Pioneer Chief Mine (Thorn Mine; Manilla), Kentucky House, San Andreas Mining District, Calaveras County, California, USAi
| Regional Level Types | |
|---|---|
| Pioneer Chief Mine (Thorn Mine; Manilla) | Mine |
| Kentucky House | - not defined - |
| San Andreas Mining District | Mining District |
| Calaveras County | County |
| California | State |
| USA | Country |
This page is currently not sponsored. Click here to sponsor this page.
Latitude & Longitude (WGS84):
38° 10' 13'' North , 120° 40' 44'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| San Andreas | 2,783 (2011) | 2.9km |
| Valley Springs | 3,553 (2011) | 13.3km |
| Mountain Ranch | 1,628 (2011) | 13.7km |
| Mokelumne Hill | 646 (2011) | 14.7km |
| Rancho Calaveras | 4,489 (2018) | 16.4km |
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 | 17km |
| Amador County Gem & Mineral Society | Sutter Creek, California | 27km |
A former lode Au mine located in the W½ (estimated) (lot 37) sec. 29, T4N, R12E, MDM, 1.0 km (0.6 mile) NNW of Kentucky House and 2.9 km (9,400 feet) S of San Andreas. Operated in the 1860's but work ceased in 1884. Reopened in 1916 and worked intermittently until the 1930's. MRDS database stated accuracy for this location is 1,000 meters.
Mineralization is a vein deposit hosted in greenstone and slate. The ore body strikes NW and dips NE. The vein isd 5 feet thick with 40 feet of gouge on the hanging walln and a greenstone footwall. The footwall is a dike of chloritic felsite and the hanging wall is serpentine . Local rocks include Paleozoic marine rocks, undivided, unit 4 (Western Sierra Nevada) and/or Jurassic marine rocks, unit 1 (Western Sierra Nevada and Western Klamath Mountains).
Workings include underground openings with an overall depth of 126.49 meters. The workings have been extended laterally and in depth for at least two periods. Early in 1931 a vertical shaft was extended to a depth of 415 feet. The 200 level was run for 125 feet. Then 350 level was 230 feet long, and the 500 foot level had been run 60 feet. Recent development work (1930's) was disappointing.
Production data are found in: Logan, Clarence August and Franke, H. (1934).
Production in 1928 averaged $2 (period values) ton/Au. Sampling in the 1930's indicated that the grade is too low to warrant production.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsDetailed Mineral List:
| ⓘ 'Chlorite Group' Description: A component of chloritic felsite. |
| ⓘ Native Gold Formula: Au |
| ⓘ Quartz Formula: SiO2 |
| ⓘ 'Serpentine Subgroup' Formula: D3[Si2O5](OH)4 Description: Occurs as country rock adjacent to the vein. |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Native Gold | 1.AA.05 | Au |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Quartz | 4.DA.05 | SiO2 |
| Unclassified | |||
| ⓘ | 'Chlorite Group' | - | |
| ⓘ | 'Serpentine Subgroup' | - | D3[Si2O5](OH)4 |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 |
| O | Oxygen | |
| O | ⓘ Quartz | SiO2 |
| O | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 |
| Si | Silicon | |
| Si | ⓘ Quartz | SiO2 |
| Si | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 |
| Au | Gold | |
| Au | ⓘ Native Gold | Au |
Other Databases
| Link to USGS MRDS: | 10102669 |
|---|
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
This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to
visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders
for access and that you are aware of all safety precautions necessary.
References
(n.d.) Minerals Availability System (MAS), U.S. Bureau of Mines.file ID #0060090399
