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Minor podiform chromite deposit, 2 of 5 in Amador county (in California)
Sections of this page: [Geologic] - [Economic] - [Reference]
| Other names | Daggett Lease, Woods and Roach Lease |
|---|---|
| Country | United States |
| State or province | California |
| Geographic location: | 38°19'41"N,
120°51'47"W (-120.863056, 38.328056) |
| Geographic context: | (click for info) |
| Deposit type | minor podiform chromite |
| Model type | Minor Podiform |
| Deposit form | small lenses, stringer |
| Deposit texture | medium-grained massive |
| Ore type | Unknown |
| Age of deposit | Permian (280±3 m.y. 206Pb/238U, 282±3 m.y. 207Pb/235U) |
| Age (m.y.) | 281million years |
| Mineralogy | chromite |
| Host rock type | serpentine |
| Host rock length | 52000 |
| Host rock width | 2000 |
| Ophiolite zone | tectonite |
| Deposits < 10km | podiform chromite |
| Rocks within 5km | serpentine dunite basalt flow basalt tuff slate graywacke conglomerate mudstone quartzite chert gabbro greenstone andesite flow andesite tuff andesite breccia rhyolite flow rhyolite tuff |
| Geologic map unit | -120.863055555556, 38.3280555555556 |
| Nearby scientific data | Find additional scientific data near this location |
| Discovery date | 1916 | |
|---|---|---|
| Startup date | 1916 | |
| Tonnage | 9.5e-05 | million metric tons |
| Mine depth | 9.8 | m |
| Ore depth | 0 | m |
| Cr2O3 grade | 39 | percent |
| Rh grade | 0.008 | g/t |
| Ir grade | 0.14 | g/t |
| Ru grade | 0.24 | g/t |
| Pt grade | 0.019 | g/t |
| Si2O2 % | 4 | percent |
| Comments | Pd <0.001 ppm. Bear Mountain ophiolitic melange. Amador County. |
|---|---|
| References | Cater, F.W., Jr., 1948, Chromite deposits of Calaveras and Amador counties, California, in Geological investigations of chromite in California, Part 3--Sierra Nevada: California Division of Mines Bulletin 134, pt. 3, ch. 2, 60 p. Wagner, D.L., Jennings, C.W., Bedrossian, T.L., and Bortugno, E.J., 1981, Geologic map of the Sacramento quadrangle: California Division of Mines and Geology Regional Geologic Map Series Map no. 1A, scale 1:250,000. Carlson, C.A., Wilson, S.A., Carlson, R.R., Bradley, L., Cornell, J., Gent, C., Gass, W., Groeneboer, H., Haffty, J., Haubert, A., Love, A., McDade, J.M., Moore, R., Riley, L., Moring, B.C., Singer, D.A., and Page, N. J, 1985, Analyses for platinum group elements in samples from podiform chromite deposits, California and Oregon: U.S. Geological Survey Open-File Report 85-442, 15 p. Saleeby, J.B., 1982, Polygenetic ophiolite belt of the California Sierra Nevada--Geochronological and tectonostratigraphic development: Journal of Geophysical Research, v. 87, no. B3, p. 1803-1824. |