Holocene palaeoclimates of southern Patagonia: Limnological and environmental history of Lago Cardiel, Argentina

• Main Authors: Markgraf, V., Bradbury, J.P., Schwalb, A., Burns, S.J., Stern, C., Ariztegui, D., Gilli, A., Anselmetti, F.S., Stine, S., Maidana, N.
• Format: Journal/Newspaper
• Language: unknown
• Subjects: Argentina; Environmental history; Holocene; Lago Cardiel; Lake levels; Multiproxy approach; Palaeoclimates; Palaeolimnology; Patagonia; South America; Stormtracks; lacustrine deposit; lake level; paleoclimate; paleolimnology; seasonal variation; storm track; Bacillariophyta; Ostracoda; Antarc*; Antarctic
• Online Access: https://hdl.handle.net/20.500.12110/paper_09596836_v13_n4_p581_Markgraf

Multiproxy palaeoenvironmental and palaeolimnological analyses of two Holocene-age sediment cores from the margin of Lago Cardiel, a 76 m deep, closed-basin lake in southern Patagonia (latitude 49°S), provide information on lake-level changes that can be related to regional palaeoclimate scenarios. Sedimentologic (magnetic susceptibility, organic and inorganic carbon content) and environmental indicators (pollen, diatoms, ostracodes and stable isotopes on ostracodes) show lake levels markedly higher than today during the early Holocene, following a rapid lake-level rise after a desiccation phase prior to 11 000 BP. After about 6000 BP, lake levels were generally lower, but underwent repeated fluctuations. These inferred changes support the previously proposed view that the southern westerly stormtracks were focused (zonal) north of latitude 50°S during the early Holocene, allowing for Antarctic cold fronts to bring easterly moisture to southern Patagonia, whereas during the late Holocene the stormtracks shifted seasonally, with an overall more meridional behaviour, resulting in less and more variable moisture at these latitudes.