The tenuous connection between high-silica rhyolites and granodiorite plutons

Abstract

Research Article| February 01, 2008 The tenuous connection between high-silica rhyolites and granodiorite plutons Allen F. Glazner; Allen F. Glazner 1Department of Geological Sciences, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA Search for other works by this author on: GSW Google Scholar Drew S. Coleman; Drew S. Coleman 1Department of Geological Sciences, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA Search for other works by this author on: GSW Google Scholar John M. Bartley John M. Bartley 2Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Allen F. Glazner 1Department of Geological Sciences, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA Drew S. Coleman 1Department of Geological Sciences, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA John M. Bartley 2Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112, USA Publisher: Geological Society of America Received: 09 Jul 2007 Revision Received: 16 Oct 2007 Accepted: 26 Oct 2007 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 The Geological Society of America, Inc. Geology (2008) 36 (2): 183–186. https://doi.org/10.1130/G24496A.1 Article history Received: 09 Jul 2007 Revision Received: 16 Oct 2007 Accepted: 26 Oct 2007 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Allen F. Glazner, Drew S. Coleman, John M. Bartley; The tenuous connection between high-silica rhyolites and granodiorite plutons. Geology 2008;; 36 (2): 183–186. doi: https://doi.org/10.1130/G24496A.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 The trace element compositions of aplite dikes in the Sierra Nevada batholith of California differ profoundly from high-silica rhyolites (HSRs) and contradict a genetic connection to them. The aplites are strongly depleted in all middle rare earth elements (REEs), whereas HSRs are strongly depleted only in Eu and enriched in other REEs; the aplites are strongly depleted in Y and variably enriched in Sr, whereas HSRs are enriched in Y and strongly depleted in Sr. Volcanic rocks with the trace element characteristics of these aplites are rare to absent in the geologic record. Aplite REE patterns are likely controlled by titanite, which has large distribution coefficients for REEs, whereas HSRs cannot have equilibrated with titanite. Titanite may crystallize late in dacitic magma and thus HSR may be extracted before titanite saturation is reached; aplites would form after titanite appears, but when the melt percentage is too low and the water content of the melt too high (at fluid saturation) for the magma to ascend without rapid crystallization, thus preventing eruption. HSRs could also form by low-degree partial melting of granodiorite plutons in which titanite melts out early. Alternatively, HSRs may be extracted from silica-rich plutons that lack titanite; leucogranite plutons with REE contents that could be complementary to HSRs are present but uncommon in the Sierra Nevada. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.