Researchers have discovered that sediments preserved within ancient supervolcanoes host large lithium-rich clay deposits.
A domestic source of lithium is necessary to meet the rising demand for lithium, that is used in consumer electrics.
Australia and Chile current produce most of the world’s lithium, but scientists believe that large deposits could be found in the lakes surrounding American supervolcanoes. In a study published in Nature Communications, scientists detail a new method for locating lithium in supervolcanic lake deposits. The findings represent an important step in finding a new supply of the metal, since Lithium is a key strategic resource, said study co-author Gail Mahood, a professor of geological sciences at Stanford’s School of Earth, Energy & Environmental Sciences.
“We’re going to have to use electric vehicles and large storage batteries to decrease our carbon footprint,” Mahood said. “It’s important to identify lithium resources in the U.S. so that our supply does not rely on single companies or countries in a way that makes us subject to economic or political manipulation.”
Supervolcanoes are distinct from conventional active volcanoes, in the sense that the eruption of a supervolcano can produce thousands of cubic kilometres of magma, up to 10 000 times the amount a normal volcano can produce. They also produce massive quantities of pumice and volcanic ash that are spread over wide areas. The shape of the supervolcano also appear as distinct huge holes in the ground, known as calderas. The resulting caldera often fills with water to form a lake, an example of this being Oregon’s Crater Lake. Over tens of thousands of years, rainfall and hot springs leach out lithium from the volcanic deposits. The lithium accumulates, along with sediments, in the caldera lake, where it becomes concentrated in a clay called hectorite. Exploring supervolcanoes for lithium would diversify its global supply. Currently most lithium deposits are currently mined from brine deposits in high-altitude salt flats in Chile and pegmatite deposits in Australia. Such supervolcanoes pose little risk of eruption because they are ancient.
“The caldera is the ideal depositional basin for all this lithium,” said lead author Thomas Benson, a recent PhD graduate at Stanford Earth, who began working on the study in 2012.
Since its discovery in the 1800s, lithium has largely been used in psychiatric treatments and nuclear weapons. Beginning in the 2000s, lithium became the major component of lithium-ion batteries, which today provide portable power for everything from cellphones and laptops to electric cars. Volvo Cars recently announced its commitment to only produce new models of its vehicles as hybrids or battery-powered options beginning in 2019, a sign that demand for lithium-ion batteries will continue to increase.
“We’ve had a gold rush, so we know how, why and where gold occurs, but we never had a lithium rush,” Benson said. “The demand for lithium has outpaced the scientific understanding of the resource, so it’s essential for the fundamental science behind these resources to catch up.”