Tungsten-182 heterogeneity in modern ocean island basalts

• Published in: Science
• Main Authors: Mundl, Andrea, Touboul, Mathieu, Jackson, Matthew G., Day, James M. D., Kurz, Mark D., Lekic, Vedran, Helz, Rosalind T., Walker, Richard J.
• Other Authors: Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: [SDU]Sciences of the Universe [physics]; Iceland; Ocean Island
• Online Access: https://univ-lyon1.hal.science/hal-02328810; https://doi.org/10.1126/science.aal4179

New tungsten isotope data for modern ocean island basalts (OIB) from Hawaii, Samoa, and Iceland reveal variable W-182/W-184, ranging from that of the ambient upper mantle to ratios as much as 18 parts per million lower. The tungsten isotopic data negatively correlate with He-3/He-4. These data indicate that each OIB system accesses domains within Earth that formed within the first 60 million years of solar system history. Combined isotopic and chemical characteristics projected for these ancient domains indicate that they contain metal and are repositories of noble gases. We suggest that the most likely source candidates are mega-ultralow-velocity zones, which lie beneath Hawaii, Samoa, and Iceland but not beneath hot spots whose OIB yield normal W-182 and homogeneously low He-3/He-4.