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Fforest Fawr
Fforest Fawr is an extensive upland area in the county of Powys, Wales. Formerly known as the Great Forest of Brecknock in English, it was a royal hunting area for several centuries but is now used primarily for sheep grazing, forestry, water catchment and recreation. It lies within the Brecon Beacons National Park. Extent The area extends from the edge of the Black Mountain in the west eastwards to the A470 Brecon to Merthyr Tydfil road, just west of the Brecon Beacons themselves. It includes the peaks of Fan Fawr (734 m), Fan Frynych (629 m), Craig Cerrig-gleisiad (629 m), Fan Llia (632 m), Fan Nedd (663 m), Fan Gyhirych (725 m), Fan Bwlch Chwyth (603 m) and Cefn Cul (562 m). Traditionally Fforest Fawr also included the peaks of Fan Hir and Fan Brycheiniog, although the modern recreational use of the name tends to be restricted to the area east of the Black Mountain of which they form a part. Geology The area is largely underlain by sandstones and mudstones of the Old ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fan Fawr - Geograph
Fan commonly refers to: * Fan (machine), a machine for producing airflow, often used for cooling ** Hand fan, an implement held and waved by hand to move air for cooling * Fan (person), short for fanatic; an enthusiast or supporter, especially with regard to entertainment Fan, FAN or fans may also refer to: Arts, entertainment, and media Music * "Fan" (song), by Pascal Michel Obispo * ''Fans'' (album), a 1984 album by Malcolm McLaren * "Fans" (song), a 2007 album track on ''Because of the Times'' by the Kings of Leon Other uses in arts, entertainment, and media * ''Fan'' (film), a 2016 Indian Hindi film * Fan, a character in the video game ''Yie Ar Kung-Fu'' Biology * Free amino nitrogen, in brewing and winemaking, amino acids available for yeast metabolism * Sea fan, a marine animal of the cnidarian phylum Computing and mathematics * Fan (geometry), the set of all planes through a given line * Fan (order), a class of preorderings on a field * FAN algorithm, an algor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fan Hir
Fan Hir is a peak at the eastern end of the Black Mountain (''Y Mynydd Du'') in the Brecon Beacons National Park (''Parc Cenedlaethol Bannau Brycheiniog'') in southern Wales. It is a subsidiary summit of Fan Brycheiniog. It falls within the county of Powys and is also a part of the traditional area of Fforest Fawr. Its Welsh name means "long peak", a fitting description, particularly if seen from the east when its steep eastern face is seen to advantage. It is about 2.5 miles or 4 km long and faces east. Its summit is 2490 feet (about 760m) above sea level. Fan Hir is separated from its higher neighbour to the north-west, Fan Brycheiniog (2633 feet or 802 metres) by a col known as Bwlch Giedd, where a path rises from Llyn y Fan Fawr via a stone staircase. The hill is drained to east and north by streams which make their way into the River Tawe. Geology The peak is formed from sandstones of the Brownstones Formation and the overlying Plateau Beds Formation of the Old Re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirques
A (; from the Latin word ') is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie (from Scottish Gaelic , meaning a pot or cauldron) and (; ). A cirque may also be a similarly shaped landform arising from fluvial erosion. The concave shape of a glacial cirque is open on the downhill side, while the cupped section is generally steep. Cliff-like slopes, down which ice and glaciated debris combine and converge, form the three or more higher sides. The floor of the cirque ends up bowl-shaped, as it is the complex convergence zone of combining ice flows from multiple directions and their accompanying rock burdens. Hence, it experiences somewhat greater erosion forces and is most often overdeepened below the level of the cirque's low-side outlet (stage) and its down-slope (backstage) valley. If the cirque is subject to seasonal melting, the floor of the cirque most often forms a tarn (small lake) behind a dam, which marks the down ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caledonian Orogeny
The Caledonian orogeny was a mountain-building era recorded in the northern parts of the British Isles, the Scandinavian Mountains, Svalbard, eastern Greenland and parts of north-central Europe. The Caledonian orogeny encompasses events that occurred from the Ordovician to Early Devonian, roughly 490–390 million years ago ( Ma). It was caused by the closure of the Iapetus Ocean when the continents and terranes of Laurentia, Baltica and Avalonia collided. The orogeny is named for Caledonia, the Latin name for Scotland. The term was first used in 1885 by Austrian geologist Eduard Suess for an episode of mountain building in northern Europe that predated the Devonian period. Geologists like Émile Haug and Hans Stille saw the Caledonian event as one of several episodic phases of mountain building that had occurred during Earth's history. Current understanding has it that the Caledonian orogeny encompasses a number of tectonic phases that can laterally be diachronous. The n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variscan Orogeny
The Variscan or Hercynian orogeny was a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica (Laurussia) and Gondwana to form the supercontinent of Pangaea. Nomenclature The name ''Variscan'', comes from the Medieval Latin name for the district '' Variscia'', the home of a Germanic tribe, the Varisci; Eduard Suess, professor of geology at the University of Vienna, coined the term in 1880. (Variscite, a rare green mineral first discovered in the Vogtland district of Saxony in Germany, which is in the Variscan belt, has the same etymology.) ''Hercynian'', on the other hand, derives from the Hercynian Forest. Both words were descriptive terms of strike directions observed by geologists in the field, ''variscan'' for southwest to northeast, ''hercynian'' for northwest to southeast. The ''variscan'' direction reflected the direction of ancient fold belts cropping out throughout Germany and adjacent countries and the meaning shifted from d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neath Disturbance
