Holocene palaeohydrology of Lake Titicaca estimated from an ostracod-based transfer function

Lacustrine deposits of Holocene age (8000 14C yr BP–Present) were studied in Lake Titicaca, Bolivia. Ostracod assemblages were identified in six cores taken in the three basins which today form Lake Titicaca. Factorial correspondence and multiple linear regression analysis of the ostracods have permitted the reconstruction of (1) lake level, (2) water salinity and (3) water Mg/Ca ratio variations. Palaeolake levels indicate a complex evolution of the three basins, with some major phases. After a flooding at about 8000 yr 14C BP, the lake level fluctuated around a mean position until 3900 14C yr BP, when a second rise took place. It seems, however, that the present-day lake level was not reached until after 680 yr 14C BP. Some major dry events are also recorded at about 5300 14C yr BP and 2300 14C yr BP. The Lake Titicaca data are consistent with other records from South America, and also seem to reflect some world-wide events.