The aeolian system of central Argentina

Abstract

The central region of Argentina comprises three main geomorphological domains, the Pampean plain, the northern Patagonia plateau and the eastern Andean piedmont. The region characterized by a complex morphostructural setting is covered by a late Quaternary aeolian apron with subordinate alluvial deposits, grading from loess and loess-like deposits in the eastern Pampas to sandy mantles and dunefields in the central, western and southern areas of the region. Eight aeolian units have been identified on the basis of the nature of the deposits, landforms and their geological-structural settings. Loess and loess-like mantles are the dominant aeolian facies of three units extending across the eastern Pampean plain: loess and loess-like mantles, loess and loess-like mantles and blowouts, sandy loess and loessial sand mantles. Dunefields and sand mantles prevail in five other units: central Pampean dunefields, western Pampean sand mantles and dunefields, western Pampean dunefields, Andean piedmont dunefields, northern Patagonia and southern Pampean sand mantles and dunefields. At a regional scale, sandy deposits are proximal facies closer to the main source area of aeolian material corresponding to the floodplain environment of the Colorado River and its tributary Desaguadero-Salado-Curacó fluvial system. The eastern loess deposits correspond to distal aeolian facies. In addition, topography governed by the complex subsurface geology and structure of the region, play a leading role as a primary controlling factor in the distribution of aeolian facies and the resulting landforms.