Lithium in waters of a polar desert

Abstract

Lithium (Li+) concentrations were measured in a series of stream and lake samples from a cold, dry desert, the McMurdo Dry Valleys (MDV) in Southern Victoria Land, Antarctica. Li+ geochemistry has been of great interest and utility, in part, because of its solubility and mobility during rockwater interactions. In general, the values determined for the streams and the dilute lake waters in this polar desert environment are similar to those found in temperate streams and lakes. The source of Li+ to these waters is a combination of marine aerosol and crustal 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 evapoconcentration. The different distributions of Li+ within the lakes is also due to past climatic changes and their effects on the chemical evolution of the lakes. The high relative mobility of Li+ controls its distribution within the aquatic systems of this cold, desert environment.