Middle to Late Pleistocene valley-slope cambering: The interglacial basin at Wing, Rutland, England

A depression in the Jurassic bedrock at Wing, Rutland (eastern England), is infilled by deposits spanning the Late Wolstonian (=Late Saalian) to Early Devensian (=Early Weichselian) substages, including the most complete Ipswichian Stage (=Eemian Stage; ~Marine Isotope Stage 5e) sequence known in Britain. This sequence forms an enclosed pocket, the origin of which remains imprecisely determined. Re-examination of its morphometry, infill and setting of the basin, implies it originated as a feature or gull formed by valley-side cambering or associated landslide mass movement process of the Northampton Sand over clay bedrock. The surface glacial diamicton surrounding the hollow, collapsed into the void created, followed 880 years later by a water ponding related to rising groundwater level. By comparison to the annually laminated lake sequence at Bispingen, north Germany, the total time represented over 10 000 years. Through the temperate period, the depression developed into a raised bog and latterly a second ponded-water phase, the hollow finally being filled by inwashed soil and slope material with passage into the subsequent cold stage. The Wing sequence is proposed as the basal boundary stratotype of the British Devensian Stage at 5.67 m below the ground surface.