Generation of plagiogranite by amphibolite anatexis in oceanic shear zones

Research Article| January 01, 1991 Generation of plagiogranite by amphibolite anatexis in oceanic shear zones Patricia A. Flagler; Patricia A. Flagler 1Department of Geology, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada Search for other works by this author on: GSW Google Scholar John G. Spray John G. Spray 1Department of Geology, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information Patricia A. Flagler 1Department of Geology, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada John G. Spray 1Department of Geology, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1991) 19 (1): 70–73. https://doi.org/10.1130/0091-7613(1991)019<0070:GOPBAA>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 MailTo Tools Icon Tools Get Permissions Search Site Citation Patricia A. Flagler, John G. Spray; Generation of plagiogranite by amphibolite anatexis in oceanic shear zones. Geology 1991;; 19 (1): 70–73. doi: https://doi.org/10.1130/0091-7613(1991)019<0070:GOPBAA>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 Field, geochronological, and rare earth element (REE) evidence obtained from the Fournier oceanic fragment of the Canadian Appalachians indicates that its plagiogranite component was generated by the anatexis of amphibolite and not by the fractionation of basic magma. We propose that the process occurred in two stages: first, gabbro was plastically deformed at high temperature to form dry, low-angle shear zones that subsequently evolved to amphibolite via the addition of light REE-enriched hydrothermal solutions; second, the amphibolite underwent partial melting during shear to yield a migmatite comprising bands of plagiogranite alternating with amphibolite restite. The plagiogranite locally coalesced to form pods, dikes, and lenses that injected the surrounding undeformed gabbro. We attribute the development of the Fournier plagiogranite to dynamothermal processes occurring in proximity to a spreading center due to asthenosphere-induced shear within ocean layer 3. This serves as an important illustration of the dynamic nature of metamorphism and melting that can occur in the ocean crust. 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.