River Haffes
Encyclopedia
The Afon Haffes is a river in Powys
, Wales
and is wholly contained within the Brecon Beacons National Park.
Its headwaters rise on the southern and western slopes of Fan Hir
at the eastern edge of the Black Mountain
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 (translated from Welsh
as 'black fall').
The river forms two distributaries as it enters the River Tawe
on account of its large bedload of boulders derived from the glacial material through which it has cut.
Powys
Powys is a local-government county and preserved county in Wales.-Geography:Powys covers the historic counties of Montgomeryshire and Radnorshire, most of Brecknockshire , and a small part of Denbighshire — an area of 5,179 km², making it the largest county in Wales by land area.It is...
, Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
and is wholly contained within the Brecon Beacons National Park.
Its headwaters rise on the southern and western slopes of Fan Hir
Fan Hir
Fan Hir is a peak at the eastern end of the Black Mountain in the Brecon Beacons National Park in south Wales. It is a subsidiary summit of Fan Brycheiniog. It falls within the county of Powys and is also a part of the traditional area of Fforest Fawr...
at the eastern edge of the Black Mountain
Black Mountain (range)
The Black Mountain is a mountain range in Mid and West Wales, straddling the county boundary between Carmarthenshire and Powys and forming the westernmost range of the Brecon Beacons National Park. Its highest point is Fan Brycheiniog at 802 metres or 2,631 ft. The Black Mountain also forms a part...
and the river joins the River Tawe
River Tawe
The River Tawe is a river in South Wales. It flows in a principally south-westerly direction for some from its source below Moel Feity in the Old Red Sandstone hills of the western Brecon Beacons to the Bristol Channel at Swansea. Its main tributaries are the right bank Upper and Lower Clydach...
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
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
along the geological boundary between the Old Red Sandstone
Old Red Sandstone
The Old Red Sandstone is a British rock formation of considerable importance to early paleontology. For convenience the short version of the term, 'ORS' is often used in literature on the subject.-Sedimentology:...
rocks to the north and the Carboniferous Limestone
Carboniferous limestone
Carboniferous Limestone is a term used to describe a variety of different types of limestone occurring widely across Great Britain and Ireland which were deposited during the Dinantian epoch of the Carboniferous period. They were formed between 363 and 325 million years ago...
rocks to the south. At the head of the incised valley is Sgwd Ddu (translated from Welsh
Welsh language
Welsh is a member of the Brythonic branch of the Celtic languages spoken natively in Wales, by some along the Welsh border in England, and in Y Wladfa...
as 'black fall').
The river forms two distributaries as it enters the River Tawe
River Tawe
The River Tawe is a river in South Wales. It flows in a principally south-westerly direction for some from its source below Moel Feity in the Old Red Sandstone hills of the western Brecon Beacons to the Bristol Channel at Swansea. Its main tributaries are the right bank Upper and Lower Clydach...
on account of its large bedload of boulders derived from the glacial material through which it has cut.