A revised model for the Pleistocene development of the River Avon, Warwickshire

Abstract

A re-examination of the Pleistocene river deposits in the valley of the Midland Avon indicates that the conventional post-Hoxnian model for their development has to be revised. Reinvestigation of two key localities, Cropthorne in the Lower Avon valley and Ailstone on the Warwickshire Stour, a left bank tributary of the Avon, shows that the deposits of at least two separate temperate episodes are represented within the sequence. Amino-acid ratios on non-marine Mollusca from the temperate deposits allow these episodes to be correlated with oxygen isotope stages 5 and 7. Since the stage 7 temperate deposit lies within sediments which post-date the Wolston glacial sequence. an older age is indicated for that sequence than is proposed in the conventional stratigraphic succession of the British Pleistocene.