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Banded podiform chromite deposit, 50 of 69 in Josephine county (in Oregon)
Sections of this page: [Geologic] - [Economic] - [Reference]
| Country | United States |
|---|---|
| State or province | Oregon |
| Geographic location: | 42°16'12"N,
123°41'32"W (-123.692222, 42.27) |
| Geographic context: | (click for info) |
| Deposit type | banded podiform chromite |
| Model type | Banded Podiform |
| Deposit form | banded |
| Deposit texture | 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 |
| Ore body length | 60m |
| Mineralogy | chromite |
| Host rock type | serpentinized 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, silica-carbonate Hg, mafic volcanogenic massive sulfide, magmatic Ni-Co-Cu, lateritic Ni, volcanogenic gold, serpentine-hosted asbestos |
| Rocks within 5km | dunite serpentine harzburgite quartz diorite metavolcanic rocks graywacke chert mudstone |
| Geologic map unit | -123.692222222222, 42.27 |
| Nearby scientific data | Find additional scientific data near this location |
| Discovery date | 1917 | |
|---|---|---|
| Startup date | 1917 | |
| Tonnage | 0.000705 | million metric tons |
| Mine depth | 6.1 | m |
| Ore depth | 0 | m |
| Cr2O3 grade | 30 | percent |
| Rh grade | 0.082 | g/t |
| Ir grade | 0.06 | g/t |
| Ru grade | 0.3 | g/t |
| Pd grade | 0.002 | g/t |
| Pt grade | 0.005 | g/t |
| Comments | Production estimated at about 50 t. Assays 44.52-53.47% Cr2O3. Reserves estimated at 655 t of 29% Cr2O3 (banded ore). 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. Evans, J.G., 1984, Structure of part of the Josephine Peridotite, northwestern California and southwestern Oregon: U.S. Geological Survey Bulletin 1546-A, p. 7-37. Harper, G.D., Saleeby, J.B., and Heizler, M., 1994, Formation and emplacement of the Josephine ophiolite and the Nevadan orogeny in the Klamath Mountains, California-Oregon--U/Pb zircon and 40Ar/39Ar geochronology: Journal of Geophysical Research, v. 99, B3, p. 4293-4321. 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. |