Glacial fluctuations in the southwestern Wicklow Mountains, Ireland.

Mapping and dating former glacial margins is a key tool for assessing the sensitivity of glaciers to changing climate conditions, both past and future. However in many regions, such as along the northeastern margins of the North Atlantic, direct chronologic control on past glacier extent can be sparse. In particular, the former extent and elevation of the Irish Ice Sheet (IIS) during the Last Glacial Maximum (LGM; 26-19 ka) and subsequent termination remain a topic of debate - due in part to the coarse resolution of existing (direct) age control on glacial margins. This includes the margins of former valley and cirque glaciers that nucleated in the Irish highlands after local retreat of the IIS. In eastern Ireland, the Wicklow Mountains host numerous valley and cirque moraines that are largely undated, evidence of past glacial fluctuations following the LGM. Here we report new geomorphic mapping and cosmogenic beryllium-10 surface-exposure ages of moraines in the Glen of Imaal in the southwestern Wicklow Mountains. Our preliminary beryllium-10 ages provide new chronologic constraint on the extent of glaciers in the Glen of Imaal following the LGM. We also compare our preliminary glacial chronology with records of wider North Atlantic climate to investigate the response of ice in the Glen of Imaal to changing climate conditions. These data provide new insight on Ireland’s glacial past, and yield vital information on climate and glaciation in the wider North Atlantic region.