Ostracodes as indicators of paleohydrochemistry in lakes: a Late Quaternary example from Lake Elmenteita, Kenya.

The tolerances of many ostracode species to particular hydrochemical parameters are known based upon studies of living taxa from eastern and southern Africa range assemblages. A hydrochemical analysis of ostracodes applied to fossils from a radiocarbon-dated core from Lake Elmenteita, suggests that about 12 000 years BP, Elmenteita was a small, closed lake of Range IV salinity and alkalinity. It underwent a period of decreasing salinity and alkalinity, passing through Range III to a Range II, high-water phase, about 10 000 years BP. The lake remained in Range II prior to its rapid return to a Range IV, highly alkaline and saline, small-lake condition about 8000 years BP. These results demonstrate the great potential for recognizing regional paleohydrologic and paleoclimatic trends from tropical lacustrine ostracodes derived from cores. -from Authors