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Minor podiform chromite deposit, 8 of 13 in San Luis Obispo county (in California)

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

Geologic Information
Other namesAlviso, Keeney
CountryUnited States
State or provinceCalifornia
Geographic location:35°21'26"N, 120°40'19"W
(-120.671944, 35.357222)
Geographic context: (click for info)
Deposit typeminor podiform chromite
Model typeBanded Podiform
Ore typeUnknown
Age of depositMiddle Jurassic (163.3±1.1 Ma, U-Pb apatite-feldspar isochron in gabbro)
Age (m.y.)163million years
Host rock typeserpentinized dunite
Host rock length20000
Host rock width4250
Paleotectonic settingsuprasubduction
Ophiolite zonetransition
Deposits < 10kmpodiform chromite
Rocks within 5kmserpentine
Geologic map unit-120.671944444444, 35.3572222222222
Nearby scientific dataFind additional scientific data near this location
Economic Information
Discovery date<1917
Startup date1917
Tonnage3.9e-05million metric tons
Ore depth0m
Cr2O3 grade38percent
Reference information
CommentsLocated below the Pick and Shovel mine. Probably mined out. San Luis Obispo County.
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.
Jennings, C.W., 1958, Geologic map of California, San Luis Obispo sheet: California Division of Mines and Geology, scale 1:250,000.
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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