|
Ysgyryd Fach
Ysgyryd Fach is a hill one mile east of Abergavenny in the county of Monmouthshire, south Wales. It is often referred to in English as 'Little Skirrid' or sometimes as 'Skirrid Fach'. Its summit height is just over 270m. A conifer plantation extends over much of the hill including its summit; prior to felling of trees on the upper slopes in 2012 outward views were therefore restricted. The hill is considered to be one of the 'seven hills of Abergavenny'. Geology The hill is formed from mudstones of the St Maughans Formation of the Old Red Sandstone laid down in the Devonian period. Thin beds of calcrete, a thin limestone of terrestrial origin, occur on the hill; its very summit consists of sandstone from the Senni Formation (formerly referred to as the 'Senni Beds'). There are few rock exposures and the lower slopes are mantled by glacial till image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abergavenny
Abergavenny (; cy, Y Fenni , archaically ''Abergafenni'' meaning "mouth of the River Gavenny") is a market town and community in Monmouthshire, Wales. Abergavenny is promoted as a ''Gateway to Wales''; it is approximately from the border with England and is located where the A40 trunk road and the A465 Heads of the Valleys road meet. Originally the site of a Roman fort, Gobannium, it became a medieval walled town within the Welsh Marches. The town contains the remains of a medieval stone castle built soon after the Norman conquest of Wales. Abergavenny is situated at the confluence of the River Usk and a tributary stream, the Gavenny. It is almost entirely surrounded by mountains and hills: the Blorenge (), the Sugar Loaf (), Ysgyryd Fawr (Great Skirrid), Ysgyryd Fach (Little Skirrid), Deri, Rholben and Mynydd Llanwenarth, known locally as " Llanwenarth Breast". Abergavenny provides access to the nearby Black Mountains and the Brecon Beacons National Park. The M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monmouthshire
Monmouthshire ( cy, Sir Fynwy) is a county in the south-east of Wales. The name derives from the historic county of the same name; the modern county covers the eastern three-fifths of the historic county. The largest town is Abergavenny, with other towns and large villages being: Caldicot, Chepstow, Monmouth, Magor and Usk. It borders Torfaen, Newport and Blaenau Gwent to the west; Herefordshire and Gloucestershire to the east; and Powys to the north. Historic county The historic county of Monmouthshire was formed from the Welsh Marches by the Laws in Wales Act 1535 bordering Gloucestershire to the east, Herefordshire to the northeast, Brecknockshire to the north, and Glamorgan to the west. The Laws in Wales Act 1542 enumerated the counties of Wales and omitted Monmouthshire, implying that the county was no longer to be treated as part of Wales. However, for all purposes Wales had become part of the Kingdom of England, and the difference had little practical effect. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wales
Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the Bristol Channel to the south. It had a population in 2021 of 3,107,500 and has a total area of . Wales has over of coastline and is largely mountainous with its higher peaks in the north and central areas, including Snowdon (), its highest summit. The country lies within the Temperateness, north temperate zone and has a changeable, maritime climate. The capital and largest city is Cardiff. Welsh national identity emerged among the Celtic Britons after the Roman withdrawal from Britain in the 5th century, and Wales was formed as a Kingdom of Wales, kingdom under Gruffydd ap Llywelyn in 1055. Wales is regarded as one of the Celtic nations. The Conquest of Wales by Edward I, conquest of Wales by Edward I of England was completed by 1283, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Old Red Sandstone
The Old Red Sandstone is an assemblage of rocks in the North Atlantic region largely of Devonian age. It extends in the east across Great Britain, Ireland and Norway, and in the west along the northeastern seaboard of North America. It also extends northwards into Greenland and Svalbard. These areas were a part of the ancient continent of Euramerica, Euramerica/Laurussia. In Britain it is a lithostratigraphy, lithostratigraphic unit (a sequence of rock strata) to which Stratigraphy, stratigraphers accord Geological unit#Lithostratigraphic units, supergroup status and which is of considerable importance to early paleontology. For convenience the short version of the term, ORS is often used in literature on the subject. The term was coined to distinguish the sequence from the younger New Red Sandstone which also occurs widely throughout Britain. Sedimentology The Old Red Sandstone describes a suite of sedimentary rocks deposited in a variety of environments during the Devonian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian Period
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcrete
Caliche () is a sedimentary rock, a hardened natural cement of calcium carbonate that binds other materials—such as gravel, sand, clay, and silt. It occurs worldwide, in aridisol and mollisol soil orders—generally in arid or semiarid regions, including in central and western Australia, in the Kalahari Desert, in the High Plains of the western United States, in the Sonoran Desert, Chihuahuan Desert and Mojave Desert of North America, and in eastern Saudi Arabia at Al-Hasa. Caliche is also known as calcrete or kankar (in India). It belongs to the duricrusts. The term ''caliche'' is Spanish and is originally from the Latin ''calx'', meaning lime. Caliche is generally light-colored, but can range from white to light pink to reddish-brown, depending on the impurities present. It generally occurs on or near the surface, but can be found in deeper subsoil deposits, as well. Layers vary from a few inches to feet thick, and multiple layers can exist in a single location. A caliche lay ... [...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] |
Glacial Till
image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as ''matrix support'', is diagnostic of till. image:Glacial till exposed in roadcut-750px.jpg, Glacial till with tufts of grass Till or glacial till is unsorted glacier, glacial sediment. Till is derived from the erosion and entrainment of material by the moving ice of a glacier. It is deposited some distance down-ice to form terminal, lateral, medial and ground moraines. Till is classified into primary deposits, laid down directly by glaciers, and secondary deposits, reworked by fluvial transport and other processes. Description Till is a form of '' glacial drift'', which is rock material transported by a glacier and deposited directly from the ice or from running water emerging from the ice. It is distinguished from other forms of drift in that it is depos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
