Pocohontas Mine, Copper Hill, Green Mountain Mining District (Ben Hur Mining District), Mariposa County, California, USAi
| Regional Level Types | |
|---|---|
| Pocohontas Mine | Mine |
| Copper Hill | Hill |
| Green Mountain Mining District (Ben Hur Mining District) | Mining District |
| Mariposa County | County |
| California | State |
| USA | Country |
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Latitude & Longitude (WGS84):
37° 20' 39'' North , 120° 3' 48'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Catheys Valley | 825 (2011) | 10.3km |
| Mariposa | 2,173 (2017) | 17.8km |
| Bootjack | 960 (2011) | 20.6km |
| Le Grand | 1,659 (2011) | 20.8km |
| Planada | 4,584 (2011) | 23.3km |
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
Local clubs are the best way to get access to collecting localities
| Club | Location | Distance |
|---|---|---|
| Mariposa Gem & Mineral Club | Mariposa, California | 18km |
A former Cu-Au-Ag mine located in the NW¼ (sec. = ??) secs. 1, 12 & 14, T7S, R17E, MDM, 6.2 km (3.8 miles) NNW of Copper Hill (coordinates of record), along Brushy Creek (1 mile N of the White Rock School). Discovered in 1862. Operated during the period 1902-1913. Operated by Eben N. Briggs (estate) C/O L. M. Olds. MRDS database accuracy for this location is not stated.
Mineralization is hosted in schist. The ore body is lenticular, strikes N35-45W, and dips 65-80NE. Sulfide ore occurs in a gangue of brecciated wall rock and introduced quartz. One ore shoot. Controls for ore emplacement include a shear zone. Wall rocks consist principally of quartz-biotite hornfels, quartz-biotite and quartz-biotite-andalusite schist. A sheet of hornblende-rich granitic rock intruded parallel to schistosity along the mineralized zone. Thin sheets of biotite-quartz diorite penetrate the schist near the mine openings. A stock of biotite-quartz diorite crops out less than 400 feet SE of the main shaft. Local alteration is hydrothermal. Local rocks include Jurassic marine rocks, unit 1 (Western Sierra Nevada and Western Klamath Mountains).
Workings include underground openings comprised of 7 shafts from 15 to 75 feet deep and a tunnel driven NW (as of 1954). Most shafts are inclined steeply SE.
Production data are found in: Bowen, O.E., Jr. & C.H. Gray, Jr. (1957).
Production information: $30,000 Cu in a 3 year period in early 1900's.
Reserve resource information: Estimation not possible due to conditions of mine workings. Numerous gossan outcroppings and shear zones parallel to the principal ore zone have not been thoroughly prospected. No indications of lowering in the grade of ore with depth.
Analytical data results: 6-12% Cu, $2.50/ton Au (period values about 1902).
Mineralization is hosted in schist. The ore body is lenticular, strikes N35-45W, and dips 65-80NE. Sulfide ore occurs in a gangue of brecciated wall rock and introduced quartz. One ore shoot. Controls for ore emplacement include a shear zone. Wall rocks consist principally of quartz-biotite hornfels, quartz-biotite and quartz-biotite-andalusite schist. A sheet of hornblende-rich granitic rock intruded parallel to schistosity along the mineralized zone. Thin sheets of biotite-quartz diorite penetrate the schist near the mine openings. A stock of biotite-quartz diorite crops out less than 400 feet SE of the main shaft. Local alteration is hydrothermal. Local rocks include Jurassic marine rocks, unit 1 (Western Sierra Nevada and Western Klamath Mountains).
Workings include underground openings comprised of 7 shafts from 15 to 75 feet deep and a tunnel driven NW (as of 1954). Most shafts are inclined steeply SE.
Production data are found in: Bowen, O.E., Jr. & C.H. Gray, Jr. (1957).
Production information: $30,000 Cu in a 3 year period in early 1900's.
Reserve resource information: Estimation not possible due to conditions of mine workings. Numerous gossan outcroppings and shear zones parallel to the principal ore zone have not been thoroughly prospected. No indications of lowering in the grade of ore with depth.
Analytical data results: 6-12% Cu, $2.50/ton Au (period values about 1902).
