The Westphalian succession of the Glyn-neath area, South Wales: an internationally important geological resource

The Glyn-neath area has the only natural exposures in the whole of Europe showing an essentially continuous section through the lower and middle Westphalian Stages (Pennsylvanian, Upper Carboniferous). There is a change from the littoral and lower delta-plain deposits of early Westphalian age, through the development of fluvio-lacustrine, coal-bearing deposits that make up most of the Productive Coal Formation, to the coarse alluvial clastic sediment of the South Wales Pennant Formation. The geology of the Westphalian Series is important because of the presence of economic coal deposits and its bearing on the Variscan evolution of Europe. This succession represents the closest analogue for the ‘icehouse’ conditions of today, when there were extensive polar ice and extensive tropical forestation. The Glyn-neath exposures provide a unique resource for the study of a critical part of the geological evolution of Europe and for helping to understand environmental changes occurring today.