Late Middle Pleistocene glaciofluvial sedimentation in western Norfolk, England

Abstract

Investigation of landforms on the eastern margin of the East Anglian Fenland basin has demonstrated that they represent a series of glaciofluvial delta-fan and related sediment accumulations (the Skertchly Line) deposited at the margin of an ice-lobe that entered the depression. This ‘Tottenhill glaciation’ dated to ca 160 ka, or the late Wolstonian (= late Saalian) Stage, is equivalent to that during the Netherlands' Drenthe Substage (Marine Isotope Stage 6). Of these landform complexes, an additional site at Shouldham Thorpe, previously nominated as the stratotype for deposits linked to a pre-Anglian Stage, Midlands'-derived Ingham/‘Bytham river’, has now been studied. Examination of the internal structure and form of the feature, using ground-penetrating radar (GPR), supported by section logging, borehole records, local landscape morphology and previous description, together indicate that the deposits rest on an eroded surface of Lowestoft Formation diamicton (Anglian Stage) and must therefore be of post-, rather than pre-Anglian age. The investigations indicate that the Shouldham deposits were laid down as a glacio-marginal subaerial (‘terminoglacial’) fan at the ice-front. In common with other sequences in the Skertchly Line complexes, deposition at Shouldham Thorpe was accompanied by minor ice-front movement, this fan potentially being deposited before retreat to the Tottenhill locality. The implications of the results are discussed.

Drainage network reorganization affecting the Nene and Welland catchments of eastern England as a result of a late Middle Pleistocene glacial advance

“…Both deposits therefore may provide support for the ice advance on the eastern side of the Fen Basin proposed by Gibbard et al. (, , ) and West, Gibbard, Boreham, and Rolfe (). The temporal and spatial grouping of the deposits investigated by Gibbard and co‐workers must remain tentative, however, as the OSL dates provided lack the essential processing data required for robust chronostratigraphic interpretation, and this remains the case for their most recent publication (Gibbard, West, & Hughes, ).…”

“…A similar situation has been described recently by Gibbard et al. (, , ), who investigated a group of positive landforms on the eastern side of the Fen Basin (Figures a and a).…”

“…The sedimentology and three‐dimensional facies architecture of the sedimentary succession north of Uffington indicates deposition as a subaqueous ice‐contact fan (Gibbard et al., , , ; Winsemann et al., ; contra Langford, , ). Coarse‐grained deltas such as the deposits described here occur in a range of depositional settings (see Colella & Prior, ), including alluvial deltas (sensu Nemec, ) and grounding‐line/subaqueous‐outwash fans (Benn & Evans, ), in which gravitational processes such as debris, grain, and turbidite flows dominate (Cohen, ; Martini, ; Mastalerz, ; Miller, ; Nemec, ; Nichols, ; Winsemann et al., ).…”

“…Until recently the only demonstrable evidence of post‐Anglian and pre‐Devensian glaciation in East Anglia was a delta at Tottenhill (Figure ) that was deposited in a lake formed by ice damming The Wash (Figure a; Gibbard, West, Andrew, & Pettit, , ). This glaciation has been attributed recently to MIS 6 on the basis of OSL (optically stimulated luminescence) dating, when a small lobe of ice advanced down the eastern side of the Fen Basin (Figure a), as evidenced by ice‐marginal sedimentation and landforms (Gibbard, Boreham, West, & Rolfe, ; Gibbard, West, Boreham, & Rolfe, ; Gibbard et al., ). West () describes the drainage network reorganization in East Anglia in response to this MIS 6 ice advance.…”

Evidence for late Middle Pleistocene glaciation of the British margin of the southern North Sea

“…The outwash deposits were assigned to MIS 6 by Lewis (), an interpretation also favoured by Gibbard and Clark () and Gibbard et al . (,b). The debate has been complicated by the inclusion of sediments at sites such as Warren Hill, High Lodge, Lakenheath, Feltwell and Shouldham Thorpe (Fig.…”