Triple oxygen isotope constraints on the origin of ocean island basalts
- 72 Downloads
Understanding the origin of ocean island basalts (OIB) has important bearings on Earth’s deep mantle. Although it is widely accepted that subducted oceanic crust, as a consequence of plate tectonics, contributes material to OIB’s formation, its exact fraction in OIB’s mantle source remains ambiguous largely due to uncertainties associated with existing geochemical proxies. Here we show, through theoretical calculation, that unlike many known proxies, triple oxygen isotope compositions (i.e. Δ17O) in olivine samples are not affected by crystallization and partial melting. This unique feature, therefore, allows olivine Δ17O values to identify subducted oceanic crusts in OIB’s mantle source. Furthermore, the fractions of subducted ocean sediments and hydrothermally altered oceanic crust in OIB’s mantle source can be quantified using their characteristic Δ17O values. Based on published Δ17O data, we estimated the fraction of subducted oceanic crust to be as high as 22.3% in certain OIB, but the affected region in the respective mantle plume is likely to be limited.
KeywordsTriple oxygen isotope Helium isotope Ocean island basalts Mantle plume Mantle heterogeneity Crustal recycling
We thank Zhengrong Wang for his helpful comments. H.B. and Y.L. are grateful for funding supports from the strategic priority research program (B) of Chinese Academy of Sciences (XDB18010104) and (XDB18010100) and Chinese NSF Project (41490635). High-performance computational resources were partially provided by Louisiana State University (http://www.hpc.lsu.edu).
Compliance with ethical standards
Conflict of interest
The authors declare no conflict of interests.
- Durben DJ, McMillan PF, Wolf GH (1993) Raman-study of the high-pressure behavior of forsterite (Mg2SiO4) crystal and glass. Am Mineral 78:1143–1148Google Scholar
- Greenwood RC, Barrat J-A, Miller MF, Anand M, Dauphas N, Franchi IA, Sillard P, Starkey NA (2018) Oxygen isotopic evidence for accretion of Earth’s water before a high-energy Moon-forming giant impact. Sci Adv 4:eaao5928Google Scholar
- Hayles JA, Cao X, Bao H (2017) The statistical mechanical basis of the triple isotope fractionation relationship. Geochem Perspect Lett 3:1–11Google Scholar
- Kurz MD, Curtice J, Lott DE, Solow A (2004) Rapid helium isotopic variability in Mauna Kea shield lavas from the Hawaiian Scientific Drilling Project. Geochem Geophys Geosyst 5:Q04G14Google Scholar
- McDonough WF, Rudnick RL (1998) Mineralogy and composition of the upper mantle. Rev Mineral Geochem 37:139–164Google Scholar
- Sobolev AV, Hofmann AW, Kuzmin DV, Yaxley GM, Arndt NT, Chung S-L, Danyushevsky LV, Elliott T, Frey FA, Garcia MO, Gurenko AA, Kamenetsky VS, Kerr AC, Krivolutskaya NA, Matvienkov VV, Nikogosian IK, Rocholl A, Sigurdsson IA, Sushchevskaya NM, Teklay M (2007) The amount of recycled crust in sources of mantle-derived melts. Science 316:412CrossRefGoogle Scholar
- Urey HC (1947) The thermodynamic properties of isotopic substances. J Chem Soc 562–581Google Scholar
- Wang Z, Kitchen Nami E, Eiler John M (2003) Oxygen isotope geochemistry of the second HSDP core. Geochem Geophys Geosyst 4:8712Google Scholar
- Yang S, Liu Y (2015) Nuclear volume effects in equilibrium stable isotope fractionations of mercury, thallium and lead. Sci Rep 5:12626Google Scholar