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Mynydd Llangatwg
Mynydd Llangatwg or Llangattock Mountain is a hill in the Brecon Beacons National Park mostly in the county of Powys, south Wales but also extending into both Monmouthshire and Blaenau Gwent. It is named from the village of Llangatwg (or ' Llangattock') which sits in the valley of the River Usk to the north of it. It is essentially an undulating plateau rising in the west to a height of at and in the east to a height of at Hen Dy-aderyn / Twr Pen-cyrn. This latter spot is marked by a trig point. The shallow pool of Pwll Gwy-rhoc sits in a broad depression towards the northern edge of the plateau whilst a smaller pool frequently occupies a large shakehole a few hundred metres to its west. The hill forms an impressive northern scarp overlooking the Usk valley and commonly referred to as the Llangattock Escarpment. Its southern margins are more subdued. Its eastern end is defined by the drops into the Clydach Gorge. Beyond the B4560 to the west the hill merges with Mynydd Llang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brecon Beacons National Park
Brecon Beacons National Park, officially named Bannau Brycheiniog National Park (), is a National parks of the United Kingdom, national park in Wales. It is named after the Brecon Beacons (), the mountain range at its centre. The national park includes the highest mountain in South Wales, Pen y Fan, which has an elevation of . The national park has a total area of . The Brecon Beacons and Fforest Fawr uplands form the central section of the park. To the east are the Black Mountains, Wales, Black Mountains, which extend beyond the national park boundary into England, and to the west is the similarly named but distinct Black Mountain (range), Black Mountain range. These ranges share much of the same basic geology, the southerly dip of the rock strata leading to north-facing escarpments. The highest peak of the Black Mountains is Waun Fach (), and Fan Brycheiniog () is the highest of the Black Mountain. The park was founded in 1957 and is the third and most recently designated Nat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ogof Y Daren Cilau
Ogof y Daren Cilau is a cave system in the limestone escarpment on Mynydd Llangatwg (Llangattock Mountain), which is south of Llangattock village and above Crickhowell in south Powys, Wales. The escarpment is the remnant of quarrying that had begun by the mid-18th century and initially provided limestone for building and agriculture as a fertiliser, and subsequently for the blast furnaces of the local ironworks as a flux. The cave system was discovered in 1957 and is one of the longest in the United Kingdom. The system is next to the Ogof Agen Allwedd system. The cave Ogof y Daren Cilau is one of the longest cave systems in the United Kingdom (over in total) and the entrance section is long, tight and strenuous, making the trip into the further parts of the cave a serious undertaking. Its awkward entrance crawl is a natural barrier to any casual visitor and precludes the need for a locked gate to protect it from vandals. Highlights of Daren Cilau include the "Time Machine", ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monmouthshire And Brecon Canal
The Monmouthshire and Brecon Canal () is a small network of canals in South Wales. For most of its currently (2018) navigable length it runs through the Brecon Beacons National Park, and its present rural character and tranquillity belies its original purpose as an industrial corridor for coal and iron, which were brought to the canal by a network of tramways and/or railroads, many of which were built and owned by the canal company. The ''"Mon and Brec"'' was originally two independent canals – the Monmouthshire Canal from Newport to Pontymoile Basin (including the Crumlin Arm) and the Brecknock and Abergavenny Canal running from Pontymoile to Brecon. Both canals were abandoned in 1962, but the Brecknock and Abergavenny route and a small section of the Monmouthshire route have been reopened since 1970. Much of the rest of the original Monmouthshire Canal is the subject of a restoration plan, which includes the construction of a new marina at the Newport end of the canal. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tramway (industrial)
Tramways are lightly laid industrial railways, often not intended to be permanent. Originally, rolling stock could be pushed by humans, pulled by animals (especially horses and mules), cable-hauled by a stationary engine, or pulled by small, light locomotives. Tramways can exist in many forms; sometimes simply tracks temporarily placed on the ground to transport materials around a factory, mine or quarry. Many use narrow-gauge railway technology, but because tramway infrastructure is not intended to support the weight of vehicles used on railways of wider track gauge, the infrastructure can be built using less substantial materials, enabling considerable cost savings. The term "tramway" is not used in North America, but is commonly used in the United Kingdom and elsewhere where British railway terminology and practices influenced management practices, terminologies and railway cultures, such as Australia, New Zealand, and those parts of Asia, Africa and South America that c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wagonway
A wagonway (or waggonway; also known as a horse-drawn railway, or horse-drawn railroad) was a method of rail transport, railway transportation that preceded the steam locomotive and used horses to haul wagons. The terms plateway and tramway (industrial), tramway were also used. The advantage of wagonways was that far bigger loads could be transported with the same power compared to horse haulage along roads. Ancient systems The earliest evidence is of the long ''Diolkos'' paved trackway, which transported boats across the Isthmus of Corinth in Greece from around 600 BC. Wheeled vehicles pulled by men and animals ran in grooves in limestone, which provided the track element, preventing the wagons from leaving the intended route. The Diolkos was in use for over 650 years, until at least the 1st century AD. Paved trackways were later built in Roman Egypt. Wooden rails Such an operation was illustrated in Germany in 1556 by Georgius Agricola (image left) in his work De re met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karst
