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Carreg Dwfn
Carreg Dwfn (also referred to as Careg Dwfn and Carregydwfn and referred to also as Careg-y-dwfan. ) is a hill four miles southeast of Llandeilo and just to the south of the village of Trap in the county of Carmarthenshire, south Wales. It lies at the western extremity of the Brecon Beacons National Park and Fforest Fawr Geopark. Its summit at is towards the eastern end of a rocky east-west-aligned ridge. Geology The hill is formed from the coarse Twrch Sandstone (formerly known as the Basal Grit) laid down during the Namurian stage of the Carboniferous period. It is defined by faults to east and west. There are a handful of disused gritstone quarries on the southern slope of the hill. Quarrying rights at these sites were stopped by the Brecon Beacons National Park Authority in 2008. To its north is the large Craigyrodyn Quarry which worked the Carboniferous Limestone Carboniferous Limestone is a collective term for the succession of limestones occurring widely throughout G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carreg Dwfn - Geograph
Aberdaron is a community, electoral ward and former fishing village at the western tip of the Llŷn Peninsula in the Welsh county of Gwynedd. It lies west of Pwllheli and south west of Caernarfon, and has a population of 965. The community includes Bardsey Island ( cy, Ynys Enlli), the coastal area around Porthor, and the villages of Anelog, Llanfaelrhys, Penycaerau, Rhoshirwaun, Rhydlios, Uwchmynydd and Y Rhiw. It covers an area of just under 50 square kilometres. Y Rhiw and Llanfaelrhys have long been linked by sharing rectors and by their close proximity, but were originally ecclesiastical parishes in themselves. The parish of Bodferin/Bodverin was assimilated in the 19th century. The village was the last rest stop for pilgrims heading to Bardsey Island (Ynys Enlli), the legendary "island of 20,000 saints". In the 18th and 19th centuries it developed as a shipbuilding centre and port. The mining and quarrying industries became major employers, and limestone, lead, jasper an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stage (stratigraphy)
In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convention have the same name, and the same boundaries. Rock series are divided into stages, just as geological epochs are divided into ages. Stages can be divided into smaller stratigraphic units called chronozones. (See chart at right for full terminology hierarchy.) Stages may also be divided into substages or indeed grouped as superstages. The term faunal stage is sometimes used, referring to the fact that the same fauna (animals) are found throughout the layer (by definition). Definition Stages are primarily defined by a consistent set of fossils (biostratigraphy) or a consistent magnetic polarity (see paleomagnetism) in the rock. Usually one or more index fossils that are common, found worldwide, easily recognized, and limited to a sing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRoW Act 2000
A crow is a bird of the genus '' Corvus'', or more broadly a synonym for all of ''Corvus''. Crows are generally black in colour. The word "crow" is used as part of the common name of many species. The related term "raven" is not pinned scientifically to any certain trait, but is rather a general grouping for larger ''Corvus spp.'' Species * ''Corvus albus'' – pied crow (Central African coasts to southern Africa) * ''Corvus bennetti'' – little crow (Australia) * ''Corvus brachyrhynchos'' – American crow (United States, southern Canada, northern Mexico) * ''Corvus capensis'' – Cape crow or Cape rook (Eastern and southern Africa) * ''Corvus cornix'' – hooded crow (Northern and Eastern Europe and Northern Africa and Middle East) * ''Corvus corone'' – carrion crow (Europe and eastern Asia) *''Corvus culminatus'' – Indian jungle crow (South Asia) * ''Corvus edithae'' – Somali crow or dwarf raven (eastern Africa) * ''Corvus enca'' – slender-billed crow (Malaysia, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacial Striae
Glacial striations or striae are scratches or gouges cut into bedrock by glacial Abrasion (geology), abrasion. These scratches and gouges were first recognized as the result of a moving glacier in the late 18th century when Swiss alpinists first associated them with moving glaciers. They also noted that if they were visible today that the glaciers must also be receding. Glacial striations are usually multiple, straight, and parallel, representing the movement of the glacier using rock fragments and sand grains, embedded in the base of the glacier, as cutting tools. Large amounts of coarse gravel and boulders carried along underneath the glacier provide the abrasive power to cut trough-like ''glacial grooves''. Finer sediments also in the base of the moving glacier further scour and polish the bedrock surface, forming a ''glacial pavement''. Ice itself is not a hard enough material to change the shape of rock but because the ice has rock embedded in the basal surface it can effec ... [...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] |
Gritstone
