The Lithium Triangle of the Central Andes: A view from Lithium concentrations and isotopic compositions of potential source rocks

FRIEDRICH LUCASSEN; CARISA SARCHI; RAUL BECCHIO; ANETTE MEIXNER; SIMONE KASEMANN

Salta

Congreso; 15th Quadrennial International Association on the Genesis of Ore Deposits Symposium; 2018

Lithium has rapidly advanced to a strategic commodity for energy storage in all kind of mobile devices andgrowing electro mobility, contributing to future low carbon societies. The Central Andes host world-class Li-depositsin endorheic evaporite basins (salars). The deposits are geographically bound to the so called Li-Triangle betweenthe southern Bolivian Altiplano, the Argentine Puna, and its western slope in Chile. Lithium is mobilized from its hostrocks during weathering or hydrothermal leaching, preferentially from igneous rocks and possibly from Li-enrichmentsin melt inclusions. In the (semi) arid climate, the run off collects and concentrates in the evaporite basins. Thereasons for the restriction of the Li-anomaly to the Lithium-Triangle remain largely unknown. We investigate the Liconcentration and Li isotope composition in mainly Early Palaeozoic metamorphic and sedimentary rocks (hereafterthe basement) of the Central Andes and follow the trace of the Li in the hybrid Cenozoic magmatic rocks, whichrecycle variable amounts of the basement. The protoliths of the basement in the Argentine Puna are Neoproterozoicto Early Cambrian rocks, regionally known as the sedimentary Puncoviscana Formation, which origins from Proterozoicprotoliths.