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The Red Crag and Norwich Crag formations in eastern Suffolk

1997; Elsevier BV; Volume: 108; Issue: 1 Linguagem: Inglês

10.1016/s0016-7878(97)80002-8

2773-0743

R.J.O. Hamblin, B.S.P. Moorlock, S.J. Booth, D.H. Jeffery, A.N. Morigi,

Geological and Geochemical Analysis

The Red Crag Formation of eastern Suffolk was deposited in structurally controlled basins during the Pre-Ludhamian, Ludhamian and Thurnian stages. A regression during the Thurnian was followed by a transgression during the Antian/Bramertonian Stage, with the Norwich Crag Formation resting unconformably on strata as old as Upper Cretaceous. A regression during the Baventian Stage led to the formation of a complex of shoreface gravels (Westleton Beds) and intertidal clays at the mouth of a river which flowed from the English Midlands to reach the sea in the Southwold area. The Chillesford Clay Member was formed penecontemporaneously at the estuary of the proto-Thames, further south. A further marine transgression occurred during the Pastonian. The Pre-Ludhamian, Antian/Bramertonian and Pastonian transgressions are tentatively correlated with the reflectors respectively at the base of the Westkapelle Ground, Smith's Knoll and Winterton Shoal formations of the southern North Sea.