ALGAL LIMESTONE IN THE UPPER COAL MEASURES (WESTPHALIAN D) AT CHESTERTON, NORTH STAFFORDSHIRE

Abstract
Summary: Small isolated lenses of algal limestone discovered at the junction of the Etruria Marl and Newcastle Group in north Staffordshire contain algae of the genera Girvanella, Ortonella, Garwoodia and Bevocastria associated with Anthraconauta, ostracods, Spirorbis and plant fragments. The lenses represent preservation in situ of sediment formed in temporary pools rich in calcium and other carbonates. The algae grew as thin crusts and small colonies in these saline pools before the deposition of the Newcastle Group and the introduction of the non-marine fauna.