Re-advance of Scottish ice into the Solway Lowlands (Cumbria, UK) during the Main Late Devensian deglaciation

Abstract

The complex glacial geomorphology and stratigraphy of the Solway Lowlands (Cumbria, UK) reflects dynamic ice flow during the Main Late Devensian Glaciation, with numerous ice-flow shifts, and re-advances now recognised. The final incursion of Scottish ice into the region (Scottish Re-advance) during a late stage of deglaciation has provoked widespread debate and even scepticism arising from ill-defined marginal limits, and a paucity of landforms, sediments and dates. In an attempt to resolve some of these issues this paper has applied both geomorphological and stratigraphic techniques to critically review evidence pertaining to the Scottish Re-advance. A major deltaic landform-sediment assemblage at Holme St. Cuthbert; a thin, patchy till sheet; and eskers at Thursby and Sowerby Wood verify that Scottish ice re-advanced into the Solway Lowlands at a late stage of deglaciation. The thin, patchy till sheet associated with the re-advance is indicative of a short-lived pulse, with ice thought to have flowed rapidly across water-saturated sediment and into proglacial lakes dammed up against higher ground to the east. The Holme St. Cuthbert delta, which evolved from a subaqueous outwash fan marks a major still-stand and development of a large ice-contact lake in the vicinity of Wigton. The extent of the glaciation is difficult to elucidate, with the till sheet disparately exposed as far east as Lannercost although identification of the Blackhall Wood Re-advance Till member probably limits its SE extent to just south of Carlisle. Coeval re-advance of Lake District ice is possible given that a final stage lobate movement of ice out of the Vale of Eden and into the Solway Lowlands is now recognised, however there is no direct stratigraphic correlation or dating control.