King Ainsworth Mine group (Oregon Mine group), Portal, California District, Chiricahua Mts, Cochise Co., Arizona, USA
|Latitude & Longitude (WGS84):||31° 58' 36'' North , 109° 11' 3'' West|
|Latitude & Longitude (decimal):||31.97667,-109.18417|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
‡Ref.: Dale, V.B., Stewart, L.A., and McKinney, W.A. (1960), Tungsten deposits of Cochise, Pima, and Santa Cruz Counties., Arizona, U.S. Bureau of Mines Report of Investigation 5650.
Keith, Stanton B. (1973), Arizona Bureau of Geology & Mineral Technology, Geological Survey Branch Bull. 187: 53 (Table 4).
MRDS database Dep. ID file #10046190, MRDS ID #M241030; and, Dep. ID #10258364, MAS ID #0040030165.
A group of former small underground Zn-Pb-Cu-Ag-Au-W-Mo mines located in the central border of sections W½ sec. 4 & sec. 5, T.17S., R. 31E, on the NE side of Davis Mountain and 1 mile S of Harris Mountain, on private land. Discovered 1885. The group was comprised of 60 unpatented claims in 1921, and 67 in 1962. Produced 1885-1952. Owned by E.F. Schaaf (1962); also, among several firms at times, including the King Copper Co.; Manning & Newton; Ainsworth Copper Co.; Cochise Consolidated Copper Co.; Portal Mines Development Co.; Coronado Copper Co.; and, the Arizona Consolidated Metal Producers Corp.
Mineralization is irregular and consists of spotty base metal oxides, carbonates and sulfides with minor scheelite along shear zones and disseminated in silicated and pyrometamorphosed Mississippian to Permian limestone along a zone of thrust faulting. The ore zone strikes E-W and dips 60-70N. Host rock units are the Escabrosa Limestone and the Naco Group Limestone. Ore control was the shear zone and associated disseminations, faults and fissures in limestone. Alteration is silicification.
Local structures include a zone of thrust faulting, orientation is WNW, NE of the mine. Pinal Schist and Bolsa Quartzite are NE of the thrust.
Workings include shaft and tunnels. One adit is 850 feet long along the contact, dips 60-70N, with crosscuts and stopes. Two vertical shafts 340 & 500 feet deep, one 250 foot adit. Open cuts and other workings caved and inaccessible in 1962. The length of workings is estimated at 762 meters with a depth of 152.4 meters.
A total of at least 1,150 tons of ore produced intermittently from the late 1880's to 1952.
Mineral ListMineral list contains entries from the region specified including sub-localities
19 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
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|Olenekian - Ediacaran|
247.2 - 635 Ma
|Paleozoic sedimentary rocks|
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052.