Hope Mine (Minnesota Development Group), Minnesota Flat, Alleghany Mining District (Forest Mining District), Sierra County, California, USAi
| Regional Level Types | |
|---|---|
| Hope Mine (Minnesota Development Group) | Mine |
| Minnesota Flat | Flat |
| Alleghany Mining District (Forest Mining District) | Mining District |
| Sierra County | County |
| California | State |
| USA | Country |
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Latitude & Longitude (WGS84):
39° 27' 6'' North , 120° 49' 34'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Washington | 185 (2011) | 10.5km |
| Downieville | 282 (2011) | 12.0km |
| Pike | 134 (2011) | 14.8km |
| Camptonville | 158 (2011) | 19.1km |
| Sierra City | 221 (2011) | 20.8km |
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 |
|---|---|---|
| Nevada County Gem & Mineral Society | Grass Valley, California | 33km |
A former lode Au occurrence/mine located in the SW¼ (estimated) sec. 2, T18N, R10E, MDM, 0.5 km (0.3 mile) ENE of Minnesota Flat, on the narrow divide between Hope Ravine on the E and Jackass Ravine on the W (1½ miles SW of Alleghany), on National Forest land. MRDS database stated accuracy for this location is 1,000 meters.
Mineralization is a vein deposit hosted in slate and serpentinite. The ore body is pinch-and-swell in form, strikes WNW and dips N at a thickness of 3.05 meters. Several parallel quartz veins at 2 to 10 feet thick, averaging 3 feet thick, have serpentine footwalls and slate hanging walls, but sometimes the vein is within slate. The veins carry gouge on both sides, in part graphitic clay with occasional tall slate casings. Local rocks include Mesozoic gabbroic rocks, unit 2 (undivided) and/or undivided pre-Cenozoic metavolcanic rocks, unit 2 (undivided).
Workings include underground openings comprised of 2 adits, one 142 feet long, with crosscuts and winzes.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsDetailed Mineral List:
| ⓘ Graphite Formula: C Description: Occurs as graphitic clay in gouge. |
| ⓘ Native Gold Formula: Au |
| ⓘ Quartz Formula: SiO2 |
| ⓘ 'Serpentine Subgroup' Formula: D3[Si2O5](OH)4 Description: Occurs in wallrocks. |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Native Gold | 1.AA.05 | Au |
| ⓘ | Graphite | 1.CB.05a | C |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Quartz | 4.DA.05 | SiO2 |
| Unclassified | |||
| ⓘ | 'Serpentine Subgroup' | - | D3[Si2O5](OH)4 |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 |
| C | Carbon | |
| C | ⓘ Graphite | C |
| O | Oxygen | |
| O | ⓘ Quartz | SiO2 |
| O | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 |
| Si | Silicon | |
| Si | ⓘ Quartz | SiO2 |
| Si | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 |
| Au | Gold | |
| Au | ⓘ Native Gold | Au |
Other Databases
| Link to USGS MRDS: | 10034783 |
|---|
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Calaveras-Baker DomainDomain
- Sierra Nevada BatholithVolcanic Arc
USA
- Sierra NevadaMountain Range
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References
(n.d.) Minerals Availability System (MAS), U.S. Bureau of Mines.file #0060910119
