|Latitude & Longitude (WGS84):||31° 41' 41'' North , 111° 23' 0'' West|
|Latitude & Longitude (decimal):||31.69472,-111.38333|
|Other regions containing this locality:||Sonoran Desert, North America|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
Ref.: Wilson, E.D. (1941), Tungsten Deposits of Arizona, Geological Series No. 14, Arizona Bureau of Mines Bull. 148: 39.
Lemmon, D.M. (1945), Tungsten Deposits of Arizona, USGS unpublished data.
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: 104.
Lemmon, D.M., and Tweto, O.L. (1962) Tungsten in the U.S., USGS map, MR-25.
Keith, Stanton B. (1974), Arizona Bureau of Geology & Mineral Technology, Geological Survey Branch Bull. 189, Index of Mining Properties in Pima County, Arizona: 104.
MRDS database Dep. ID file #10039531, MRDS ID #M050228.
Arizona Bureau of Mines file data.
A former small underground W-Au-Ag-Pb-Zn-Cu group of 3 unpatented claims located in the NW ¼ sec. 13, T.20S., R.9E., about 2 miles North of Las Guijas. Discovered 1936. Produced 1936-1940. Owned and operated by E. & L.G. Fernstrom (1940).
Mineralization is small, spotty, irregular oreshoots containing wolframite and minor scheelite, and sulfides in a lensing and branching quartz-fissure vein cutting Cretaceous andesite. Ore control was the narrow quartz vein.
Workings include a shallow, 40 foot deep, shaft and a 70 foot adit. Produced some 10,000 pounds of picked tungsten concentrates in the late 1930's. The mine was closed in 1940 when the vein became too narrow to work.
Commodity ListThis is a list of exploitable or exploited mineral commodities recorded at this locality.
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
|Quaternary - Miocene|
0 - 23.03 Ma
|Cenozoic sedimentary rocks|
Age: Cenozoic (0 - 23.03 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. 
|Campanian - Oxfordian|
72.1 - 163.5 Ma
|Cretaceous to Late Jurassic sedimentary rocks with minor volcanic rocks|
Age: Mesozoic (72.1 - 163.5 Ma)
Stratigraphic Name: Temporal Formation; Bathtub Formation; Sand Wells Formation; Fort Crittenden Formation; McCoy Mountains Formation
Description: Sandstone and conglomerate, rarely forms prominent outcrops; massive conglomerate is typical near base of unit and locally in upper part. These deposits are nonmarine except in southeastern Arizona, where prominent gray marine limestone (Mural Limestone) forms the middle of the Bisbee Group. Sandstones are typically medium-bedded, drab brown, lithic-feldspathic arenites. Includes Bisbee Group (largely Early Cretaceous) and related rocks, Temporal, Bathtub, and Sand Wells formations, rocks of Gu Achi, McCoy Mountains Formation, and Upper Cretaceous Fort Crittenden Formation and equivalent rocks. (80-160 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.