Some Features of the Lower Carboniferous Reef Limestones of Clitheroe, Lancashire

Abstract

The Clitheroe Limestone of Coplow, Salt Hill, and Bellman quarries is redescribed, particularly from the point of view of the origin and structure of the reef knolls and their relation to the surrounding deposits. Coplow knoll is considered to be the exposed part of a lenticular mass of upper C 1 reef limestone which originally sloped steeply east. An earth movement within the C 2 zone is marked by limestone breccias and a boulder bed, but there seems no evidence of pronounced erosion. A later uplift preceded the deposition of the Worston Shales. Slickensiding in the reef limestone is briefly discussed and possible effects of compaction of the sediments are considered. Three growth stages in reef formation are postulated.