Natroalunite deposit (Sugar Loaf prospect; Sugarloaf Butte Alunite deposit), Sugarloaf Peak, Middle Camp-Oro Fino District, Dome Rock Mts, La Paz Co., Arizona, USA
|Latitude & Longitude (WGS84):||33° 38' 3'' North , 114° 18' 55'' West|
|Latitude & Longitude (decimal):||33.63417,-114.31528|
|Other regions containing this locality:||Sonoran Desert, North America|
Ref.: Jones, Jr., E.L. (1915), Gold Deposits near Quartzsite, Arizona, in Contributions to Economic Geology by F.L. Ransome & H.S. Gale, USGS Bull. 620-C: Plate IV, 45-57.
Ross, Clyde P. (1922) USGS Professional Paper 129: 183-197.
Wilson, E.D. (1933) Geology and Mineral Deposits of Southern Yuma County, Arizona. Arizona Bureau of Mines Bulletin 134: 167.
Heineman (1935) Sugarloaf Butte Alunite. Engineering and Mining Journal: 136: 138-139.
Thoenen (1941) Alunite Resources of the United States. US Bureau of Mines Report of Investigation 3561: 10-11.
Keith, Stanton B. (1978) State of Arizona Bureau of Geology and Mineral Technology, Geological Survey Branch Bull. 192, Index of Mining Properties in Yuma County, Arizona: 161 (Table 4).
Crowl (1979) MS Thesis, University of Arizona.
Phillips, K.A. (1987), Arizona Industrial Minerals, 2nd. Edition, Arizona Department of Mines & Minerals Mineral Report 4, 185 pp.
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.
Hall, Robert B., unpublished data, Arizona Bureau of Mines files (1990).
U.S. Bureau of Mines file data.
Arizona Bureau of Mines file data.
MRDS database Dep. ID file #10009277, MRDS ID #D002156; and, Dep. ID #10113322, MAS ID #0040120459; and, Dep. ID #10137700, MAS ID #0040120008.
A former surface and underground Natroalunite (Al)-Pb-Mo-Bi-W-Sn mine located in the NW¼ sec. 3, T3N, R20W (protracted), 5 miles WSW of Quartzsite, on federal land. Discovered in 1929. Owned and operated by the Ropp Brothers (?).
Mineralization is natroalunite in schistose and porphyritic dacite intruding Mesozoic schist. Host unit is the Dome Rock formation. Alteration is quartz-sericite-pyrite and silicification of schist. X-ray & chemical data indicate vein alunite is sodic. The ore zone is 1219.2 meters long, 304.8 meters wide, and 60.96 meters thick. Quartzite overlies sericite schist which overlies dacite. There are Pb, Mo, Bi, W, & Sn geochemical anomalies. Branching irregular veins. Alunite veins a few inches to 1 foot wide cut dacite and altered schist. Some are nearly pure alunite, but many are contaminated with quartz and a few contain gypsum. The purer alunite is white, massive, fine-grained and porcelain-like. The deposit is high in Na - natroalunite. Deposit dimensions are for the mineralized area.
Several anomalies have been drilled in the recent past. The known deposit is too small to serve as raw material for the aluminium industry. The value of the deposit for other uses is decreased by low grade and high Na content.
Reserves in veins only; host rock is only slightly alunized. No resources other than the vein are apparent. Only considered total rock within 20 feetfrom surface. There is probably additional alunite at greater depths but no estimate has been made. Estimate does not distinguish alunite from natroalunite but analysis indicates natroalunite.
Workings are comprised of prospect pits & a 200 foot tunnel.
5 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
|Oxfordian - Hettangian|
157.3 - 201.3 Ma
|Jurassic volcanic rocks|
Age: Jurassic (157.3 - 201.3 Ma)
Description: Massive quartz-feldspar porphyry, generally interpreted as thick, welded rhyolitic tuffs, with locally abundant lava, and sandstone and conglomerate derived from volcanic rocks. Rare eolian quartzite units are interbedded in southern Arizona. Includes Ali Molina Formation, Mount Wrightson Formation, part of the Canelo Hills Volcanics, Cobre Ridge tuff, Black Rock volcanics, Planet Volcanics, and equivalent rocks. (160-200 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.