Do glaciers reset the luminescence signal of the sediment at their base?

Haut Glacier d'Arolla, Switzerland

Lots of interesting discussions at last week's UK TL/OSL/ESR conference at Oxford University, but of particular interest to geomorphologists was Mark Bateman's talk 'Do glaciers reset their beds?'. Mark told us about the work that he and Darrel Swift are doing at Sheffield to investigate the effect of subglacial transport on the luminescence signal of basal sediments, which is about to be published in Boreas. Darrel drilled a core through the Haut Glacier d'Arolla, Switzerland to collect sediment from its base for initial luminescence measurements. Then they moved the lab, using a ring-shear 'donut' machine to recreate subglacial stresses on quartz sand with substantial known luminescence characteristics.This indicated that increased strain increases the number of zero dose grains and reduces the overall paleodose of the sediment. So yes, it would appear that glaciers do reset their beds, raising the possibility of using luminescence to date glacial retreat stages and sediment transport to a high resolution.