The Bytham river reconsidered

The English Midlands is one of the most important regions for British Pleistocene geology. The Middle Pleistocene glacial sediments of the region, termed the Wolston Formation, overlie deposits of a pre-existing river system, the Baginton Formation. The latter are characteristically composed of quartz-rich sediment derived from underlying Triassic bedrock. This SW–NE aligned proto-Soar system was overridden by the Wolstonian ice. Its lack of terraces or discrete sedimentary units implies that the river can only have existed for a limited period. The deposits accumulated during a period of climate change from boreal (?interstadial) to subarctic conditions. A reinterpretation of these sediments as the headwaters of a pre-Anglian ‘Bytham river’, aligned towards East Anglia across the Fenland, where they were linked to the Ingham Formation deposits, found favour for two decades. This was especially so when the Wolston Formation sediments were reassigned to the earlier, Anglian Stage. However, recent work has shown that the ‘Bytham river’ could not have existed in the form suggested by some authors since pre-Anglian-age fluvial sediments are absent from the eastern Fenland margin, except possibly certain deposits at High Lodge, Suffolk. Therefore a re-examination of the evidence is required.