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Re-examination of isotopic relationships in Colorado Front Range uranium ores

Banks, P. O. and Silver, Leon T. (1964) Re-examination of isotopic relationships in Colorado Front Range uranium ores. Geological Society of America Bulletin, 75 (5). pp. 469-476. ISSN 0016-7606. doi:10.1130/0016-7606(1964)75[469:ROIRIC]2.0.CO;2.

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Some new isotopic analyses of Front Range pitchblende samples and comparisons with published data indicate a complex history of isotopic disturbance in these ores. Relationships in the U^(238)-Pb^(206) and U^(235)-Pb^(207) systems indicate extensive and protracted mobilizations of parents and daughters, and particularly intermediate daughters, in both isotopic series. These relationships preclude a simple, much less unique interpretation of the absolute age of the uranium mineralization in the Front Range. Considering the lack of close definition in the stratigraphic age assignment for this mineralization, it is suggested that the common use of the inferred age in the construction of geologic time scales is not justified.

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URLURL TypeDescription[469:ROIRIC]2.0.CO;2DOIArticle
Additional Information:Copyright © 1964, The Geological Society of America, Inc. Received October 14, 1963. We are indebted to Dr. George Phair, U. S. Geological Survey, for providing us with selected sample materials, for discussions of the problems, and for critical reading of the manuscript, without necessarily concurring in all that we have said. Dr. P. K. Sims has provided information on the geologic setting of the ores. This work was supported by the U. S. Atomic Energy Commission, Contract AT (04-3)-427, as part of an investigation of geologically young U-Pb isotopic systems.
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Atomic Energy CommissionAT (04-3)-427
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Caltech Division of Geological Sciences1201
Issue or Number:5
Record Number:CaltechAUTHORS:20140801-125831579
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:47815
Deposited By: George Porter
Deposited On:01 Aug 2014 20:44
Last Modified:18 Jul 2022 18:00

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