Optical Dates from British Isles ‘Solifluction Sheets’ Suggests Rapid Landscape Response to Late Pleistocene Climate Change

Abstract

The most widespread depositional landforms in many of the upland valleys of the British Isles which have undergone glaciation during the Last Glacial Maximum (LGM) are so-called solifluction sheets. These form a landform-sediment association consisting of smoothed-slopes underlain by poorly-sorted deposits. The timing and nature of sediment deposition is unclear in the absence of a dating framework within which solifluction sheet development can be placed. This paper presents the first dates from these landforms in the British Isles. We used optical dating on deposits exposed at Linhope Burn in the Cheviot Hills of North East England. The results suggest that the bulk of sediment deposition at this site happened over a period spanning the Younger Dryas. We argue that both paraglacial and periglacial processes can account for the main periods of deposition and that the timing of sediment deposition reflects the rapidity with which landform development responded to climatic shifts.