Late Quaternary palaeohydrology of Lake Huinaymarca (Bolivia)

In lake Titicaca, the distribution of the modern ostracod fauna appears to be controlled by a combination of two factors: a) the equilibrium between carbonates and organic matter, b) the ionic composition of the lake water and its tributaries. Therefore, the Limnocythere-Pampacythere group generally predominates on an alkaline-carbonate lake floor. In parts of the lake receiving an NaCl input from tributaries, Cyprideis and Cyprinotus occur. These are generally absent elsewhere. The Candonopsis group is found in the deepest part of the lake.Analysis of ostracod assemblages recovered from a number of cores permitted the reconstruction of the hydrological evolution of lake Huinaymarca for the last 10000 years. This included: low water levels, variations of oxygenation related to the position of the thermocline, and interconnections between different basins of the lake.