In situ U-Pb ages of zircons from the Bishop Tuff: No evidence for long crystal residence times

Abstract

Research Article| May 01, 2000 In situ U-Pb ages of zircons from the Bishop Tuff: No evidence for long crystal residence times M.R. Reid; M.R. Reid 1W. M. Keck Foundation for Isotope Geochemistry, Department of Earth and Space Sciences, University of California, Los Angeles, California 90095-1567, USA Search for other works by this author on: GSW Google Scholar C.D. Coath C.D. Coath 1W. M. Keck Foundation for Isotope Geochemistry, Department of Earth and Space Sciences, University of California, Los Angeles, California 90095-1567, USA Search for other works by this author on: GSW Google Scholar Author and Article Information M.R. Reid 1W. M. Keck Foundation for Isotope Geochemistry, Department of Earth and Space Sciences, University of California, Los Angeles, California 90095-1567, USA C.D. Coath 1W. M. Keck Foundation for Isotope Geochemistry, Department of Earth and Space Sciences, University of California, Los Angeles, California 90095-1567, USA Publisher: Geological Society of America Received: 14 Oct 1999 Revision Received: 04 Feb 2000 Accepted: 15 Feb 2000 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2000) 28 (5): 443–446. https://doi.org/10.1130/0091-7613(2000)28<443:ISUAOZ>2.0.CO;2 Article history Received: 14 Oct 1999 Revision Received: 04 Feb 2000 Accepted: 15 Feb 2000 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation M.R. Reid, C.D. Coath; In situ U-Pb ages of zircons from the Bishop Tuff: No evidence for long crystal residence times. Geology 2000;; 28 (5): 443–446. doi: https://doi.org/10.1130/0091-7613(2000)28<443:ISUAOZ>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Ion microprobe U-Pb isotope analyses of zircons from fallout and intercalated ash-flow deposits of the early, most chemically evolved Bishop Tuff (east-central California) yield a weighted mean age of 823 ± 11 ka (mean square of weighted deviates, MSWD = 0.8; n = 22). A similar mean age of 839 ± 36 ka (MSWD = 0.6, n = 15) obtained on unpolished zircon rims suggests that the difference between these ages and that of 760 ka for the Bishop Tuff obtained by recent Ar isotope determinations may be largely analytical in origin. Considerations based only on the effect of 230Th-234U disequilibria on the U-Pb ages yield an apparent maximum mean crystal residence time for zircon of ∼100 k.y. The zircon residence times are significantly shorter than those inferred from previous estimates for the timing of phenocryst growth and suggest that, once evolved, the early Bishop Tuff rhyolite was not stored for long before erupting. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.