Geochemical window into subduction and accretion processes: Raspas metamorphic complex, Ecuador

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Research Article| June 01, 1999 Geochemical window into subduction and accretion processes: Raspas metamorphic complex, Ecuador R. J. Arculus; R. J. Arculus 1ARC National Key Centre for the Geochemical Evolution and Metallogeny of Continents, Department of Geology, Australian National University, Canberra, ACT 0200, Australia Search for other works by this author on: GSW Google Scholar H. Lapierre; H. Lapierre 2UPRES A-5025, Université Joseph Fourier, Institut Dolomieu, 15 rue M. Gignoux, 38031 Grenoble Cedex, France Search for other works by this author on: GSW Google Scholar É. Jaillard É. Jaillard 2UPRES A-5025, Université Joseph Fourier, Institut Dolomieu, 15 rue M. Gignoux, 38031 Grenoble Cedex, France3ORSTOM, Département TOA, 209-213 rue La Fayette, 75840 Paris Cedex, France Search for other works by this author on: GSW Google Scholar Geology (1999) 27 (6): 547–550. https://doi.org/10.1130/0091-7613(1999)027<0547:GWISAA>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 R. J. Arculus, H. Lapierre, É. Jaillard; Geochemical window into subduction and accretion processes: Raspas metamorphic complex, Ecuador. Geology 1999;; 27 (6): 547–550. doi: https://doi.org/10.1130/0091-7613(1999)027<0547:GWISAA>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 The high-pressure, low-temperature (P = 1.3–2 GPa; T is ≤ 600 °C) Raspas metamorphic complex is an exhumed fragment of the partially accreted, partially subducted Amotape-Chaucha terrane in southwest Ecuador. Comparative analysis of major and trace elements plus Sr, Nd, and Pb isotopes in bulk lithologies and individual crystalline phases shows that the complex includes one to three layers of ordinary oceanic crust and underlying mantle lithosphere together with oceanic plateau fragments. Subduction (and exhumation) of oceanic lithosphere resulted in selective bulk trace element geochemical changes: Rb, Ba, and Sr have been lost (in amounts from approximately 85%–50%) from the high-P, low-T metamorphosed pelites and basalts, whereas Pb is enriched in mafic rocks. During formation of the eclogite, U, Pb, and rare earth elements (REEs) were immobile. High-P, low-T metamorphosed terranes form the basement of active Ecuadorian arc volcanoes; partial melting of this basement by mantle-wedge–derived basalt is a likely source of adakitic components. 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.