Belmont Mine (Belmont lease; South Belmont incline; North Belmont shaft; Silver Bill Mine), Washington Camp-Duquesne District, Patagonia District, Patagonia Mts, Santa Cruz Co., Arizona, USA
|Latitude & Longitude (WGS84):||31° 22' 5'' North , 110° 41' 42'' West|
|Latitude & Longitude (decimal):||31.36806,-110.69500|
|Other regions containing this locality:||Sonoran Desert, North America|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
‡Ref.: Crosby, W.O. (1906) The limestone-granite contact deposits of Washington Camp, Arizona: American Institute of Mining Engineers, Transactions: 36: 120-122.
Bancroft, H. (1909), Notes on the occurrence of cinnabar in central western Arizona, USGS Bull. 430: 161.
Schrader, F.C. & J.M. Hill (1915), Mineral deposits of the Santa Rita and Patagonia Mountains, Arizona, USGS Bull. 582: 340-341.
Tenney, J.B. (1927-1929) History of Mining in Arizona, Special Collection, University of Arizona Library & Arizona Bureau of Mines Library: 293-300.
Simons, F.S. (1974) Geologic map and sections of the Nogales and Lochiel quadrangles, Santa Cruz County, Arizona: U.S. Geological Survey Miscellaneous Investigations Series Map I-762, 9 p., 1 sheet, scale 1:48,000.
Keith, Stanton B. (1975), Arizona Bureau of Mines Bull. 191, Index of Mining Properties in Santa Cruz County Arizona: 76 (Table 4).
Lehman, Norman E. (1978) The Geology and Pyrometasomatic Ore Deposits of the Washington Camp-Duquesne District, Santa Cruz County, Arizona. PhD dissertation, University of Arizona: 126-143.
Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 347.
U.S. Bureau of Mines - Arizona Bureau of Geology and Mineral Technology file data.
U.S. Bureau of Mines District Mining Sheet #727.
Arizona Bureau of Mines file data.
MRDS database Dep. ID file #10046335, MRDS ID #M241311; and, Dep. ID #10113827, MAS ID #0040230109.
A former small surface and underground Zn-Pb-Ag-Cu-Au-Mo mine located in East-central (center W½SE¼ sec. 3, T.24S., R.16E (protracted), in the southwest corner of the camp, adjacent on the W to the Empire Mine, about 2,000 feet south of the Holland mine, on the upper south slope of a low hill, about 1.0 mile SSW of Washington Camp, at an elevation of about 5,500 feet, on private land. Discovered by Mexicans prior to 1860. Rediscovered by Thomas yerkes in the 1870's. Produced 1932-1947. Owned and operated by the Rosario Exploration Co. (1973). Owned/operated at times, or in part, by Mr. Bacon, of San Francisco (1870'S-1905); Duquesne Mining & Reduction Co. (1905- ); Mr. F.O. Bostwick (1930); Bracey Curtis Estate (1934); Mr. De la Ossa (1936); McGregor (1937); Rivera and Weaver (1937); Byrd (1946-1947); the Nash Mines (1955-1964); Carl Sandberg and Fred Williams; D.C. Gilbert; Hugo Miller; and, Juan Sesteaga. The property comprises one patented claim; part of the Nash Mines Belmont lease (Belmont, Silver Bill, Silver Jack, and the Wedge claims) in 1955.
Mineralization is sulfides, partly oxidized near the surface, in a large, irregular, and massive lenses of garnetized and silicated Permian Naco Group limestone along a contact with Laramide granodiorite. The ore zone is 243.84 meters long, 30.48 meters wide, strikes N-S and dips 60W. Alteration is pyrometamorphosed limestone. Gangue minerals are quartz, calcite and calcium silicates. The ore is mostly found on contacts between limestone and garnet; some of the sulfide ore is well-embedded in quartz.
The deposit occurs in a north-south metamorphosed mineralized zone in the crystalline limestone near its contact with the intrusive diorite on the south. The zone is about 100 feet in width and 800 feet in length. It lies approximately conformably with the limestone, which on the north dips 60ºW. but on the south curves to the east. On the west at a point about 50 feet from the open cut the limestones are unaltered. The mineralized zone is composed principally of garnet and silicated limestone with quartz and calcite. It contains much actinolite with other metamorphic minerals and the ore minerals, which are chiefly sphalerite and chalcopyrite. Some of the sulphide ore is well-embedded in quartz. In the open cut the ore was largely a mixture of limonite, malachite, azurite, and sphalerite, contained in an 8 foot wide bed of a siliceous garnetiferous gangue that overlies the white crystalline limestone. Tectonic elements include the Duquesne Fault Block.
Mineral deposits of the Washington-Duquesne area occupy a limestone-sediment belt (2.5 miles long by 1.25 miles wide) surrounded by igneous rocks which also form detached masses and dikes within the belt.
Workings include a 90 foot deep shaft, a 200 foot shaft, an open cut (150 feet long, 50 feet wide and 15 feet at the face), an inclined drift, and tunnel operations, extensive stopes, a 200 foot long tunnel, and several the shaft inclines 40 SW. Belmont lease workings as of 1955 included a 600 foot tunnel, a 200 foot tunnel, a 50 foot raise connecting 2 tunnels. There are 4 old shafts on the Belmont and Silver Bill (South Belmont properties). Worked by Mexicans for lead and silver prior to 1860. In the 1930's and 1940's it was mined by lessees. Total production was probably 2-3 thousand tons of ore averaging about 9% Zn, 3% Cu, 3% Pb, 6 oz. Ag/T and minor Au.
10 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
66 - 145 Ma
|Mesozoic sedimentary rocks|
Age: Cretaceous (66 - 145 Ma)
Lithology: Sedimentary rocks
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. 
|Kungurian - Moscovian|
272.3 - 315.2 Ma
|Permian to Pennsylvanian sedimentary rocks|
Age: Paleozoic (272.3 - 315.2 Ma)
Stratigraphic Name: Hermit Formation; Supai Group; Schnebly Hill Formation; Naco Group
Description: Interbedded sandstone, shale, and limestone usually characterized by ledgy outcrops. Orange to reddish sandstone forms cliffs near Sedona. This unit includes Supai Group and Hermit Shale in northern Arizona and Naco Group in southern Arizona. It was deposited in coastal-plain to shallow-marine settings during time of variable and changing sea level. Rocks of this map unit in southern Arizona may be in part equivalent to Permian rocks of map unit P in central and northern Arizona. (280-310 Ma)
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.