Deep Nitrogen Fluxes and Sources Constrained by Arc Lava Phenocrysts
Abstract Nitrogen (N) dominates Earth's atmosphere (78% N 2 ) but occurs in trace abundances in silicate minerals, making it a sensitive tracer of recycled surface materials into the mantle. The mechanisms controlling N transfer between terrestrial reservoirs remain uncertain because low N abundances in mineral‐hosted fluid inclusions (FIs) are difficult to measure. Using new techniques, we analyzed N and He isotope compositions and abundances in olivine‐ and pyroxene‐hosted FIs from arc volcanoes in Southern Chile, Cascadia, Central America, and the Southern Marianas. These measurements enable an estimate of the global flux of N outgassing from arcs (4.0 × 10 10 mol/yr). This suggests that Earth is currently in a state of net N ingassing, with roughly half of subducted N returned to the mantle. Additionally, the N outgassing flux of individual arcs correlates with the thickness of subducting pelagic sediment, suggesting that N cycling in the modern solid Earth is largely controlled by sediment subduction.
Authors
- Rebecca Tyne (ORCID: https://orcid.org/0000-0003-1316-3119)
- Sune G. Nielsen (ORCID: https://orcid.org/0000-0002-0458-3739)
- A. M. Shaw
- Mark D. Kurz (ORCID: https://orcid.org/0000-0003-1745-2356)
- Kristina Walowski (ORCID: https://orcid.org/0000-0003-2491-2955)
- Michael W. Broadley (ORCID: https://orcid.org/0000-0002-5031-4687)
- Michael R. Hudak (ORCID: https://orcid.org/0000-0002-0583-5424)
- Peter H. Barry (ORCID: https://orcid.org/0000-0002-6960-1555)
- Michelle Muth (ORCID: https://orcid.org/0000-0002-4393-4976)
- Joshua Curtice
- David V. Bekaert (ORCID: https://orcid.org/0000-0002-1062-6221)
- Emily Cahoon (ORCID: https://orcid.org/0000-0002-3162-5383)
- Kan Li (ORCID: https://orcid.org/0000-0002-1161-8434)
- Stephen J. Turner (ORCID: https://orcid.org/0000-0001-5412-2829)
- Paul Wallace (ORCID: https://orcid.org/0000-0003-4292-3092)
Institutions
- Centre National de la Recherche Scientifique (FR)
- Oregon State University (US)
- University of Oregon (US)
- University of Washington (US)
- Williams College (US)
- University of Massachusetts Amherst (US)
- University of Manchester (GB)
- Centre de Recherches Pétrographiques et Géochimiques (FR)
- Earth and Space Research (US)
- University of Houston (US)
- Western Washington University (US)
- Woods Hole Oceanographic Institution (US)
- Université de Lorraine (FR)
Publication Details
- Journal
- Geophysical Research Letters
- Published
- 2024-12-12
- DOI
- https://doi.org/10.1029/2024gl111312
- Citations
- 4
- Primary Topic
- Geological and Geochemical Analysis
- Type
- article
- Field-Weighted Citation Impact
- 2.14
Funders
- National Science Foundation
- Sight Research UK
- Engineering and Physical Sciences Research Council
- Natural Environment Research Council
- Division of Earth Sciences