Huge reserve of ‘hidden treasures’ found beneath Arkansas

A US Geological Survey (USGS)-led investigation has uncovered a massive lithium deposit in southwestern Arkansas that could potentially revolutionize the global electric vehicle industry.

Using innovative water testing methods combined with machine learning, researchers estimate that the region contains between 5 and 19 million tons of lithium reserves – enough to meet nine times the expected global demand for lithium in car batteries by 2030.

The discovery focuses on lithium-rich brines in the Smackover Formation, an ancient seafloor that extends across several southern states. The finding is particularly important because it could reduce US dependence on raw material imports.

“Lithium is a critical mineral for the energy transition, and the potential for increased U.S. production to replace imports has implications for jobs, production and supply chain resiliency,” said David Applegate, director of the USGS, in a statement declaration. “This study illustrates the value of science in addressing economically important issues.”

According to the World Economic Forum, the US was the world’s largest producer of lithium in the 1990s. However, in 2021, lithium was responsible for just 1 percent of global production, despite its critical role in powering the coming electric vehicle boom.

Lithium is often called the “white gold” of the energy transition – or, as the USGS puts it, “hidden treasure” – because of its crucial role in battery technology that will power the green revolution.

“Our study was for the first time able to estimate total lithium content in the southwestern part of the Smackover in Arkansas,” Katherine Knierim, the study’s lead researcher, said in a statement. “We estimate there is enough dissolved lithium in that region to replace U.S. imports of lithium and more.”

But Knierim urged caution, stating that “these estimates are an internal assessment. We have not estimated what is technically recoverable based on newer methods of extracting lithium from brine.”

The discovery comes at a crucial time as global demand for lithium continues to rise, driven by the rapid adoption of electric vehicles and renewable energy technologies. Currently, the US relies on imports for more than 25 percent of its lithium needs.

Energy company Exxon Mobil has already taken steps to tap this promising resource. The company has drilled exploratory wells in Arkansas and is actively evaluating the economic viability of lithium mining in the region.

The company has set ambitious production goals, aiming to begin mining lithium by 2027. By 2030, Exxon plans to produce enough lithium to supply more than one million electric vehicles annually.

The Smackover Formation, which dates back to the Jurassic period, is already known for its oil and bromine deposits. It extends beyond Arkansas into parts of Louisiana, Texas, Alabama, Mississippi and Florida.

The potential extraction of lithium from brines co-produced during oil and gas operations provides an opportunity to harvest valuable resources from what would otherwise be considered waste material.

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Reference

Knierim, K.J., Blondes, M.S., Masterson, A., Freeman, P., McDevitt, B., Herzberg, A., Li, P., Mills, C., Doolan, C., Jubb, A.M., Ausbrooks, S.M. , & Chenault, J. (2024). Evaluating the lithium resource in the Smackover Formation brine of southern Arkansas using machine learning. ScienceProgress, 10(39). https://doi.org/10.1126/sciadv.adp8149