A rock volume accumulation curve for the late Ordovician-Silurian Welsh Basin

Abstract

AbstractA rock accumulation curve is presented for the Ordovician-Silurian Welsh Basin, based on the volume of sediment entering the basin during each graptolite biozone. Even allowing for its inherent uncertainties, the curve still illustrates a significant and sudden increase in the rate of sedimentation in early Silurian time. This may be explained by submarine fan migration, large scale climate change, or river capture in the hinterland, but is most likely caused by tectonic uplift at source. This would support models for either an early Silurian, or late Ordovician closure of the Iapetus Ocean