Dos Pobres Mine (Dos Pobres ore body; Los Pobres; Safford Mine; Safford Phelps Dodge; Phelps Dodge Safford project; Arrowhead Mine), Lone Star District (Safford District; Dos Pobres District), Gila Mts, Graham Co., Arizona, USA
|Latitude & Longitude (WGS84):||32° 57' 41'' North , 109° 40' 26'' West|
|Latitude & Longitude (decimal):||32.9613888889, -109.673888889|
|Other regions containing this locality:||Sonoran Desert, North America|
An surface and underground Cu-Mo-Au-Ag prospect located in secs. 27 & 28, T5S, R26E, 9 miles N of Safford, on private property. Discovered 1957 by prospectors. Unpatented claims extend into secs. 7, 8, 17-19, 21, 25, 26, 29-31 of T5S, R26E. Patented claims extend into secs. 22, 23, 26-28, 33-35 of T5S, R26E. Section 21 is a state lease in T5S, R26E. Owned by the Phelps Dodge Corp. (1960). Additional names that apply to this property: BLM patented claims MS 4579; Bryce; Greater Arrowhead group.
Mineralization is an irregular and massive ore body 1200 meters long with a depth to top of 740 meters, and a thickness of 114 meters. The ore body is hosted in quartz monzonite and diorite. Ore control was NE fractures and dikes. Ore concentration was supergene enrichment. Alteration was hydrothermal and oxidation.
Area structures include the NW-striking Butte Fault.
Workings are 762 meters deep. Optioned October 1957 from Ruskin Lines by Phelps Dodge. Began drilling November 21, 1957 and exercised option to purchase in 1960. Began shaft sinking and underground development November 1968. By July 1979, had drilled 189,000 feet rotary and diamond drill holes and developed 79,000 feet of shafts, drifts, and cross-cuts. Underground development suspended in 1982 and workings were allowed to flood in August 1984. By 1991 drilling and development work had resumed. Proposed that this deposit be mined by block caving. Reserve-Resource is sulfide; leachable.; Total resource ore contains 0.003 to 0.009% Mo.
6 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.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
|Ypresian - Campanian|
47.8 - 83.6 Ma
|Early Tertiary to Late Cretaceous volcanic rocks|
Age: Phanerozoic (47.8 - 83.6 Ma)
Stratigraphic Name: Williamson Canyon Volcanics
Description: Rhyolite to andesite and closely associated sedimentary and near-surface intrusive rocks; commonly dark gray to dark greenish gray or greenish brown. In the ranges west of Tucson, this unit includes thick welded ash-flow tuffs. Volcanic rocks of this unit are inferred to be derived from vents and volcanoes above magma chambers that solidified to form the granitic rocks of map unit TKg. These rocks are restricted to southeastern Arizona except for a small outcrop near Bagdad. (50-82 Ma)
Comments: Related, broadly, to unit TKg
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. 
Pay Dirt (1973) Phelps Dodge Evaluating Test Results at Safford, No. 412 (10/29/73): 24.
Mining Record (1974) Phelps Dodge to Spend $30 Million at Arizona Copper Mine: 85(7) (2/13/74).
World Mining (1974) Phelps Dodge Accelerates Safford Underground Development, (May, 1974): 27(5).
Pay Dirt (1975) Phelps Dodge Okays More Development at Safford, No. 416 (2/25/75): 3.
Pay Dirt (1975) Cities Service Joins Hunt for Safford Area Copper, No. 435 (Sep 22, 75): 52.
Skillings, David N., Jr. (1975) Phelps Dodge Corp's Safford Copper Project, Skillings Mining Review: 64(8) (2/22/75): 1, 6.
Dunn, P.G. (1978) Geologic structure of the Safford district, Arizona, in Jenney, J.P., and Hauck, H.R., eds., Proceedings of the Porphyry Copper Symposium, Tucson, Arizona, March 18-20, 1976: Arizona Geological Society Digest: 11: 9-15.
Greeley (1978) Arizona Department of Mineral Resources Special Report #2.
U.S. Bureau of Land Management Mining Claims Lead File #4003 (Jul, 1980).
Eastern Arizona Courier (1981) Mine Cut-Back Announced, Aug 26, 1981.
Langton, J.M. and S.A. Williams (1982) Structural, Petrological and Mineralogical Controls for the Dos Pobres Orebody, in Advances in Geology of the Porphyry Copper Deposits, edited by Titley, S.R. Tucson, University of Arizona Press: 335-352.
U.S. Bureau of Land Management Mining District Sheets 815 & 816.
Sawyer, M.B., Gurmendi, A.C., Daley, M.R., and Howell, S.B. (1992) Principal Deposits of Strategic and Critical Minerals in Arizona, U.S. Bureau of Mines Special Publication, 334 pp.
USGS Safford Quadrangle map.
Arizona Department of Mineral Resources Greater Arrowhead group file.
Arizona Department of Mineral Resources Phelps Dodge Corp. (Safford Branch), active file.
Arizona Department of Mineral Resources Superior Safford property file.
MRDS database Dep. ID #10096999, MRDS ID #M001628; and Dep. ID #10161266, MAS ID #0040090227; and Dep. ID #10282581, MAS ID #0040090004.