Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

A primary magmatic source of nitrogen to Earth’s crust


The igneous portion of Earth’s continental crust represents a long-term sink of terrestrial nitrogen, but the origin of the nitrogen in this reservoir remains ambiguous. Possible sources include magmatic differentiation of mantle-derived melts (that is, magmatic nitrogen) and/or the burial of biomass (that is, fixed atmospheric nitrogen). Identifying the sources of crustal nitrogen is required to accurately reconstruct the evolution of Earth’s atmospheric pressure, and therefore habitability, over geologic timescales. Here we present analyses of the nitrogen geochemistry of extrusive igneous rocks from Hekla volcano, Iceland, which has been previously used as a natural laboratory to study the effects of magmatic differentiation on stable isotope systems. We find that bulk rock nitrogen abundance increases as rocks become more evolved, with up to 23 μg g−1 of nitrogen in felsic igneous samples and non-systematic and negligible nitrogen isotopic fractionation across the suite. Our findings indicate that this nitrogen is magmatic in origin and provides evidence that nitrogen behaves as an incompatible trace element during magmatic differentiation. Assuming Hekla is representative of differentiating systems more broadly, the observed nitrogen enrichment would satisfy 31–52% of Earth’s felsic crust-hosted nitrogen. We suggest that continental crust formation can act as nitrogen trap between the mantle and the atmosphere. Therefore, nitrogen degassing from Earth’s interior to the atmosphere over geological time may have been previously overestimated.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Earth reservoir size and abundance estimates for nitrogen.
Fig. 2: Nitrogen abundance and isotope systematics for the Hekla volcanic suite.
Fig. 3: Nitrogen versus rubidium for the Hekla suite and fractional crystallization model.

Similar content being viewed by others

Data availability

All supporting data for this study are included in the extended data files associated with this manuscript and are deposited in a figshare repository that can be accessed at


  1. Johnson, B. W. & Goldblatt, C. The nitrogen budget of Earth. Earth Sci. Rev. 148, 150–173 (2015).

    Article  Google Scholar 

  2. Zerkle, A. L. & Mikhail, S. The geobiological nitrogen cycle: from microbes to the mantle. Geobiology 15, 343–352 (2017).

    Article  Google Scholar 

  3. Sano, Y. et al. Volcanic flux of nitrogen from the Earth. Chem. Geol. 171, 263–271 (2001).

    Article  Google Scholar 

  4. Halama, R., Bebout, G. E., John, T. & Schenk, V. Nitrogen recycling in subducted oceanic lithosphere: the record in high- and ultrahigh-pressure metabasaltic rocks. Geochim. Cosmochim. Acta 74, 1636–1652 (2010).

    Article  Google Scholar 

  5. Geist, D. et al. Hekla revisited: fractionation of a magma body at historical timescales. J. Petrol. 62, egab001 (2021).

    Article  Google Scholar 

  6. Savage, P. S., Georg, R. B., Williams, H. M., Burton, K. W. & Halliday, A. N. Silicon isotope fractionation during magmatic differentiation. Geochim. Cosmochim. Acta 75, 6124–6139 (2011).

    Article  Google Scholar 

  7. Sigmarsson, O., Condomines, M. & Fourcade, S. A detailed Th, Sr and O isotope study of Hekla: differentiation processes in an Icelandic volcano. Contrib. Mineral. Petrol. 112, 20–34 (1992).

    Article  Google Scholar 

  8. Geirsson, H. et al. Volcano deformation at active plate boundaries: deep magma accumulation at Hekla volcano and plate boundary deformation in south Iceland. J. Geophys. Res. Solid Earth 117, 11409 (2012).

    Article  Google Scholar 

  9. Sigmarsson, O., Bergþórsdóttir, I. A., Devidal, J. L., Larsen, G. & Gannoun, A. Long or short silicic magma residence time beneath Hekla volcano, Iceland? Contrib. Mineral. Petrol. 177, 1–15 (2022).

    Article  Google Scholar 

  10. Schuessler, J. A., Schoenberg, R. & Sigmarsson, O. Iron and lithium isotope systematics of the Hekla volcano, Iceland—evidence for Fe isotope fractionation during magma differentiation. Chem. Geol. 258, 78–91 (2009).

    Article  Google Scholar 

  11. Yang, J. et al. Absence of molybdenum isotope fractionation during magmatic differentiation at Hekla volcano, Iceland. Geochim. Cosmochim. Acta 162, 126–136 (2015).

    Article  Google Scholar 

  12. Prytulak, J. et al. Stable vanadium isotopes as a redox proxy in magmatic systems? Geochem. Perspect. Lett. 3, 75–84 (2017).

