Aeolian Landscapes and Paleoclimatic Legacy in the Southern Chacopampean Plain, Argentina

Abstract

The Chacopampean Plain is a major physiographic unit in Argentina, bounded by theColorado River to the south, the Sierras Pampeanas and Subandinas to the west, and theParaná River, Río de la Plata Estuary, and the Argentine Sea to the east. Its subsurfacepreserves sediments from the Miocene marine transgression, while the surface hosts someof the country’s most productive soils. Two main geomorphological domains are recognized:fluvial systems dominated by alluvial megafans in the north, and aeolian systemscharacterized by loess accumulation and wind erosion in the south. The southern sectorexhibits diverse landforms such as deflation basins, ridges, dune corridors, lunettes, andmantiform loess deposits. Despite their regional extent, the origin and chronology of manyaeolian features remain poorly constrained, as previous studies have primarily focusedon depositional units rather than wind-sculpted erosional features. This study integratesremote sensing data, field observations, and a synthesis of published chronometric andsedimentological information to characterize these aeolian landforms and elucidate theirgenesis. Our findings confirm wind as the dominant morphogenetic agent during LateQuaternary glacial stadials. These aeolian morphologies significantly influence the region’shydrology, as many permanent and ephemeral water bodies occupy deflation basins orintermediate low-lying sectors prone to flooding under modern climatic conditions, whichare considerably wetter than during their original formation.