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The Mountain Pass Rare-Earth Deposits

Olson, J. C. and Pray, L. C. (1954) The Mountain Pass Rare-Earth Deposits. In: Geology of Southern California. California Division of Mines and Geology Bulletin. Vol.1. No.170. California Division of Mines and Geology , Sacramento, CA, pp. 23-29.

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Rare-earth minerals were discovered near Mountain Pass in northeastern San Bernardino County, Calif., in April 1949, and in the following year the Sulphide Queen carbonate body was found. This body is the world's greatest known concentration of rare-earth metals with a tonnage larger than the total of all rare earths used in the world prior to 1950. The rare earths in the Mountain Pass district are chiefly cerium, lanthanum, and neodymium. These elements occur principally in bastnaesite, a rare-earth fluocarbonate, heretofore reported from only about 10 localities in the world. The bastnaesite was discovered in samples from Mountain Pass obtained by H. E. Woodward and Clarence Watkins of Goodsprings, Nev., and its identity was established in laboratory studies by E . T. Schenk of the U. S. Bureau of Mines and D. F. Hewett of the U. S. Geological Survey. Subsequent prospecting by individuals and geologic investigations by the U. S. Geological Survey resulted in the discovery of bastnaesite in the Sulphide Queen carbonate body and numerous other deposits in a belt 6 miles long. Investigations by the U. S. Geological Survey since 1949 (Olson et al., in preparation) include detailed mapping of the site of the initial discovery-the Birthday claims-by L. C. Pray and W. N. Sharp; geologic mapping of the district by J. C. Olson; detailed mapping of the Sulphide Queen carbonate body and several smaller deposits by D. R. Shawe and W. N. Sharp; and laboratory mineralogic investigations by H. W. Jaffe.

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Additional Information:© 1954 California Division of Mines and Geology. Contribution No. 660, Division of the Geological Sciences, California Institute of Technology.
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Caltech Division of Geological Sciences660
Series Name:California Division of Mines and Geology Bulletin
Issue or Number:170
Record Number:CaltechAUTHORS:20200305-132012785
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:101724
Deposited By: Tony Diaz
Deposited On:06 Mar 2020 15:38
Last Modified:06 Mar 2020 15:38

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