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Uranium-Thorium-Lead Isotope Relations in Lunar Materials

Silver, Leon T. (1970) Uranium-Thorium-Lead Isotope Relations in Lunar Materials. Science, 167 (3918). pp. 468-471. ISSN 0036-8075.

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The lead isotopic compositions and uranium, thorium, and lead concentrations have been measured on six samples of material from the Sea of Tranquillity. The leads are moderately to very radiogenic; the initial lead concentrations are very low; the uranium and thorium levels are 0.26 to 0.88 and 0.87 to 3.35 parts per million, respectively. The Th/U ratios cluster about a 3.6 value. Apparent ages calculated for four rocks are 4.1 to 4.2 x 10^9 years. Dust and breccia yield apparent ages of 4.60 to 4.63 x 10^9 years. The uranium-lead ages are concordant, or nearly so, in all cases. The lunar surface is an ancient region with an extended record of events in the early history of the solar system. The discrepancy between the rock ages and dust ages poses a fundamental question about rock genesis on the moon.

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Additional Information:© 1970 American Association for the Advancement of Science. Received 4 January 1970. Essential to this work was the dedicated laboratory participation and cheer of Geraldine Baenteli and Dolly Pearson. E. V. Nenow and C. Bauman provided important technical support. E. Brown wrestled untiringly with NASA, which supported the major part of this research under contract NAS 9-7963. California Institute of Technology Contribution No. 1707.
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NASANAS 9-7963
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Other Numbering System NameOther Numbering System ID
Caltech Division of Geological Sciences1707
Issue or Number:3918
Record Number:CaltechAUTHORS:20150217-155839306
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Official Citation:Uranium-Thorium-Lead Isotope Relations in Lunar Materials Leon T. Silver Science 30 January 1970: 167 (3918), 468-471. [DOI:10.1126/science.167.3918.468]
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:54896
Deposited By: Tony Diaz
Deposited On:18 Feb 2015 02:58
Last Modified:03 Oct 2019 08:01

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