Gritstone or grit is a hard, coarse-grained, siliceous sandstone. This term is especially applied to such sandstones that are quarried for building material. British gritstone was used for millstones to mill flour, to grind wood into pulp for paper and for grindstones to sharpen blades. "Grit" is often applied to sandstones composed of angular sand grains. It may commonly contain small pebbles. " Millstone Grit" is an informal term for a succession of gritstones which are to be found in the Pennines (including the Peak District) of northern England. These sediments were laid down in the late (upper) Paleozoic era, in the Carboniferous period, in deltaic conditions. The Millstone Grit Group is a formal stratigraphic term for this sequence of rocks. The gritstone edges of the Peak District are an important climbing area and the rock is much relished by English climbers, among whom it has almost cult status and is often referred to as "God's own rock". The rough surface provide ... [...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] |
Carboniferous Period
The Carboniferous ( ) is a Period (geology), geologic period and System (stratigraphy), system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago (Myr, Mya), to the beginning of the Permian Period, million years ago. The name ''Carboniferous'' means "coal-bearing", from the Latin ''wikt:carbo#Latin, carbō'' ("coal") and ''wikt:fero#Latin, ferō'' ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern 'system' names, it was coined by geologists William Conybeare (geologist), William Conybeare and William Phillips (geologist), William Phillips in 1822, based on a study of the British rock succession. The Carboniferous is often treated in North America as two geological periods, the earlier Mississippian (geology), Mississippian and the later Pennsylvanian (geology), Pennsylvanian. Terrestrial animal life was well established by the Carboniferous Period. Stegocephalia, Tetrapods ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Namurian
The Namurian is a stage in the regional stratigraphy of northwest Europe with an age between roughly 326 and 313 Ma (million years ago). It is a subdivision of the Carboniferous system or period and the regional Silesian series. The Namurian is named for the Belgian city and province of Namur where strata of this age occur (part of the Belgian Coal Measures). The Millstone Grit Group in the lithostratigraphy of northern England and parts of Wales is also of Namurian age. The Namurian age lasted from 326 to 313 million years ago. It is preceded by the Visean stage/age (which corresponds to the upper Carboniferous Limestone of Great Britain) and succeeded by the Westphalian stage/age (which corresponds to the lower and middle Coal Measures of Great Britain). In the official geologic timescale of the International Commission on Stratigraphy (ICS), the Namurian straddles the boundary between the Mississippian epoch (359-318 Ma) and the Pennsylvanian epoch (318-299 Ma). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Llandeilo
Llandeilo () is a town and community in Carmarthenshire, Wales, situated at the crossing of the River Towy by the A483 on a 19th-century stone bridge. Its population was 1,795 at the 2011 Census. It is adjacent to the westernmost point of the Brecon Beacons National Park. The town is served by Llandeilo railway station on the Heart of Wales Line. In 2021, ''The Sunday Times'' called the town one of the top six places to live in Wales. The newspaper praised the town as a ‘sophisticated shopping destination and a great showcase for local arts and crafts’. Early history Roman soldiers were active in the area around Llandeilo around AD74, as evidenced by the foundations of two castra discovered on the grounds of the Dinefwr estate. The fortifications measured 3.85 hectares and 1.54 hectares, respectively. Roman roads linked Llandeilo with Llandovery and Carmarthen. A small civil settlement developed outside the gates of the fort and may have continued in use as the embryonic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marros Group
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] |
Fforest Fawr Geopark
Fforest Fawr Geopark is a Geopark in the Brecon Beacons National Park, south Wales. It is the first designated Geopark in Wales having gained membership of both the European Geoparks Network and the UNESCO-assisted Global Network of National Geoparks in October 2005. The Geopark aims to promote and support sustainable tourism and other opportunities to improve the economy of the area whilst safeguarding the natural environment. Its aims largely coincide with the statutory duties and purpose of the National Park within which it sits. History of designation An initial application to the European Geoparks Network (EGN) made for a more geographically restricted Geopark based on the upper Swansea Valley was turned down in 2003 but the present area which extends to was accepted by the EGN at their meeting in October 2005. A Geopark Development Officer was appointed in January 2007 whilst the National Park Authority also employs an education officer part of whose time is dedicated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
