Generation of alkaline magmas in subduction zones by partial melting of mélange diapirs—An experimental study

Research Article| February 15, 2018 Generation of alkaline magmas in subduction zones by partial melting of mélange diapirs—An experimental study Alicia M. Cruz-Uribe; Alicia M. Cruz-Uribe 1Geology and Geophysics, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, Massachusetts 02543, USA Search for other works by this author on: GSW Google Scholar Horst R. Marschall; Horst R. Marschall 1Geology and Geophysics, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, Massachusetts 02543, USA2Institut für Geowissenschaften, Goethe-Universität Frankfurt, Altenhöferallee 1, 60438 Frankfurt am Main, Germany Search for other works by this author on: GSW Google Scholar Glenn A. Gaetani; Glenn A. Gaetani 1Geology and Geophysics, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, Massachusetts 02543, USA Search for other works by this author on: GSW Google Scholar Véronique Le Roux Véronique Le Roux 1Geology and Geophysics, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, Massachusetts 02543, USA Search for other works by this author on: GSW Google Scholar Geology (2018) 46 (4): 343–346. https://doi.org/10.1130/G39956.1 Article history received: 04 Dec 2017 rev-recd: 22 Jan 2018 accepted: 22 Jan 2018 first online: 15 Feb 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Alicia M. Cruz-Uribe, Horst R. Marschall, Glenn A. Gaetani, Véronique Le Roux; Generation of alkaline magmas in subduction zones by partial melting of mélange diapirs—An experimental study. Geology 2018;; 46 (4): 343–346. doi: https://doi.org/10.1130/G39956.1 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 Alkaline lavas occur globally in subduction-related volcanic arcs. Conventional models for the origin of these lavas typically invoke a multi-stage process in which mantle wedge peridotite, enriched in phlogopite and/or amphibole due to prior metasomatism, partially melts during infiltration by fluids and melts derived from subducted oceanic lithosphere. However, geochemical systematics in the majority of subduction-related alkaline lavas require physical mixing of subducted components and peridotite prior to partial melting. This can be explained by the mélange diapir model, which predicts the generation of arc magmas during advection of buoyant material from the slab-wedge interface into the mantle wedge below arcs. Here we report results from experiments in which natural mélange materials were partially melted at upper mantle conditions to produce alkaline magmas. Partial melts produced in our experiments have trace-element abundance patterns that are typical of alkaline arc lavas, such as enrichment in large ion lithophile elements (LILEs) and depletion in Nb and Ta. These results favor generation of alkaline magmas in the arc and backarc regions of subduction zones by partial melting of mélange materials rather than previously metasomatized peridotite. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.