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

International audience17 Salars of the Andean Plateau in the Central Andes are the largest lithium deposits on Earth. The most 18 notorious are the Chilean Salar de Atacama, and Uyuni in the Bolivian Altiplano. Despite the relevance of the 19 region concerning the lithium resources, there is still scarce scientific literature on the hydrochemistry of lithium 20 deposits in the Argentine portion of the Andean Plateau. In this article we present new hydrochemical data from 21 the first regional-scale reconnaissance exploration of the four major salars in the northernmost Argentine Andes. 22 Data revealed that brines in the studied salars are characterized by mean Li + concentrations ranging between 82 23 and 1,014 mg L-1 , and mean Li:Mg ratios from 0.92 to 0.54. The size of the study salars becomes a potential 24 limitation for the whole Li resources in comparison with the giant Atacama and Uyuni. Nonetheless, when 25 considering the Li grade and the Li:Mg ratio of brines, the Northern Puna salars turn out to be very remarkable 26 lithium prospects. Data emerged from this survey represent a valuable tool for: 1) private investment projects by 27 defining Li mining targets, 2) for the administration of natural resources and the definition of the State's politics, 28 and 3) for scientific purposes, especially in investigations meant to better understand the processes involved in 29 the formation of Li brine deposits, salars, and endorheic basins. 30 3