272-3 Revised tectonic framework for the Clayton Valley, NV volcano-sedimentary lithium deposits

Session: Faults, Fractures, and Geomechanics for the Energy Transition (Posters)

Poster Booth No.: 243

Presenting Author:

Isaac Rangel

Authors:

Rangel, Isaac A.¹, CAWOOD, ADAM J.², Butler, Kristina³, Sickmann, Zachary T.⁴, Blake, Madigan⁵, Swanson, Brandon⁶, Ibarra, Daniel Enrique⁷, Gagnon, Catherine Anne⁸, Munk, Lee Ann⁹, Boutt, David¹⁰, Ferrill, David A.¹¹, Smart, Kevin J.¹²

Abstract:

Clayton Valley, Nevada, hosts the only commercial lithium-producing mine in the United States. The structural evolution of the basin and the role of extensional tectonics in lithium sourcing, enrichment, and trapping remains poorly understood. We present new U-Pb zircon ages coupled with subsurface and outcrop data to generate a refined tectonic framework for the structural and depositional history of the Clayton Valley system. The basin evolution reflects a history of extensional deformation, including low-angle detachment faulting and high-angle normal faulting in response to regional Basin and Range extension and right-lateral motion along the Furnace Creek Fault. Sedimentary infill of fault-bounded extensional basins is composed of sediment shed from surrounding mountain ranges, which expose exhumed Precambrian to lower Paleozoic rocks representing both upper and lower plates of regional detachment faults, along with overlying Tertiary volcanics. The late Miocene-Pleistocene Esmeralda Formation represents a sequence of interbedded volcaniclastic, siliciclastic, and evaporite deposits that constitute the primary basin fill and contain the highest concentrations of lithium across the basin. Our new U-Pb zircon data from subaerial exposures of the Esmeralda Formation yielded ages between 6.3 ± 0.06 and 2.17 ± 0.04 Ma, providing revised depositional timing and allowing for chronostratigraphic correlation to previously dated subsurface units, including a lithic tuff (~6.1 Ma) and lithium-rich lacustrine muds (~3.0 Ma to present). These data indicate that surface exposures east and southeast of Angel Island are broadly equivalent in age to subsurface brine reservoirs in central Clayton Valley, and that outcrops in eastern Clayton Valley are highly relevant analogs for subsurface lithium brine reservoir units. Our refined tectonic framework model and structural cross sections integrate geochronologic data, geologic mapping, and subsurface data to build upon existing basin reconstruction models. We find that the current basin configuration at Clayton Valley is due to (1) early regional extension and low-angle detachment faulting generating older half-graben extensional basins filled with Miocene (ca. 15-17 Ma) sequences of volcano sedimentary deposits, and (2) more recent (6 Ma and younger) higher-angle normal faulting that generated accommodation space for deposition of  interbedded volcaniclastic, siliciclastic, and evaporite units. This tectonic framework is consistent with previous outcrop studies in and around Clayton Valley, and more generally, with deformation styles characteristic of the Basin and Range province and other analogous extensional systems.  

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-9119

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