The aeolian systems of central Argentina

ZÁRATE, MARCELO A.; TRIPALDI, ALFONSINA

Santa Rosa, Argentina

Congreso; VII International Conference Aeolian Research; 2010

INTA

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} p.MsoTitle, li.MsoTitle, div.MsoTitle {margin:0cm; margin-bottom:.0001pt; text-align:center; mso-pagination:widow-orphan; font-size:12.0pt; mso-bidi-font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES-MX; font-weight:bold; mso-bidi-font-weight:normal; text-decoration:underline; text-underline:single;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> The central region of Argentina between 33˚S and 39˚S is an area of around 600,000 km2 which comprises two main geomorphological domains, the Pampean plain and the eastern Andean piedmont both characterized by complex morphostructural settings. The region is covered by a late Quaternary aeolian mantle with subordinated alluvial deposits along the major fluvial systems (Paraná river, Salado river of Buenos Aires province, Desaguadero-Salado-Curacó river system). During the past two decades, the aeolian and alluvial records of the Pampas and the Andean piedmont have received increasing attention as potential archives of Quaternary paleoclimatic conditions. The aeolian mantle grades from loess and loessoid deposits in the eastern Pampas to sandy mantles and dune fields 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 and their geological settings. Loess and loessoid mantles are the dominant aeolian facies of four units extending across the eastern Pampean plain (inter-range and piedmont areas of Tandilia and Ventania; Undulating Pampa, Low Pampa, Pampean ranges of Córdoba and San Luis); dune fields predominate in three other units (eastern Pampean dune field, western Pampean dune field, eastern Andean piedmont dune fields); and dune fields and sand sheets are present in northern Patagonia and the central Pampas. At a regional scale, sandy deposits are proximal facies closer to the main source area of aeolian material thought to be the floodplain environment of the Desaguadero-Salado-Curacó fluvial system. The eastern loess deposits correspond to distal aeolian facies.