Cochise District, Little Dragoon Mts, Cochise Co., Arizona, USA

Ref.: Rickard, F. (1904), Notes on tungsten deposits in Arizona, Engineering and Mining Journal: 78: 263.

Kellogg, L.O. (1906), Sketch of the geology and ore deposits of the Cochise mining district, Cochise County, Arizona, Economic Geology: 1: 651-659.

Romslo, T.M. (1949), Investigation of Keystone and St. George copper-zinc deposits, Cochise County, Arizona, U.S. Bureau of Mines Report of Investigation 4504.

Cooper, J.R. (1957), Metamorphism and volume losses in carbonate rocks near Johnson Camp, Cochise County, Arizona, Geological Society of America Bull. 68: 577-610.

Cooper, J.R. & L.T. Silver (1964), Geology and ore deposits of the Dragoon quadrangle, Cochise County, Arizona, USGS Professional Paper 416.

Keith, Stanton B. (1973), Arizona Bureau of Geology & Mineral Technology, Geol. Sur. Branch Bull. 187, Index of Mining Properties in Cochise County, Arizona: 7-8, 55 (Table 4).

Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd. ed.: 142, 165, 196, 306, 423.

This district is located in T.15, R.22; T.16S., R.23E. and encompasses the Johnson Camp (now obliterated) and the Gunnison Hills in the Little Dragoon Mountains. The town of Dragoon is in the district, which straddles Interstate 10. Some of the district's workings are visible from the roadway. Another feature visible from the interstate is a striking geological feature - the weathered outcrop of the Texas Canyon stock (pluton)(Texas Canyon Quartz Monzonite). Interstate 10 traverses the outcrop with its spectacular rounded boulders and spires of this rock, including "balancing rocks" on top of spires.

Mineralization includes a variety of ore deposits, including: 1. Copper and zinc mineralization in pyrometasomatic, tabular masses and irregular chimneys replacing Paleozoic limestone formations along or near fissure zones; 2. Hübnerite with minor scheelite and fluorite in quartz veins or lodes in granitic intrusives; 3. Small, oxidized lead-silver replacement bodies along beds and in fracture zones in Paleozoic limestone; 4. Tungsten placer deposits; and, 5. Gold and silver values in oxidized zone of faults and fractures.

It was worked back into the late 1800's. There was a period from 1920 to 1942 where it was virtually dormant. The halcion years of production were 1945-1957. This district produced copper, zinc and tungsten along with some silver and gold. Total production amounted to 1.64 million tons of ore yielding more than 37,000 tons of copper, 300 tons of lead, 47,000 tons of zinc, 734,000 ounces of silver and about 300 ounces of gold.