Fourth of July Mine (Fourth of July claims; Ellis shaft; Billingsley Fluorspar Mines; Sydney Mine), Duncan, Ash Peak District (Twin Peaks District), Greenlee Co., Arizona, USA
|Latitude & Longitude (WGS84):||32° 51' 37'' North , 109° 4' 32'' West|
|Latitude & Longitude (decimal):||32.86028,-109.07556|
|Other regions containing this locality:||Sonoran Desert, North America|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
A former surface and underground Fluorspar-Mn-W-Cu-Au-Ag-Be mine located on 7 unpatented claims, in the NW¼NE¼NW¼ sec. 4, T8S, R32E, and the SW¼ sec. 33, T7S, R32E, 7.5 miles ESE of York between Willow Creek and Daniels Camp Canyon, adjacent to the Luckie No. 1 and 2 claims, near Duncan, on BLM-administered land. Geodetic and UTM coordinates describe the Fourth of July mine shaft in sec. 4; the northernmost open cut on the property is located in the SW quarter of sec. 33. Discovered 1937 by Robert T. Ellis. Produced 1917-1955. Owned by Mr. Ben Billingsley (1975). Operated by Producers Minerals Co. (1975). Other past operators included A.T. Laisne; R.T. Ellis Mining Co.; and the Arizona Eastern Fluorspar Corporation.
Mineralization is lens-shaped orebodies in two veins (east vein and west vein) hosted in basalt, with an overall length of 762 meters and a width of 1.52 meters, and 45.72 meters thick. The west vein strikes NW and the east vein strikes SE. Their dips are N70W and N55W, respectively. Fluorspar minerals form lenticular veins and pockets. An associated rock unit is Tertiary volcanic flows. Ore control is fault breccia zones and fissures in basalt. Ore concentration is mineralization along fault breccia zones in irregular concentrations. Alteration involves ferromagnesian minerals altered to iron oxide and carbonate of dolomitic composition; devitrified and hydrothermally altered rhyolitic tuff on claim No. 2. Mn oxides are W-bearing. Only small sections of the total length of the vein system are known to contain fluorspar (ie: one section along the strike is 400 feet long). The Riverview vein carries Cu, Au, and Ag (strikes due E-W and dips almost vertically). Secondary coatings and thin stringers of psilomelane are associated with fluorspar veins. Fluorspar mineralization occurred after regional faulting. Calcite is commonly concentrated near the hanging wall edge of the vein as a result of leaching from the vein.
Area structures include well-jointed basalt in northerly and easterly directions; undulating contact between upper dark red basaltic flow and underlying greenish basaltic flow; fluorspar occurs in fissure veins interlaced with a network of iron-stained quartz veinlets.
Tectonic component is the Mule Creek Mountain foothills.
Workings are 242.32 meters in length. Development occurred on 2 veins about 25-30 feet apart near the center of claim No. 2. Workings on the east vein consist of 2 long trenches 60-70 feet long and 60 feet deep, 1 pit about 20 feet deep, and a glory hole about 20 feet in diameter that connects with underground workings. West vein workings consist of a small pit, a large glory hole about 15 feet deep, and the 150 foot deep inclined Ellis shaft with 45 foot long crosscuts to the east vein on 3 levels (stopes of 60 feet, 100 feet, and 148 feet connect crosscut with surface); and 500 feet of drifts.
These claims were first located in the early 1900's for prospecting copper, silver, and gold (some ore produced in 1917 and 1918). Small amounts of Cu, Au, and Ag were produced in the 1930's or earlier; however, there are no production records.
3 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 - Bartonian|
7.246 - 41.3 Ma
|Middle Miocene to Oligocene volcanic rocks|
Age: Cenozoic (7.246 - 41.3 Ma)
Description: Lava, tuff, fine-grained intrusive rock, and diverse pyroclastic rocks. These compositionally variable volcanic rocks include basalt, andesite, dacite, and rhyolite. Thick felsic volcanic sequences form prominent cliffs and range fronts in the Black (Mohave County), Superstition, Kofa, Eagletail, Galiuro, and Chiricahua Mountains. This unit includes regionally extensive ash-flow tuffs, such as the Peach Springs tuff of northwestern Arizona and the Apache Leap tuff east of Phoenix. Most volcanic rocks are 20-30 Ma in southeastern Arizona and 15 to 25 Ma in central and western Arizona, but this unit includes some late Eocene rocks near the New Mexico border in east-central Arizona. (11-38 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.