A MULTI-STAGE MODEL FOR EARLY AND MIDDLE PLEISTOCENE GLACIATIONS OF WALES AND MIDLAND AND EASTERN ENGLAND

This presentation will report the results of new research involving systematic mapping and lithostratigraphic studies. The results suggest that there were four major glaciations across the lowlands of midland and eastern England during the later part of the Middle Pleistocene. Each glaciations is related to well defined lithostratigraphic evidence, and each glaciation is attributed to eccentricity forced, global climatic deterioration. The glaciations recognised are: Happisburgh Glaciation (OIS 16), Lowestoft Glaciaton of the Anglian Stage (OIS 12), Oadby Glaciation (OIS 10) and Welton Glaciation (OIS 6). There is indirect be evidence for a number of older glaciation associated with obliquity climatic forcing. This scheme is substantially different from the model of Mitchell et al. (1973) which identified two Middle Pleistocene lowland glaciations, and that of Bowen (1999) in which the three Middle Pleistocene lowland glacial events are recognised and attributed to OIS 16, 12, and 6. The age allocation presented here is based primarily on the links between the glacial deposits of lowland Midland and Eastern England with the major terrace systems of the Thames, Severn and Bytham rivers, a continuity with Northern Europe in the case of OIS 6, and available geochronometry. Like Mitchell et al. and Bowen et al., there is no independent non-glacial or biological evidence to separate the glaciations. All of the glaciations except one derive from Scottish ice sources. Scandinavian ice reached Britain only in OIS 6 when it also reached its greatest extent in the Netherlands and western Northern Germany. It is considered that this scheme provides a model for lowland-scale glaciation of the British Isles and is in accord with the global history of glaciation (Ehlers, 2003), rather than being anomalous, as has been the case for Britain in the past.

References

Bowen, D.Q. (ed.). 1999. A revised correlation of Quaternary deposits in the British Isles. The Geological Society Special Report No 23. Ehlers, J. & Gibbard, P.L. (eds) (2003): Quaternary Glaciations - Extent and Chronology, Part I: Europe. Elsevier Publishers, Amsterdam Mitchell, G.F., Penny, L.F., Shotton, F.W. and West R.G. 1973. A Correlation of Quaternary deposits in the British Isles. Geological Society of London Special Report No. 4.