Climax-Sweet Home

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 focus area encompasses the Climax Mo porphyry deposit, the Sweet Home IS epithermal deposit (latitude 39.3125, longitude -106.1187). These deposits occur in neighboring Climax-type porphyry systems. Since Climax-type porphyry systems commonly occur in clusters, a 15 km buffer was applied to Climax and Sweet Home to encompass undiscovered occurrences in adjacent areas. Area includes the USMIN Climax district outline for W.
Identified resources Identified resources of molybdenum, rhenium, and tungsten; historical production of fluorite, gold, lead, molybdenum, REE, rhodochrosite, silver, tin, tungsten, and zinc.
Production Total production from the Climax mine from 1918 to 1991 was about 470 million tons of ore at an average grade of 0.22% Mo. Tungsten, Sn, and REE have been produced as byproducts in the past. Gold, Ag, Pb, Zn and rhodochrosite specimens have been produced from Stungsteneet Home. Sweet Home mine produced an estimated > $5 million in gem-quality rhodochrosite. Small producers of fluorite and Mn ore located in district; production volumes unknown.
Status Past and current mining (Climax, as of 2019). Production at Climax stopped in 1985 due to low Mo prices, but started up again in 2012.
Estimated resources As of December 2018 reserves and resources of 158 million metric tons of ore at 0.15% Mo (Karl and others, 2020). Rhenium concentration in molybdenite ore at the Climax mine estimated to be 13 ppm (range: 10 to 80 ppm), resulting in an estimated 35 metric tons of contained Re at the deposit (John and others, 2017). Climax also has an estimated 102,000 metric tons of WO3 (John and others, 2017, references therein).
Geologic maps Tweto (1953), scale 14,400; Wallace and others (2005), scale 1:24,000; Widmann, Bartos, Madole and others (2004), scale 1:24,000; Widmann, Bartos, McCalpin and Jackson (2004), scale 1:24,000; Ruleman and others (2018), scale 1:24,000.
Geophysical data Inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Quartz monzonite and granite.
Deposits Climax mine (MRDS dep_id: 10214926; USMIN Site_ID: CO00029), Sweet Home mine (MRDS dep_id: 10008726) (gemstones, rhodochrosite).
Evidence from mineral occurrences MRDS; USMIN.
Geochemical evidence The Chalk Mountain rhyolite is interpreted to be an eruptive equivalent to mineralizing intrusions at Climax, and contains aeschynite and monazite (Audétat, 2015). Hübnerite mineralization has been reported in the Sweet Home rhodochrosite gem mine (Lüders and others, 2009).
Geophysical evidence Climax-Alma Bouguer gravity low (Bookstrom, 1989). Gravity lows indicate underlying batholiths and aeromagnetic lows or subdued areas indicate alteration.
Evidence from other sources State-wide trend of similar occurrences. Arcuate values with subparallel vein systems and the presence of a small bouguer gravity low have been interpreted as doming above an upper crustal magma system extending from Climax through Alma (~ Sweet Home; Bookstrom, 1989).
Comments The Climax ore deposit is the type example of the Climax-type porphyry Mo deposit. The geology of this type of ore deposit is described by Ludington and Plumlee (2009). They note that Climax-type Mo deposits are quite rare and give only 13 examples. Of these, the Climax ore deposit is far and away the largest. The next largest, the Henderson deposit, is approximately 60% the size of Climax. Vein-hosted Mn deposits is associated with Climax-style mineralization. For many years Climax was an underground mine worked through adits. Ore was produced by a block caving system. In 1968, production was 22,000 tons per day, all from the Storke level. Starting with a 60 inch gyratory crusher the entire 22,000 tons was reduced by ranks of rod and ball mills to a particle size sufficiently small to move in suspension. Separation of minerals was accomplished by flotation (molybdenite, monazite), Humphrey spirals (pyrite) and shaker table (wolframite). Possible Nb-Ta, Be mineralization.
Cover thickness and description Shallow to unknown depths.
Authors Ryan D. Taylor, Albert H. Hofstra, Joshua M. Rosera, V.J.S. (Tien) Grauch.
New data needs More detailed aeromagnetic data in areas near large gravity lows would help locate altered areas that are smaller than Climax itself.
Geologic mapping and modeling needs 1:24,000 scale geologic maps exist for most of this area.
Geophysical survey and modeling needs High resolution aeromagnetics and aeroradiometrics. Rank 1 geophysical surveys may assist with delineating altered areas.
Digital elevation data needs Lidar available.