Grassely claims (Grassely group; Grassley claims; Grassley group; Lopez lease [1918]; Lopes lease), Peoria Flat, Yosemite Junction, Tuolumne County, California, USAi
| Regional Level Types | |
|---|---|
| Grassely claims (Grassely group; Grassley claims; Grassley group; Lopez lease [1918]; Lopes lease) | Group of Claims |
| Peoria Flat | Flat |
| Yosemite Junction | - not defined - |
| Tuolumne County | County |
| California | State |
| USA | Country |
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Latitude & Longitude (WGS84):
37° 54' 16'' North , 120° 30' 15'' West
Latitude & Longitude (decimal):
Type:
Group of Claims
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Chinese Camp | 126 (2011) | 7.2km |
| Jamestown | 3,433 (2011) | 9.0km |
| Tuttletown | 668 (2011) | 10.4km |
| Sonora | 4,818 (2017) | 13.9km |
| Copperopolis | 3,671 (2011) | 14.8km |
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 |
|---|---|---|
| Calaveras Gem & Mineral Society | Angels Camp, California | 18km |
A former Cr occurrence/group of claims/mine located in sec. 25, T1N, R13E, MDM, 0.7 km (2,200 feet) W of Peoria Flat (coordinates of record) (approximately 10.5 miles SW of Sonora), on private (patented) land within a Bureau of Land Management administered area. Operated during the period 1914 to 1917. Owned by Eugene Grassley (100%) (1978). Operated by George Everhart. MRDS database stated accuracy for this location is 100 meters.
Mineralization is hosted in Late Jurassic dunite. The deposit consists of vertically-dipping bands of chromite that strike NW, except at the May Faction claim, where the ore bands strike N12W and the lireation of the ore pitches 10SE. The deposit occurs in the northern part of the westernmost of 2 serpentine belts which trend NW-SE across the county. The belt is exposed over an area 30 km by 6 km. Local rocks include ultramafic rocks, chiefly Mesozoic, unit 2 (Western Sierra Nevada and Klamath Mountains).
Workings include surface and underground openings comprised of small trenches, pits, open cuts and shallow caved shafts.
Local strutures include extensive shearing in the host rock; and, serpentinization of dunite.
Production data are found in: Cater, F.W., Jr. (1948a): 26, 27.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsMineral List
Mineral list contains entries from the region specified including sub-localities1 valid mineral. 1 erroneous literature entry.
Detailed Mineral List:
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 4 - Oxides and Hydroxides | |||
|---|---|---|---|
| ⓘ | Chromite ? | 4.BB.05 | Fe2+Cr3+2O4 |
| ⓘ | Magnesiochromite | 4.BB.05 | MgCr2O4 |
List of minerals for each chemical element
| O | Oxygen | |
|---|---|---|
| O | ⓘ Chromite | Fe2+Cr23+O4 |
| O | ⓘ Magnesiochromite | MgCr2O4 |
| Mg | Magnesium | |
| Mg | ⓘ Magnesiochromite | MgCr2O4 |
| Cr | Chromium | |
| Cr | ⓘ Chromite | Fe2+Cr23+O4 |
| Cr | ⓘ Magnesiochromite | MgCr2O4 |
| Fe | Iron | |
| Fe | ⓘ Chromite | Fe2+Cr23+O4 |
Other Databases
| Link to USGS MRDS: | 10043702 |
|---|
Localities in this Region
- California
- Tuolumne County
- Yosemite Junction
- Peoria Flat
- Grassely claims (Grassely group; Grassley claims; Grassley group; Lopez lease [1918]; Lopes lease)
- Peoria Flat
- Yosemite Junction
- Tuolumne County
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Calaveras-Baker DomainDomain
- Sierra Nevada BatholithVolcanic Arc
USA
- California
- Mother Lode BeltBelt
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References
(n.d.) Minerals Availability System (MAS), U.S. Bureau of Mines.file ID #0061090849
