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Minor podiform chromite deposit, 61 of 69 in Josephine county (in Oregon)
Sections of this page: [Geologic] - [Economic] - [Reference]
| Country | United States |
|---|---|
| State or province | Oregon |
| Geographic location: | 42°11'38"N,
123°43'12"W (-123.72, 42.193889) |
| Geographic context: | (click for info) |
| Deposit type | minor podiform chromite |
| Model type | Minor Podiform |
| Deposit form | lenses |
| Deposit texture | coarse-grained massive, fine-grained disseminated |
| Ore type | Metallurgical |
| Age of deposit | Late Triassic-Early Jurassic (>173 and >175 Ma U-Pb zircon in plagiogranite) |
| Age (m.y.) | 203million years |
| Mineralogy | chromite |
| Host rock type | dunite |
| Host rock length | 60000 |
| Host rock width | 8000 |
| Paleotectonic setting | suprasubduction |
| Ophiolite zone | tectonite |
| Deposits < 10km | podiform chromite, low-sulfide gold veins, placer gold, volcanogenic gold, lateritic Ni, serpentine-hosted asbestos |
| Rocks within 5km | dunite serpentine harzburgite gabbro quartz diorite siltstone sandstone shale |
| Geologic map unit | -123.72, 42.1938888888889 |
| Nearby scientific data | Find additional scientific data near this location |
| Tonnage | 2.1e-05 | million metric tons |
|---|---|---|
| Ore depth | 0 | m |
| Cr2O3 grade | 52.6 | percent |
| Rh grade | 0.018 | g/t |
| Ir grade | 0.07 | g/t |
| Ru grade | 0.3 | g/t |
| Pd grade | 0.002 | g/t |
| Pt grade | 0.005 | g/t |
| Fe % | 11.41 | percent |
| Si2O2 % | 3.64 | percent |
| Comments | 0.31 m thick. Produced 21 t of 52.58% Cr2O3. Assays 53.6-55.54% Cr2O3, 11.08-12.99% Fe. Disseminated ore is slightly magnetic. Analysis <0.004 ppm Pd, <0.01 ppm Pt (Carlson and others, 1985). Josephine County. |
|---|---|
| References | Ramp, Len, 1961, Chromite in southwestern Oregon: Oregon Department of Geology and Mineral Industries Bulletin 52, 169 p. Ramp, Len, and Peterson, N.V., 1979, Geology and mineral resources of Josephine County, Oregon: Oregon Department of Geology and Mineral Industries Bulletin 100, 45 p. and geologic map, scale 1:500,000. 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. Yule, J.D., Saleeby, J.B., and Barnes, C.G., 2006, A rift-edge facies of the Late Jurassic Rogue-Chetco arc and Josephine ophiolite, Klamath Mountains, Oregon, in Snoke, A.W., and Barnes, C.G., eds., Geological studies in the Klamath Mountains province, California and Oregon: Geological Society of America Special Paper, v. 410, p. 53-76. |