Moose Jaw

Prospect, Inactive

Commodities and mineralogy

Main commodities Au; Sb
Other commodities As; Hg
Ore minerals stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale MD
Quadrangle map, 1:63,360-scale C-6
Latitude 63.546
Longitude -155.994
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Moose Jaw prospect is located in the apex of a north-facing, steep spur of the Cripple Creek Mountains at an elevation of 2,050 feet (625 m) in Section 32, T. 22 S., R. 15 E., of the Kateel River Meridian. Location is precisely known; reporter visited the site in 1996.

Geologic setting

Geologic description

The Moose Jaw deposit is a quartz-stibnite vein deposit that cuts the hornfels aurole of the Cripple Creek Mountains Pluton near the head of Colorado Creek drainage. The deposit is conspicuously marked by a slight break or notch in a steep scree slope of hornfels outcrops and rubble. The quartz-stibnite vein trends north 55 degrees east for a distance of at least 700 feet (213 m); talus buries the vein on both ends. Where exposed, the vein varies from 1.5 to 4.0 feet (0.45 to 1.20 m) in width.
Very coarse stibnite blades up to 12 inches (30 cm) long form clusters and rosettes throughout the vein structure. Massive, finer grained stibnite makes up about 20 percent of the Moose Jaw vein, whereas disseminated stibnite zones characterize about 30 percent of the vein. About 50 percent of the vein consists of mixtures of massive to coarse, bladed stibnite and euhedral quartz crystals, disseminated quartz, and stockwork style zones in hornfels. Age of mineralization is inferred to be Late Cretaceous based on 71.0 Ma age of adjacent pluton (Bundtzen and others, 1997). Pits have been dug along about 400 feet (122 m) of strike of the vein; however, the first published descriptions are from Bundtzen and other (1997). Four chip-channel samples along about 600 feet (182 m) of the Moose Jaw prospect contained 31 to 1,675 ppb gold, 0.20 to 44.90 percent antimony, 40 to 50 ppm mercury, and 580 to 14,600 ppm arsenic.
Geologic map unit (-155.996375744211, 63.545389215774)
Mineral deposit model Simple stibnite deposit (Cox and Singer, 1986; model 27d).
Mineral deposit model number 27d
Age of mineralization Late Cretaceous (inferred) based on 71.0 Ma age of adjacent pluton (Bundtzen and others, 1997).
Alteration of deposit Stibnite locally altered to stibiconite.

Production and reserves

Workings or exploration In previous years, pits were dug along about 400 feet (122 m) of strike of the vein; however, the first published descriptions are from Bundtzen and other (1997). Four chip-channel samples along about 600 feet (182 m) of the Moose Jaw prospect contained 31 to 1,675 ppb gold, 0.20 to 44.90 percent antimony, 40 to 50 ppm mercury, and 580 to 14,600 ppm arsenic.
Indication of production None
Reserve estimates None.
Production notes Large and impressive stibnite crystals and blades that are very abundant throughout vein structure might have mineral specimen potential.

Additional comments

See Wyoming Lode (MD016) in Medfra C-6 quadrangle.

References