|
Mynydd Epynt is an upland area of Mid Wales within the county of Powys, Wales. It is bounded to the south by the upper section of the valley of the River Usk, to the north by that of the Afon Irfon and to the east by the valley of the River Wye. Its western boundary is less distinct but lies eastward of the A483 Llandovery to Llanwrtyd Wells road. Its character is that of an extensive though dissected moorland plateau lying between 400 and 450m above sea level and whose highest point of 478m (1,568 ft) is reached at an unnamed rise at OS grid ref SN 961464. The south-western part of Mynydd Epynt is known as Mynydd Bwlch-y-groes. The area is drained by several southward-flowing rivers which empty into the River Usk. These include (from west to east) the Cilieni, Nant Bran, Afon Ysgir (with its two headwaters the Ysgir Fechan and Ysgir Fawr) and Afon Honddu. The Duhonw drains north-eastward into the River Wye.〔Ordnance Survey Explorer maps 187 & 188 'Llandovery' & 'Builth Wells'〕 The highest point is a Marilyn (having topographic prominence of at least 150m). The Welsh-language name means ''mountain (crossed by a) horse-path''. It is often misspelt as ''Mynydd Eppynt''. In earlier times it was known simply as ''Epynt'' and is commonly referred to today as 'the Epynt'.〔Owen, H.W. & Morgan, R. 2007 'Dictionary of the Place-names of Wales' Gomer Press, Ceredigion〕 == Geology == Mynydd Epynt is largely formed from the Raglan Mudstone Formation and the St Maughans Formation of the Old Red Sandstone laid down during the latest part of the Silurian period and the succeeding Devonian period though there is little in the way of rock exposures at the surface. The northern and western escarpment of Mynydd Epynt is formed from a suite of rocks assigned to the Ludlow stage of the late Silurian and which include the Temeside Mudstone, the Tilestones, the Cae'r Mynach, Fibua, Aberedw, Cwm Craig Ddu and Irfon Formations. These consist variously of sandstones, mudstones and siltstones. There is a broken spread of glacial till across the area resulting from its inundation by ice from the mid Wales ice sheet to the north during the ice ages and hill peat has accumulated in some areas in post-glacial times.〔British Geological Survey 1:50,000 map sheet 196 'Builth Wells' & accompanying sheet explanation〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Mynydd Epynt」の詳細全文を読む スポンサード リンク
|