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Tennessee Chromite

Minor podiform chromite deposit, 61 of 69 in Josephine county (in Oregon)

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

Geologic Information
CountryUnited States
State or provinceOregon
Geographic location:42°11'38"N, 123°43'12"W
(-123.72, 42.193889)
Geographic context: (click for info)
Deposit typeminor podiform chromite
Model typeMinor Podiform
Deposit formlenses
Deposit texturecoarse-grained massive, fine-grained disseminated
Ore typeMetallurgical
Age of depositLate Triassic-Early Jurassic (>173 and >175 Ma U-Pb zircon in plagiogranite)
Age (m.y.)203million years
Host rock typedunite
Host rock length60000
Host rock width8000
Paleotectonic settingsuprasubduction
Ophiolite zonetectonite
Deposits < 10kmpodiform chromite, low-sulfide gold veins, placer gold, volcanogenic gold, lateritic Ni, serpentine-hosted asbestos
Rocks within 5kmdunite
quartz diorite
Geologic map unit-123.72, 42.1938888888889
Nearby scientific dataFind additional scientific data near this location
Economic Information
Tonnage2.1e-05million metric tons
Ore depth0m
Cr2O3 grade52.6percent
Rh grade0.018g/t
Ir grade0.07g/t
Ru grade0.3g/t
Pd grade0.002g/t
Pt grade0.005g/t
Fe %11.41percent
Si2O2 %3.64percent
Reference information
Comments0.31 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.
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.
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