Research Professor Tim White and postdoctoral scholar Nick Sullivan will give a public talk, "Patterns and processes of lithium enrichment in coal measure strata from the Northern Appalachian Basin," at 4 p.m. on Monday, Oct. 27, in 112 Walker Building at Penn State University Park.
The free presentation, part of the EarthTalks series held by Penn State's Earth and Environmental Systems Institute (EESI), also will be available via Zoom.
White and Sullivan will discuss lithium in the Mercer Formation, a geologic formation long mined in central Pennsylvania for its coal and claystone deposits. Using new and published data, they investigated lithium variations in Mercer claystones, discovering lithium enrichment at its greatest in areas historically mined for refractory clay.
Also known as fire clay, refractory clay can stand up to high temperatures before melting or deforming. Lithium appears to be structurally bound within certain crystal structures, White and Sullivan said, likely in layers of the mineral groups chlorite or illite.
"These minerals most likely formed through pedogenic alteration of fine-grained, lithium-bearing volcanogenic material or through subsequent burial diagenesis of lithium-adsorbed clays," they wrote in their abstract for the talk. Federally classified as a critical mineral, lithium is used widely in electric vehicles, electronics and other technologies.
White, a faculty member in Penn State's Department of Geosciences, is an EESI associate and the sustainability officer for the College of Earth and Mineral Sciences. He specializes in field sedimentary geology and is passionate about environmental sustainability. Before joining Penn State, White worked in the environmental-hydrogeologic consulting industry and with the U.S. Geological Survey in Anchorage, Alaska. His recent research has focused on reconstructing the climate during the Paleocene-Eocene Thermal Maximum nearly 56 million years ago.
Sullivan, who joined EESI in fall 2024, is a geologist who studies cyclic patterns in the sedimentary record. Experienced in industry and academia, he focuses his research at EESI on Pennsylvanian cyclothems as part of Penn State's initiative in critical minerals. He is involved in new, automated mineral mapping methods using a scanning electron microscope in the Materials Characterization Lab.
White and Sullivan's talk is part of the EarthTalks fall 2025 series, "Critical Minerals - A National Economic and Security Imperative," which focuses on the need for a reliable supply chain of critical minerals and the ongoing research to provide them domestically. For more about the series, visit the EarthTalks website.
