Deglaciation of the eastern Cumbria glaciokarst, northwest England, as determined by cosmogenic nuclide ( 10 Be) surface exposure dating, and the pattern and significance of subsequent environmental changes. Peter WILSON 1 , Tom LORD 2 , Ángel RODÉS 3 1 Environmental Sciences Research Institute, School of Environmental Sciences, University of Ulster, Coleraine, Co. Londonderry, BT52 1SA, UK. 2 Lower Winskill, Langcliffe, Settle, BD24 9PZ, UK. 3 NERC Cosmogenic Isotope Analysis Facility, Scottish Universities Environmental Research Centre, Rankine Avenue, East Kilbride, G75 0QF, UK. Corresponding author: Peter Wilson (p.wilson@ulster.ac.uk) Abstract: Four erratic boulders of Shap granite on the limestone terrain of eastern Cumbria have yielded cosmogenic nuclide ( 10 Be) surface exposure ages that indicate the area was deglaciated c.17 ka ago. This timing is in accord with other ages pertaining to the loss of glacial ice cover in the Yorkshire Dales and north Lancashire, to the south, and the Lake District, to the west, and constrains the resumption of landscape (re)colonization and surface and sub-surface karstic processes. Marked shifts in climate are known to have occurred since deglaciation and combined with human impacts on the landscape the glaciokarst has experienced a complex pattern of environmental changes. Understanding these changes and their effects is crucial if the ‘post-glacial’ evolution of the glaciokarst is to be deciphered. Keywords: Cosmogenic nuclide surface exposure dating, deglaciation, climate shifts, Shap granite erratics, eastern Cumbria glaciokarst Received: 18 December 2012; Accepted: 25 February 2013 © British Cave Research Association 2013 ISSN 1356-191X CAVE AND KARST SCIENCE, Vol.40, No.1, 2013 Transactions of the British Cave Research Association In order to constrain the timing of plant and animal (re)colonization and the resumption of surface and sub-surface karstic processes it is important that karst geomorphologists know when the glaciokarstic landscapes of northwestern England (Fig.1) emerged from beneath the last (Late Devensian) ice sheet. Additionally, the pattern and timing of subsequent climate shifts, and human activities, must be understood so that their impacts on landscape can be assessed and placed within the broader context of environmental change. In recent years some progress has been made on these themes for the western part of the Yorkshire Dales glaciokarst. Accelerator Mass Spectrometry (AMS) 14 C dating of sub-fossil faunas in Kinsey Cave (SD 8040 6572) and Victoria Cave (SD 8380 6505) (Lord et al., 2007) showed that large carnivores (brown bear: Ursus arctos) were present at 14.7–14.6±0.4 cal. ka, coincident with the marked temperature rise that defines the start of the Lateglacial (Windermere) Interstade (Greenland Interstade 1) in the NGRIP ice core record (Andersen et al., 2006). Figure 1: Northwest England showing the locations of sites mentioned in the text. 22