Stone Mine (Trask Mine; Longton Mine; Coffer Mine; Trask and Stone lease), Copperopolis, Foothill Copper Belt, Calaveras County, California, USAi
Regional Level Types | |
---|---|
Stone Mine (Trask Mine; Longton Mine; Coffer Mine; Trask and Stone lease) | Mine |
Copperopolis | - not defined - |
Foothill Copper Belt | Belt |
Calaveras County | County |
California | State |
USA | Country |
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Latitude & Longitude (WGS84):
38° 0' 25'' North , 120° 36' 29'' West
Latitude & Longitude (decimal):
Type:
KΓΆppen climate type:
Nearest Settlements:
Place | Population | Distance |
---|---|---|
Copperopolis | 3,671 (2011) | 4.1km |
Angels Camp | 2,677 (2012) | 9.1km |
Tuttletown | 668 (2011) | 13.1km |
Vallecito | 442 (2011) | 15.0km |
Jamestown | 3,433 (2011) | 17.3km |
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 |
---|---|---|
Calaveras Gem & Mineral Society | Angels Camp, California | 9km |
Amador County Gem & Mineral Society | Sutter Creek, California | 46km |
Mindat Locality ID:
75959
Long-form identifier:
mindat:1:2:75959:8
GUID (UUID V4):
f0b493ba-5fb8-450d-a172-65553e7a8239
A former Cr-Fe-talc mine located in secs. 23 & 24, T2N, R12E, MDM, 4.1 km (2.5 miles) NE of Copperopolis, along Empire Creek (located claim). Discovered and first operated in 1917. Owned by C.E. Longton during WWI, California (as of 1976). Operated by Coffer, Trask and Stone, California (1976), who leased the deposit from Longton. Owned by Charles J. Stone, California (1976). Last active during World War I. MRDS database stated accuracy for this location is 100 meters.
Mineralization is a Cr deposit hosted in serpentine. The ore bodies strike and dip N55E. Ore body No. 1 is disseminated, massive and ore body No. 2 is lenticular. The primary mode of origin was magmatic differentiation. Primary ore control was lithology. The secondary ore control was a contact zone. Wallrock alteration is intense (carbonitization). Chromite lenses as much as 3 feet thick striking N25W. Also disseminated chromite in serpentine is present. The country rock is sheared, talcose serpentine. Ore from the dump is massive, medium- to coarse-grained chromite. All the ore bodies lie near the E contact of the serpentine. Local rocks include ultramafic rocks, chiefly Mesozoic, unit 2 (Western Sierra Nevada and Klamath Mountains) and/or Mesozoic volcanic rocks, unit 2 (Western Sierra Foothills and Western Klamath Mountains).
Workings include underground openings comprised of 5 shafts and 2 drifts.
Output was 92 long tons of ore, most of which came from the main shaft.
Reserves are probably small.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsDetailed Mineral List:
β Formula: Fe2+Cr3+2O4 |
β Magnesiochromite Formula: MgCr2O4 |
β 'Serpentine Subgroup' Formula: D3[Si2O5](OH)4 |
β Talc Formula: Mg3Si4O10(OH)2 Description: Occurs as talcose serpentine. |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
Group 4 - Oxides and Hydroxides | |||
---|---|---|---|
β | Chromite ? | 4.BB.05 | Fe2+Cr3+2O4 |
β | Magnesiochromite | 4.BB.05 | MgCr2O4 |
Group 9 - Silicates | |||
β | Talc | 9.EC.05 | Mg3Si4O10(OH)2 |
Unclassified | |||
β | 'Serpentine Subgroup' | - | D3[Si2O5](OH)4 |
List of minerals for each chemical element
H | Hydrogen | |
---|---|---|
H | β Talc | Mg3Si4O10(OH)2 |
H | β Serpentine Subgroup | D3[Si2O5](OH)4 |
O | Oxygen | |
O | β Chromite | Fe2+Cr23+O4 |
O | β Magnesiochromite | MgCr2O4 |
O | β Talc | Mg3Si4O10(OH)2 |
O | β Serpentine Subgroup | D3[Si2O5](OH)4 |
Mg | Magnesium | |
Mg | β Magnesiochromite | MgCr2O4 |
Mg | β Talc | Mg3Si4O10(OH)2 |
Si | Silicon | |
Si | β Talc | Mg3Si4O10(OH)2 |
Si | β Serpentine Subgroup | D3[Si2O5](OH)4 |
Cr | Chromium | |
Cr | β Chromite | Fe2+Cr23+O4 |
Cr | β Magnesiochromite | MgCr2O4 |
Fe | Iron | |
Fe | β Chromite | Fe2+Cr23+O4 |
Other Databases
Link to USGS MRDS: | 10109155 |
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References
(n.d.) Minerals Availability System (MAS), U.S. Bureau of Mines.file ID #0060090417
Eric, John H. (1955) Geology and mineral deposits of the Angels Camp and Sonora quadrangles, Calaveras and Tuolumne Counties, California. Special Report 41. California Division of Mines p.52 - plate 3