Lunettes dunes in the Desaguadero River environment and its paleoenvi- ronmental implication. Mendoza, Argentina

Acta Geológica Lilloana 24 (1-2): 2012

Abstract

On the right bank of the Desaguadero River, natural border between San Luis and Mendoza provinces, in the section between the Arco del Desaguadero and El Tapón localities, sandy mounds are presented in the form of cords that stretch for several kilometers, parallel to the western edges of dried ponds. These landforms, up to 14 meters high, have a moderately asymmetrical cross-section and elongated crescent morphologies in plan. Based on the data obtained, they are interpreted as ”lunettes” dunes with a source linked to the deflation of sediments from the floor of the paleolakes and their accumulation on the leeward margins. Considering their morphological and stratigraphic features, they are tentatively correlated with sand dunes in the region referred to the Upper Holocene, developed under arid and cold climates, dominated by the circulation of winds from the South Pacific anticyclone.