Libro: Pampean Lakes
Capítulo: Paleolimnological Records in the Western Pampa Plain
Autores: Vera Maciel, Alfonsina Tripaldi, Isabel Vilanova, Leandro Rojo, Eduardo L. Piovano & Karsten Schittek
Abstract
The Late Quaternary history of the Western Pampa plain was characterised by aeolian morphogenesis and sedimentation under drier conditions than the present, that built an extensive dunefield associated with aeolian sand sheets. The Holocene was dominated by aeolian aggradation that evolved to a present-day semiarid-subhumid grass steppe, including various shallow lakes developed in deflation basins of blowout dunes, as well. The lacustrine records provide valuable evidence for reconstructing palaeoenvironmental and paleoecological conditions, allowing to infer climatic variability and human impacts. In this chapter we present paleolimnological reconstructions spanning the last ~ 1400 years of shallow lakes developed within this aeolian setting. Inferences from a novel multiproxy analysis at Laguna Pocitos, and a review of previous results from Primera Laguna and Laguna Nassau, are analysed in order to compare/complement former interpretations and to correlate regionally with other Pampean shallow lake records. Four similar chronologically constrained trends were recognised: ~ 575–1210 CE; ~ 1210–1750 CE; ~ 1750–1970 CE; ~ 1970–2015 CE. Comparable lake conditions at other sites of the Pampa plain along these intervals suggest that this area shared similar patterns of climatic variability, modulated by the local geological and ecological signatures.
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