Exploration for gold in Central Wales

Wales has a long history of gold mining, with the main centre of activity being the "Dolgellau Gold Belt" where the Clogau St Davids and Gwynfynedd mines have been worked in recent times. Further south, within the Welsh Basin, gold has been worked at Dolaucothi to the south-east of the village of Pumpsaint (SN 666 402) since Roman times. Gold was last worked here between 1905 - 1912 and 1935 - 1939. This is the only worked occurrence of gold within the Welsh Basin. It lies 77km south of the "Dolgellau Gold Belt" and at the southern limit of the Central Wales Mining Field (Pb, Zn and Cu). The gold mineralisation at Dolaucothi occurs within a folded and sheared succession of upper Ordovician/lower Silurian shales, within the core of the Cothi anticline. Gold occurs in quartz vein structures and pyritiferous shales associated with arsenopyrite. There is no evidence of volcanic rocks at Dolaucothi, the nearest volcanic centre being close to Llanwrtyd Wells, 22 km to the north-east. There is evidence to suggest that the mineralisation was emplaced in faults during or immediately after the Acadian ( end Caledonian) Orogeny. The richest gold ores are associated with abundant pyrite which pre-dates the mineralisation and most probably played a key role in the precipitation of the gold. Annels and Roberts {1989) suggested that gold was leached from volcanic rocks in the underlying basement and that the metal-bearing fluids were channelled along faults to higher crustal levels where gold was precipitated.