The Neath Disturbance is a geological structure which stretches across south Wales from Swansea Bay northeastwards as far as Hereford in western England. It consists of a series of both faults and associated folds which were active during the mountain-building period known as the Variscan orogeny. This line of weakness probably featured in the earlier Caledonian Orogeny and perhaps reflects a more ancient line of weakness in the basement rocks. The Disturbance gives rise to a lineament crossing the region, that is to say that it is responsible for a number of significant landscape features along its 100 km length. Prominent amongst these is the Vale of Neath, a deep valley incised by a glacier during the ice ages along this line of weakness in the Earth's crust and now occupied by the River Neath between Pontneddfechan and Swansea Bay. The hill of Moel Penderyn also lies on the Disturbance a little further east. A part of the Vale of Grwyne north of The Sugarloaf and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cribarth Disturbance
The Cribarth Disturbance is a geological structure forming a lineament which stretches across south Wales from Swansea up the Swansea Valley then northeastwards to Brecon and beyond. It consists of both a series of faults and associated folds which were active during the mountain-building period known as the Variscan orogeny. This line of weakness probably featured in the earlier Caledonian Orogeny and perhaps reflects a more ancient line of weakness in the basement rocks. It is also known (in part) as the Tawe Valley Disturbance or the Swansea Valley Disturbance. Influence on the landscape The Disturbance is responsible for a number of significant landscape features along its 50 km length. Prominent amongst these is the Swansea Valley, formed both by glacial action during the ice ages and river erosion along this line of weakness in the Earth's crust between Abercraf and Swansea. It is now occupied by the River Tawe. The geologically complex mountain of Cribarth also li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault (geology)
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep. A ''fault plane'' is the plane that represents the fracture surface of a fault. A ''fault trace'' or ''fault line'' is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geologic maps to represent a fault. A ''fault zone'' is a cluster of parallel faults. However, the term is also used for the zone of crushed rock along a single fault. Prolonged motion along closely spaced faults can blur the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Wales Coalfield
The South Wales Coalfield ( cy, Maes glo De Cymru) extends across Pembrokeshire, Carmarthenshire, Swansea, Neath Port Talbot, Bridgend, Rhondda Cynon Taf, Merthyr Tydfil, Caerphilly, Blaenau Gwent and Torfaen. It is rich in coal deposits, especially in the South Wales Valleys. Description It comprises a fully exposed synclinorium with a varying thickness of coal measures (Upper Carboniferous/Pennsylvanian) with thick, workable seams in the lower parts and generally thinner and sparser seams in the upper parts, together with a development of sandstones (Pennant Sandstone). These sandstones have been much used in building construction (including the characteristic terraces of former miners' houses) and give rise to bleak uplands rising 300–600 metres above sea level between the steep-sided valleys in which most deep mines were developed. The coal generally increases in grade or "rank" from east to west, with bituminous coals in the east, and anthracite in the west, mostly to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twrch Sandstone
The Marros Group is the name given to a suite of rocks of Namurian age laid down during the Carboniferous Period in South Wales. These rocks were formerly known as the Millstone Grit Series but are now distinguished from the similar but geographically separate rock sequences of the Pennines and Peak District of northern England and northeast Wales by this new name. Stratigraphy The Group comprises a thick unit of coarse sandstone known as the Twrch Sandstone (formerly the ‘Basal Grit’) which is overlain by the Bishopston Mudstone and the Telpyn Point Sandstone. The mudstones of these latter two formations was formerly known as the ‘Middle Shales’, a name reflecting the position of this sequence sandwiched between the Basal Grit below and the Farewell Rock, the lowermost sandstone of the South Wales Coal Measures, above. The mudstone itself contains a few bands of sandstone such as the ‘Twelve Foot Sandstone’ and locally the ‘Cumbriense Sandstone’. Likewise the Twrc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboniferous Limestone
Carboniferous Limestone is a collective term for the succession of limestones occurring widely throughout Great Britain and Ireland that were deposited during the Dinantian Epoch of the Carboniferous Period. These rocks formed between 363 and 325 million years ago. Within England and Wales, the entire limestone succession, which includes subordinate mudstones and some thin sandstones, is known as the Carboniferous Limestone Supergroup. Depositional basins Within Great Britain the suite of rocks known traditionally as the Carboniferous Limestone Series was deposited as marine sediments in three distinct ‘provinces’ separated by contemporary landmasses. One of these landmasses was the Wales-London-Brabant Massif, an east–west aligned belt of land stretching through central Wales and the English Midlands to East Anglia and on into Belgium. The limestones deposited to its south form a distinct South Wales-Mendip province which extends from Pembrokeshire in the west through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
