A central European Variscide source for Upper Carboniferous sediments in SW England: Ar-40/Ar-39 detrital white mica ages from the Forest of Dean Basin

Ar-40/Ar-39 detrital white mica ages from a Westphalian CID sediment in the Varisan foreland Forest of Dean Basin (SW England) range from 309 +/- 12 t o 371 +/- 2 Ma, Combining these ages with chemical data from the detrital w hite micas constrain their provenance to two sources: reworked Westphalian A to C, and, more controversially, the central European Variscides. Taking into account the palaeogeography of the Late Devonian to Late Carboniferous , the sediment derived from the central European Variscides must have resid ed in a holding basin proximal to their source for 30-40 Ma. During the Mid - to Late Carboniferous sediment was transported longitudinally from east t o west along the Variscan front. Deposition and mixing of the two source co mponents took place in the Forest of Dean Basin at approximately 307 Ma.