Phanerozoic sanukitoids from Caledonian Scotland: Implications for Archean subduction

Research Article| December 01, 2012 Phanerozoic sanukitoids from Caledonian Scotland: Implications for Archean subduction Mike Fowler; Mike Fowler * 1Earth and Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth PO1 3QL, UK *E-mail: mike.fowler@port.ac.uk. Search for other works by this author on: GSW Google Scholar Hugh Rollinson Hugh Rollinson 2School of Science, University of Derby, Kedleston Road, Derby DE22 1GB, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Mike Fowler * 1Earth and Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth PO1 3QL, UK Hugh Rollinson 2School of Science, University of Derby, Kedleston Road, Derby DE22 1GB, UK *E-mail: mike.fowler@port.ac.uk. Publisher: Geological Society of America Received: 03 Mar 2012 Revision Received: 14 May 2012 Accepted: 16 May 2012 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2012 Geological Society of America Geology (2012) 40 (12): 1079–1082. https://doi.org/10.1130/G33371.1 Article history Received: 03 Mar 2012 Revision Received: 14 May 2012 Accepted: 16 May 2012 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Mike Fowler, Hugh Rollinson; Phanerozoic sanukitoids from Caledonian Scotland: Implications for Archean subduction. Geology 2012;; 40 (12): 1079–1082. doi: https://doi.org/10.1130/G33371.1 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 Sanukitoids represent a volumetrically minor but important series of Neoarchean granitoids enriched in large-ion lithophile elements (e.g., Ba, Sr, and light rare earth elements), and with relatively high compatible elements (e.g., Mg, Ni, and Cr). Petrogenetic models have favored an origin in the suprasubduction mantle wedge, so their sudden appearance ca. 2.95–2.68 Ga has made them central to the ongoing debate about the beginnings of modern plate tectonics. Caledonian high Ba-Sr granites from the Northern Highlands of Scotland are petrological and compositional equivalents. The Caledonian examples have not undergone subsequent reworking, and their petrogenetic setting can be used to inform genetic models for sanukitoids. Prolonged subduction preceded emplacement of the high Ba-Sr granites in a short interval (∼10 Ma) at the end of the Caledonian orogeny. Sediment subduction was responsible for elemental and isotopic enrichments and slab breakoff triggered melting in the subcontinental lithospheric mantle. This implies that during the Neoarchean the evolving tectonothermal regime moved the locus of melting from the basaltic slab to the sediment-infused mantle wedge, creating the first subcontinental lithospheric mantle. Sanukitoids may then have resulted from widespread, closely subsequent slab-breakoff events, producing evolved magmas by familiar fractionation mechanisms. Careful study of secular variations in high Ba-Sr magmas could constrain the evolution of the subcontinental lithosphere. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.