Rethinking the emplacement and evolution of zoned plutons: Geochronologic evidence for incremental assembly of the Tuolumne Intrusive Suite, California

Abstract

Research Article| May 01, 2004 Rethinking the emplacement and evolution of zoned plutons: Geochronologic evidence for incremental assembly of the Tuolumne Intrusive Suite, California Drew S. Coleman; Drew S. Coleman 1Department of Geological Sciences, CB 3315 Mitchell Hall, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA Search for other works by this author on: GSW Google Scholar Walt Gray; Walt Gray 1Department of Geological Sciences, CB 3315 Mitchell Hall, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA Search for other works by this author on: GSW Google Scholar Allen F. Glazner Allen F. Glazner 1Department of Geological Sciences, CB 3315 Mitchell Hall, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Drew S. Coleman 1Department of Geological Sciences, CB 3315 Mitchell Hall, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA Walt Gray 1Department of Geological Sciences, CB 3315 Mitchell Hall, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA Allen F. Glazner 1Department of Geological Sciences, CB 3315 Mitchell Hall, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA Publisher: Geological Society of America Received: 01 Oct 2003 Revision Received: 07 Jan 2004 Accepted: 07 Jan 2004 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2004) 32 (5): 433–436. https://doi.org/10.1130/G20220.1 Article history Received: 01 Oct 2003 Revision Received: 07 Jan 2004 Accepted: 07 Jan 2004 First Online: 02 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 Drew S. Coleman, Walt Gray, Allen F. Glazner; Rethinking the emplacement and evolution of zoned plutons: Geochronologic evidence for incremental assembly of the Tuolumne Intrusive Suite, California. Geology 2004;; 32 (5): 433–436. doi: https://doi.org/10.1130/G20220.1 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 New U-Pb geochronologic data indicate that the Tuolumne Intrusive Suite, California, was assembled over a period of at least 10 m.y. between 95 and 85 Ma, and that the Half Dome Granodiorite intruded over a period approaching 4 m.y. Simple thermal considerations preclude the possibility that a magma chamber the size of the Half Dome pluton could have existed as a liquid at shallow crustal depths for that long. Rather, field evidence for sheeting along the margins of the suite, the range of ages, and the regular decrease of ages toward the center of the suite and within individual plutons suggest incremental assembly. Geochronologic evidence for incremental assembly is consistent with the failure of geophysical methods to detect large magma chambers with more than ∼20% melt, even in active volcanic areas. Because it is unlikely that the individual plutons composing the Tuolumne ever coexisted as liquid-rich magmas, the chemical evolution of the suite cannot be the result of simple fractionation and/or mixing between exposed units, but instead must reflect processes occurring during magma generation. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.