RESTON, VA—Lithium is a critical ingredient in electric vehicle batteries. The lightweight material, which is used to produce cathodes, traditionally comes from countires such as Australia, Chile and China. However, a major deposit of lithium has been discovered in Arkansas.
Using a combination of water testing and machine learning, a U.S. Geological Survey (USGS)-led study estimates that between 5 and 19 million tons of lithium reserves are located beneath southwestern Arkansas as part of the Smackover Formation. If commercially recoverable, the amount of lithium present would meet projected 2030 world demand for lithium in car batteries nine times over.
“Lithium is a critical mineral for the energy transition, and the potential for increased U.S. production to replace imports has implications for employment, manufacturing and supply-chain resilience. This study illustrates the value of science in addressing economically important issues,” says David Applegate, USGS director.
“Our research was able to estimate total lithium present in the southwestern portion of the Smackover in Arkansas for the first time,” adds Katherine Knierim, a USGS hydrologist and the study’s principal researcher. “We estimate there is enough dissolved lithium present in that region to replace U.S. imports of lithium and more.
“It is important to caution that these estimates are an in-place assessment,” warns Knierim. “We have not estimated what is technically recoverable based on newer methods to extract lithium from brines.”
The Smackover Formation is a relic of an ancient sea that left an extensive, porous and permeable limestone geologic unit that extends under parts of Alabama, Arkansas, Florida, Louisiana, Mississippi and Texas. It dates to the Jurassic geological time period and is known for its rich deposits of oil and bromine. In recent years, the Smackover Formation has also gained attention for potential lithium in brines—high-salinity waters associated with deep salt deposits.
