Lithium Discovered in US Could Be Biggest Deposit Ever

A substantial lithium deposit located along the Nevada–Oregon border has the potential to meet the growing global demand for lithium, according to a recent analysis. This deposit, estimated to contain 20 to 40 million tonnes of lithium metal, surpasses the previously largest lithium deposit found beneath a Bolivian salt flat. However, mining at this site is contentious due to its cultural significance to Native Americans and its historical association with a massacre in 1865.

The analysis revealed that an unusual claystone, composed mainly of the mineral illite, contains 1.3% to 2.4% of lithium in the volcanic crater, nearly double the lithium content found in the more common magnesium smectite clay mineral. This unique deposit was formed within the McDermitt caldera, created around 16.4 million years ago by a massive volcanic explosion.

A lake later formed in the crater, and weathered volcanic and surrounding materials formed a clay-rich sediment at its bottom. Subsequent volcanic activity exposed the sediments to a hot, alkaline brine rich in lithium and potassium, leading to the formation of the lithium-rich claystone.

While some experts have questioned the proposed timeline of the crater’s geological history, the discovery has the potential to significantly impact the lithium market by providing a domestic supply source for the United States. The mining process is expected to begin in 2026, involving the extraction of lithium-bearing grains from the clay, followed by leaching to extract the lithium.

The unique nature of this lithium-rich claystone suggests that future exploration for lithium deposits should focus on similar volcanic calderas with hydrothermally altered lake sediments, which have the potential to become valuable lithium sources.