Anomalous terrain at Dove Crags ‘cirqueform’ and Gasgale Gill asymmetric valley, English Lake District, attributed to large-scale rock slope failure of pre-LGM origins

Research at Dove Crags, English Lake District, reveals evidence of a substantial pre-Last Glacial Maximum (LGM) rock slope failure (RSF), one of the first identified in Britain and Ireland. The study proposes that an anomalous cirque-like cavity and asymmetric valley were shaped by a large-scale RSF, estimated at 50 million m³, which was subsequently modified by glacial activity. Field evidence, including dry gullies, a tarnless hollow, and a sharp flank scarp, supports this interpretation. A novel 'clone-stamping' reconstruction method was used to model the pre-RSF landscape, while comparisons with other RSFs and a proposed 'zone of crush' model further validate the findings. The study resolves a landscape paradox by suggesting that the RSF predates the LGM, allowing for glacial exploitation and post-LGM reactivation, which explains the current asymmetric valley profile.

Jarman, D., & Wilson, P. (2015). Anomalous terrain at Dove Crags ‘cirqueform’ and Gasgale Gill asymmetric valley, English Lake District, attributed to large-scale rock slope failure of pre-LGM origins. Proceedings of the Yorkshire Geological Society, 60(4), 243–257. https://doi.org/10.1144/pygs2015-348