Grand Central Mine, Contention-Grand Central Mine group, Tombstone District, Tombstone Hills, Cochise Co., Arizona, USA

‡Ref.: The Resources of Arizona - A Manual of Reliable Information Concerning the Territory, compiled by Patrick Hamilton (1881), Scottsdale, AZ: 36-37.

Blake, W.P. (1882) The geology and veins of Tombstone, Arizona: American Institute of Mining Engineers, Transactions: 10: 335-339, 342-343.

Church, J.A. (1903) The Tombstone, Arizona, mining district: American Institute of Mining Engineers, Transactions: 33: 4, 8, 11-12, 16, 18-20, 23-25, 28, 33-34.

Butler, B.S., Wilson, E.D., and Rasor, C.A. (1938b), Geology and ore deposits of the Tombstone district, Arizona, Arizona Bureau of Mines Bull. 143: 41, 43-45, 51, 69-71, Pl. IV, VIII, IX.

Keith, Stanton B. (1973), Arizona Bureau of Mines Bull. 187, Index of Mining Properties in Cochise County, Arizona: 74.

Williams, S.A. (1979), Girdite, oboyerite, fairbankite, and winstanleyite, four new tellurium minerals from Tombstone, Arizona, Mineralogical Magazine: 43: 453-457.

Rocks & Minerals (1982): 57: 12.

Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 210, 218, 232, 315, 421.

Arizona Bureau of Mines files.

MRDS database Dep. ID file #10039606, MRDS ID #M050475.

A former large output underground Ag-Au-Pb-Cu-Zn mine located in T.20S., R.22E., on a claim of 1,500 feet by 600 feet, ¾ mile S of Tombstone, on private land. Owned at times, or in part, by the Western Mining Co.; the Centurion-Arizona Mining Co.; the Grand Central Mining Co.; the Tombstone Mill & Mining Co.; the Head Center Co.; the Head Center & Tranquility Co.; the Contention Mining Co.; the Tombstone Consolidated Mines Co.; the Bunker Hill Mines Co.; A.P. Giacoma; and the Tombstone Development Co.

Mineralization is oxidized argentiferous and auriferous galena and minor copper and zinc ores in large, rich orebodies in faulted and fractured segments of a large dike, and in brecciated footwall zones of the dike. Ore was also found in replacements of Cretaceous Bisbee Group limestone beds where intersected by "northeast" fissures. The Bisbee Group limestone is recrystallized.

The shaft is in the N-S Tranquility Fault, dipping 67-70SE. This fault is cut within the workings by the Grand Central Fault, which strikes NW.

Local structures include the Tombstone Basin.

Workings included extensive shaft(s), with one to 500 feet deep; 3 levels at 500, 600 & 1100 feet. Workings total 1524 meters long and 137.16 meters deep. Workings were on six levels, many stopes were in the upper 250 feet. The total length of workings is estimated. There are 2 shafts with the northerly shaft is deepest. The workings adjoin the Contention workings to the north. One of the earliest and most productive mines of the district. Over $10,000,000 was produced prior to 1886 and several hundred thousand tons were produced from the 1880's to the early 1900's. After 1886, production includes the Contention shaft. There was some sporadic production up to 1929.