|
River Haffes
The Afon Haffes is a river in Powys, Wales and is wholly contained within the Brecon Beacons National Park (Parc Cenedlaethol Bannau Brycheiniog). Its headwaters rise on the southern and western slopes of Fan Hir at the eastern edge of the Black Mountain (Y Mynydd Du) and the river joins the River Tawe at Glyntawe after a short and steep south-eastward descent of 3 km / 2 miles. Cwm Haffes is a trench which has been incised into the glacial till left by the glaciers of the last ice age along the geological boundary between the Old Red Sandstone rocks to the north and the Carboniferous Limestone rocks to the south. At the head of the incised valley is Sgwd Ddu (meaning 'black fall').British Geological Survey 1:50,000 shett 231 'Merthyr Tydfil' & accompanying memoir The river forms two distributaries as it enters the River Tawe The River Tawe (; cy, Afon Tawe ) is a long river in South Wales. Its headwaters flow initially east from its source below Llyn y Fan Fawr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Afon Haffes Near Glyntawe - Geograph
''The'' () is a grammatical article in English, denoting persons or things already mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with pronouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of pronoun ''thee'') when followed by a v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Age
An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and greenhouse periods, during which there are no glaciers on the planet. Earth is currently in the Quaternary glaciation. Individual pulses of cold climate within an ice age are termed ''glacial periods'' (or, alternatively, ''glacials, glaciations, glacial stages, stadials, stades'', or colloquially, ''ice ages''), and intermittent warm periods within an ice age are called '' interglacials'' or ''interstadials''. In glaciology, ''ice age'' implies the presence of extensive ice sheets in both northern and southern hemispheres. By this definition, Earth is currently in an interglacial period—the Holocene. The amount of anthropogenic greenhouse gases emitted into Earth's oceans and atmosphere is predicted to prevent the next glacial period for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Black Mountain (hill)
Twyn Llech, also known as Black Mountain, is a mountain in the Black Mountains. It is the only Marilyn to fall exactly on the Welsh–English border, straddling Brecknockshire (currently administered as part of the unitary authority of Powys) and Herefordshire. Its parent peak, Waun Fach, lies to the west. Access The Black Mountain is the highest point on Hatterrall Ridge. Offa's Dyke Path passes along the ridge, more or less from south to north. A steeper path leads to the summit from near the former youth hostel in the Vale of Ewyas to the west. The summit is unmarked and, because of the very shallow gradients along the summit ridge, virtually impossible to determine ''in situ''. Open access to all the moorland here means that deviation from the paths is allowed. The ground is peaty and normally very wet even in good weather, especially on the highest ground. It is the highest summit in England south of Great Whernside in the Yorkshire Dales, even though higher neighbour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributaries
A distributary, or a distributary channel, is a stream that branches off and flows away from a main stream channel. Distributaries are a common feature of river deltas. The phenomenon is known as river bifurcation. The opposite of a distributary is a tributary, which flows ''towards'' and joins another stream. Distributaries are often found where a stream approaches a lake or an ocean. They can also occur inland, on alluvial fans, or where a tributary stream bifurcates as it nears its confluence with a larger stream. In some cases, a minor distributary can divert so much water from the main channel that it can later become the main route. Related terms Common terms to name individual river distributaries in English-speaking countries are ''arm'' and ''channel''. These terms may refer to a distributary that does not rejoin the channel from which it has branched (e.g., the North, Middle, and South Arms of the Fraser River, or the West Channel of the Mackenzie River), or to one tha ... [...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] |
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] |
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] |
Powys
Powys (; ) is a Local government in Wales#Principal areas, county and Preserved counties of Wales, preserved county in Wales. It is named after the Kingdom of Powys which was a Welsh succession of states, successor state, petty kingdom and principality that emerged during the Middle Ages following the end of Roman rule in Britain. Geography Powys covers the historic counties of Montgomeryshire and Radnorshire, most of Brecknockshire, and part of Denbighshire (historic), historic Denbighshire. With an area of about , it is now the largest administrative area in Wales by land and area (Dyfed was until 1996 before several Preserved counties of Wales, former counties created by the Local Government Act 1972 were abolished). It is bounded to the north by Gwynedd, Denbighshire and Wrexham County Borough; to the west by Ceredigion and Carmarthenshire; to the east by Shropshire and Herefordshire; and to the south by Rhondda Cynon Taf, Merthyr Tydfil County Borough, Caerphilly County Bor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glyntawe
Glyntawe is a hamlet and parish on the upper reaches of the River Tawe in Powys, Wales, in the community of Tawe-Uchaf. It has always been sparsely populated. Today it attracts tourists for outdoor activities in the Brecon Beacons National Park and for caving. Location A Topographical Dictionary of Wales (1849) describes Glyntawe as, "a chapelry, attached to the parish of Devynock, in the hundred of Devynock, union and county of Brecknock, South Wales, 15 miles (W. S. W.) from Brecknock. It is situated at the south-western extremity of the extensive parish of Devynock, in a vale between elevated and dreary mountains, not far from the source of the river Tawe." Theophilus Jones in 1809 wrote of Devynock parish that, Prehistory A prehistoric site at Waun Fignen Felen, Glyntawe, has been carefully studied by paleo-ecologists and archaeologists. During the Mesolithic the area contained a small open lake that was gradually choked by weeds. At first it was surrounded by open count ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River Tawe
The River Tawe (; cy, Afon Tawe ) is a long river in South Wales. Its headwaters flow initially east from its source below Llyn y Fan Fawr south of Moel Feity in the Black Mountains, the westernmost range of the Brecon Beacons National Park, before the river turns south and then southwest to its estuary at Swansea. Its main tributaries are the right bank Upper and Lower Clydach Rivers and the Afon Twrch. The total area of the catchment is some . The Tawe passes through a number of towns and villages including Ystradgynlais, Ystalyfera, Pontardawe, and Clydach and meets the sea at Swansea Bay below Swansea. The Tawe Valley ( in Welsh) is more commonly known as the Swansea Valley. Ownership of the riverbed was granted to the Duke of Beaufort in the 17th century by Charles II resulting in exclusive mineral and fishing rights, which is extended as far as requiring permission and payment for bridges which are built over it. This was last exercised in 2008 when Swansea Cou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.png "Click for more on -> The Afon Haffes Near Glyntawe - Geograph")
