TY - JOUR
T1 - The age and stratigraphic context of the Easington Raised Beach, County Durham, UK
AU - Davies, Bethan J.
AU - Bridgland, David R.
AU - Roberts, David H.
AU - Cofaigh, Colm O.
AU - Pawley, Stephen M.
AU - Candy, Ian
AU - Demarchi, Beatrice
AU - Penkman, Kirsty E. H.
AU - Austin, William E. N.
PY - 2009
Y1 - 2009
N2 - The Easington Raised Beach, in Shippersea Bay, County Durham, is the most northerly known interglacial beach deposit in England. It lies directly on Magnesian Limestone bedrock at 33 m O.D. and is covered by glacial sediments attributed to the Devensian. Detailed sedimentological analysis suggests that it is an interglacial beach, which is supported by the presence of pebbles bored by marine organisms and littoral, temperate-climate, marine macro- and micro-fossils. It comprises beds of unconsolidated, bedded, imbricated, well-rounded sands and gravels, overlain by similar, but calcreted, deposits. The gravel fraction is dominated by Magnesian and Carboniferous limestone, with orthoquartzite, flint, and porphyries also present; these are far-travelled erratics that must have derived from the erosion of older glacially transported sediments. Previous workers have described erratics derived from the Oslofjord region of Norway in the raised beach gravel, although rocks diagnostic of a Scandinavian origin have not been recovered as part of this study. The heavy-mineral Suite is rich in epidote, dolomite, clinopyroxenes, garnet, tourmaline, and micas. The beach was dated previously by conventional amino acid analysis of the shells, which suggested a Marine Isotope Stage (MIS) 7 age, albeit with a reworked component from MIS 9. This has been confirmed by new optically stimulated luminescence (OSL) dates, which indicate that the beach formed between 240 and 200 ka BP. New amino acid racemisation analyses, using a modified technique, broadly support this interpretation but Must await more comparative data before they can be assessed fully. The strong indication of an MIS 7 age for the formation of the beach has implications for the uplift history of northeastern England during the Pleistocene, and indicates an uplift rate of 0.19 mm a(-1). The stable isotope geochemistry indicates that the cementation occurred during an interglacial period, whilst U-Series dating of the cement indicates that cementation occurred mostly during the Holocene, and is genetically related to the overlying Devensian till. This work has formed part of a full re-appraisal of the glacial sequence in eastern County Durham, the results of which suggest that the Warren House Formation pre-dates the raised beach, and that the Devensian Horden Till overlies the raised beach. (C) 2009 The Geologists' Association. Published by Elsevier Ltd. All rights reserved.
AB - The Easington Raised Beach, in Shippersea Bay, County Durham, is the most northerly known interglacial beach deposit in England. It lies directly on Magnesian Limestone bedrock at 33 m O.D. and is covered by glacial sediments attributed to the Devensian. Detailed sedimentological analysis suggests that it is an interglacial beach, which is supported by the presence of pebbles bored by marine organisms and littoral, temperate-climate, marine macro- and micro-fossils. It comprises beds of unconsolidated, bedded, imbricated, well-rounded sands and gravels, overlain by similar, but calcreted, deposits. The gravel fraction is dominated by Magnesian and Carboniferous limestone, with orthoquartzite, flint, and porphyries also present; these are far-travelled erratics that must have derived from the erosion of older glacially transported sediments. Previous workers have described erratics derived from the Oslofjord region of Norway in the raised beach gravel, although rocks diagnostic of a Scandinavian origin have not been recovered as part of this study. The heavy-mineral Suite is rich in epidote, dolomite, clinopyroxenes, garnet, tourmaline, and micas. The beach was dated previously by conventional amino acid analysis of the shells, which suggested a Marine Isotope Stage (MIS) 7 age, albeit with a reworked component from MIS 9. This has been confirmed by new optically stimulated luminescence (OSL) dates, which indicate that the beach formed between 240 and 200 ka BP. New amino acid racemisation analyses, using a modified technique, broadly support this interpretation but Must await more comparative data before they can be assessed fully. The strong indication of an MIS 7 age for the formation of the beach has implications for the uplift history of northeastern England during the Pleistocene, and indicates an uplift rate of 0.19 mm a(-1). The stable isotope geochemistry indicates that the cementation occurred during an interglacial period, whilst U-Series dating of the cement indicates that cementation occurred mostly during the Holocene, and is genetically related to the overlying Devensian till. This work has formed part of a full re-appraisal of the glacial sequence in eastern County Durham, the results of which suggest that the Warren House Formation pre-dates the raised beach, and that the Devensian Horden Till overlies the raised beach. (C) 2009 The Geologists' Association. Published by Elsevier Ltd. All rights reserved.
KW - Quaternary
KW - MIS 7
KW - Raised beach
KW - County Durham
KW - Gravel
KW - NORTHERN NORTH-SEA
KW - SOUTHERN ENGLAND
KW - EASTERN ENGLAND
KW - QUATERNARY UPLIFT
KW - MASS-SPECTROMETRY
KW - DEPOSITS
KW - RIVER
KW - CARBONATE
KW - SEDIMENTS
KW - NORFOLK
UR - http://www.scopus.com/inward/record.url?scp=71749088744&partnerID=8YFLogxK
U2 - 10.1016/j.pgeola.2009.04.001
DO - 10.1016/j.pgeola.2009.04.001
M3 - Article
VL - 120
SP - 183
EP - 198
JO - Proceedings of the Geologists' Association
JF - Proceedings of the Geologists' Association
IS - 4
ER -