New evidence of intra-formational piping at two separate horizons in the Carboniferous limestone (Dibunophyllum zone) at South Cornelly, Glamorgan

New sections exposed in a limestone quarry east of South Cornelly, Glamorgan, south Wales, show deep piping at two horizons in the Dibunophyllum zone (Carboniferous). The evidence points to rapid fluctuation in depositional conditions, with two periods of emergence, followed by a lagoonal environment during which marl was deposited in the irregularities of the rock surface.