Late Pleistocene paleolakes in Andean and Extra-Andean Patagonia at mid-latitudes of South America

Natural Dams (glaciers, moraines) that maintained a high water level in glacial paleolakes were melted or cut by erosion during Late Pleistocene climate amelioration. With the retreat of the glacier from the Andean valleys during prominent regional deglaciation, water levels in glacial paleolakes fell rapidly in stages due to the outflow from the eastern side of Andes to the Pacific Ocean at about 13.2 ka BP.

These changes were often preceded by volcanic-tectonic activity, which is suggested to be the "touch of butterfly" releasing mass balance adjustment in changing landscape. The lacustrine tephra stratigraphic pattern from the Andes, comprising more than 50 horizons since the last glaciation, is presented. The correlation of palaeoenvironmental changes between the Andes and the Patagonian Steppe is suggested on the basis of two dacite marker horizons.