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Lucky Girl

Minor podiform chromite deposit, 5 of 6 in Stanislaus county (in California)

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

Geologic Information
CountryUnited States
State or provinceCalifornia
Geographic location:37°24'6"N, 121°25'11"W
(-121.419722, 37.401667)
Geographic context: (click for info)
Deposit typeminor podiform chromite
Model typeBanded Podiform
Deposit formlenses, pods
Deposit texturegranular, massive
Ore typeMetallurgical
Age of depositMiddle Jurassic (161.13±0.11, 161.167±0.093 Ma, CA-TIMS, zircon in plagiogranite)
Age (m.y.)161million years
Area of deposit912sq m
Ore body length152m
Ore body width6m
Host rock typedunite
Host rock length15200
Host rock width3000
Paleotectonic settingsuprasubduction
Ophiolite zonetransition
Deposits < 10kmpodiform chromite, Franciscan Mn, silica-carbonate magnesite, silica-carbonate Hg
Rocks within 5kmwehrlite
glaucophane schist
quartz keratophyre
mafic metavolcanic rocks
Geologic map unit-121.419722222222, 37.4016666666667
Nearby scientific dataFind additional scientific data near this location
Economic Information
Discovery date<1918
Startup date1918
Tonnage0.000152million metric tons
Ore depth0m
Cr2O3 grade42percent
Rh grade0.019g/t
Ir grade0.73g/t
Ru grade0.51g/t
Pd grade0.013g/t
Pt grade0.061g/t
Reference information
CommentsStanislaus County.
Evarts, R.C., Coleman, R.G., and Schiffman, P., 1999, The Del Puerto Ophiolite--Petrology and tectonic setting, in Wagner, D.L., and Graham, S.A., eds., Geologic field trips in northern California, Centennial Meeting of the Cordilleran Section of the Geological Society of America: California Division of Mines and Geology Special Publication 119, p. 136-149.
Rogers, T.H., 1966, Geologic map of California, San Jose sheet: California Division of Mines and Geology, scale 1:250,000.
Choi, S.H., Shervais, J.W., and Mukasa, S.B., 2008, Supra-subduction and abyssal mantle peridotites of the Coast Range ophiolite, California: Contributions to Mineralogy and Petrology, v. 156, p. 551-576.
Walker, G.W., and Griggs, A.B., 1953, Chromite deposits of the southern Coast Ranges of California, in Geological investigations of chromite in California, Part 2--Coast Ranges: California Division of Mines Bulletin 134, pt. 2, ch. 2, 88 p.
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.
Hopson, C.A., Mattinson, J.M., Pessagno, E.A., Jr., and Luyendyk, B.P., 2008, California Coast Range ophiolite--Composite Middle and Late Jurassic oceanic lithosphere: Geological Society of America Special Paper 438, p. 1-101.
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