ABSTRACT. Terrigenous clastic sediment is abundant in many of the lakes of the Antarctic dry valleys. Sedimentation patterns are strongly influenced by the ice covers of these lakes, resulting in dispersal of coarse sediment across the lake surfaces, even far from shore. The resulting deposits are thus very different from the deposits of most lakes in temperate latitudes. In adition, sediment deposition in many lakes is highly localized and is probably controlled by fractures or porous conduits through the ice. The resulting ridges and mounds of pebbly sand may be unique to the ice-covered lake environment. With changes in the conditions of the lakes through time, clastic sediment becomes interstratified with biogenic sediment and evaporites. Changes in the rates of clastic sediment deposition probably result from ice-sediment interactions and from external controls, such as climatic changes; and the sedimentary deposits in these lakes may provide sensitive local climatic records.