EuroSpeleo 2016

The caves of Gigglewick Scar - examples of deglacial speleogenesis?

Oral|Dr Trevor Faulkner

Abstract

Abstract
The prominent Giggleswick Scar at the South Craven Fault extremity of the Carboniferous limestone of the Askrigg Block in North Yorkshire contains relict phreatic caves whose speleogenesis is enigmatic. This paper examines the local geomorphological evidence and proposes that some, but not necessarily all, karst features formed after the Last Glacial Maximum. Building on a previous deglacial model, it is hypothesised that inception fractures and bedding plane partings were created during isostatic uplift. These were enlarged by dissolution in cold unsaturated meltwater beneath a deglacial ice-dammed lake that formed initially at an altitude of c. 300m. As the icesheet downwasted further, the surface of the lake lowered past the newly-formed cave entrances, some of which were probably enlarged by freeze-thaw and lake-ice push and pull processes. If this hypothesis is correct, it has wider implications for cave speleogenesis and sedimentation in the Yorkshire Dales and in other deglaciated regions.

Full Paper:
Murphy, PJ, Faulkner, TL, Lord, TC and Thorp, JA. 2015. The caves of Giggleswick Scar – examples of deglacial speleogenesis? Cave and Karst Science 42 (1) 42-53.