Climatic control on Quaternary fluvial sedimentology of a Fenland Basin river, England

Abstract

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.

Quaternary river terraces in England: Forms, sediments and processes

“…Where genuine aggradation did occur (rather than a co-formational "working depth" of sediment in transit) then basal erosion became ineffective. Multiple truncations within terrace gravel sequences suggest that vertical oscillations within a notably limited range (c. 10 m) was characteristic, being both autogenically-and, where biostratigraphic evidence in particular indicates it, allogenically-driven in relation to oscilating climate (e.g., Maddy et al, 1998;Briant et al, 2005;Langford et al, 2007). But as with many erosional features, and during the Pleistocene more generally (Porter, 1989), much of the terrestrial evidence for extended periods of activity is now missing.…”

“…These are essentially of type 1(c). In recent years, they have been viewed predominantly as recording MIS stages and uplift (Bridgland and Westaway, 2008), whilst there have been numerous studies of site stratigraphy (e.g., Collins et al, 1996;Coope et al, 1997Coope et al, , 2002Maddy et al, 1998;Lewis et al, 2001;Gao et al, 1998Gao et al, , 2007Briant et al, 2004Briant et al, , 2005Briant et al, , 2008Langford et al, 2007;Rose et al, 2000).…”

Colluvial and alluvial response to land use change in Midland England: An integrated geoarchaeological approach

“…The evidence from tree roots suggests a Mid to Late Holocene change in floodplain conditions and in situ decay rather than fluvial erosion. The general pattern seems to be that of continued deposition and reworking of gravels into the late Devensian with meandering in the late Devensian interstadial (Brown et al, 1994Briant et al, 2005), a lack of deposition and limited channel change in the Early Holocene, then hydrological change, some abandonment of channels, and the overbank alluviation in the Mid to Late Holocene and greatly accelerated channel siltation and abandonment from the Late Saxon period (c. 1100 BP) onwards.…”

Late Quaternary lake-level changes of Lake El'gygytgyn, NE Siberia

“…Radiocarbon dating indicates a minimum age of MIS 3 but the samples could be considerably older (cf. Briant et al, 2005). The IRSL age determination of the base unit of core Lz1028 turned out with an age of about 185 ka.…”