Publication Date:
2012-04-15
Description:
Investigation of isolated landforms on the eastern margin of the East Anglian Fenland at Feltwell and Methwold Hythe, Norfolk has demonstrated that they represent glacifluvial delta-fan and related sediments. Section logging, borehole records and previous descriptions together indicate that the deposits were laid down as an ice-marginal delta complex and feeder channel into a proglacial lake. The internal structure and form of the delta and related feeder channel have also been determined using ground-penetrating radar. The sequence indicates deposition at the ice front, together with minor ice-front movements, a substantial discharge event and repeated solutional collapse of the underlying bedrock. Postdepositional solifluction and cryoturbation also occurred. The glaciomarginal landform complexes form part of a line of delta-fan and associated accumulations (the ‘Skertchly Line’) deposited at the margin of an ice lobe that entered the Fenland. Here the ice dammed westward-aligned rivers to form a lake, here called Lake Paterson. These observations reinforce earlier descriptions of a late Middle Pleistocene glaciation of the Fenland termed the ‘Tottenhill glaciation’. Previous research concluded that the glaciation occurred at c . 160 ka, that is, during the late Wolstonian (= late Saalian) Stage (Drenthe Substage, early Marine Isotope Stage 6), a correlation supported by evidence from the North Sea floor. The implications of these conclusions are discussed.
Print ISSN:
0300-9483
Electronic ISSN:
1502-3885
Topics:
Geography
,
Geosciences
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