The Submerged Glacial Landscape off the Lincolnshire Coast

THE RECOGNITION of glacial features on the bed of the North Sea was first attempted by 0. Pratje.1 Using the evidence of extensive gravel spreads on the sea floor, which he interpreted as outwash fans laid down in front of a stationary ice sheet, he reconstructed the supposed positions of a number of end moraines across the northern part of the North Sea basin, and correlated them with moraines of the Last (Weichsel) Glaciation inJutland and north Germany. Three main lines of moraine were established on the sea floor, corresponding to the Warthe, Frankfurt and Pomeranian phases on the mainland. Although the evidence on which Pratje based the positions of his various ice fronts is fragmentary in many areas, particularly away from the coast, the method of approach seems to be the only practical one, bearing in mind that any actual morainic ridges of boulder clay must have been largely destroyed or considerably modified by marine erosion during the subsequent Flandrian transgression. No corresponding attempt has been made to trace the possible retreat stages along the English side of the North Sea, largely because detailed information relating to sea-bed deposits has been lacking. In the past 2 years, however, the activities of dredging companies seeking supplies of marine shingle have stimulated research in this direction and provided evidence of undoubted fluvioglacial deposits off the east coast of England between north Norfolk and Flamborough Head. Particularly detailed information exists for an area off the Lincolnshire coast near Mablethorpe based on hundreds of grab samples and geophysical profiles of the sub-surface deposits. The data obtained are thus more complete and informative than were available to Pratje, though necessarily covering a more limited area. Coupled with the evidence from glacial studies of the adjacent coastlands of Lincolnshire, north Norfolk and Holderess, by A. Straw, H. H. Swinnerton and P. E. Kent, and H. Valentin,2 it is now possible to reconstruct the retreat stages of the ice margin along the east coast of England during the Last Glaciation. The study also has wider implications in view of the controversy regarding the southern limit of ice advance at this time3 and also the relationship of the English and Scandinavian ice margins throughout the period

Archaeology · Geography · Glacial period · Geology · Geology and Paleoclimatology Research · Marine and environmental studies · Oceanography · Paleontology