Notes on some Ferruginous Strata in Buckinghamshire and Wiltshire

Abstract

AbstractThe name Whitchurch Sands is proposed for patches of ferruginous strata scattered for 75 miles along the western edge of the Cretaceous from Stewkley, Buckinghamshire, to the Vale of Pewsey, in Wiltshire. They are interpreted as the vestiges of a marine-brackish formation of Middle Purbeck age indicating the transgressive front of an advancing sea thought to have come from the north and which left its mark farther south in the Cinder Bed of Dorset. In the past they have been regarded as Lower Greensand, Wealden, or Portland Sand. In places, e.g. Quainton, Buckinghamshire, they are overlain by undoubted Lower Greensand (Seend Ironsand) of Upper Aptian date. Both in faunal characters and in stratigraphical relations the Whitchurch Sands have much in common with the Serpulite of Hanover and the basal “Wealden” of the Bas Boulonnais.