Premium
Middle Pleistocene lacustrine deposits in eastern Essex, England and their palaeogeographical implications
Author(s) -
GIBBARD P. L.,
BOREHAM S.,
ROE H. M.,
BURGER A. W.
Publication year - 1996
Publication title -
journal of quaternary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.142
H-Index - 94
eISSN - 1099-1417
pISSN - 0267-8179
DOI - 10.1002/(sici)1099-1417(199607/08)11:4<281::aid-jqs254>3.0.co;2-3
Subject(s) - geology , progradation , aggradation , fluvial , glacial period , pleistocene , interglacial , geomorphology , delta , marine transgression , alluvium , deposition (geology) , paleontology , structural basin , geochemistry , archaeology , facies , geography , aerospace engineering , engineering
Investigations in quarry exposures in the Asheldham Gravel and related deposits of southeast Essex are described. Section logging, mapping and borehole investigations are supported by clast lithological, heavy and clay mineralogical determinations. The sediments are derived from reworking of local Thames basin materials, fine sediment being predominantly from the London Clay. The sequence is shown to represent an aggradation that began as the fluvial infilling of the River Medway valley. The River Thames, diverted into this valley by glaciation further west, overwhelmed the Medway, reworking the deposits. The valley was subsequently drowned and fine laminated lake sediment was initially deposited. This was during a period when the valley was drowned by the glacial lake ponded in the southern North Sea basin by the Anglian/Elsterian ice sheet. Progradation by a braid‐delta complex advanced along the valley and subsequently fluvial deposition returned. Valley widening and straightening accompanied the delta progradation. The deposits were dissected by deep fluvial valleys infilled by Hoxnian interglacial sediments. The Asheldham Gravel is therefore placed in the Anglian/Elsterian Stage.