A 3 m-long continuous sediment record recovered from Laguna Meseta (LME), one of the lakes located on Meseta Chile Chico, Central Patagonia, Chile. Its radiocarbon chronology documents sediments of the last ~10,000 years indicating a minimum age for postglacial ice-free lacustrine conditions due to a westward retreat of the Large Patagonian Ice sheet. At this time, lacustrine productivity reached its maximum and decreased afterwards. Between 5,500 and 4,600 cal yr BP, a major shift towards allochthonous sediment accumulation occurred, caused by an abrupt increase in clastic deposition from basaltic lithologies of the Meseta Chile Chico. This episode correlates with the precipitation-driven Mid-Holocene glacier advance of Patagonian glaciers, suggesting a persisting glacial influence on the Meseta Chile Chico. After 4,600 cal yr BP wetter climate conditions returned to feed LME with fluvial sediments until a stepped decrease around 1,000 cal yr BP. Thereupon, lacustrine productivity distinctly increased and stabilized around 300 cal yr BP. Our reconstructions and comparisons with other regional paleoenvironmental studies indicate that environmental conditions of LME were mainly controlled by humidity changes on the Meseta Chile Chico and reflect Holocene climate variability.

Further funding:Environmental and climate reconstruction for Chilean Patagonia - Investigations of lacustrine sediment record at Chile Chico Plateau and its surrounding area, Award: DAAD Doctoral programmes in Germany 2020/21