Eldorado Mine (Terrible; Eldorado Extension; Eldorado Ext), Alleghany, Alleghany Mining District (Forest Mining District), Sierra County, California, USAi
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Latitude & Longitude (WGS84):
39° 28' 0'' North , 120° 49' 57'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Downieville | 282 (2011) | 10.3km |
| Washington | 185 (2011) | 12.3km |
| Pike | 134 (2011) | 14.5km |
| Camptonville | 158 (2011) | 18.6km |
| Sierra City | 221 (2011) | 20.3km |
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 |
|---|---|---|
| Nevada County Gem & Mineral Society | Grass Valley, California | 34km |
Mindat Locality ID:
93243
Long-form identifier:
mindat:1:2:93243:8
GUID (UUID V4):
ca6a16cc-10b2-4f3c-b7a1-52a42cce242f
A former lode Au-Zn-Pb-Cu occurrence/mine located in the SE¼ sec. 34 & sec. 35, T19N, R10E, and in secs 2 & 3, T18N, R10E, MDM, about 1.2 km (2/3 mile) SE of Alleghany, along the S canyon wall of Kanaka Creek, on National Forest land. The property is comprised of 3 unpatented claims. MRDS database stated accuracy for this location is 100 meters.
Mineralization is a vein deposit with ore shoots hosted in serpentinite, gabbro, granite, schist & aplite. The ore body strikes NNW and dips E. There are 3 veins: the Eastern vein, MAin vein and El Dorado vein, continuous except at bend, with a strike of N50W to N30E. The bend may be due to the crossing of a serpentine dike. Post-mineralization thrusts & inter-mineral thrusts are present. There is an outcrop of coarse-crystalline marble at the portal. Dikes of gabbro are also faulted by the Eldorado vein. Two small masses of aplite outcrop in the S part of the claim. Country rock is amphibolite schist. Grooving on the hanging wall has a N85E, and elsewhere a N65E strike, the latter being the most intense. The vein reopening is indicated by quartz-cemented breccia along the hanging wall. The vein follows a reverse fault, same as the Plumbago vein maybe. Displacement 50 feet in the N, 100 feet in the S. Middle and Bullion veins, strike N30W and N20W. The ore shoots contain high-grade ore. All high-grade ore of the vein is in the bend, where quartz is present only in lenses. The principal gold is associated with arsenopyrite. 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 at least 3 adits, winzes and sub-levels with 3,600 feet of drifts and 1,000 feet of raises and winzes.
Production data are found in: Ferguson & Gannett (1932).
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsDetailed Mineral List:
| ⓘ Arsenopyrite Formula: FeAsS |
| ⓘ Galena Formula: PbS |
| ⓘ Gold Formula: Au |
| ⓘ Pyrite Formula: FeS2 |
| ⓘ Quartz Formula: SiO2 |
| ⓘ 'Tetrahedrite Subgroup' Formula: Cu6(Cu4C2+2)Sb4S12S |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Gold | 1.AA.05 | Au |
| Group 2 - Sulphides and Sulfosalts | |||
| ⓘ | Galena | 2.CD.10 | PbS |
| ⓘ | Pyrite | 2.EB.05a | FeS2 |
| ⓘ | Arsenopyrite | 2.EB.20 | FeAsS |
| ⓘ | 'Tetrahedrite Subgroup' | 2.GB.05 | Cu6(Cu4C2+2)Sb4S12S |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Quartz | 4.DA.05 | SiO2 |
List of minerals for each chemical element
| O | Oxygen | |
|---|---|---|
| O | ⓘ Quartz | SiO2 |
| Si | Silicon | |
| Si | ⓘ Quartz | SiO2 |
| S | Sulfur | |
| S | ⓘ Arsenopyrite | FeAsS |
| S | ⓘ Galena | PbS |
| S | ⓘ Pyrite | FeS2 |
| S | ⓘ Tetrahedrite Subgroup | Cu6(Cu4C22+)Sb4S12S |
| Fe | Iron | |
| Fe | ⓘ Arsenopyrite | FeAsS |
| Fe | ⓘ Pyrite | FeS2 |
| Cu | Copper | |
| Cu | ⓘ Tetrahedrite Subgroup | Cu6(Cu4C22+)Sb4S12S |
| As | Arsenic | |
| As | ⓘ Arsenopyrite | FeAsS |
| Sb | Antimony | |
| Sb | ⓘ Tetrahedrite Subgroup | Cu6(Cu4C22+)Sb4S12S |
| Au | Gold | |
| Au | ⓘ Gold | Au |
| Pb | Lead | |
| Pb | ⓘ Galena | PbS |
Other Databases
| Link to USGS MRDS: | 10106527 |
|---|
Other Regions, Features and Areas containing this locality
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References
(n.d.) Minerals Availability System (MAS), U.S. Bureau of Mines.file #0060910122
