Brynmawr Sections
Geology & landscape
Geological Period: Carboniferous · Rock Type: Sandstone
Description
Description The best exposure of the lower Westphalian A (Carboniferous) rocks in the eastern part of South Wales. It clearly shows the condensed sequence typical of this part of the coalfield, suggesting the close proximity of the shoreline. It also shows that the Farewell Rock occurs in a different position relative to the sequence of marine bands, compared with other parts of the coalfield, proving that this rock unit was formed at different times in different places. This is of some significance since this sandstone band has been widely used in the past to define the base of the ‘Coal Measures’. A site of outstanding stratigraphical and palaeogeographical significance. Remarks: A large part of this site lies within the Brecon Beacons National Park