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La Porte Mining District, Plumas County, California, USAi
| Regional Level Types | |
|---|---|
| La Porte Mining District | Mining District |
| Plumas County | County |
| California | State |
| USA | Country |
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Latitude & Longitude (WGS84):
40° North , 120° West (est.)
Estimate based on other nearby localities or region boundaries.
Margin of Error:
~75km
Type:
Kรถppen climate type:
This district is in southwestern Plumas County in the general vicinity of the old mining town of La Porte, 25 miles south of Quincy and 50 miles northeast of Oroville. It was one of the great placer mining districts of the state.
History
The streams were placer-mined early in the gold rush and were reported to have had very rich yields. The town, first known as Rabbit Creek, was renamed in 1857 after La Porte, Indiana. Hydraulic mining began in the middle 1850s and continued through the 1880s. During this time the district was enormously productive; the output from 1855 to 1871 alone was reported to have been at least $60 million. Appreciable drift mining and some lode mining were carried on. Some mining activity continued until the period of World War I. The district was prospected again during the 1930s, but apparently little mining has been done here since. La Porte was a noted early-day "snowshoe" or ski resort.
Geology
The main Tertiary channel of the North Fork of the Yuba River, known as the La Porte channel, extended south-southwest from Gibsonville into this district. From here the channel continued southwest and south again to be joined by a branch from the east from the St. Louis-Table Rock area. The main channel today continues on south to the Poverty Hill and Brandy City districts. At La Porte, the channel is 500 to 1 500 feet wide and as much as 500 feet thick. The lower gravels are quartz-rich and up to 80 feet thick. Most of the gold was recovered from near bedrock. The gravels are capped by thick beds of sand and "pipe" clay. During the heyday of mining in the district, these lower gravels yielded from no to as much as one ounce of gold per cubic yard. To the east the channel deposits are capped by andesite as much as 800 feet thick. Also to the east, considerable faulting has disturbed the channel gravels. Bedrock consists principally of amphibolite, with a one-mile wide belt of slate and quartzite of the Calaveras Formation (Carboniferous to Permian) in the central portion. There are some narrow gold-quartz veins in the district.
History
The streams were placer-mined early in the gold rush and were reported to have had very rich yields. The town, first known as Rabbit Creek, was renamed in 1857 after La Porte, Indiana. Hydraulic mining began in the middle 1850s and continued through the 1880s. During this time the district was enormously productive; the output from 1855 to 1871 alone was reported to have been at least $60 million. Appreciable drift mining and some lode mining were carried on. Some mining activity continued until the period of World War I. The district was prospected again during the 1930s, but apparently little mining has been done here since. La Porte was a noted early-day "snowshoe" or ski resort.
Geology
The main Tertiary channel of the North Fork of the Yuba River, known as the La Porte channel, extended south-southwest from Gibsonville into this district. From here the channel continued southwest and south again to be joined by a branch from the east from the St. Louis-Table Rock area. The main channel today continues on south to the Poverty Hill and Brandy City districts. At La Porte, the channel is 500 to 1 500 feet wide and as much as 500 feet thick. The lower gravels are quartz-rich and up to 80 feet thick. Most of the gold was recovered from near bedrock. The gravels are capped by thick beds of sand and "pipe" clay. During the heyday of mining in the district, these lower gravels yielded from no to as much as one ounce of gold per cubic yard. To the east the channel deposits are capped by andesite as much as 800 feet thick. Also to the east, considerable faulting has disturbed the channel gravels. Bedrock consists principally of amphibolite, with a one-mile wide belt of slate and quartzite of the Calaveras Formation (Carboniferous to Permian) in the central portion. There are some narrow gold-quartz veins in the district.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsCommodity List
This is a list of exploitable or exploited mineral commodities recorded from this region.Mineral List
Mineral list contains entries from the region specified including sub-localities2 valid minerals.
Detailed Mineral List:
| โ 'Chabazite' Habit: Pseudo-cubic Description: Occurs as pseudo-cubic crystals in basalt. |
| โ 'Hypersthene' Formula: (Mg,Fe)SiO3 Description: Occurs as a constituent of hypersthene-andesite. References: |
| โ Native Gold Formula: Au Localities: Reported from at least 26 localities in this region. Description: Placer material. |
| โ Native Platinum Formula: Pt Locality: Slate Creek (Plumas County), La Porte, La Porte Mining District, Plumas County, California, USA Description: Placer material. Noted that, "The platinum metals of Slate creek generally run in sizes from 1/16 inch to microscopic particles, the latter predominating." (Edman, 1898). |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| โ | Native Gold | 1.AA.05 | Au |
| โ | Native Platinum | 1.AF.10 | Pt |
| Unclassified | |||
| โ | 'Chabazite' | - | |
| โ | 'Hypersthene' | - | (Mg,Fe)SiO3 |
List of minerals for each chemical element
| O | Oxygen | |
|---|---|---|
| O | โ Hypersthene | (Mg,Fe)SiO3 |
| Mg | Magnesium | |
| Mg | โ Hypersthene | (Mg,Fe)SiO3 |
| Si | Silicon | |
| Si | โ Hypersthene | (Mg,Fe)SiO3 |
| Fe | Iron | |
| Fe | โ Hypersthene | (Mg,Fe)SiO3 |
| Pt | Platinum | |
| Pt | โ Native Platinum | Pt |
| Au | Gold | |
| Au | โ Native Gold | Au |
Localities in this Region
- California
- Plumas County
- La Porte Mining District
- Plumas County
- California
- Plumas County
- La Porte Mining District
- Grass Valley Bald Mountain
- La Porte
- Antlered Crest Company placer
- Bernards' Diggings Placer Mine (Bernards' diggings; Chinese placer)
- Blue Gravel Sanborn Mine
- Boundary Placer Mine
- Claybark Mine
- Illinois Ridge
- La Porte placer deposit
- Only Chance Placer Mine
- Pendleton Placer Mine
- R and M Dredge Mine
- Riley occurrence
- Slate Creek (Plumas County)
- Unnamed Au occurrence [12]
- Unnamed Au occurrence [33] (Unnamed placer diggings)
- Unnamed placer Au occurrence [65]
- Unnamed Ti-Zr occurrence [4]
- Mooreville Ridge
- La Porte Mining District
- Plumas County
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Columbia Basin and RangeWide Rift
- Shoofly-Olds Ferry DomainDomain
USA
- Sierra NevadaMountain Range
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
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References
