DOI: 10.5066/p13fkbut
title: Rare Earth Element (REE), Critical Mineral, and Geochemical Characterization of Manganese Oxide Ore Deposits in the Virginia Piedmont and Valley & Ridge

description: Manganese is a designated critical mineral, being industrially utilized for producing steel and batteries, including in the production of electric vehicles (Rozelle and others, 2021). The eastern United States hosts hundreds of manganese oxide mines that served steel production until their abandonment in the mid-twentieth century (Pegau, 1958). Many relict mines still feature accessible pits, waste rock, and unmined ore materials to varying degrees. Preliminary assessments of supergene manganese oxides in the Appalachian Mountains have revealed extensive enrichment in critical minerals and rare earth elements (REE) (Carmichael and others, 2017; Odom, 2020). The Appalachian Manganese Oxide Research Effort (AMORE) was established to: (1) characterize the location and extent of Appalachian manganese oxide mines using artificial intelligence mapping applied to high-resolution lidar elevation models and (2) assess the geochemical nature of remnant manganese oxide ore in the context of critical minerals. Previous work done through AMORE has examined distributions of REE and critical minerals in the Appalachian Mountains of Tennessee, Virginia, and West Virginia (Odom and others, 2025).

We expand upon this work by presenting new geochemical data of manganese oxide ores and associated materials in the Piedmont and Valley & Ridge provinces of Virginia. Manganese oxide ores included massive manganese oxide growths, botryoidal nodules, manganese oxide-cemented breccias and sandstones, and quartzites with manganese oxide veneers. Associated materials included iron oxide ores, bedrock, and soils. The following concentrations are reported following an SiO2 content correction that assumes negligible REE enrichment in quartz. This correction was performed because some of these samples contained abundant quartz, which typically features extremely low concentrations of REE (Götze and others, 2023). Total REE content varied widely between samples, with cerium (Ce) present in the greatest abundance (median concentration across all samples = 239 ppm). Other REE with median concentrations ≥ 100 ppm across all samples were yttrium, lathanum, and neodymium. Cobalt, a superalloy and battery component, was notably high in nodules (median concentration = 2,131 ppm), sandstone cements (median concentration = 1,917 ppm), and breccias (median concentration = 1,829 ppm). Additional concentrated critical minerals and their median concentrations across manganese oxide ores include barium (12,480 ppm), zinc (739 ppm), and nickel (277 ppm). Ongoing work seeks to identify potential relationships between manganese oxide phase and critical element enrichment within given sample morphologies.

References

Carmichael, S. K., Doctor, D. H., Wilson, C. G., Feierstein, J., & McAleer, R. J. (2017). New insight into the origin of manganese oxide ore deposits in the Appalachian Valley and Ridge of northeastern Tennessee and northern Virginia, USA. GSA Bulletin, 129(9-10), 1158-1180. https://doi.org/10.1130/B31682.1
Götze, J., Pan, Y., & Müller, A. (2021). Mineralogy and mineral chemistry of quartz: A review. Mineralogical Magazine, 85(5), 639-664.
Odom, W.E. (2020). Dating the Cenozoic incision history of the Tennessee and Shenandoah Rivers with cosmogenic nuclides and 40Ar/39Ar in manganese oxides [Ph.D. dissertation]: West Lafayette, Indiana, Purdue University, 309 p., https://doi.org/10.25394/PGS.13275017.v1
Odom, W.E., Doctor, D.H., McAleer, R.J., Benton, J.R., Gray, A.A., Pitts, A.D., 2025, Rare Earth Element (REE), Critical Mineral, and Geochemical Characterization of Manganese Oxide Ore Deposits in the Appalachian Mountains of Tennessee, Virginia, and West Virginia: U.S. Geological Survey data release, https://doi.org/10.5066/P13WA9AS
Pegau, A.A. (1958). Virginia manganese minerals and ores, Virginia Division of Mineral Resources, Mineral Resources Circular No. 7.
Rozelle, P. L., Mamula, N., Arnold, B. J., O’Brien, T., Rezaee, M., & Pisupati, S. V. (2021). Secondary Cobalt and Manganese Resources in Pennsylvania: Quantities, Linkage with Mine Reclamation, and Preliminary Flowsheet Evaluation for the US Domestic Lithium-Ion Battery Supply Chain. The Pennsylvania State University, Center for Critical Minerals, University Park.