INVESTIGADORES
PEREZ Alejandra patricia
artículos
Título:
Reconstruction of the hydrological history of a shallow Patagonian steppe lake during the past 700 years, using chemical, geological, and biological proxies
Autor/es:
COVIAGA, CORINA; RIZZO, ANDREA; PEREZ, ALEJANDRA PATRICIA; DAGA, ROMINA; POIRÉ, DANIEL; CUSMINSKY GABRIELA; RIBEIRO GUEVARA, SERGIO
Revista:
QUATERNARY RESEARCH
Editorial:
ACADEMIC PRESS INC ELSEVIER SCIENCE
Referencias:
Lugar: Amsterdam; Año: 2017 vol. 87 p. 208 - 226
ISSN:
0033-5894
Resumen:
The limnological conditions during the last 700 years were reconstructed based on multi?proxy analysis of a short sedimentary sequence from Lake El Toro (~40ºS 70ºW). Mineralogical and geochemical features, and ostracods and chironomids, recorded hydrological changes in the basin and in consequence, the region?s climate. The ostracod Limnocythere rionegroensis var. 1 was a reliable indicator of high salinity, and Eucypris fontana an eurihaline species with preferences for moderate salinity waters. The chironomid fauna indicated more dilute conditions in the mid-20th century. These salinity changes were interpreted in terms of negative?positive hydrological balance, associated with dry and wet periods. High lake level and low salinity in El Toro between AD 1500?1700 match with the wetter and cold climate during the second pulse of LIA in northern Patagonia. High salinity conditions occurred during early and late 19th century, corresponding the later with the driest period occurred in the north?east Patagonia during the last 400 years. An increase in the precipitation trend around middle of 20th century, opposite to the Chilean side records, correlated with a positive phase of the Southern Annular Mode associated, in turn, with a strengthening, poleward shift of the westerlies, possibly enhancing easterly moist air inflows to center-north Patagonia.