    Article  Google Scholar 

  13. Prytulak, J. et al. Thallium elemental behavior and stable isotope fractionation during magmatic processes. Chem. Geol. 448, 71–83 (2017).

    Article  Google Scholar 

  14. Tuller-Ross, B., Savage, P. S., Chen, H. & Wang, K. Potassium isotope fractionation during magmatic differentiation of basalt to rhyolite. Chem. Geol. 525, 37–45 (2019).

    Article  Google Scholar 

  15. Chekol, T. A., Kobayashi, K., Yokoyama, T., Sakaguchi, C. & Nakamura, E. Timescales of magma differentiation from basalt to andesite beneath Hekla Volcano, Iceland: constraints from U-series disequilibria in lavas from the last quarter-millennium flows. Geochim. Cosmochim. Acta 75, 256–283 (2011).

    Article  Google Scholar 

  16. Chen, H., Savage, P. S., Teng, F. Z., Helz, R. T. & Moynier, F. Zinc isotope fractionation during magmatic differentiation and the isotopic composition of the bulk Earth. Earth Planet. Sci. Lett. 369–370, 34–42 (2013).

    Article  Google Scholar 

  17. Inglis, E. C. et al. Isotopic fractionation of zirconium during magmatic differentiation and the stable isotope composition of the silicate Earth. Geochim. Cosmochim. Acta 250, 311–323 (2019).

    Article  Google Scholar 

  18. Boocock, T. J. et al. Nitrogen mass fraction and stable isotope ratios for fourteen geological reference materials: evaluating the applicability of elemental analyser versus sealed tube combustion methods. Geostand. Geoanal. Res. 44, 537–551 (2020).

    Article  Google Scholar 

  19. Mikhail, S. & Sverjensky, D. A. Nitrogen speciation in upper mantle fluids and the origin of Earth’s nitrogen-rich atmosphere. Nat. Geosci. 7, 816–819 (2014).

    Article  Google Scholar 

  20. Jackson, C. R. M., Cottrell, E. & Andrews, B. Warm and oxidizing slabs limit ingassing efficiency of nitrogen to the mantle. Earth Planet. Sci. Lett. 553, 116615 (2021).

    Article  Google Scholar 

  21. Mysen, B. Nitrogen in the Earth: abundance and transport. Prog. Earth Planet. Sci. 6, 1–15 (2019).

    Article  Google Scholar 

  22. Halldórsson, S. A., Hilton, D. R., Barry, P. H., Füri, E. & Grönvold, K. Recycling of crustal material by the Iceland mantle plume: new evidence from nitrogen elemental and isotope systematics of subglacial basalts. Geochim. Cosmochim. Acta 176, 206–226 (2016).

    Article  Google Scholar 

  23. Li, Y., Li, L. & Wu, Z. First-principles calculations of equilibrium nitrogen isotope fractionations among aqueous ammonium, silicate minerals and salts. Geochim. Cosmochim. Acta 297, 220–232 (2021).

    Article  Google Scholar 

  24. Li, Y., Huang, R., Wiedenbeck, M. & Keppler, H. Nitrogen distribution between aqueous fluids and silicate melts. Earth Planet. Sci. Lett. 411, 218–228 (2015).

    Article  Google Scholar 

  25. Bucholz, C. E., Jagoutz, O., VanTongeren, J. A., Setera, J. & Wang, Z. Oxygen isotope trajectories of crystallizing melts: Insights from modeling and the plutonic record. Geochim. Cosmochim. Acta 207, 154–184 (2017).

    Article  Google Scholar 

  26. Cartigny, P., Jendrzejewski, N., Pineau, F., Petit, E. & Javoy, M. Volatile (C, N, Ar) variability in MORB and the respective roles of mantle source heterogeneity and degassing: the case of the Southwest Indian Ridge. Earth Planet. Sci. Lett. 194, 241–257 (2001).

    Article  Google Scholar 

  27. Haendel, D., Muehle, K., Nitzsche, H.-M., Stiehl, G. & Wand, U. Isotopic variations of the fixed nitrogen in metamorphic rocks. Geochim. Cosmochim. Acta 50, 749–758 (1986).

    Article  Google Scholar 

  28. Fischer, T. P., Takahata, N., Sano, Y., Sumino, H. & Hilton, D. R. Nitrogen isotopes of the mantle: insights from mineral separates. Geophys. Res. Lett. 32, 1–5 (2005).

    Article  Google Scholar 

  29. Rudnick, R. and Gao, S. In Treatise on Geochemistry, Vol. 3 (eds Holland, H. D. & Turekian, K. K.) 1–64 (Elsevier-Pergamon, 2003).

