Antimony Canyon
The Antimony (Coyote Canyon) mining district lies about 30 mi southeast of Marysvale in north-central Garfield County. The district was discovered in 1879 and became a modest producer of hand-cobbed, high-grade Sb ores from 1880 to about 1908 and intermittently into the 1960s (Doelling, 1975). Total district metal production at modern metal prices is estimated at $1,120,000.
The district is the largest Sb producer in Utah and minor, intermittent production occurred during high demand and high Sb prices, especially during the World Wars. The Emma-Albion mine is believed to be the largest producer. The Antimony district lies in the southeastern corner of the Marysvale volcanic field in the transition zone from the Basin and Range Province on the west to the Colorado Plateau on the east. The Sb deposits occur as irregular lenses, rosettes, and veinlets (USGS Model 27d) in two limey sandstones of the Paleocene Flagstaff Formation near the base of the overlying Oligocene and Miocene Bullion Canyon Volcanics (Doelling, 1975). The ore zones typically range from 5 to 20 ft thick. The primary ore mineral is stibnite which occurs as masses of acicular crystals perpendicular to the attitude of the veinlets/lenses. Gangue minerals include pyrite, realgar, orpiment, fluorite, quartz, kaolinite, and probably arsenopyrite. The average grade from 486 U.S. Bureau of Mines channel samples is 0.79% Sb, although a 500 lb mine dump sample had 3.7% Sb, 600 ppm As, 4.1 ppm Ag, and 79.2% SiO2 (Traver, 1949). Doelling (1975) suggests a subeconomic inferred resource based on the channel samples near the old mines of about 14 million tons at an average grade of 0.75% Sb. The deposits are hydrothermal sandy carbonate replacements associated with Tertiary volcanism.
Doelling, H.H., 1975, Geology and mineral resources of Garfield County, Utah: Utah Geological and Mineral Survey Bulletin 107, 172 p.
Traver, W.M., 1949, Investigation of the Coyote Creek antimony deposits, Garfield County, Utah: U.S. Bureau of Mines Report of Investigation 4470, 18 p.