Publication Abstract

Towards mapping the Post-Glacial chronology and archaeological potential of the southern North Sea: a sedimentary and geomorphological view

Towards mapping the Post-Glacial chronology and archaeological potential of the southern North Sea: a sedimentary and geomorphological view

Ward, I. & Larcombe, P.*

During most of the last glaciation, the southern North Sea floor was exposed and accessible to humans before subsequently being drowned in the period 12 - 6 ky BP. Provisional palaeoenvironmental reconstructions of this drowned landscape are based on limited published sea-level index points and limited detailed physical and chronological surveys. Similarly the Palaeolithic and Mesolithic archaeological potential is unknown but artefacts and fossils have been found around Brown Bank, Dogger Bank and the Norfolk Banks. Recent finds elsewhere include a mammoth tusk dredged 100 kilometres east of the River Humber and dated to around 44,000 years old and a stone axes reported to be over 100,000 years old found off the coast of East Anglia.

A review of the post-glacial geochronology for the southern North Sea, reveals 54 radiocarbon ages derived from peat, 17 from molluscs and 1 known dated artefact. The lack of detailed contextual information for many dated samples means that there remains uncertainty in some elevation data, and thus in the resulting interpreted sea level. The archaeological artefacts are mostly derived deposits and thus are of limited use in palaeoenvironmental reconstruction. Overall, the data are consistent with current models of relative sea-level change back to about 10 ky BP (~ 45 m depth) but beyond this, there is very little published data. Whilst models of relative sea-level change exist for the area, these are constrained almost exclusively at the coast, contributing to uncertainty on the likely post-glacial geomorphological evolution of the southern North Sea.

The post-glacial deposits and post-glacial reworking of older deposits may contain significant archaeological material, and however constrained, there is no existing framework for translating knowledge on palaeoenvironment and geomorphological evolution into an indication of archaeological potential. We introduce a geomorphological approach to assessing the preservation potential of primary and secondary archaeological material around Brown Bank, Dogger Bank and the Norfolk Banks: a) in the context of the post-glacial evolution of the southern North Sea and; b) regarding natural and anthropogenic processes. In general, low-energy deposits associated with former intertidal, floodplain or lacustrine environments are likely to preserve primary archaeological material, including organic remains, whilst (high-energy) riverine environments are more likely to preserve inorganic secondary archaeological material. The main possible anthropogenic impacts on submerged archaeology result from beam trawling and aggregate dredging but both these factors are increasingly contributing to knowledge of the southern North Sea landscape.

Integration of geological, sediment dynamic and archaeological disciplines provides the best means towards more reliable palaeoenvironmental and archaeological reconstructions of the history of the southern North Sea and development of predictive maps of archaeological potential and risk, which can serve the needs of managers of the marine archaeological heritage. It is hoped the first-order approach presented here helps stimulate such development.  

Reference

Ward, I. & Larcombe, P.* (2008) Towards mapping the Post-Glacial chronology and archaeological potential of the southern North Sea: a sedimentary and geomorphological view. IKUWA3: The Third International Congress on Underwater Archaeology, University College London, 10-12 July.  Abstracts book, p. 52.  (Available at http://www.ikuwa3.com/documents/IKUWA3_programme.pdf)

Ward, I. & Larcombe, P.*

IKUWA3: The Third International Congress on Underwater Archaeology, University College London, 10-12 July. Abstracts book, p. 52. (Available at http://www.ikuwa3.com/documents/IKUWA3_programme.pdf)