Karst () is a topography formed from the dissolution of soluble carbonate rocks such as limestone and Dolomite (rock), dolomite. It is characterized by features like poljes above and drainage systems with sinkholes and caves underground. There is some evidence that karst may occur in more weathering-resistant rocks such as quartzite given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes. In regions where the dissolved bedrock is covered (perhaps by debris) or confined by one or more superimposed non-soluble rock strata, distinctive karst features may occur only at subsurface levels and can be totally missing above ground. The study of ''paleokarst'' (buried karst in the stratigraphic column) is important in petroleum geology because as much as 50% of the world's Oil and gas reserves and resource quantification, hydrocarbon reserves are hosted in carbonate rock, and much of this is found in porous karst systems. Etymology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shakehole
A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are also known as shakeholes, and to openings where surface water enters into underground passages known as ''ponor'', swallow hole or swallet. A ''cenote'' is a type of sinkhole that exposes groundwater underneath. ''Sink'', and ''stream sink'' are more general terms for sites that drain surface water, possibly by infiltration into sediment or crumbled rock. Most sinkholes are caused by karst processes – the chemical dissolution of carbonate rocks, collapse or suffosion processes. Sinkholes are usually circular and vary in size from tens to hundreds of meters both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. Sinkholes may form gradually or suddenly, and are found worldwide. Formation Natural processes Sinkholes may capture surface drainage from runni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal Measures Group
The Coal Measures Group is a lithostratigraphical term coined to refer to the coal-bearing succession of rock strata which occur in the United Kingdom within the Westphalian Stage of the Carboniferous Period. The succession was previously referred to as the 'Productive Coal Measures'. Other than in Northern Ireland the term is now obsolete in formal use and is replaced by the Pennine Coal Measures Group, Scottish Coal Measures Group and the South Wales Coal Measures Group for the three distinct depositional provinces of the British mainland. Pennine Coal Measures Group Within the Pennine Basin the Pennine Coal Measures Group is preceded (underlain) by the Millstone Grit Group which is of Namurian age. It is succeeded (overlain) by the Warwickshire Group which comprises a largely non-productive sequence of red beds. It comprises the: :* Pennine Upper Coal Measures Formation :* Pennine Middle Coal Measures Formation :* Pennine Lower Coal Measures Formation The 'Pennine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farewell Rock
The Farewell Rock is the name given to a series of sandstones at the boundary of the Coal Measures with the underlying Marros Group in South Wales. Once thought to be a single sandstone, it is now accepted that the same name has been applied to several different sandstones of similar age across the South Wales Coalfield. The sandstone unit known as the Farewell Rock in the Pembrokeshire Coalfield is continuous with the Cumbriense Quartzite of the main South Wales Coalfield. These are assigned to the uppermost part of the Marros Group (the former Millstone Grit Series) which is of Namurian age. In the South Wales Coalfield, the name is given to a thicker, overlying (and hence younger) sandstone unit which, though formerly assigned to the Millstone Grit Series, is now assigned to the Lower Coal Measures which are of Westphalian age. The name is said to have been coined by ironstone miners who once worked the siderite deposits which stratigraphically overlie this rock unit. Diggi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Westphalian (stage)
The Westphalian is a regional stage or age in the regional stratigraphy of northwest Europe, with an age between roughly 315 and 307 Ma (million years ago). It is a subdivision of the Carboniferous System or Period and the regional Silesian Series. The Westphalian is named for the region of Westphalia ( German: ''Westfalen'') in western Germany where strata of this age occur. The Coal Measures of England and Wales are also largely of Westphalian age, though they also extend into the succeeding Stephanian. The Westphalian is preceded by the Namurian Stage/Age (which corresponds to the Millstone Grit Series of Great Britain) and succeeded by the Stephanian Stage/Age (which corresponds to the uppermost part of the Coal Measures of Great Britain). In the official geologic time scale of the International Commission on Stratigraphy (ICS), the Westphalian is placed within the Pennsylvanian Subsystem/Subperiod (323-299 Ma) of the Carboniferous System/Period. As a regionally defi ... [...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 (geology), Period in South Wales. These rocks were formerly known as the Millstone Grit, Millstone Grit Series but are now distinguished from the similar but geographically separate rock sequences of the Pennine Range, Pennines and Peak District of northern England and northeast Wales by this new name. Stratigraphy The Group comprises a thick rock unit, 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’ an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conglomerate (geology)
Conglomerate () is a sedimentary rock made up of rounded gravel-sized pieces of rock surrounded by finer-grained sediments (such as sand, silt, or clay). The larger fragments within conglomerate are called clasts, while the finer sediment surrounding the clasts is called the matrix. The clasts and matrix are typically cemented by calcium carbonate, iron oxide, silica, or hardened clay. Conglomerates form when rounded gravels deposited by water or glaciers become solidified and cemented by pressure over time. They can be found in sedimentary rock sequences of all ages but probably make up less than 1 percent by weight of all sedimentary rocks. They are closely related to sandstones in origin, and exhibit many of the same types of sedimentary structures, such as tabular and trough cross-bedding and graded bedding.Boggs, S. (2006) ''Principles of Sedimentology and Stratigraphy.'', 2nd ed. Prentice Hall, New York. 662 pp. Friedman, G.M. (2003) ''Classification of sediments and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
