Late Quaternary hydrological variability in southeastern Patagonia - 45,000 years of terrestrial evidence from Laguna Potrok Aike

Abstract

The maar lake Laguna Potrok Aike is located in the dry Patagonian steppe, an area with hitherto only scarce paleoenvironmental information. Within the project SALSA (South Argentinean Lake Sediment Archives and modelling) Laguna Potrok Aike turned out to be the key site for paleoenvironmental reconstruction in that area. With a continuous, high-resolution multi-proxy approach applied to the well radiocarbon and tephra dated sediments it was possible to distinguish between lake level high and low stands. Those do not only give information about the hydrological state of climatic periods like the Little Ice Age or the Medieval Climate Anomaly but also reflect hydrological variations for southern Patagonia during the past 16,000 cal. BP as well as Oxygen Isotope Stage 3. In this context the total inorganic carbon content was identified as a sensitive lake level indicator which was supported by various other proxies for lake level changes, minerogenic input or redox-conditions which are also suited for reconstructing paleoenvironmental conditions.