Lithium Brines<subtitle>A Global Perspective</subtitle>

Regional groundwater flow and accumulation of a massive evaporite deposit at the margin of the Chilean Altiplano

“…Arid, tectonically active regions may accumulate continental brines in closed basins that host economic lithium resources and rare ecosystems and preserve distinct paleoclimatic, geologic, and geochemical records in the form of evaporite accumulation [e.g., Munk et al, 2016;Lowenstein et al, 2003;Houston et al, 2011]. Demand for lithium, critical to Li-ion batteries and pharmaceuticals, has been increasing, and lithium brine deposits represent an important global resource.…”

“…Demand for lithium, critical to Li-ion batteries and pharmaceuticals, has been increasing, and lithium brine deposits represent an important global resource. These Li-brine deposits occur in arid regions where groundwater flow paths converge into closed basins and discharge through evapotranspiration, concentrating and precipitating solutes into evaporite minerals and high-conductivity brines [Munk et al, 2016]. Therefore, these depocenters integrate hydrologic, geochemical, paleoclimatic, and tectonic processes interacting across multiple spatial and temporal scales and permit evaluation of fundamental questions about water and solute movement along orogenic margins.…”

Andean hypersaline lakes in the Atacama Desert, northern Chile: Between lithium exploitation and unique biodiversity conservation

“…The Salar (3,067 km 2 ), located over 2,300 m above sea level in the Altiplano-Puna region of the Central Andes, is flanked by the Pacific Ocean to the west and the mountains to the east. It contains the world's largest lithium reserves and exploitation from brines (Cubillos, Aguilar, Grágeda, & Dorador, 2018) with the highest average lithium concentration: 1,400 mg/L; range: 900-7,000 (Munk et al, 2016).…”

“…Salar de Atacama's lithium richness originated by a combination of geological and climatic factors commonly found in lithium-producing countries in the Andes such as Argentina, Chile, and Bolivia, the so-called lithium triangle. These are: arid climate, a closed evaporitic basin containing a salt flat and salty lagoons or brines, volcanic and hydrothermal activities that leach lithium from volcanic rocks that is drained underground to the basin floor (aquifer), and a prolonged history that has allowed to concentrate brines (see Munk et al, 2016). Several channels and small shallow hypersaline lagoons are important staging areas for interhemispheric migrations for birds such as Baird's Sandpiper (Calidris bairdii), Greater yellowlegs (Tringa melanoleuca), Lesser yellowlegs (Tringa flavipes), and Wilson's phalarope (Phalaropus tricolor), but also are habitat for three South American flamingo species: Chilean flamingo (Phoenicopterus chilensis), James's flamingo (Phoenicoparrus jamesi), and Andean flamingo (Phoenicoparrus andinus).…”

“…Despite the international recognition of these hypersaline lagoons and wetlands as invaluable natural resources, conservation efforts are needed to maintain their intrinsic value and biodiversity under a future scenario of continued or even increased aridity, water shortage and increased brine diversion by lithium companies. Salar de Atacama has longstanding arid climate stability (aridity index: 0, 0326) with evaporation rate (1,440 mm/year) exceeding rainfall (39 mm/year) (Munk et al, 2016; see also Cubillos et al, 2018). Nevertheless, highly unusual summer rains (December-March) have flooded the area in recent years (Azua-Bustos et al, 2018).…”