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Folsom Mine (American River District; Natomas Company; Capital Dredging Company; Folsom-Natoma District), Folsom Mining District, Sacramento County, California, USAi
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Latitude & Longitude (WGS84):
38° 36' 43'' North , 121° 13' 11'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Gold River | 7,912 (2011) | 2.8km |
| Fair Oaks | 30,912 (2011) | 5.8km |
| Orangevale | 33,960 (2011) | 7.4km |
| Rancho Cordova | 71,017 (2017) | 7.6km |
| Folsom | 76,375 (2017) | 8.3km |
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 |
|---|---|---|
| Fossils for Fun Society, Inc. | North Highlands, California | 16km |
| Sacramento Valley Detecting Buffs | North Highlands, California | 16km |
| Roseville Rock Rollers | Roseville, California | 17km |
| Sacramento Mineral Society | Sacramento, California | 24km |
| El Dorado County Mineral and Gem Society | Placerville, California | 39km |
A former placer Au-PGE (Os-Pt-Ir) mine located in T9N, R7E, MDM, (along the S bank of the American River 10 miles downstream to Fair Oaks from Folsom to 6 miles above Folsom). Tailings also located in Carmichael and Citrus Heights quadrangles. Location given is near water treatment ponds on Buffalo Creek in the quadrangle by the same name. Discovered in 1860 (sic). First production was 1848 (sic). Ceased operations in 1962. Operated by the Natomas Co. (1962). MRDS database stated accuracy for this location is 100 meters.
Mineralization is a Holocene placer Au-PGE deposit (Deposit type: stream placer; Deposit model: 119: Placer Au-PGE), hosted in the Vedaboorde Formation (gravels) and/or the Laguna Formation (silt, sand, gravel). The ore body is tabular in form at a thickness of 33.53 meters, a width of 11,265.1 meters and a length of 24,139.5 meters. Controls for ore emplacement
included stream hydraulics. Gravels are in or along the American River and near lower contacts of the Laguna and Mehrten Formations. Local rocks include Quaternary alluvium and marine deposits.
Related tectonic structure: Base of the Sierra Nevada foothills.
Workings included surface dredging operations.
production information: Year: 1958: Gravels = 0.0017 ounces/ton Au (58 ppb). 1914-1916: Pt = 0.00017 ounces/ton (6 ppb).
Analytical data results: Average of 5 PGE samples yielded 43.40% Pt; 20.81% Ir; 30% Os (estimated)(Logan).
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsDetailed Mineral List:
| ⓘ Native Gold Formula: Au |
| ⓘ Native Platinum Formula: Pt Description: Placer material. |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Native Gold | 1.AA.05 | Au |
| ⓘ | Native Platinum | 1.AF.10 | Pt |
List of minerals for each chemical element
| Pt | Platinum | |
|---|---|---|
| Pt | ⓘ Native Platinum | Pt |
| Au | Gold | |
| Au | ⓘ Native Gold | Au |
Other Databases
| Link to USGS MRDS: | 10103627 |
|---|
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- California Central ValleyAccretionary Complex
- Great Valley BasinBasin
- Great Valley DomainDomain
- Sacramento BasinBasin
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