Steppe Mine (Steppe claim; Little Mary Mine), Mildren Mine group, Ko Vaya, Cababi District (Comobabi District), Comobabi Mts, Tohono O'odom (Papago) Indian Reservation, Pima Co., Arizona, USA

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‡Ref.: Wilson, E.D., Cunningham, J.B., and Butler, G.M. (1934), Arizona Lode Gold Mines and Gold Mining. Arizona Bureau of Mines Bull. 137.

Williams, S.A. (1962) The mineralogy of the Mildren and Steppe mining districts, Pima County, Arizona: Tucson, University of Arizona, Ph.D. dissertation, 145 p.

Williams, S.A. (1963), Oxidation of sulfide ores in the Mildren and Steppe mining districts, Pima County, Arizona, Economic Geology: 58: 1119-1125.

Keith, Stanton B. (1974), Arizona Bureau of Geology & Mineral Technology, Geological Survey Branch Bull. 189, Index of Mining Properties in Pima County, Arizona: 111 (Table 4).

Elevatorski, E.A. (1978), Arizona Industrial Minerals, Arizona Department of Mineral Resources, Minerals Report No. 2: 49.

Phillips, K.A. (1987), Arizona Industrial Minerals, 2nd. Edition, Arizona Department of Mines & Minerals Mineral Report 4, 185 pp.

Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd. ed.: 112, 121, 126, 128, 146, 149, 163, 166, 169, 174, 186, 188, 194, 196, 202, 207, 220, 229, 233, 235, 238, 242, 251, 259, 262, 274, 275, 279, 291, 298, 302, 307, 344, 357, 370, 374, 385, 387, 411, 420, 426.

MRDS database Dep. ID file #10039670, MRDS ID #M050622; and, Dep. ID #10113599, MAS ID #0040190295.

A former small underground Cu-Au-Ag-Pb-Zn-Mo-Rh-Baryte mine located in the SW ¼ sec. 23 & the NW ¼ sec. 26, T.16S., R.4E. (protracted), 8 miles WSW of Comobabi and 1 mile NE of Wickchoupai village. Produced 1917-1970. Owned/operated by the Stepp Brothers; Como-Pima Mining Corp.; G.A. Withers; Beids Mining Co.; Hardy; Rogers; and, Medd.

Mineralization is lensing, quartz-fissure veins, partly brecciated, containing shoots of barite and stringers of dolomite. 2 veins about 500 feet apart. Iron and copper oxides occur in the upper part and change to sulfides, including ruby silver, with depth. Minor tetrahedrite and molybdenite are also found. The wall rock is Cretaceous (?) amygdaloidal andesite flows. Ore control was the altered andesite, and brecciated fissure veins in gently dipping andesites. Alteration was oxidation and leaching of wall rock. Rhenium found spectrographically in bornite. Ore width is 3.05 meters with a NW strike and dip of 70NE.

Local structures include a NE vertical fault displacing the Little Mary and Chicago veins; A NW fault, with a dip of 40NE, displacing the Little Mary vain. Flows are intruded by dikes, Picacho Andesite, and Coon Canyon Volcanics.

Workings include shaft and tunnel operations to a depth of 76.2 meters, and, as of 1925, a 50 ton flotation mill. Worked from 1917 to 1970 and produced some 800 tons of picked ore averaging about 0.2 oz. Au/T, 15 oz. Ag/T, 54% Pb, 4% Cu, and a little zinc.

Mineral List

Anglesite Atacamite Azurite Baryte Bornite Brochantite Buttgenbachite Chalcocite Chalcopyrite Chlorargyrite Chrysocolla Copper

Crocoite Cuprite Devilline var: Zincian Devilline Dolomite var: Zincian Dolomite Ferrimolybdite Galena Goethite Gold Goslarite Gypsum Hisingerite

Iodargyrite Jarosite Leadhillite Lepidocrocite Litharge Massicot Miersite Molybdenite Mottramite Pyrite Pyromorphite Quartz var: Milky Quartz

Rosasite Siderite Smithsonite Stromeyerite Svanbergite Tetrahedrite Vanadinite Willemite Wulfenite

45 entries listed. 42 valid minerals.