  30. Taylor, S. R. Abundance of chemical elements in the continental crust: a new table. Geochim. Cosmochim. Acta 28, 1273–1285 (1964).

    Article  Google Scholar 

  31. McDonough, W. F., Sun, S., Ringwood, A. E., Jagoutz, E. & Hofmann, A. W. Potassium, rubidium, and cesium in the Earth and moon and the evolution of the mantle of the Earth. Geochim. Cosmochim. Acta 56, 1001–1012 (1992).

    Article  Google Scholar 

  32. Marty, B. Nitrogen content of the mantle inferred from N2–Ar correlation in oceanic basalts. Nature 377, 326–329 (1995).

    Article  Google Scholar 

  33. Galloway, J. N. The global nitrogen cycle. Treatise Geochem. 8, 682 (2003).

    Google Scholar 

  34. Gruber, N. & Galloway, J. N. An Earth-system perspective of the global nitrogen cycle. Nature 451, 293–296 (2008).

    Article  Google Scholar 

  35. Goldblatt, C. et al. Nitrogen-enhanced greenhouse warming on early Earth. Nat. Geosci. 2, 891–896 (2009).

    Article  Google Scholar 

  36. Kerrich, R., Jia, Y., Manikyamba, C. & Naqvi, S. M., Chapter 5: Secular variations of N-isotopes in terrestrial reservoirs and ore deposits. In Evolution of Early Earth’s Atmosphere, Hydrosphere, and Biosphere: Constraints from Ore Deposits (eds Kesler, S. & Ohmoto, H.) (Geological Society of America, 2006).

  37. Busigny, V., Cartigny, P., Philippot, P., Ader, M. & Javoy, M. Massive recycling of nitrogen and other fluid-mobile elements (K, Rb, Cs, H) in a cold slab environment: evidence from HP to UHP oceanic metasediments of the Schistes Lustrés nappe (western Alps, Europe). Earth Planet. Sci. Lett. 215, 27–42 (2003).

    Article  Google Scholar 

  38. Yokochi, R., Marty, B., Chazot, G. & Burnard, P. Nitrogen in peridotite xenoliths: lithophile behavior and magmatic isotope fractionation. Geochim. Cosmochim. Acta 73, 4843–4861 (2009).

    Article  Google Scholar 

  39. Feng, L., Li, H. & Liu, W. Nitrogen mass fraction and isotope determinations in geological reference materials using sealed-tube combustion coupled with continuous-flow isotope-ratio mass spectrometry. Geostand. Geoanal. Res. 42, 539–548 (2018).

    Article  Google Scholar 

  40. Sharp, Z. A laser-based microanalytical method for the in situ determination of oxygen isotope ratios of silicates and oxides. Geochim. Cosmochim. Acta 54, 1353–1357 (1990).

    Article  Google Scholar 

  41. Stüeken, E. E., Boocock, T. J., Robinson, A., Mikhail, S. & Johnson, B. W. Hydrothermal recycling of sedimentary ammonium into oceanic crust and the Archean ocean at 3.24 Ga. Geology 49, 822–826 (2021).

    Article  Google Scholar 

Download references


Funding was provided by a Natural Environment Research Council (NERC) studentship (grant NE/R012253/1) to T.J.B. and a National Environmental Isotope Facility access in-kind grant (NEIF–2313.0920) to E.E.S., S.M. and T.J.B. S.M. acknowledges support from NERC standard grant NE/PO12167/1. E.E.S. is financially supported by a NERC Frontiers grant (NE/V010824/1). We thank A. MacDonald at Scottish Universities Environmental Research Centre for technical support when obtaining the bulk oxygen isotope data.

Author information

Authors and Affiliations



T.J.B., S.M., J.P. and E.E.S. designed the study. P.S.S. collected the samples and undertook initial sample preparation and major/trace element characterization. T.J.B. collected the nitrogen data and wrote the original manuscript draft. A.J.B. collected the oxygen isotope data. All authors contributed to the interpretation of the results and the review and editing of the manuscript and supplemental information.

Corresponding authors

Correspondence to Toby J. Boocock or Sami Mikhail.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Geoscience thanks Tobias Fischer, Ralf Halama, Olgeir Sigmarsson and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Primary handling editors: Tamara Goldin and Rebecca Neely, in collaboration with the Nature Geoscience team.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figs. 1–6 and Discussion.

Supplementary Data 1

Supplementary data.

Supplementary Data 2

Supplementary data.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Boocock, T.J., Mikhail, S., Boyce, A.J. et al. A primary magmatic source of nitrogen to Earth’s crust. Nat. Geosci. 16, 521–526 (2023).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing