The Salar de Uyuni in Bolivia, at an altitude of 3,650 metres covers an area of 9,000 Km2. Unlike the major lithium containing salares in Chile and Argentina it is completely flat due to annual flooding.
Ballivian and Risacher (1981) reported on brine grades of 0.035% Li and 0.72%K. Grades are highest in the southeastern portion of the salar. They calculated total lithium reserves as 5,500,000 tonnes.
The magnesium/lithium ratio is high at 22/1.
Other salares, also found as the result of shrinkage by evaporation from a Lake Minchin of Pleistocene age, include the large salares of Emprexa and Coiposa with spot samples grading up to 370 and 580 ppm Li respectively.