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Minor podiform chromite deposit, 12 of 24 in Nevada county (in California)
Sections of this page: [Geologic] - [Economic] - [Reference]
| Country | United States |
|---|---|
| State or province | California |
| Geographic location: | 39°14'31"N,
121°4'33"W (-121.075833, 39.241944) |
| Geographic context: | (click for info) |
| Deposit type | minor podiform chromite |
| Model type | Minor Podiform |
| Deposit form | lens |
| Ore type | Unknown |
| Age of deposit | Middle Jurassic |
| Age (m.y.) | 157million years |
| Mineralogy | chromite |
| Host rock type | serpentinized dunite |
| Host rock length | 8600 |
| Host rock width | 1500 |
| Paleotectonic setting | suprasubduction |
| Ophiolite zone | tectonite |
| Deposits < 10km | podiform chromite |
| Rocks within 5km | serpentine dunite harzburgite pyroxenite slate chert schist quartzite limestone metaconglomerate phyllite metavolcanic rocks granodiorite granite trondhjemite diorite monzonite quartz porphyrite granulite alaskite gabbro diorite diabase amphibolite basalt andesite andesite mudflow andesite tuff andesite breccia sandstone claystone siltstone gravel conglomerate |
| Geologic map unit | -121.075833333333, 39.2419444444444 |
| Nearby scientific data | Find additional scientific data near this location |
| Tonnage | 0.00012 | million metric tons |
|---|---|---|
| Ore depth | 0 | m |
| Cr2O3 grade | 14 | percent |
| Comments | Produced 120 t @ 37% Cr2O3. Reserves 100 t @ 9% Cr2O3. Lake Combie Complex. Nevada County. |
|---|---|
| References | Burnett, J.L., and Jennings, C.W., 1962, Geologic map of California, Chico sheet: California Division of Mines and Geology, scale 1:250,000. Rynearson, G.A., 1951, Chromite deposits in the northern Sierra Nevada, California (Placer, Nevada, Sierra, Yuba, Butte, and Plumas counties), in Geological investigations of chromite in California, Part 3--Sierra Nevada: California Division of Mines Bulletin 134, pt. 3, ch. 5, 321 p. Day, H.W., Moores, E.M., and Tuminas, A.C., 1985, Structure and tectonics of the northern Sierra Nevada: Geological Society of America Bulletin, v. 96, p. 436-450. |