CONSOLIDATION OF SEDIMENTS BY GLACIERS - RELATIONS BETWEEN SEDIMENT GEOTECHNICS, SOFT-BED GLACIER DYNAMICS AND SUBGLACIAL GROUNDWATER-FLOW

A theory of subglacial consolidation is developed which shows how the meltwater flux beneath a glacier leaves a consolidation signature from which many important glacier-dynamic properties can be inferred. Cond itions under which water is discharged through channels or in a thin f ilm at the ice-bed interface or by ground-water flow are discussed, an d it is concluded that glaciers flowing over aquifers of high transmis sibility can induce deep circulation patterns quite different from non -glacial circulation. Examples of glacial pre-consolidation profiles i n sediments from The Netherlands and England are used to illustrate ho w basal melting rates, subglacial ground-water flow patterns, ice over burden, basal shear stress, ice-surface profile and the amount of sedi ment removed by erosion can be inferred.