Background
The rapid expansion of global lithium demand poses major challenges for U.S. energy independence, as domestic production accounts for only a small fraction of global supply. To reduce reliance on foreign imports, new exploration strategies must resolve the geologic processes and timescales that lead to lithium enrichment in closed-basin settings. This project is a spinoff of the SPRINT IR&D project, “Toward Domestic Lithium Independence: Tectonic Controls on Critical Emerging Lithium Deposits” (15-R6492; PI Cawood) and is more directly focused on the application of advanced geochemical techniques to improve understanding of fluid chemistry, mineralization conditions, and fault timing in and around Clayton Valley, Nevada. Specifically, the project evaluated the role of faults and fractures as conduits or barriers to groundwater flow and assessed whether these structures facilitated lithium transport and enrichment within the basin.
Approach
The project objective was to test an integrated suite of sophisticated techniques to analyze the chemistry, temperature, and timing of calcite veins deposited along structurally controlled fluid pathways associated with lithium deposits in the western U.S., with a specific focus on Clayton Valley, Nevada. To address this objective, the project team performed a series of technical tasks, including (i) field work and collection of calcite samples from faults, fractures, and spring deposits in and around Clayton Valley, Nevada; (ii) laboratory analysis to determine elemental composition, including lithium and other trace elements; (iii) uranium-lead (U-Pb) calcite geochronology of calcite veins to establish sample ages; and (iv) stable and clumped isotope analysis to investigate lithium sourcing and transport, and to estimate calcite mineralization temperatures. This approach was aimed at improving our understanding of the structural and geochemical controls on timing, sources, and migration pathways of lithium-bearing fluids in fault-controlled systems, which are essential for refining exploration models for lithium brines and volcano-sedimentary lithium deposits critical for reaching domestic lithium production targets.
Accomplishments
Geochemical analyses showed that lithium concentrations in calcite veins and spring deposits ranged from <2 to 460 parts per million for analyzed samples, suggesting episodic transport of lithium-enriched brines along faults and fractures in Clayton Valley and the surrounding areas. U-Pb calcite ages spanned ~241 to 4 Ma, indicating a long structural history, with younger ages consistent with Basin and Range tectonism and Clayton Valley basin development, supporting tectonic controls on lithium enrichment and accumulation development. Clumped isotope thermometry yielded calcite crystallization temperatures from ~25°C to ~140°C, with higher-temperature values linked to basement-hosted structures, consistent with deep-sourced fluids and associated potential transport of lithium from deep crustal sources. Stable isotopic compositions suggest mixing of meteoric waters and deeply sourced, evolved fluids, providing evidence for fluid flow and associated mixing of crustal fluids within fault and fracture networks in the subsurface. Collectively, these results demonstrate that lithium enrichment in Clayton Valley is a protracted, structurally controlled process, emphasizing the importance of integrating structural geology with geochemical techniques to refine exploration models for domestic lithium resources.
Presentations
Cawood, A., Ferrill, D., Rangel-Landeros, I., Butler, K., Sickmann, Z., Blake, M., Ibarra, D., Swanson, B., Munk, L., Boutt, D., Stockli, L., Stockli, D., and Gagnon, C., 2025, Geochemical constraints on lithium transport in fault and fracture systems: Geological Society of America Abstracts with Programs, Vol. 57, No. 6, Paper No. 272-9. GSA Connects 2025 – Geological Society of America Annual Meeting, San Antonio, Texas.
Rangel, I., Cawood, A., Butler, K., Sickmann, Z., Blake, M., Swanson, B., Ibarra, D., Gagnon, C., Munk, L., Boutt, D., Ferrill, D., and Smart, K., 2025, Revised tectonic framework for the Clayton Valley, NV volcano-sedimentary lithium deposits. Geological Society of America Abstracts with Programs, Vol. 57, No. 6, Paper No. 272-3. GSA Connects 2025 – Geological Society of America Annual Meeting, San Antonio, Texas.