A remarkable lithium deposit situated along the Nevada–Oregon border has garnered attention as it holds the potential to meet the soaring global demand for this critical metal. This discovery, featuring an estimated 20 to 40 million tonnes of lithium metal, surpasses the size of previously identified deposits, including one beneath a Bolivian salt flat previously considered the world’s largest.
In-depth analysis conducted in situ has unveiled an unconventional claystone, primarily composed of the mineral illite, which contains approximately 1.3% to 2.4% lithium within the volcanic crater. This lithium-rich claystone, found within the McDermitt caldera, remarkably contains nearly double the lithium content compared to the more common lithium-bearing clay mineral, magnesium smectite.
The geological history behind this uniquely rich volcanic deposit involves the formation of the McDermitt caldera around 16.4 million years ago, resulting from a massive volcanic eruption. Subsequent events, including the presence of a lake within the crater, weathering processes, and exposure to hot alkaline brine, contributed to the formation of lithium-rich particles within the sediments.
Researchers have proposed that a layer of illite, approximately 40 meters thick, developed in the lake sediments due to the influence of hot brine. As volcanic activity recommenced, hydrothermal fluids altered lithium-bearing smectite into illite, resulting in a claystone with a high lithium content.
Despite its unassuming appearance, described as resembling brown potter’s clay, this material contains an exceptional lithium concentration. This discovery has the potential to significantly impact the global lithium landscape, affecting factors such as pricing, supply security, and geopolitics.
Thomas Benson, a geologist at Lithium Americas Corporation, envisions the mining of this lithium-rich claystone commencing in 2026. The extraction process involves removing clay with water, followed by the separation of small lithium-bearing grains from larger minerals through centrifugation. Subsequently, the clay undergoes leaching in sulfuric acid vats to extract lithium.
The economic significance of this discovery depends on the efficiency of the lithium extraction process, which could have far-reaching implications, including ensuring a domestic supply of lithium for the United States and reducing industry concerns regarding supply shortages.
While experts acknowledge the significance of this discovery, there is some debate about the precise geological history of the crater. Nonetheless, the potential for a substantial lithium supply has garnered substantial attention within the industry.
In conclusion, this vast lithium deposit in the Nevada–Oregon border region could be a game-changer in terms of global lithium supply and its role in various industries, including clean energy and electric vehicles.