DYNAMICS AND TIMING OF THE EARLIEST LOWLAND GLACIATION OF EASTERN ENGLAND: THE OIS 16 HAPPISBURGH GLACIATION OF THE EARLY MIDDLE PLEISTOCENE

This poster outlines evidence for the timing and dynamics of the first lowland glaciation of eastern England during the early Middle Pleistocene – the OIS 16 Happisburgh Glaciation. Climatic deterioration and the onset of this glaciation within adjacent upland areas is represented within the geological record by periglacial features, changes in the dynamics of the regions rivers, and the appearance of far-travelled glacially-derived clasts and heavy minerals within contemporaneous fluvial and marine sediments.

Incursion of glacial ice into eastern England led to the accretion of a layer-cake sequence comprised of several till and outwash units (Happisburgh Formation) that at their southern extent, pass laterally into sediments of the Bytham River, the major river system of eastern England of the time. This river system was destroyed by glacial ice during OIS 12. Analysis of preserved glacial landforms, and the sedimentology and lithology of the till units reveals deposition by the deforming bed of a surging British Ice Sheet, and by gravity flow as a series of subaqueous flow tills representing the subaqueous grounding-line positions of several ice-marginal oscillations that terminated within a standing body of water.

An OIS 16 timing for this glaciation is determined by the correlation of glacial sediments. This is based on the presence of derived till clasts, heavy minerals and exotic clast lithologies within a terrace of the Bytham River, the terraces of which provides evidence for at least one cold stage between OIS 12 and the Happisburgh Glaciation. The Happisburgh Glaciation, equivalent to the Don Glaciation of northern Europe, is recognised within the oxygen isotope record as a period of high global ice volume and illustrates that the British Ice Sheet was in phase with global patterns of glaciation.