Geomorphological reconstruction of the last glacial maximum in San Juan river basin, Argentina

Evidence of Quaternary glaciations is present in numerous places of the surface of the Earth. The Central Andes of Argentina and Chile are not the exception. Enormous "U" shaped valleys and till deposits demonstrate the widespread occurrence of this phenomenon. However, the area covered by ancient glaciers and the volume of water discharge remains poorly constrained. In this paper, we present a geomorphological map and, for the first time, a paleogeographic reconstruction of the maximum extent of glaciers during the Last Glacial Maximum. This work was carried out by surveying the area occupied by "U" shaped valleys, asymmetric valleys, and moraine deposits, using high-resolution satellite images, aerial photographs, and field data. Results show that the Pleistocene glaciers covered an area of 582.3 km(2), about 25.5% of the study area (2,085 km(2)). Nowadays, glaciers and glacierets occupy only 3.94% of this area.