Emerald Mine, Silver Plume Mine (Emerald & Silver Plume Mine group), Tombstone District, Tombstone Hills, Cochise Co., Arizona, USA
|Latitude & Longitude (WGS84):||31° 41' 20'' North , 110° 4' 8'' West|
|Latitude & Longitude (decimal):||31.68889,-110.06889|
|Other regions containing this locality:||Sonoran Desert, North America|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
A former medium output underground Ag-Pb-Zn-Cu-Au-Mo occurrence/mine located in the NW¼ sec. 14, T20S, R22E, 1.52 km NE of the peak of Ajax Hill in the Tombstone Hills, on private land. The Grand Central Mining Co. operated the Emerald and the Silver Plume for most of the productive years. The Emerald had one of the largest ore bodies in the district. The Silver Plume shaft is located in the NE¼NW¼ sec. 23, approximately 50 feet S of the boundary between sec. 14 and sec. 23, 1000 feet SW of the Emerald shaft.
Mineralization is hosted in Abrigo Limestone and Bolsa Quartzite and consisted of partially oxidized base metal sulfides with some wulfenite and horn silver in fault breccia in limestone and quartzite. Ore control was a N-S dike-fissure, striking N20E and dipping 76W. The ore zone is 335.28 meters long and 3.05 meters wide.
Local structures include the north side of the Ajax Hill Horst, south of the Oregon-Prompter Fault Zone. The Abrigo limestone dips 35 to 45E.
Workings were to a depth of 268.22 meters. The mine has 9 levels. The Silver Plume shaft, 788 feet deep, adjoins to the S. Underground working did not reach the limit of the ore shoot. Work was discontinued because of water. This mine had the largest body of copper ore in the district. Production statistics were included under the Grand Central Mine. Smaller amounts were produced up to 1928. One carload yielded 40% Cu.
30 valid minerals. 1 (TL) - type locality of valid minerals. 1 (FRL) - first recorded locality of unapproved mineral/variety/etc.
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
|Serpukhovian - Early Cambrian|
323.2 - 541 Ma
|Mississippian, Devonian, and Cambrian sedimentary rocks|
Age: Paleozoic (323.2 - 541 Ma)
Description: Brown to dark gray sandstone grades upward into green and gray shale, overlain by light to medium gray or tan limestone and dolostone. This unit includes the Tapeats Sandstone, Bright Angel Shale, Muav Limestone, Temple Butte Formation and Redwall Limestone in northern Arizona, and the Bolsa Quartzite, Abrigo Formation, Martin Formation, and Escabrosa Limestone in southern Arizona. These rocks record intermittent sea-level rise and inundation in early Paleozoic time. (330-540 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.