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U-Pb dating of zircon in the Bishop Tuff at the millennial scale

2007; Geological Society of America; Volume: 35; Issue: 12 Linguagem: Inglês

10.1130/g24017a.1

1943-2682

James L. Crowley, Blair Schoene, Samuel A. Bowring,

Geochemistry and Geologic Mapping

Research Article| December 01, 2007 U-Pb dating of zircon in the Bishop Tuff at the millennial scale J.L. Crowley; J.L. Crowley 1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar B. Schoene; B. Schoene 1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar S.A. Bowring S.A. Bowring 1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar Author and Article Information J.L. Crowley 1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA B. Schoene 1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA S.A. Bowring 1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Publisher: Geological Society of America Received: 26 Apr 2007 Revision Received: 06 Aug 2007 Accepted: 09 Aug 2007 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 The Geological Society of America, Inc. Geology (2007) 35 (12): 1123–1126. https://doi.org/10.1130/G24017A.1 Article history Received: 26 Apr 2007 Revision Received: 06 Aug 2007 Accepted: 09 Aug 2007 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation J.L. Crowley, B. Schoene, S.A. Bowring; U-Pb dating of zircon in the Bishop Tuff at the millennial scale. Geology 2007;; 35 (12): 1123–1126. doi: https://doi.org/10.1130/G24017A.1 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 Zircon from the Bishop Tuff (eastern California) was dated by the U-Pb isotope dilution thermal ionization mass spectrometry (ID-TIMS) method to evaluate time scales of magmatic evolution and applicability of the method to rocks younger than 1 Ma. The 206Pb/238U dates from 17 of 19 grains are equivalent with a weighted mean of 767.1 ± 0.9 ka that overlaps with the published 40Ar/39Ar sanidine age, requiring that most zircon crystallized immediately before eruption. Dates from two grains that are 6 and 12 k.y. older indicate minimum times that a small portion of the grains resided in the magma. These findings are consistent with chemical zoning patterns in zircon that suggest a relatively simple crystallization history, yet contrast with previous results of ion microprobe dating of zircon that show 50–80 k.y. of magma residence. The weighted mean 207Pb/235U date is ∼52 k.y. older than the 206Pb/238U date, a difference that is attributed to excess 207Pb from initial Pa/U disequilibrium. The results demonstrate that high-precision ID-TIMS geochronology can resolve magma chamber dynamics of <1 Ma silicic eruptions at the millennial scale. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.