stone. The predominantly rural landscape contains stone-built villages, towns, and stately homes and gardens featuring the local stone. Designated as an Area of Outstanding Natural Beauty (AONB) in 1966, the Cotswolds covers making it the largest AONB. It is the third largest protected landscape in England after the Lake District and Yorkshire Dales national parks. Its boundaries are roughly across and long, stretching southwest from just south of Stratford-upon-Avon to just south of Bath near Radstock. It lies across the boundaries of several English counties; mainly Gloucestershire and Oxfordshire, and parts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breccia
Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of different origins, as indicated by the named types including sedimentary breccia, tectonic breccia, igneous breccia, impact breccia, and hydrothermal breccia. A megabreccia is a breccia composed of very large rock fragments, sometimes kilometers across, which can be formed by landslides, impact events, or caldera collapse. Types Breccia is composed of coarse rock fragments held together by cement or a fine-grained matrix. Like conglomerate, breccia contains at least 30 percent of gravel-sized particles (particles over 2mm in size), but it is distinguished from conglomerate because the rock fragments have sharp edges that have not been worn down. These indicate that the gravel was deposited very close to its source area, since otherwise th ... [...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] |
Inferior Oolite
The Inferior Oolite is a sequence of Jurassic age sedimentary rocks in Europe. It was deposited during the Middle Jurassic.Weishampel, David B; et al. (2004). "Dinosaur distribution (Middle Jurassic, Europe)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 538–541. . The Inferior Oolite Group as more recently defined is a Jurassic lithostratigraphic group (a sequence of rock strata) in southern and eastern England . It has been variously known in the past as the Under Oolite (or Oolyte), the Inferior Oolite, the Inferior Oolite Series and the Redbourne Group. Outcrops The rocks are exposed from Dorset and Somerset eastwards and northwards through the English Midlands to Yorkshire. It is present at depth in the Wessex-Weald Basin, where it reaches its greatest thickness of 120 m. Lithology and stratigraphy The group consists of up to 120 m thickness of oolitic limestones and su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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