Middlesex Mine, Goodsprings, Goodsprings District, Spring Mts, Clark Co., Nevada, USA
|Latitude & Longitude (WGS84):||35° 51' North , 115° 29' West|
|Latitude & Longitude (decimal):||35.85000,-115.48333|
|Köppen climate type:||BWk : Cold desert climate|
A former Cu-Pb-Ag-Zn mine located in secs. 20 & 21, T24S, R58E, MDM, 4.8 km (3.0 miles) WNW of Goodsprings and E of Shenandoah Peak (½ mile SE of the Yellow Pine Mine), on private land within a Bureau of Land Management administered area. MRDS database stated accuracy for this location is 10 meters.
Mineralization is a deposit hosted in dolomite. The ore body strikes NS (N-S ?) and dips 35W. Controls for ore emplacement included a bedding surface fracture. Galena in coarse cubic crystals embedded in white, coarse dolomite. A granite porphyry sill is 40 feet stratigraphically below the fracture. Associated rocks include Paleocene/Pennsylvanian granite. Local rocks include limestone and sparse dolomite, siltstone, and sandstone.
Regional geologic structures include large scale overthrusts.
Workings include underground openings comprised of 2 tunnels. The upper tunnel is 100 feet long and the lower is 400 feet long. Also, 3 other tunnels were driven within 600 feet from the mine, which explore the same ore zone.
Production data are found in: Hewett (1931).
No recorded production, but estimated at 200 tons of Pb/Zn ore.
2 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
|Holocene - Pleistocene|
0 - 2.588 Ma
Age: Pleistocene (0 - 2.588 Ma)
Description: Unit is present in all counties. Some counties divided the alluvium into younger and older units, and some did not. For those that did not, or used other generalized terms for Quaternary rocks, the unit Qal has been used for the general undivided alluvium. Additionally, when polygons have been edited and changed to alluvium, Qal was used as the general value; hence it now is present in all counties. Qya-Younger alluvium: Map unit is used in Churchill, Elko, Esmeralda, Eureka, Humboldt, Lander, and Lincoln Counties where geologic information suggests better-defined younger versus older alluvium. It is mostly interchangeable with Qal, except that it implies some specifically younger Quaternary deposits.
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. 
|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.