Covariance of initial 87Sr/86Sr ratios, δ18O, and SiO2 in continental flood basalt suites: The role of contamination and alteration

Research Article| July 01, 1989 Covariance of initial 87Sr/86Sr ratios, δ18O, and SiO2 in continental flood basalt suites: The role of contamination and alteration Chris Harris Chris Harris 1Department of Geochemistry, University of Cape Town, Rondebosch 7700, South Africa Search for other works by this author on: GSW Google Scholar Author and Article Information Chris Harris 1Department of Geochemistry, University of Cape Town, Rondebosch 7700, South Africa Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1989) 17 (7): 634–636. https://doi.org/10.1130/0091-7613(1989)017<0634:COISSR>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 Chris Harris; Covariance of initial 87Sr/86Sr ratios, δ18O, and SiO2 in continental flood basalt suites: The role of contamination and alteration. Geology 1989;; 17 (7): 634–636. doi: https://doi.org/10.1130/0091-7613(1989)017<0634:COISSR>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 When mutual positive correlations occur between δ18O, 87Sr/86Sr initial ratio (Ro), and SiO2 in continental flood basalt suites, they are generally accepted as being due to crustal contamination. In continental flood basalt suites that have undergone coupled assimilation fractional crystallization in which the contaminant is granitic continental crust, Ro reflects the degree of contamination and will correlate positively with SiO2, which reflects the degree of differentiation. Posteruptive alteration of a suite having a range of SiO2 values should result in a positive correlation between SiO2 and δ18O because the ability of a volcanic rock to concentrate 18O depends, in part, on silica content. Suites that have undergone assimilation-fractional crystallization followed by alteration after eruption may therefore exhibit a positive correlation between δ18O, SiO2, and Ro. The δ18O data in such suites may consequently suggest erroneously high degrees of contamination. 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.