United Verde Mine (The Big Hole; Big Hole property; Hull Mine; Hopewell tunnel; Patented claim 3480; Patented claim 2812; Patented claims 3348), Jerome, Verde District, Black Hills (Black Hill Range), Yavapai Co., Arizona, USA
|Latitude & Longitude (WGS84):||34° 45' 0'' North , 112° 7' 19'' West|
|Latitude & Longitude (decimal):||34.75000,-112.12222|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
A former surface and underground Cu-Pb-Au-Ag-Zn mine located in the center sec. 22, T.16N., R.2E. (Clarkdale 7.5 minute topo map). Discovered 1875. Started about 1876. First produced 1883. Claims extend into the NW¼, the N½SW¼ and the W½W½NE¼ of sec. 22, and the S½SW¼ of sec. 15.
Mineralization is a steeply-dipping, cylindrical body approximately 700 to 800 feet (215 to 246 meters) in diameter, extending down to a depth of 2,400 feet (or 3,100 feet if calculated from the level of the Precambrian peneplain). This was perhaps the world's largest pyritic sulfide orebody.
This mine was the site of a sulfide ore mine fire in which the sulfide ores burned for several years (the fire started in 1894), forming a suite of new species (Lausen, 1928). Mining operations included various mechanisms to control the fire and its resulting fumes while the burning ore was mined.
Workings throughout the period the property was in operation totalled 81 miles of underground workings. Workings reached to the 3,515 level. The workings included a total of 8 shafts, of which 2 were the principal shafts, the No. 3 shaft collar was at about 5,509 feet of altitude and descended vertically to the 1950-foot level; the No. 4 shaft collar was at about 5,530 feet of altitude and went to the 1000 foot level. The 1000-foot level tunnel was the main haulage adit (Hopewell tunnel = 6,600 feet long). There was a 1,200-foot long adit at the 500-foot level. The No. 6 shaft went from the 500-foot level to the 1950 level. The No. 5 shaft went from the 800 level to the 2500 level. Production was 8,200,000 tons of ore to the end of 1918; or, 20,314,000 tons of ore (1880-1930). The ore yielded 1,959,098,900 pounds of Cu, 1,009,800 oz. Au and 34,586,000 oz. Ag.
58 valid minerals. 6 (TL) - type locality of 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
1600 - 1800 Ma
|Early Proterozoic granitic rocks|
Age: Statherian (1600 - 1800 Ma)
Description: Wide variety of granitic rocks, including granite, granodiorite, tonalite, quartz diorite, diorite, and gabbro. These rocks commonly are characterized by steep, northeast-striking foliation. (1600-1800 Ma)
Comments: ~ 1.6 - 1.8 Ga
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. 
1600 - 2500 Ma
|Altered rhyolitic tuff|
Age: Proterozoic (1600 - 2500 Ma)
Description: Chlorite-rich crystal tuff of Cleopatra Formation south of Jerome in zone 6B. Similar pattern of chemical alteration as in altered rhyolite. Also includes muscovite- and quartz-rich rocks derived from tuff and crystal-rich rhyolite tuff. Crops out as elongate to circular areas zoned from muscovite-rich margins to quartz-rich core. Exposed east and southeast of Townsend Butte
Comments: Early Proterozoic plutonic rocks are widely exposed throughout map area. In order to aid in the discussion of these rocks, the exposures of plutonic and metavolcanic rocks are divided into six zones (zones 1–6, from west to east). These zones are roughly parallel to regional foliation and contain rock units that are similar to one another. The zones are not crustal blocks nor are they necessarily separated from one another by discrete tectonic structures
Reference: DeWitt, E., V. Langenheim, E. Force, R.K. Vance, P.A. Lindberg, R.L. Driscoll. Geologic map of the Prescott National Forest and the headwaters of the Verde River, Yavapai and Coconino Counties, Arizona. Scientific Investigations Map SIM-2996.