A study by volcanologists and geologists from Lithium Americas Corporation, GNS Science and Oregon State University (United States) whose results have been published this week in the journal Science Advances confirms that the McDermitt Caldera, an extinct volcano on the border between Nevada and Oregon (United States), may host some of the largest known lithium deposits on Earth.
It is not the first time that the richness of the McDermitt caldera in this geological resource has been reported, but the work now signed by researchers Thomas Benson, Matthew Coble and John Dilles presents an unknown quantification and for the first time presents a detailed hypothesis of the formation of this volcano and the reason for the accumulation of this alkaline metal which is currently the base element for a large part of the batteries used in electric vehicles.
The known and available resources of lithium throughout the world are limited and as a raw material in new technologies it has become an element of great economic and strategic-political value.
The McDermitt caldera is approximately 45 kilometers long and 35 kilometers wide. Previous research has suggested that it formed as part of the Yellowstone hotspot, leading to the formation of a caldera sequence. Its origin dates back to approximately 19 million years ago.
In 2017, another team of researchers found evidence that a part of the caldera called Thacker Pass could be among the largest sources of lithium ever found. Lithium Americas obtained an interest in the site and began testing mining operations. Soon after, they ran into opposition from locals and Native American groups, but eventually won the right to mine at this site.
For the last two years, the company and various scientific groups have been collecting and analyzing samples, looking for the best place to start the main mining operations. But to find it, they and many other experts in the field believe they must find an explanation for how the lithium got there in the first place. In their article, the researchers suggest a theory: one that Lithium Americas plans to use to start its mining operations.
The proposed hypothesis indicates that after a volcano erupted (creating, among other things, lithium), hydrothermal enrichment occurred: magma deep underground forced its way to the center of what is now the caldera, resulting in led to the formation of the mountains of Montana.
As that happened, faults, fissures, and fractures were created, allowing lithium to seep down to the surface. This process also transformed much of the smectite into illite (different forms of lithium), which ended up along the southern edge of the basin. This complex process would explain the wealth of lithium in this volcanic area, according to the authors of the study in an informative note released by the promoting company and the universities involved in the research.
