Big Mine, Owl Head Buttes area, Owl Head District, Tortolita Mts, Pinal Co., Arizona, USA
|Latitude & Longitude (WGS84):||32° 37' 27'' North , 111° 4' 3'' West|
|Latitude & Longitude (decimal):||32.62417,-111.06750|
|Other regions containing this locality:||Sonoran Desert, North America|
A former surface and underground Ba-Cu-Pb-Ag mine located in sec. 26, T9S, R12E, about 3 miles ENE of Owl Head Buttes, on private land.
Mineralization is a vein deposit hosted in the Pinal Schist. Veins are 1 to 2 cm distributed sparsely over a 500 foot width. The ore zone strikes N30-60W, dips 45-80W, at 152.4 meters wide and 2133.6 meters long. Gossan is seen on the outcrop. One prospect pit is salted with Laramide porphyry. Mineralization is largely baryte along a fault with some copper oxide and occasional galena. Veins are crosscut by faults. Alteration is propylitic, sericitic with oxidized veins, illite. Related structure is a fault trending N35W, dipping 65S.
Workings include a major shaft deeper than 675 feet; a minor shaft approximately 610 feet; an adit with raises to the surface; and 10-15 prospect pits. No production data is available. A likely producer.
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
|Tortonian - Rupelian|
7.246 - 33.9 Ma
|Middle Miocene to Oligocene volcanic and sedimentary rocks, undivided|
Age: Cenozoic (7.246 - 33.9 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. 
Banks, N.G. (1976) Field Exam.
Moore, R.T. & R.J. Varga (1976), Maps showing nonmetallic mineral deposits in the Phoenix area, Arizona: USGS Misc. Investigations map I-845-J, 1:250,000.
Yale Peabody GNIS database (NOTE: this database is derived from USGS 1:24,000 topographic map data).
MRDS database Dep. ID #10039657; RDS ID #M050594.