Sunda arc mantle source δ18O value revealed by intracrystal isotope analysis
Autor: | Chris Harris, Petrus le Roux, Heejin Jeon, Martin J. Whitehouse, Harri Geiger, Marcel van Helden, Frances M. Deegan, Valentin R. Troll, Osvaldo González-Maurel |
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Přispěvatelé: | Earth Sciences |
Jazyk: | angličtina |
Rok vydání: | 2021 |
Předmět: |
010504 meteorology & atmospheric sciences
Science Geochemistry General Physics and Astronomy Volcanology 010502 geochemistry & geophysics 01 natural sciences General Biochemistry Genetics and Molecular Biology Isotopes of oxygen Mantle (geology) Article SDG 14 - Life Below Water Metasomatism 0105 earth and related environmental sciences Petrology Basalt geography Multidisciplinary geography.geographical_feature_category Subduction Mid-ocean ridge Crust Geology General Chemistry Geokemi Magma Geologi |
Zdroj: | Nature Communications, Vol 12, Iss 1, Pp 1-10 (2021) Nature Communications Deegan, F M, Whitehouse, M J, Troll, V R, Geiger, H, Jeon, H, le Roux, P, Harris, C, van Helden, M & González-Maurel, O 2021, ' Sunda arc mantle source δ18O value revealed by intracrystal isotope analysis ', Nature Communications, vol. 12, 3930, pp. 1-10 . https://doi.org/10.1038/s41467-021-24143-3 Nature Communications, 12:3930, 1-10. Nature Publishing Group |
ISSN: | 2041-1723 |
Popis: | Magma plumbing systems underlying subduction zone volcanoes extend from the mantle through the overlying crust and facilitate protracted fractional crystallisation, assimilation, and mixing, which frequently obscures a clear view of mantle source compositions. In order to see through this crustal noise, we present intracrystal Secondary Ion Mass Spectrometry (SIMS) δ18O values in clinopyroxene from Merapi, Kelut, Batur, and Agung volcanoes in the Sunda arc, Indonesia, under which the thickness of the crust decreases from ca. 30 km at Merapi to ≤20 km at Agung. Here we show that mean clinopyroxene δ18O values decrease concomitantly with crustal thickness and that lavas from Agung possess mantle-like He-Sr-Nd-Pb isotope ratios and clinopyroxene mean equilibrium melt δ18O values of 5.7 ‰ (±0.2 1 SD) indistinguishable from the δ18O range for Mid Ocean Ridge Basalt (MORB). The oxygen isotope composition of the mantle underlying the East Sunda Arc is therefore largely unaffected by subduction-driven metasomatism and may thus represent a sediment-poor arc end-member. Subduction zone volcanoes are underlain by extensive magma plumbing systems, which can obscure original mantle source signals. Here, the authors show that intra-crystal oxygen isotope analysis of clinopyroxenes from the Sunda arc (Indonesia) reveal the δ18 O value of the sub-arc mantle. |
Databáze: | OpenAIRE |
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