The Cwm Llwyd Fault is a
fault in the west of the
Black Mountain of
South Wales
South Wales ( cy, De Cymru) is a loosely defined region of Wales bordered by England to the east and mid Wales to the north. Generally considered to include the historic counties of Glamorgan and Monmouthshire, south Wales extends westwards ...
. It runs north, parallel to the A4069 road, for over 4 km from near
Brynaman
Brynamman ( cy, Brynaman) is a village on the south side of the Black Mountain (''Y Mynydd Du''), part of the Brecon Beacons National Park (''Parc Cenedlaethol Bannau Brycheiniog''). The village is split into Upper Brynamman and Lower Brynamman ...
to meet the
Carreg Cennen Disturbance
The Carreg Cennen Disturbance is a zone of geological faults and folds in south and mid Wales which forms a part of both the Church Stretton Fault Zone and the Welsh Borderland Fault System. To the southwest it is known as the 'Llandyfaelog Dist ...
near Brest Cwm Llwyd.
It moved as a sinistral (left lateral) strike-slip fault during the
Variscan Orogeny. Together with the Llwyn Celyn Fault it formed a left-stepping offset that created a
pull apart structure, which preserved the Cwm Llwyd
Outlier
In statistics, an outlier is a data point that differs significantly from other observations. An outlier may be due to a variability in the measurement, an indication of novel data, or it may be the result of experimental error; the latter are ...
of
Namurian rocks.
See also
*
List of geological faults of Wales
References
Geology of Wales
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