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Banded podiform chromite deposit, 50 of 69 in Josephine county (in Oregon)

Sections of this page: [Geologic] - [Economic] - [Reference]

Geologic Information
CountryUnited States
State or provinceOregon
Geographic location:42°16'12"N, 123°41'32"W
(-123.692222, 42.27)
Geographic context: (click for info)
Deposit typebanded podiform chromite
Model typeBanded Podiform
Deposit formbanded
Deposit texturedisseminated
Ore typeMetallurgical
Age of depositLate Triassic-Early Jurassic (>173 and >175 Ma U-Pb zircon in plagiogranite)
Age (m.y.)203million years
Ore body length60m
Host rock typeserpentinized dunite
Host rock length60000
Host rock width8000
Paleotectonic settingsuprasubduction
Ophiolite zonetectonite
Deposits < 10kmpodiform 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 5kmdunite
quartz diorite
metavolcanic rocks
Geologic map unit-123.692222222222, 42.27
Nearby scientific dataFind additional scientific data near this location
Economic Information
Discovery date1917
Startup date1917
Tonnage0.000705million metric tons
Mine depth6.1m
Ore depth0m
Cr2O3 grade30percent
Rh grade0.082g/t
Ir grade0.06g/t
Ru grade0.3g/t
Pd grade0.002g/t
Pt grade0.005g/t
Reference information
CommentsProduction 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.
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.
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