Keele Research Repository

The stratigraphy-, sedimentology and geotechnical properties of the Quaternary sequence in Holderness were examined in detail, with the aim of relating depositional history to observed geotechnical behaviour. Both the Withernsea and Skipsea Till units were found to possess the sedimentary and geotechnical characteristics of a diamict deposited beneath a wet based ice sheet. No evidence could be found for the downwasting of a complex stratified ice sheet as previously proposed for the sequence. Critical state theory was found to accurately predict the reaction of the diamict to shear and was used to predict the behaviour under theoretical stress/environmental situations. An alternative depositional model is proposed which explains the Skipsea - Withernsea Till succession as the product of the slow accretion of basal debris under an active ice stream. The multiple stratigraphy is interpreted in terms of a shift in the east coast flow units, carrying distinct mixes of lithologies along individual flow lines, within a single ice sheet. The key sections through the Quaternary in Holderness are reexamined in terms of deposition from an active ice sheet. It is concluded that-the Basement Till represents the initial advance of the cold-ice margin and is Devensian in age rather than pre-Devensian as previously proposed.