Characteristic mineralogy of arc-related cumulate gabbros: Implications for the tectonic setting of gabbroic plutons and for andesite genesis

Research Article| October 01, 1986 Characteristic mineralogy of arc-related cumulate gabbros: Implications for the tectonic setting of gabbroic plutons and for andesite genesis James S. Beard James S. Beard 1Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560 Search for other works by this author on: GSW Google Scholar Author and Article Information James S. Beard 1Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1986) 14 (10): 848–851. https://doi.org/10.1130/0091-7613(1986)14<848:CMOACG>2.0.CO;2 Article history First Online: 01 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 James S. Beard; Characteristic mineralogy of arc-related cumulate gabbros: Implications for the tectonic setting of gabbroic plutons and for andesite genesis. Geology 1986;; 14 (10): 848–851. doi: https://doi.org/10.1130/0091-7613(1986)14<848:CMOACG>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 Several mineralogically distinct suites of gabbroic cumulates occur as xenoliths in basalt and andesite from active arc volcanos and in plutons exposed in deeply eroded arcs. Calcic (An85–100) plagioclase and moderately Fe-rich (Fo60–80) olivine commonly occur together in arc cumulate gabbros but not in cumulate gabbros from mid-ocean ridges, ocean islands, or tholeiitic layered intrusions. Compositions of coexisting olivine and plagioclase in gabbro cumulates can establish the tectonic setting of ancient volcano-plutonic complexes.In deeply eroded arcs, gabbroic cumulates typically occur in zoned plutons that also contain gabbros, diorites, and quartz diorites of basaltic to andesitic composition. In many cases, it is clear that the cumulate gabbros are chemically and physically related to the gabbro-diorite (= basalt-andesite) fractionation trends seen in the zoned plutons. Zoned plutons in deeply eroded arcs provide physical evidence that crystal fractionation plays an important role in andesite petrogenesis. 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.