Trichrug
Encyclopedia
Trichrug is a hill four miles east of Llandeilo
and 3 miles south of Llangadog
in the county of Carmarthenshire
, southwest Wales
. It lies within the Brecon Beacons National Park and Fforest Fawr Geopark
. Its summit at a height of 415m above sea level is marked by a trig point
.
age which are tilted steeply towards the southeast forming a part of the Myddfai Steep Belt
. The summit and the crest of the ridge extending southwest and northeast is formed from the Trichrug Sandstone. Its northwestern slopes are largely formed in the mudstones and sandstones of the Hafod Fawr Formation whilst its southeastern slopes are largely formed from the Raglan Mudstone Formation. These rocks are the uppermost (ie youngest) Silurian rocks of the area but are also considered to be the lowermost (ie oldest) beds of the Old Red Sandstone
succession.
known as Bwlch y Gors immediately to its west. The Beacons Way descends this track northwards towards Y Garn Goch
en route for Llangadog.
Llandeilo
Llandeilo is a town in Carmarthenshire, Wales, situated at the crossing of the River Towy by the A483 on a 19th century stone bridge. Its population is 1,731.The town is served by Llandeilo railway station on the Heart of Wales Line.- Early history :...
and 3 miles south of Llangadog
Llangadog
Llangadog is a community located in Carmarthenshire, Wales, which includes the villages of Llangadog, Bethlehem and Capel Gwynfe. A notable local landscape feature is Y Garn Goch with two Iron Age hill forts....
in the county of Carmarthenshire
Carmarthenshire
Carmarthenshire is a unitary authority in the south west of Wales and one of thirteen historic counties. It is the 3rd largest in Wales. Its three largest towns are Llanelli, Carmarthen and Ammanford...
, southwest 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...
. It lies within the Brecon Beacons National Park and Fforest Fawr Geopark
Fforest Fawr Geopark
Fforest Fawr Geopark was the first Geopark to be designated in Wales having gained membership of both the European Geoparks Network and the UNESCO-assisted Global Network of National Geoparks in October 2005. The Geopark aims to promote and support sustainable tourism and other opportunities to...
. Its summit at a height of 415m above sea level is marked by a trig point
Trig point
A triangulation station, also known as a triangulation pillar, trigonometrical station, trigonometrical point, trig station, trig beacon or trig point, and sometimes informally as a trig, is a fixed surveying station, used in geodetic surveying and other surveying projects in its vicinity...
.
Geology
The hill is formed from a suite of rocks of mid-SilurianSilurian
The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
age which are tilted steeply towards the southeast forming a part of the Myddfai Steep Belt
Myddfai Steep Belt
The Myddfai Steep Belt is the name given to a geological structure which affects rocks of Silurian and Devonian age in mid Wales. It extends for tens of miles across country from near Carmarthen northeastwards via Mynydd Myddfai, Mynydd Bach Trecastell and Mynydd Epynt to the vicinity of...
. The summit and the crest of the ridge extending southwest and northeast is formed from the Trichrug Sandstone. Its northwestern slopes are largely formed in the mudstones and sandstones of the Hafod Fawr Formation whilst its southeastern slopes are largely formed from the Raglan Mudstone Formation. These rocks are the uppermost (ie youngest) Silurian rocks of the area but are also considered to be the lowermost (ie oldest) beds of 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:...
succession.
Access
There is no public access to the summit though a public footpath contours the hill at half-height on its northwestern side and an unmetalled public road passes through the colMountain pass
A mountain pass is a route through a mountain range or over a ridge. If following the lowest possible route, a pass is locally the highest point on that route...
known as Bwlch y Gors immediately to its west. The Beacons Way descends this track northwards towards Y Garn Goch
Y Garn Goch
Y Garn Goch, is a hill in the Brecon Beacons National Park in the east of Carmarthenshire, Wales. It lies near the village of Bethlehem, three miles southwest of Llangadog and four miles east of Llandeilo on the southern side of the broad Towy Valley. It is also commonly known as either Garn Goch...
en route for Llangadog.