Andean Cenozoic volcanic centers reflect basement isotopic domains

Research Article| December 01, 1992 Andean Cenozoic volcanic centers reflect basement isotopic domains Gerhard Wörner; Gerhard Wörner 1Institut für Geowissenschaften, Universität Mainz, 6500 Mainz, Germany Search for other works by this author on: GSW Google Scholar Stephen Moorbath; Stephen Moorbath 2Department of Earth Sciences, University of Oxford, Oxford OX1 3PR, England Search for other works by this author on: GSW Google Scholar Russell S. Harmon Russell S. Harmon 3Isotope Geosciences Laboratory, Natural Environmental Research Council, Keyworth NG12 5GG, England Search for other works by this author on: GSW Google Scholar Author and Article Information Gerhard Wörner 1Institut für Geowissenschaften, Universität Mainz, 6500 Mainz, Germany Stephen Moorbath 2Department of Earth Sciences, University of Oxford, Oxford OX1 3PR, England Russell S. Harmon 3Isotope Geosciences Laboratory, Natural Environmental Research Council, Keyworth NG12 5GG, England Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1992) 20 (12): 1103–1106. https://doi.org/10.1130/0091-7613(1992)020<1103:ACVCRB>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 Email Permissions Search Site Citation Gerhard Wörner, Stephen Moorbath, Russell S. Harmon; Andean Cenozoic volcanic centers reflect basement isotopic domains. Geology 1992;; 20 (12): 1103–1106. doi: https://doi.org/10.1130/0091-7613(1992)020<1103:ACVCRB>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 Isotopic data for Quaternary volcanic centers from lat 17.5° to 22°S in northern Chile provide evidence for crustal contributions to arc magma genesis in the central Andes and delineate basement domains. Crustal thickness, distance from trench, height of volcanic edifices above the seismically active subduction zone, and sediment supply to the trench are all constant along this segment of the arc. The only significant variable is crustal age (Paleozoic in the south, Proterozoic in the north). Pb isotopic compositions of Quaternary lavas in the northern sector are lower (206Pb/204Pb = 17.89-18.28) and Sr and O isotope ratios are less variable (87Sr/86Sr = 0.7058-0.7077, δ18O = +6.5‰-+8.4‰) than in the southern sector (206Pb/204Pb = 18.59-18.79, 87Sr/86Sr = 0.7053-0.7083, δ18O = +6.4‰-+9.3‰) for rocks similar in bulk composition, from 53 to 74 wt% SiO2. Together, these features are interpreted to reflect interaction of magmas with crustal contaminants of different isotopic character, rather than changes in the mantle source of central Andean are magmas resulting from either subduction erosion or involvement of old enriched lithosphere. 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.