Lithium in unconsolidated sediments and plants of the Basin and Range Province, southern California and Nevada

Geochemica l and geobotanical sampling of 20 hydro logica lly closed and open basins in the southern part of the Basin and Range province shows contrasting lithium conten ts of their sediments, vegetation, and natural waters.These findings have significant economic a nd environmental implications.In hydrologically closed basins, where groundwater discharge is mainly by evapotranspiration, economic concentrations of lithium are o f three types-as lithium chloride in evaporites and brines, in th e crystal lattice of montmorillonitic clays, and in carbonate precipitates in hot-spring and lacustrine deposits.Along with potassium, boron, and halite, lithium compounds are precipitated at a la te stage of evaporation.Sediments collected from low areas of closed basins contain 30-1,500 ppm lithium, whereas sediments from open, drained basins contain 20-150 ppm lithium.Recycled concentrations occur in association with hot springs at the a llu vium-playa con tact, where lithium dissolved at depth is precipitated around hydrophytic plants and organic debris.The average lithium content of native vegetation sampled in closed basins is 100 times the content reported for average plants.The lithium content of halophytic vegetation is closely related to that of the soil, anoma lous accu mulations occurring in plants that also take up large concentrations of sodium chloride.Ground water contains 50 times more lithium than average municipal water supplies in the U nited States.Lithium is produced commercially from volcanic clays and, also, by brine evaporation in several closed basins; ana lysis of vegetation may furnish a means of prospecting for deep-seated lithium brines.Contents of as much as 3,000 ppm lithium were fou nd in the ash of pickleweed (A llenrolfea ) and in rushes rooted in hot springs.An average of 150 ppm lithium in the ash and 25.8 ppm in the dry weight of all plants that were collected in both closed and open arid basins is considerably higher than the average of 1.3 ppm in dry weight reported for plants growing in a nonarid climate.The high lithium content in well waters and vegetation of closed basins is probably beneficial, rather than harmful, to animals and man.EXPLANATION Valley fill Sedimentary rocks-Largely Paleozoic limestones Igneous rocks -Largely volcan ic tuffs w Closed basin discharged by evapotranspiration © Playa --.Direction of ground-water movement Lithium in sediment sample -In parts per million.Plants were collected at all sample localities 0 <100