The Lower Bunter Sandstones of North Worcestershire and East Shropshire

Abstract

The Composition of the Sand.The Lower Bunter consists of sand whose average grain size is about ·2 mm. Particles below 0·05 mm. or above 1 mm. are virtually absent.The fineness of the sand and restricted limits of size variation in the whole thickness of the deposit, and the high perfection of sorting in individual samples indicate an aeolian origin.The False Bedding.No true bedding exists in the Lower Bunter examined.The false-bedding is only explicable on an aeolian origin. It is argued that it must represent cross-sections of barchan dunes advancing in a sand sea that was steadily increasing in thickness.The frequency distribution of the values of the false-bedding dips confirms this interpretation.The directions of different types of false-bedding indicate that transport and deposition was effected almost entirely by a prevailing east wind.Relation of the Lower Bunter to the Mercian Highlands.The establishment of an easterly origin for the sand indicates that the “ Mercian Highlands ” of the Birmingham district were the source of sand supply.Arguments are adduced towards the correlation of the Barr Beacon Beds and the Lower Bunter Sandstone, the former being regarded as the thin piedmont spread of scree material fringing the desert.