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Oregon Chrome

Minor podiform chromite deposit, 19 of 69 in Josephine county (in Oregon)

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

Geologic Information
CountryUnited States
State or provinceOregon
Geographic location:42°20'39"N, 123°46'20"W
(-123.772222, 42.344167)
Geographic context: (click for info)
Deposit typeminor podiform chromite
Model typeMinor Podiform
Deposit formtabular lenses, pods, stringers
Deposit texturecoarse-grained massive, disseminated
Ore typeMetallurgical
Age of depositMiddle Jurassic (164-162 Ma)
Age (m.y.)163million years
Area of deposit13832sq m
Ore body length152m
Ore body width91m
Host rock typeharzburgite
Host rock length18000
Host rock width6300
Paleotectonic settingsuprasubduction
Ophiolite zonetectonite
Deposits < 10kmpodiform chromite, low-sulfide gold veins, placer gold, silica-carbonate Hg, mafic volcanogenic massive sulfide, volcanogenic gold, volcanogenic Hg, magmatic Ni-Co-Cu
Rocks within 5kmdunite
hornblende diorite
metavolcanic rocks
amphibole gneiss
Geologic map unit-123.772222222222, 42.3441666666667
Nearby scientific dataFind additional scientific data near this location
Economic Information
Discovery date1917
Startup date1917
Tonnage0.032429million metric tons
Ore depth0m
Cr2O3 grade46percent
Rh grade0.003g/t
Ir grade0g/t
Ru grade0g/t
Pd grade0.003g/t
Pt grade0g/t
Cr:Fe ratio2.7
Reference information
CommentsLargest producer in Oregon. Production to 1958 was 32,429 t. Possible ore extensions at depth, but drilling beyond a major shear zone on the northeast side of the orebody found no additional ore. Analysis 0-0.006 ppm Rh, 0.002-0.003 ppm Pd (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.
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