EARTH MRI AIRBORNE ELECTROMAGNETIC SURVEY REVEALS GRAPHITE POTENTIAL AND TECTONIC COMPLEXITY OF THE ALABAMA GRAPHITE-VANADIUM BELT

Graphite, a critical mineral essential for green energy technologies, plays a pivotal role in achieving sustainable development goals for the energy storage and transportation sectors. However, the United States heavily relies on foreign sources of graphite with no current domestic production. Historically, flake graphite was mined in the Alabama Graphite-Vanadium Belt, within the Piedmont Province of the southern Appalachian Mountains. To aid in graphite resource assessment and unraveling the tectonic complexities of this region, the U.S. Geological Survey, in collaboration with the Geological Survey of Alabama, conducted an airborne electromagnetic survey in spring 2023 as part of the Earth MRI program. Electromagnetic methods are well suited for graphite resource studies, as graphite-bearing deposits are highly conductive.

Key results of the survey include detailed mapping of potential graphite resources and geologic structures. Resistivity models generated from survey data 1) directly map graphite-bearing lithologies within the Higgins Ferry and Poe Bridge Mountain Groups and the thickness of overlying weathered graphitic zones which were the target of most historic mining; 2) map graphite-bearing lithologies in the Wedowee Group, Emuckfaw Group, and other units; 3) indicate potential continuations of the graphite belt beneath the Coastal Plain, the Millerville Reentrant; and 4) image province- and terrane-bounding faults and provide constraints on subsurface geological structures.

The identification of graphite-bearing formations and the potential extension of the Alabama Graphite-Vanadium Belt into previously unexplored areas provide constraints on quantitative graphite resource assessments, while insights gained into the complex structures of the southern Appalachians contribute to our understanding of the geodynamic processes that shaped this region.