SAR dating of the Holocene eolian sand depositional record San Luis Province, western Argentina

FORMAN, S.L.; TRIPALDI, A.

Utah

Workshop; 9th New World Luminescence Dating Workshop; 2013

Utah State University

Stabilized dune fields are common in western Argentina and reflect potentially drought variability in the late Quaternary. Geochronologic studies focused on the San Luis dune field on the western Pampas, with a mean annual precipitation of ~ 700 mm. Compound and digitate parabolic dune exposures reveal a complex eolian history with multiple buried soils and intercalated eolian sand. Optical dating employed the 100-150 micron quartz grains using single aliquot regeneration (SAR) protocols. These eolian sands are immature mineralogically with quartz percentages between 40 and 50%. Unlike other Andean-sourced quartz, Pampean sediments show a clear dominance of fast luminescence component with medium and slow components near background levels. This quartz exhibits relatively small sensitivity changes (