| Basis for focus area |
Brine, Li clay, evaporite in outline of Willcox Playa, and Upper Gila-San Carlos Reservoir, Lordsburg playa and Animas Valley HUC8 boundaries that contain Li exploration projects for brine (salars). Lithium exploration projects and high Li in NURE geochemistry in New Mexico include Buckhorn area. The Popotosa Formation in this focus area is reported to contain as much as 1200 ppm Li in playa deposits (Brenner-Tourtelot and Machette, 1979). Estancia Basin also may have potential (McLemore, 2021). |
| Identified resources |
None. |
| Production |
None. |
| Status |
Current exploration in New Mexico, including proposed drilling. Current exploration of Wilcox Playa in Arizona by Stria Lithium. |
| Estimated resources |
None. |
| Geologic maps |
Cooper (1960), scale 1:62,500; Wilson (1959), scale 1:375,000; Thorman and Drewes (1978), scale 1:24,000; Machette (1978), scale 1:24,000; Fleischhauer and Stone (1982), scale 1:48.000. |
| Geophysical data |
Inadequate aeromagnetic and aeroradiometric coverage. |
| Favorable rocks and structures |
Playa lakes and brines. |
| Deposits |
Lordsburg Lithium Project (Hawkstone Mining), Wilcox Lithium Project (Lithium Energy Products), Buckhorn area (McLemore, 2021). |
| Evidence from mineral occurrences |
NURE water and sediment geochemistry, current exploration. |
| Geochemical evidence |
NURE water and sediment geochemistry. A NURE stream sediment sample near the Lordsburg playa contained 124 ppm Li and a water sample contained 4,896 ppb Li. |
| Geophysical evidence |
Inadequate Rank 4 and 5 aeromagnetic and aeroradiometric coverage. |
| Evidence from other sources |
McIntosh and Bryan (2000); Fleischhauer and Stone (1982); O'Brien and Stone (1982); https://www.emnrd.nm.gov/mmd/mining-act-reclamation-program/pending-and-approved-exploration-applications/minimal-impact/hi018em-lordsburg-playa-lithium-in-brine-exploration/. |
| Comments |
Exploration has happened in the Wilcox and Lordsburg playas. The Lordsburg Lithium Project in the Animas Valley, a closed basin with a playa surface, bounded by the Pyramid Mountains to the east and Peloncillo Mountains to the west and comprises of clays, silts and highly saline brines. Additional mapping and geophysics would aid in better understanding of hydrology and energy systems in the area. Geophysics should include the nearby Lordsburg metal district where exploration for porphyry Cu is occurring. Exploration is ongoing in the Wilcox and Lordsburg playas, and there may be potential in the Buckhorn area. Lithium potential in New Mexico playa lakes is underestimated (McLemore, 2021). Neogene volcanic rocks to south of Willcox Playa and sedimentary rocks drilled by USGS encountered Li-bearing sediments, but Li-content in water was very low. |
| Cover thickness and description |
Surface, shallow subsurface. |
| Authors |
Lisa L. Stillings, Carson A. Richardson, Virginia T. McLemore, Shari Kelley. |
| New data needs |
Geologic mapping of playa lakes, geochemistry of rhyolites in adjacent mountain ranges, aeromagnetic, gravity (include Lordsburg district and Buckhorn area). Detailed geologic mapping of this area has been minimal with most geologic maps of the area are at a scale >1:50,000. There are volcanic rocks south of Willcox playa that could benefit from new geologic mapping as they have not been remapped or fully described since the 1960s or earlier. Breaking them out and conducting geochemical analyses on them would be beneficial to help determine their potential role in contributing to the hydrology of the basin. |
| Geologic mapping and modeling needs |
The Lordsburg playas are on the Model and Summit 7.5 minute quadrangle; neither quadrangle has been mapped. The USGS I-1151 map of Thorman and Drewes (1978) of the adjacent Gary quadrangle shows shoreline deposits, but includes no detailed description or geochemistry of these units. Models for Li brines and clays both require a Li source, and the source will be Neogene middle Cenozoic volcanic and sedimentary rocks within a HUC or within a neighboring HUC. For Lordsburg, source rocks in the Pyramid Mountains and Peloncillo Mountains need to be sampled and analyzed for Li and other trace elements. Mapping could identify these lithologies and their location with respect to basins (in the center of a HUC). Mapping of the playas needed. Geochronology on when the clays formed and fossils will aid in age dating. Water chemistry needed. Chemistry of source rhyolites. Although the geochronology of the rhyolites is well characterized, some additional data may be needed. |
| Geophysical survey and modeling needs |
Any geophysics (especially gravity) that can define basin depth, geometry, volume, cross-cutting structures would be helpful for calculating the volume of brine, where to drill in the basin, or whether basin fluids might flow into an adjacent basin. |
| Digital elevation data needs |
Lidar complete or in progress over much of the area; incomplete in the northwest. |
