Leucite Hills volcanics

Region West, Rocky Mountains
Mineral systems
Deposit types
Critical minerals
Other minerals

Information leading to the delineation of this focus area

Basis for focus area The ca. 3.1–0.9 Ma Leucite Hills volcanic field is composed of lamproitic ultrapotassic mafic volcanoes. It is one of the world's largest lamproite fields in the world and lies on the Rock Springs uplift. Hausel (2006) notes it has potential for potash and diamond resources. Wyoming State Geological Survey data indicate elevated concentrations (5 times crustal abundance) of Ba, Cr, Hf, and Zr.
Identified resources Historical production during WWI for KCl (potash).
Production Unknown amount mined from Zirkel Mesa during WWI for potash (KCl). Liberty Potash Company mined Zirkel Mesa for KCl to use in fertilizer (Hausel, 2006, Thoenen, 1932).
Status Zirkel Mesa mined during WWI for potash.
Estimated resources Schultz and Cross (1912) estimated approximately 200 tons potash for the entire Leucite Hills field. However, Johnston (1959), Smithson (1959), and Ogden (1979) suggest that this estimate may be too high due to inaccuracies in deposit thickness and K2O percent concentration.
Geologic maps Hausel (2006, plate 1), scale 1:100,000; Jones and Scott (2010), scale 1:100,000.
Geophysical data Inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Ultrapotassic mafic lamproites (wyomingite, madupite, orendite), perhaps(?) controlled by major structures of the Rock Springs uplift and/or regional lineaments.
Deposits Zirkel Mesa (MRDS dep_id: 10303263), North Table Mountain (MRDS dep_id: 10134639), Boar's Tusk (MRDS dep_id: 10303401), Table Mountain (MRDS dep_id: 10206251).
Evidence from mineral occurrences MRDS.
Geochemical evidence The Wyoming State Geological Survey mines and minerals database (Sutherland and others, 2018) indicates elevated concentrations (5 times crustal abundance) of Ba, Cr, Hf, and Zr in Leucite Hills samples; Carmichael (1967), Kuehner (1980), and Ogden (1979) reported Wyoming lamproites being enriched in Ba, K, LREE, P, Rb, Sr, Nb, and Zr, with addition enrichment in Cr, Ni, and Sc reported by Vollmer and others (1984); Osterwald and others (1966) summarizes estimated reserves and whole rock percent compositions for Leucite Hills flows reported by Schultz and Cross (1912).
Geophysical evidence No data.
Evidence from other sources No data.
Comments The deposit type is in questions, but lithocap alunite that best match with the table at this time. This geologic setting is tailor-made for new 1:24,000 geologic mapping supported by Rank 1 aeromagnetic and aeroradiometric data. Of course, full lidar coverage would also be very helpful.
Cover thickness and description Flows and necks mostly exposed, although some olivine lamproites may be covered.
Authors Rachel N. Toner, Benjamin J. Drenth, Joshua M. Rosera.
New data needs Rank 1 aeromagnetic and radiometric data, geologic mapping, complete lidar coverage.
Geologic mapping and modeling needs 1:24,000 scale geologic mapping.
Geophysical survey and modeling needs Rank 1 aeromagnetic and aeroradiometric data.
Digital elevation data needs Lidar in progress.