Sedimentation in an ice-contact subaqueous setting: The mid-Pleistocene ‘North Sea Drifts’ of Norfolk, U.K.

摘要: In East Anglia, the mid-Pleistocene ‘North Sea Drifts’ extend over some 1500 km2 of coastal zone North Norfolk. They are oldest Pleistocene glacial sequences exposed in Britain, deposited during Anglian Glaciation (ca. 450 ka BP?). Laminated and stratified pebbly mud (diamict) facies Drifts widely regarded as product subglacial deposition below a terrestrial ice margin. this paper these identified subaqueous front margin an sheet terminating large water body. Laminated, stratified, massive diamict were by ‘rain-out’ fine-grained sediment from suspension coarse debris floating ice, combined with downslope gravity flow. Intraformational folds episodic slumping identify regional paleoslope to east, away major marginal moraine ridge (The Cromer Ridge). Exposures at show bulldozed ice-contact sediments ice-thrust chalk rafts. A fall water-level emplaced shelly shoreface sands beach gravels which loaded into underlying diamicts pan-shaped ‘sag basins’ diapiric structures their margins. Comparable sedimentary elsewhere around southern Basin; glaciomarine setting response glacio-isostatic depression is suggested.