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Title: Hydrogen isotopic evidence for a core component in Baffin Island lavas
The nature of chemical exchange between Earth’s core and mantle is fundamental to understanding their evolution. Tungsten-182 and helium-3 anomalies in volcanic rocks from deeply sourced mantle plumes have been attributed to core-mantle exchange. Hydrogen (H) is potentially abundant in the core. Therefore, H may also be a sensitive tracer of core-mantle exchange. We measured2H/1H ratios (reported as δD) in olivine-hosted basaltic melt inclusions from a Baffin Island lava to test whether mantle plumes contain H from the core. The average δD value (−144 ± 24 per mil) is lower than some estimates for the average depleted upper mantle (δD ≈ −60 ± 20 per mil). The low δD composition likely derives from isotopic diffusion or H leakage from the core, not isotopic fractionation during magmatism or crustal contamination. Over geologic time, core-mantle exchange of H may have overprinted the isotopic composition of mantle plume source regions and much of the upper mantle.  more » « less
Award ID(s):
2232531
PAR ID:
10661983
Author(s) / Creator(s):
; ; ; ; ; ; ;
Publisher / Repository:
AAAS
Date Published:
Journal Name:
Science Advances
Volume:
11
Issue:
17
ISSN:
2375-2548
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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