Four Hills Mine, Hawley Lake, Sierra City Mining District, Sierra County, California, USAi
| Regional Level Types | |
|---|---|
| Four Hills Mine | Mine |
| Hawley Lake | Lake |
| Sierra City Mining District | Mining District |
| Sierra County | County |
| California | State |
| USA | Country |
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Latitude & Longitude (WGS84):
39° 41' 56'' North , 120° 42' 33'' West
Latitude & Longitude (decimal):
Type:
KΓΆppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Plumas Eureka (historical) | 339 (2011) | 6.7km |
| Graeagle | 737 (2011) | 10.8km |
| Plumas Eureka | 339 (2017) | 11.3km |
| Valley Ranch | 109 (2011) | 13.0km |
| C-Road | 150 (2011) | 13.3km |
Mindat Locality ID:
8178
Long-form identifier:
mindat:1:2:8178:1
GUID (UUID V4):
3703faa3-40d1-46b8-99b2-5fc169ef81c6
A former lode Au-Pb-Cu mine located in the NEΒΌ sec. 10 & in secs 2, 9 & 11, T21N, R11E, MDM, 1.7 km (1.1 miles) N of Hawley Lake (coordinates of record), about 15 km NW of Bassetts and about 16 km (10 miles) NNW of Sierra City (about 10-12 miles NE of Downieville), on private land within a National Forest area. MRDS database stated accuracy for this location is 1,000 meters.
Mineralization is a vein deposit (Mineral occurrence model information: Model code: 273; USGS model code: 36a; Deposit model name: Low-sulfide Au-quartz vein; Mark3 model number: 27) hosted in Late Permian mafic intrusive rock and mica schist. The ore body strikes E10N and dips 45SW at a thickness of 6.1 meters. Large bodies of quartz were formed by the intersection of veins. E stringers intersect with the main vein, which varies from 1 to 20 feet in thickness, and averages 4 to 5 feet in thickness. The vein strikes E on the N end and N on the S end. The vein was said to resemble the Plumas-Eureka. Most ore occurred in pockets or small, rich ore shoots. Pockets ranged from $1500 to $6000 (period values) near surface. Also, high-grade ore occurs where the vein comes in contact with mica schist and where veinlets leave the main vein and butt against, and are cut off by, mica schist. Local rocks include Paleozoic metavolcanic rocks, unit 2 (Northeastern Sierra Nevada).
Workings include surface and underground openings with an overall depth of 100.58 meters and comprised of a shaft, a 1,100 foot adit that intersects the shaft at 150 feet; also, surface and near surface pocket mines. 2 adits adjacent to the Four Hills are supposedly part of the Four Hills. The USGS mineral record card for the Sierra Iron Company also includes these adits on their property. A possible error exists here.
Production data are found in: MacBoyle, Errol (1920b).
Production occurred from Spanish times onward, intermittently. Totasl estimated yield was from $1,000,000 to $3,300,000 (period values). The early output was $1,000,000 to $1,500,000 (period values).
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsDetailed Mineral List:
| β Chalcopyrite Formula: CuFeS2 |
| β Galena Formula: PbS |
| β Gold Formula: Au |
| β Hematite Formula: Fe2O3 Description: Pure and abundant. References: |
| β Hematite var. Specularite Formula: Fe2O3 Description: Pure and abundant. References: |
| β Pyrite Formula: FeS2 |
| β Quartz Formula: SiO2 |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| β | Gold | 1.AA.05 | Au |
| Group 2 - Sulphides and Sulfosalts | |||
| β | Chalcopyrite | 2.CB.10a | CuFeS2 |
| β | Galena | 2.CD.10 | PbS |
| β | Pyrite | 2.EB.05a | FeS2 |
| Group 4 - Oxides and Hydroxides | |||
| β | Hematite | 4.CB.05 | Fe2O3 |
| β | var. Specularite | 4.CB.05 | Fe2O3 |
| β | Quartz | 4.DA.05 | SiO2 |
List of minerals for each chemical element
| O | Oxygen | |
|---|---|---|
| O | β Hematite | Fe2O3 |
| O | β Quartz | SiO2 |
| O | β Hematite var. Specularite | Fe2O3 |
| Si | Silicon | |
| Si | β Quartz | SiO2 |
| S | Sulfur | |
| S | β Chalcopyrite | CuFeS2 |
| S | β Galena | PbS |
| S | β Pyrite | FeS2 |
| Fe | Iron | |
| Fe | β Chalcopyrite | CuFeS2 |
| Fe | β Hematite | Fe2O3 |
| Fe | β Pyrite | FeS2 |
| Fe | β Hematite var. Specularite | Fe2O3 |
| Cu | Copper | |
| Cu | β Chalcopyrite | CuFeS2 |
| Au | Gold | |
| Au | β Gold | Au |
| Pb | Lead | |
| Pb | β Galena | PbS |
Other Databases
| Link to USGS MRDS: | 10086586 |
|---|
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 #0060910464