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsDetailed Mineral List:
| ⓘ Andalusite Formula: Al2(SiO4)O Description: Occurs in quartz-biotite-andalusite wall rocks. |
| ⓘ Azurite Formula: Cu3(CO3)2(OH)2 References: |
| ⓘ 'Biotite' Formula: K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 Description: Occurs in quartz-biotite-andalusite wall rocks. |
| ⓘ Chalcocite ? Formula: Cu2S Colour: Dark blue, blue-black Description: Described as a dark blue or blue-black sulphide. |
| ⓘ Chalcopyrite Formula: CuFeS2 |
| ⓘ 'Limonite' Description: Occurs in abundant gossan outcroppings. |
| ⓘ Malachite Formula: Cu2(CO3)(OH)2 References: |
| ⓘ Pyrite Formula: FeS2 |
| ⓘ Pyrrhotite Formula: Fe1-xS References: |
| ⓘ Quartz Formula: SiO2 |
| ⓘ Sphalerite Formula: ZnS |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 2 - Sulphides and Sulfosalts | |||
|---|---|---|---|
| ⓘ | Chalcocite ? | 2.BA.05 | Cu2S |
| ⓘ | Sphalerite | 2.CB.05a | ZnS |
| ⓘ | Chalcopyrite | 2.CB.10a | CuFeS2 |
| ⓘ | Pyrrhotite | 2.CC.10 | Fe1-xS |
| ⓘ | Pyrite | 2.EB.05a | FeS2 |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Quartz | 4.DA.05 | SiO2 |
| Group 5 - Nitrates and Carbonates | |||
| ⓘ | Azurite | 5.BA.05 | Cu3(CO3)2(OH)2 |
| ⓘ | Malachite | 5.BA.10 | Cu2(CO3)(OH)2 |
| Group 9 - Silicates | |||
| ⓘ | Andalusite | 9.AF.10 | Al2(SiO4)O |
| Unclassified | |||
| ⓘ | 'Biotite' | - | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| ⓘ | 'Limonite' | - | |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Azurite | Cu3(CO3)2(OH)2 |
| H | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| H | ⓘ Malachite | Cu2(CO3)(OH)2 |
| C | Carbon | |
| C | ⓘ Azurite | Cu3(CO3)2(OH)2 |
| C | ⓘ Malachite | Cu2(CO3)(OH)2 |
| O | Oxygen | |
| O | ⓘ Andalusite | Al2(SiO4)O |
| O | ⓘ Azurite | Cu3(CO3)2(OH)2 |
| O | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| O | ⓘ Malachite | Cu2(CO3)(OH)2 |
| O | ⓘ Quartz | SiO2 |
| F | Fluorine | |
| F | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| Mg | Magnesium | |
| Mg | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| Al | Aluminium | |
| Al | ⓘ Andalusite | Al2(SiO4)O |
| Al | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| Si | Silicon | |
| Si | ⓘ Andalusite | Al2(SiO4)O |
| Si | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| Si | ⓘ Quartz | SiO2 |
| S | Sulfur | |
| S | ⓘ Chalcopyrite | CuFeS2 |
| S | ⓘ Chalcocite | Cu2S |
| S | ⓘ Pyrite | FeS2 |
| S | ⓘ Pyrrhotite | Fe1-xS |
| S | ⓘ Sphalerite | ZnS |
| K | Potassium | |
| K | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| Ti | Titanium | |
| Ti | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| Fe | Iron | |
| Fe | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| Fe | ⓘ Chalcopyrite | CuFeS2 |
| Fe | ⓘ Pyrite | FeS2 |
| Fe | ⓘ Pyrrhotite | Fe1-xS |
| Cu | Copper | |
| Cu | ⓘ Azurite | Cu3(CO3)2(OH)2 |
| Cu | ⓘ Chalcopyrite | CuFeS2 |
| Cu | ⓘ Chalcocite | Cu2S |
| Cu | ⓘ Malachite | Cu2(CO3)(OH)2 |
| Zn | Zinc | |
| Zn | ⓘ Sphalerite | ZnS |
Other Databases
| Link to USGS MRDS: | 10031051 |
|---|
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Foothills-Wallowa DomainDomain
- Sierra Nevada BatholithVolcanic Arc
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References
Aubury, Lewis E. (1905) The Copper Resources of California. Bulletin 23. California State Mining Bureau pages 215, 210
