Fractional crystallization in granites of the Sierra Nevada: How important is it?

Abstract

Research Article| July 01, 1993 Fractional crystallization in granites of the Sierra Nevada: How important is it? John B. Reid, Jr.; John B. Reid, Jr. 1School of Natural Science, Hampshire College, Amherst, Massachusetts 01002 Search for other works by this author on: GSW Google Scholar Daniel P. Murray; Daniel P. Murray 2Department of Geology, University of Rhode Island, Kingston, Rhode Island 02881 Search for other works by this author on: GSW Google Scholar O. Don Hermes; O. Don Hermes 2Department of Geology, University of Rhode Island, Kingston, Rhode Island 02881 Search for other works by this author on: GSW Google Scholar Eric J. Steig Eric J. Steig 1School of Natural Science, Hampshire College, Amherst, Massachusetts 01002 Search for other works by this author on: GSW Google Scholar Author and Article Information John B. Reid, Jr. 1School of Natural Science, Hampshire College, Amherst, Massachusetts 01002 Daniel P. Murray 2Department of Geology, University of Rhode Island, Kingston, Rhode Island 02881 O. Don Hermes 2Department of Geology, University of Rhode Island, Kingston, Rhode Island 02881 Eric J. Steig 1School of Natural Science, Hampshire College, Amherst, Massachusetts 01002 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1993) 21 (7): 587–590. https://doi.org/10.1130/0091-7613(1993)021<0587:FCIGOT>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation John B. Reid, Daniel P. Murray, O. Don Hermes, Eric J. Steig; Fractional crystallization in granites of the Sierra Nevada: How important is it?. Geology 1993;; 21 (7): 587–590. doi: https://doi.org/10.1130/0091-7613(1993)021<0587:FCIGOT>2.3.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 Although compositional variation in zoned calc-alkalic plutons is often ascribed to crystal fractionation, diagnostic large-scale field evidence of crystal accumulation in these slowly cooled bodies is generally missing. In many plutons, however, small-scale crystal cumulates have been preserved as layered schlieren and in microcosm may allow an assessment of the importance of crystal fractionation in their host pluton's development. Small, widely separated patches of schlieren in the Tuolumne Intrusive Series, Yosemite National Park, California, formed as cumulates. Their darkest layers show high concentrations of magnetite, sphene, biotite, horn-blende, and zircon, and have unusually fractionated major and trace element compositions (FeO >33%; Al2O3 <7%; La/Lain chondrites ∼750; Zr ∼2000 ppm). The layers define smooth trends on major and trace element Al2O3 variation diagrams that diverge strongly from patterns for the main-sequence rocks of the Tuolumne Series and granitoids throughout the Sierra Nevada. Removal of such cumulates from any main-sequence magma would produce Al-rich evolved rocks, not the Al- poor felsic rocks of the pluton. The findings suggest that fractional crystallization did not produce the dominant chemical patterns seen in the Tuolumne and similar Sierra Nevada granites. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.