Battery Metals
September 13, 2023

McDermitt Caldera: Unearthing the Earths Largest Lithium Treasure Trove

Exploring the Ancient Volcano that Could Power Our Future

A team of American geologists have identified what appears to be a colossal lithium deposit within an ancient supervolcano. Located on the Nevada-Oregon border, the Mcdermitt Caldera, a large volcanic crater that hosts claystone’s containing 20-40M metric tons of lithium and could be enough to meet global demand for decades to come. This could give the US a massive boot to it’s EV supply chain which was already struggling to meet demands.

A claystone is a type of hard mud rock that doesn’t easily break into thin layers. To be called a claystone, it needs to have about half or less of its particles made up of tiny clay bits that are much smaller than a grain of sand. Clay minerals are really common in mud rocks and there are 35 different types of clay minerals found on Earth. Other particles and minerals like quartz, feldspar and certain types of rocks can also wear down to become as small as clay particles.

This estimated resource dwarfs in comparison to the amount of lithium found in Bolivia’s salt flats. One that has held the record for the highest lithium resource found at 23M metric tons. Even if this estimation is grossly high, the lithium inventory contained in McDermitt Caldera would still be on par with the 10.2M tonnes estimated to be contained in what was previously considered to be the planets largest lithium deposit. More importantly, the lithium that miners plan to extract from the caldera can be collected in a way that’s allegedly less harmful to the environment.

The two main methods of extraction are mining the resources ore from the Earth and brine recovery. Brine recovery, requires heating up rocks to more than 1000° Fahrenheit using up a significant amount of fossil fuels and the latter is costly, labour intensive and requires pumping out underground aquifers – causing the land to sink and making it irreversibly denser, increasing surface flooding and permanently possible contamination. However due to the way the caldera was formed, harvesting its lithium could be done through a third process where mining it in the right places will yield abundant lithium and leaves minimal waste.

Fig. 1: Google Map screenshot of McDermitt Caldera, where Thacker Pass is located, an area that is well-known for it's lithium-rich ore.

The Bureau of Land Management is currently seeking public input in response to the proposal to expand lithium exploration in the McDermitt Caldera area in anticipation of future mining. however, this proposal has already drawn criticism from area tribes.

At present, the primary sources of lithium are predominantly found in two geological formations: pegmatites and greisen veins, known as hard rock sources and evaporitic brines in high-elevation areas as depicted in Fig. 2.

Fig. 2: primary sources of lithium extracted according to resource type

The McDermitt Caldera introduces a new category of lithium resource known as volcanic sedimentary. This type of resource is located in sediment deposits associated with regions of silicic volcanic activity. This caldera is estimated to gave formed 19 million years ago, with its most recent eruption occurring 16 million years ago. Geologists propose that this volcanic event resulted in the emergence of lithium-rich smectite clay. The explosion also created faults and fractures, establishing pathways through which lithium could ascend to the surface.

This massive Lithium discovery is one of many multiple global endeavours to explore  global electrification, a worldwide transition from traditional energy sources, such as fossil fuels (coal, oil, natural gas), towards greater reliance on electricity as a primary energy carrier. This shift is driven by several interconnected factors such as environmental concerns, technological advancements, and the desire for energy efficiency. The renewable energy segment held the largest market share last year and is expected to grow more in the next ten years. Transportation, specifically in the use of Electric Vehicles (EVs) dominated the electrification market and is expected to continue growing exponentially in the following years. Currently, North America is dominated the global electrification market with the highest revenue share in 2022.

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