Cosumnes Mine (Cosumnes Melton; Melton; Middle End), Grizzly Flat, Grizzly Flat Mining District, East Belt, El Dorado Co., California, USAi
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Key
Latitude & Longitude (WGS84):
38° 39' 53'' North , 120° 32' 0'' West
Latitude & Longitude (decimal):
Locality type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Pollock Pines | 6,871 (2017) | 11.7km |
| Camino | 1,750 (2011) | 14.8km |
| River Pines | 379 (2011) | 22.5km |
| Buckhorn | 2,429 (2017) | 23.6km |
| Placerville | 10,650 (2017) | 24.1km |
A former lode Cu-Au-Zn-Pb-Ag-Sb occurrence/mine located in secs. 3 & 4, T9N, R13E, MDM, 3.2 km (2.0 miles) N of Grizzly Flat, just S of the Cosumnes River, on private land. Operated by the Caldor Lumber Company. Operated in the 1880's, 1894, 1928 to 1942 & 1942 to 1951. MRDS database stated accuracy for this location is 100 meters. Active during the 1880's and in 1894 as the Melton Mine; reopened in 1928 as the Middle End Mine and operated almost continuously until 1942. Operated by the Cosumnes Mines, Inc. from 1945 to 1950, when purchased by the present owner. The workings are shown in the W½NW¼ sec. 3 on USGS topo map.
Mineralization is a vein deposit hosted in diorite. The ore body strikes NNE and dips W at a thickness of 0.91 meter. Most ore was from the Main or Middle vein that dips steeply at an average of 3 feet thick. Appreciable amounts of galena and pyrite, with sphalerite, chalcopyrite, stibnite and arsenopyrite are present in the ore. Local rocks include Mesozoic gabbroic rocks, unit 2 (undivided).
Workings include underground openings comprised of a 380 foot crosscut adit and several thousand feet of drifts.
Production data are found in: Goodwin, Joseph Grant (1957).
About 10,000 pounds of Pb and some Cu were produced during the period 1928 to 1951, in addition to Au & Ag.
During the last years of production the ore contained up to $25 (period values) Au/ton with sulfide concentrates yielding $100 to $200 (period values) Au/ton.
Select Mineral List Type
Standard Detailed Gallery Strunz Dana Chemical ElementsDetailed Mineral List:
| ⓘ Arsenopyrite Formula: FeAsS Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10101158. |
| ⓘ Chalcopyrite Formula: CuFeS2 Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10101158. |
| ⓘ Galena Formula: PbS Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10101158. |
| ⓘ Gold Formula: Au Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10101158. |
| ⓘ Pyrite Formula: FeS2 Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10101158. |
| ⓘ Quartz Formula: SiO2 Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10101158. |
| ⓘ Sphalerite Formula: ZnS Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10101158. |
| ⓘ Stibnite Formula: Sb2S3 Reference: Clark, Wm. B. & D.W. Carlson (1956), Mines and mineral resources of El Dorado County, California: California Journal of Mines and Geology: 52(4): 413; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 127; ; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10101158. |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Gold | 1.AA.05 | Au |
| Group 2 - Sulphides and Sulfosalts | |||
| ⓘ | Arsenopyrite | 2.EB.20 | FeAsS |
| ⓘ | Chalcopyrite | 2.CB.10a | CuFeS2 |
| ⓘ | Galena | 2.CD.10 | PbS |
| ⓘ | Pyrite | 2.EB.05a | FeS2 |
| ⓘ | Sphalerite | 2.CB.05a | ZnS |
| ⓘ | Stibnite | 2.DB.05 | Sb2S3 |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Quartz | 4.DA.05 | SiO2 |
List of minerals arranged by Dana 8th Edition classification
| Group 1 - NATIVE ELEMENTS AND ALLOYS | |||
|---|---|---|---|
| Metals, other than the Platinum Group | |||
| ⓘ | Gold | 1.1.1.1 | Au |
| Group 2 - SULFIDES | |||
| AmXp, with m:p = 1:1 | |||
| ⓘ | Galena | 2.8.1.1 | PbS |
| ⓘ | Sphalerite | 2.8.2.1 | ZnS |
| AmBnXp, with (m+n):p = 1:1 | |||
| ⓘ | Chalcopyrite | 2.9.1.1 | CuFeS2 |
| AmBnXp, with (m+n):p = 2:3 | |||
| ⓘ | Stibnite | 2.11.2.1 | Sb2S3 |
| AmBnXp, with (m+n):p = 1:2 | |||
| ⓘ | Arsenopyrite | 2.12.4.1 | FeAsS |
| ⓘ | Pyrite | 2.12.1.1 | FeS2 |
| Group 75 - TECTOSILICATES Si Tetrahedral Frameworks | |||
| Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si | |||
| ⓘ | Quartz | 75.1.3.1 | SiO2 |
List of minerals for each chemical element
| O | Oxygen | |
|---|---|---|
| O | ⓘ Quartz | SiO2 |
| Si | Silicon | |
| Si | ⓘ Quartz | SiO2 |
| S | Sulfur | |
| S | ⓘ Chalcopyrite | CuFeS2 |
| S | ⓘ Stibnite | Sb2S3 |
| S | ⓘ Arsenopyrite | FeAsS |
| S | ⓘ Galena | PbS |
| S | ⓘ Pyrite | FeS2 |
| S | ⓘ Sphalerite | ZnS |
| Fe | Iron | |
| Fe | ⓘ Chalcopyrite | CuFeS2 |
| Fe | ⓘ Arsenopyrite | FeAsS |
| Fe | ⓘ Pyrite | FeS2 |
| Cu | Copper | |
| Cu | ⓘ Chalcopyrite | CuFeS2 |
| Zn | Zinc | |
| Zn | ⓘ Sphalerite | ZnS |
| As | Arsenic | |
| As | ⓘ Arsenopyrite | FeAsS |
| Sb | Antimony | |
| Sb | ⓘ Stibnite | Sb2S3 |
| Au | Gold | |
| Au | ⓘ Gold | Au |
| Pb | Lead | |
| Pb | ⓘ Galena | PbS |
References
Sort by
Year (asc) Year (desc) Author (A-Z) Author (Z-A) In-text Citation No.Logan, Clarence August (1938), Mineral resources of El Dorado County: California Journal of Mines and Geology, California Division Mines (Report 34): 34(3): 265.
USGS quadrangle Sly Park, California, topo map (1953).
Clark, Wm. B. & D.W. Carlson (1956), Mines and mineral resources of El Dorado County, California: California Journal of Mines and Geology: 52(4): 413, 494.
Goodwin, Joseph Grant (1957), Lead and zinc in California. California Journal of Mines and Geology, Division of Mines (Report 53): 53(3&4): 441.
Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 82, 127.
USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10030434, 10101158 & 10236224.
U.S. Bureau of Mines, Minerals Availability System (MAS) file #0060171082.
Other Databases
| Link to USGS MRDS: | 10030434 |
|---|
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