Oxygen isotopes in titanite and apatite, and their potential for crustal evolution research

• Published in: Geochimica et Cosmochimica Acta
• Main Authors: Bruand, Emilie, Storey, C., Fowler, M., Heilimo, E.
• Other Authors: Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS), School of Earth and Environmental Sciences Portsmouth, University of Portsmouth, Geological Survey of Finland = Geologian tutkimuskeskus tuottaa (GKT), ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: apatite; titanite; Oxygen isotopes; granitoids; crustal evolution; [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; Guernsey; karelia*
• Online Access: https://hal.archives-ouvertes.fr/hal-02124580; https://hal.archives-ouvertes.fr/hal-02124580/document; https://hal.archives-ouvertes.fr/hal-02124580/file/Bruandetal.pdf; https://doi.org/10.1016/j.gca.2019.04.002

Co-auteur étranger International audience Oxygen isotope analysis of zircon, often combined with geochronology and Hf isotope analysis, has been pivotal in understanding the evolution of continental crust. In this contribution, we expand the use of underexplored accessory phases (titanite and apatite) by demonstrating that their oxygen isotope systems can be robust, and by developing geochemical indicators involving O isotopes and trace element concentrations to better constrain magma petrogenesis. These minerals have the advantage over zircon of being present in less evolved magmas and being more responsive to igneous processes and crustal metamorphism. We present new data on titanite, apatite and zircon from carefully-selected granitoids through geological time: the Phanerozoic high Ba-Sr granites (Caledonian province, Scotland), Archean sanukitoids (Karelia province, Finland) and a Neoproterozoic basalt-andesite-dacite-rhyolite suite (BADR; Guernsey, Channel Island). We demonstrate: (i) that d 18 O values of the studied accessory minerals are not affected by crystal fractionation, (ii) a strong correlation between d 18 O in all three accessory minerals, showing that apatite and titanite can faithfully record the magmatic d 18 O; (iii) that these accessory minerals can also record metamorphic and/or fluid circulation events during the syn-to post-magmatic history of granitoids.