Is erosion by deforming subglacial sediments significant? (Toward till continuity)

A glacier moving by deformation of subglacial sediments will tend to exhaust its own sediment supply, unless new sediment is generated subglacially. We explore the potential for deforming sediments to overcome this difficulty and replenish themselves by abrading their beds. We review abrasion experiments and theory for brittle materials and conclude that a theoretical calculation of abrasion is not possible yet. Instead, we use fault-gouge production data to estimate a likely upper bound to abrasion rates, and conclude that sufficient erosion to maintain a steady deforming-layer thickness is difficult to achieve, and will only be possible if the substrate is very soft and if there is a moderate rate of slip at the base of the deforming layer. Slow abrasion, which can leave a geologic signature, is possible under most deforming layers that are deforming at the sediment/bedrock interface.