Geological notes for the Quaternary deposits of the Thetford District (1:50,000 Sheet 174)

Lee, J.R.; Bateman, M.D.; Burke, H.F.; Hitchens, S.; Morigi, A.; Phillips, E.. 2011 Geological notes for the Quaternary deposits of the Thetford District (1:50,000 Sheet 174). Nottingham, UK, British Geological Survey, 37pp. (IR/08/070) (Unpublished)

Before downloading, please read NORA policies.

Preview

Text IR08070.pdf Download (1MB) | Preview

Abstract/Summary

This report provides an overview of the superficial geology of the Thetford District based upon the resurvey of Sheet 174 between 2007-2008 and should be used in conjunction with the newly published 1:50,000 geological map: BRITISH GEOLOGICAL SURVEY. 2010. Thetford. England and Wales Sheet 174, Bedrock and Superficial Deposits. 1:50 000. Keyworth, Nottingham, British Geological Survey. The superficial geology of the Thetford District provides a record of environmental change that has taken place in Eastern England over the past 2.6 million years. Prior to glaciation during the Middle Pleistocene, the District consisted of Chalk Downs dissected by a major river system – called the Bytham River, which extended eastwards from the West Midlands into East Anglia and the North Sea. At this time, the Bytham was probably one of the largest river systems of Southern Britain. Around Thetford, evidence for this river is preserved within a series of quartzose-rich gravels and a major buried valley that extends along the southern sheet boundary. During the Middle Pleistocene, the region was glaciated. Not only did this glaciation deposit extensive tracts of till (boulder clay) across Eastern England, but it destroyed the Bytham River system and excavated the Fen Basin leading to the generation of the modern drainage network. Compared to the rest of East Anglia, comparatively little till was deposited within the Thetford District suggesting that the area was one of net erosion beneath the Middle Pleistocene ice sheet. The District lay beyond the limit of later glaciations, but was none-the-less, strongly affected by cold climate processes that acted to disrupt the upper horizons of the Chalk bedrock and deposit extensive sheets of aeolian sediment (coversand). Since the end of the last Ice Age, humans have had a progressively more intrusive impact on the environment. Changes in land-use and management, as well as millennial-scale climatic oscillations, have led to major changes in geography and geological processes. For instance river channel migration and incision, reactivation of coversand sheets (‘sand blows’), and the construction of artificial ground. This also serves to highlight the degree of interaction between humans and the environment, and the value of understanding geology in order to protect and manage our natural resources and heritage.

Item Type:	Publication - Report
Programmes:	BGS Programmes 2008 > Geology and Landscape England
Funders/Sponsors:	British Geological Survey, University of Sheffield
Additional Information:	This item has been internally reviewed, but not externally peer-reviewed.
Date made live:	05 Aug 2025 13:24 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/540013

Actions (login required)

View Item

Document Downloads

More statistics for this item...