South America’s Lithium Triangle holds approximately 43% of the world’s identified lithium resources, but differences in brine chemistry and water availability complicate efforts to turn that geological wealth into new supply.
A review by geologist José Cabello, published in September in Andean Geology, examines 43 evaluated salt flats across Argentina, Bolivia and Chile, drawing on scientific studies, company disclosures and government reports to assess the region’s lithium potential.
The three countries collectively hold 64 million tonnes of identified lithium resources, out of a global total of about 150 million tonnes, according to the US Geological Survey’s 2026 estimates. Argentina accounts for 28 million tonnes, Bolivia for 23 million and Chile for 13 million.
Cabello told MINING.COM the review’s main finding was the extensive confirmation of the quality and quantity of lithium reserves in the Central Andean salt flats. His compilation reports more than 16 million tonnes across Argentina and Chile, drawing on individual deposit estimates rather than the USGS country totals.
Those figures describe contained lithium, rather than lithium carbonate equivalent, the measure frequently used in project announcements. Resources also differ from reserves, which represent the economically recoverable portion of a deposit under defined conditions.
The distinction matters in a region where deposits vary substantially in concentration, impurities and groundwater behaviour. A large lithium inventory alone does not establish how much a project can recover, at what cost or with what environmental consequences.
The region already has around 10 operations across Argentina and Chile, alongside several projects under development, Cabello said.
His review places the evaluated deposits within a broader landscape of approximately 130 salt flats, saline lakes and lagoons in the Central Andes. Their lithium-rich brines developed through the interaction of volcanic rocks, tectonic activity and an arid climate over thousands of years.
Weathering releases lithium from surrounding rocks, and water carries it into closed basins. Evaporation then concentrates the dissolved metal, alongside other elements such as potassium, boron and magnesium.
Unlike hard-rock deposits, these resources occur in a mobile groundwater system, creating particular challenges for exploration, sampling and estimating recoverable supply.
Water trade-offs
Chile’s Salar de Atacama illustrates the advantages that favourable conditions can offer. The review attributes its development into a leading lithium brine source partly to a drier climate, fewer impurities and better export routes than some neighbouring deposits.
Argentina and Chile together produced an estimated 79,000 tonnes of lithium in 2025, equivalent to about 27% of global mine output, according to the USGS figures cited in the paper.
Cabello identified brine quality and quantity as fundamental factors shaping new developments. He highlighted Altoandinos and Pedernales in Chile, along with Hombre Muerto Oeste, Rincón, Sal de los Ángeles and Sal de Vida in Argentina, as particularly promising sites.
Expanding production elsewhere requires developers to understand how pumping will affect each basin’s groundwater system and the ecosystems it supports. Freshwater availability adds another constraint in environments already characterized by low rainfall.
Direct lithium extraction, or DLE, could help develop deposits that are less suited to conventional evaporation ponds. Developers are investing in these technologies to shorten processing times and improve the economics of extracting lithium from brines, the review says.
In his comments to MINING.COM, Cabello emphasised DLE’s potential to facilitate development by consuming less water, describing that advantage as crucial in the arid environments hosting lithium-bearing brines.
His paper, however, distinguishes between brine withdrawals and freshwater consumption, noting that the water requirements of different technologies vary. Some extraction approaches withdraw less brine but consume more freshwater, while others involve the opposite trade-off. That makes the choice of processing technology a question of local conditions as well as recovery performance.
The review’s resource compilation excludes inferred resources, a less certain geological category that could warrant additional investigation. Cabello suggests future work could examine those estimates and assess individual salt flats in greater detail. Remote reconnaissance could also help identify smaller closed basins with exploration potential.
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