ABSTRACTThe specific geomorphological problem addressed in this paper is which thermal conditions determined moraine formation in west Greenland during Holocene deglaciation. Ice sheet modelling and geothermal research are used to delineate boundary conditions for landform formation and thereby improve and evaluate geomorphological hypotheses concerning moraine formation. Marginal thermal conditions are reconstructed from modelled basal temperature and estimates of Mean Annual ground Surface Temperature (MAST) contemporaneous to moraine formation. In mountainous areas with an altitude above 800 m, ice marginal morphology will be characterized by landforms typical for cold conditions owing to the combination of relatively thin ice throughout Holocene deglaciation and pronounced negative MAST values in the proglacial area. Low lying areas (0–250 m), with a sufficient areal extension in the direction of ice flow, have relatively thick ice throughout Holocene deglaciation. The combination of basal temperatures at the pressure melting point with positive MAST values in the proglacial area is postulated to produce deposits related to temperate beds and margins.