Multidisciplinary analysis of the last glacial loess at the NE of the Pampean aeolian system.

KRÖHLING, D., PASSEGGI, E., ZUCOL, A., ERRA, G., MIQUEL, S. BREA, M.

Mendoza

Congreso; 18th International Sedimentological Congress.; 2010

CIG CONICET-UNLP

Loess deposits are the main component of the Late Quaternary sequences of Pampa plain, covering the largest loessic area of Southern Hemisphere. Pampean loess region lies downwind from source areas located to the S and SW, comprising a large sand sea and alluvial systems that drain the eastern Andean piedmont. The loess unit of the last glacial maximum (LGM) at the leeward side of the Pampean aeolian system represents a primary loess, indicating the expansion of semiarid conditions to the NE. Stratigraphic, sedimentologic, mollusk and phytolith data, including OSL and 14C ages, are presented for a loessic area of 14,000 km² at the SW of Entre Ríos province, Argentina. LGM loess is a homogeneous unit, characterized by considerable spatial continuity in the North Pampa. It occurs as a mantle of 2-4 m thickness; only locally the loess has been fluvially re -worked or evolved under non- permanent swamp conditions.