Rebecca M. Briant

This paper presents numerical dating from a Middle to Late Pleistocene terrace deposit sequence in the Solent Basin, southern England. The sequence from the western part of the former Solent river system is one of the longest in Britain, with 18 mapped terrace aggradations. A set of 23 optically stimulated luminescence (OSL) dates aim to provide dated tie‐points within the lower part of the sequence at five stratotype locations. These dates are replicated at single sites, providing age estimates for fewer members, but increasing the reliability for those members that have been dated. The results provide two reliably dated tie‐points within the sequence and suggest that (i) the lowest six terrace aggradations all postdate ca. 275 kyr (MIS 8), (ii) terraces may have aggraded during cold phases within the penultimate interglacial (MIS 7) and (iii) the interglacial deposits at Stone Point whose age has previously been contested are likely to be of Ipswichian (last interglacial, MIS 5e) age. These findings are compared to previous age models in the western Solent basin, with which they agree in part. They may suggest that fluvial activity in the Solent was particularly dynamic during MIS 7. Copyright © 2006 John Wiley & Sons, Ltd.

Understanding and interpreting climate response from ancient fluvial deposits requires a combined approach of detailed sedimentological description and interpretation, local climate proxies, and the accurate comparison of these sequences with further independent climate records. Application of these multiple lines of evidence is particularly effective in the Quaternary Period, where higher resolution and more detailed palaeoenvironmental reconstruction are possible. This paper presents results from a Devensian (Weichselian) age sequence in northern Fenland, England, that integrates these approaches. Detailed sedimentological description has identified three fluvial facies associations overlain by a period of ice‐wedge cast formation. Fossil plant and coleopteran material within these sediments have been studied to provide palaeoenvironmental reconstructions for the local landscape, including quantitative temperature estimates using the mutual climatic range method on fossil Coleoptera. In addition, joint application of radiocarbon and optically stimulated luminescence (OSL) dating allows this sequence to be compared with the stacked marine isotope record, although dates do not agree well at the limit of the radiocarbon technique. Sedimentological interpretations, palaeoenvironments and global ice‐volume variations (a proxy for climatic severity) are all in agreement and show clearly how the River Nene responded to subtle changes in climate and vegetation cover during the Devensian (Weichselian) Stage. The level of detail possible in this reconstruction shows the importance of this approach in understanding fluvial response to past climate changes.