USGS: Lithium in Carolinas Could Replace Imports for a Century or More
RESTON, Va. — The southern Appalachian region of the eastern United States contains an estimated 1.43 million metric tons of undiscovered, economically recoverable lithium oxide, enough to replace 201 years of U.S. imports at last year’s level, according to new research by the U.S. Geological Survey.
The lithium is concentrated in the Carolinas, according to estimates in a new USGS scientific paper published in Natural Resources Research, companion to a similar study that estimated 900,000 metric tons of lithium oxide in the northern Appalachians. The lithium is present in pegmatites, large-grained rocks similar to granite.
World lithium production has grown more than 40 times in the past 30 years, driven by the need for lithium-ion batteries that power computers, military equipment, vehicles, phones, electric tools, and energy-grid storage, as well as in aerospace alloys. The USGS study estimated the undiscovered total that could be produced at current prices to meet lithium demand.
Before the boom in lithium demand, North Carolina’s Kings Mountain and Hallman-Beam mines produced lithium from pegmatites but closed in the 1990s when production shifted to lower-cost sources such as lithium from dried lakebeds in South America and pegmatites in Australia. At the time, lithium was principally used for ceramics, glass and lubricating grease.
“This research shows that the Carolinas contain enough lithium to help meet the nation’s growing needs – a major contribution to U.S. mineral security, at a time when global lithium demand is rising rapidly,” said USGS Director Ned Mamula. “USGS mineral science is the leading edge in the effort to restore America’s mineral independence by mapping our nation’s mineral resources. Everything else follows on the science: permitting reform and other policy changes to support investment in clean, responsible mining to 21st century standards, and mining workforce training for new American jobs. The United States was the dominant world producer of lithium three decades ago when North Carolina’s lithium mines were active, and while the USGS is assessing many other lithium resources, this research highlights the abundant domestic potential.”
The estimated 1.43 million metric tons of lithium oxide in the southern Appalachian region would be enough lithium for batteries in:
- 1 million grid-scale batteries large enough to stabilize an electric grid
- 80 million electric vehicles
- 110 billion laptops, or a 600 year-supply of laptops for the world (at 2025 levels)
- 300 billion cellphones, or 36 cellphones for each person on earth
The United States has one sole producer of lithium and relied on imports for more than half the lithium used last year, factors that contributed to its inclusion on the 2025 List of Critical Minerals published by the USGS. The United States also imports lithium indirectly, in the form of lithium-ion batteries inside finished products. While Australia is the world’s largest producer of lithium, China is second, and accounts for the majority of world lithium refining and consumption.
The USGS projects that world production capacity for lithium will double again by 2029, driven by increasing demand. Lithium supply security has become a priority for technology companies.
Assessing the mineral resources of the United States has been a responsibility of the USGS since it was created in 1879. Its mission was reinforced in the Energy Act of 2020, which called on the USGS to assess all minerals and the USGS is playing a major role in implementing Executive Orders 14154, Unleashing American Energy, and 14241, Immediate Measures to Increase American Mineral Production.
These studies present the 50% confidence level, meaning there is an equal chance that the southern Appalachians contain more or less than 1.43 million metric tons of lithium oxide. There is 90% confidence of at least 60,000 metric tons, and a 10% probability that as much as 6.9 million metric tons that remain undiscovered in the southern Appalachians alone. The median estimate of 2.2 million metric tons of resource in place was then screened for economic recoverability based on global lithium mining experience and lithium prices.
Lithium pegmatites in the Appalachian region have long attracted scientific attention – the Kings Mountain area of North Carolina was the site of the first large-scale lithium pegmatite mining in the United States, and large Maine deposits have been studied. The new USGS assessments build on that legacy with a more systematic, detailed approach.
A team of USGS geologists worked together on the northern and southern assessments, combining geologic maps, tectonic history, geochemical sampling, geophysical surveys, and records of mineral occurrences. They then conducted simulations using a global dataset for lithium pegmatites to estimate how many undiscovered lithium deposits there are in the study area, and how much lithium they hold.
Lithium-rich pegmatites in the southern Appalachians formed from the same geologic forces that built the mountains more than 250 million years ago. The high heat and pressure during the mountain-building caused some of the deeper crustal rocks to melt, and some of these magmas were rich in lithium. This melting occurred when plate tectonics forced Africa, Europe, and North America together into a supercontinent named Pangea. Pegmatites like the ones found in the Appalachian mountain belt are found in corresponding areas of Ireland and Portugal, both of which formerly bordered the Appalachians.
The southern Appalachian study completes the USGS lithium assessment of the region. USGS scientists continue to assess other domestic sources of lithium to complete a national assessment, including in California lakebeds, volcanic deposits in Nevada, and wastes from energy production along the Gulf Coast. In 2024, USGS researchers assessed that a resource of 5 to 19 million metric tons of lithium is present in brines in the Smackover Formation of southwest Arkansas. The USGS did not assess what amount would be economically recoverable.
Read the southern Appalachians lithium assessment. This assessment was conducted by the USGS Mineral Resources Program as part of the Mineral Resource Assessment Training project. An accompanying data release is available.
Source: U.S. Geological Survey