LITHIUM IN WATERS OF A POLAR DESERT

Lithium (Li+) concentrations were measured in a series of stream and l ake samples from a cold, dry desert, the McMurdo Dry Valleys (MDV) in Southern Victoria Land, Antarctica. Li+ goeochemistry has been of grea t interest and utility, in part, because of its solubility and mobilit y during rock-water interactions. In general, the values determined fo r the streams and the dilute lake waters in this polar desert environm ent are similar to those found in temperate streams and lakes. The sou rce of Li+ to these waters is a combination of marine aerosol and crus tal weathering within the stream channels The hypersaline hypolimnion of Lake Bonney has extremely high concentrations of Li+ which has been concentrated via a previous drawdown of the lake and its subsequent e vapoconcentration. The different distributions of Li+ within the lakes is also due to past climatic changes and their effects on the chemica l evolution of the lakes. The high relative mobility of Li+ controls i ts distribution within the aquatic systems of this cold, desert enviro nment. Copyright (C) 1997 Elsevier Science Ltd.