Northern Puna Plateau-scale survey of Li brine-type deposits in the Andes of NW Argentina

Abstract

Salars of the Andean Plateau in the Central Andes are the largest lithium deposits on Earth. The most notorious are the Chilean Salar de Atacama, and Uyuni in the Bolivian Altiplano. Despite the relevance of the region concerning the lithium resources, there is still scarce scientific literature on the hydrochemistry of lithium deposits in the Argentine portion of the Andean Plateau. In this article we present new hydrochemical data from the first regional-scale reconnaissance exploration of the four major salars in the northernmost Argentine Andes. Data revealed that brines in the studied salars are characterized by mean Li concentrations ranging between 82 and 1014 mg L−1, and mean Li:Mg ratios from 0.92 to 0.54. The size of the study salars becomes a potential limitation for the whole Li resources in comparison with the giant Atacama and Uyuni. Nonetheless, when considering the Li grade and the Li:Mg ratio of brines, the Northern Puna salars turn out to be very remarkable lithium prospects. Data emerged from this survey represent a valuable tool for: 1) private investment projects by defining Li mining targets, 2) for the administration of natural resources and the definition of the State's politics, and 3) for scientific purposes, especially in investigations meant to better understand the processes involved in the formation of Li brine deposits, salars, and endorheic basins.