Reactive ammonia in the solar protoplanetary disk and the origin of Earths nitrogen

Journal name:
Nature Geoscience
Year published:
Published online

Terrestrial nitrogen isotopic compositions are distinct from solar and cometary values and similar to those of primitive meteorites, suggesting that Earths atmospheric nitrogen originates from a primordial cosmochemical source1, 2. Prebiotic organic compounds containing nitrogen that formed in the solar protoplanetary disk, such as amino acids, may have contributed to the emergence of life on Earth3, 4. However, the original reservoirs of these volatile compounds and the processes involved in their distribution and chemical modification before accretion remain unclear. Here we report the occurrence of the mineral carlsbergite (chromium nitride) within nanocrystalline sulphide inclusions of primitive chondritic meteorites using transmission electron microscopy and secondary ion mass spectrometry. The characteristics and occurrence of carlsbergite are consistent with precipitation from a chromium-bearing metal in the presence of reactive ammonia. The carlsbergite crystals have nitrogen isotopic compositions that differ from ammonia in cometary ices, but are similar to Earths atmospheric nitrogen. We suggest that the reactive ammonia proposed to have initiated formation of the carlsbergite came from ices within regions of the protoplanetary disk that were affected by the distal wakes of shock waves. Our findings imply that these primordial ammonia-bearing ices were a nitrogen reservoir within the formation region of the chondritic meteorite parent bodies and could have been a source of volatiles for the early Earth.

At a glance


  1. Mineralogy of PCS grain 98F03 from Y-791198.
    Figure 1: Mineralogy of PCS grain 98F03 from Y-791198.

    a, Backscattered electron image of the PCS grain before FIB sectioning. b, SAED pattern (~12 μm2 area) of the FIB sample showing the main lattice spacings of nanocrystalline pentlandite (n-Pn) as two broad rings accompanied by ring segments of carlsbergite (CrN) reflections, which indicate a non-random crystal orientation. c, Bright-field TEM image of the FIB sample showing carlsbergite platelets embedded in n-Pn. d, High-resolution image of a single carlsbergite platelet showing the dominant {100} face with measured lattice spacings (95% confidence of the mean, n = 4).

  2. Localization of nitrogen by NanoSIMS.
    Figure 2: Localization of nitrogen by NanoSIMS.

    a, Secondary electron SEM image of the surface after NanoSIMS analysis. The nanocrystalline pentlandite (n-Pn) has been sputtered preferentially and exposed internal grains. b, The same image overlaid with the distribution of 12C14N secondary ions obtained by NanoSIMS. Exposed carlsbergite grains correlate with local maxima (blue–violet) of the ion intensity. Grains not associated with intensity maxima are probably schreibersite. Organic material is present in the periphery.

  3. Kinetic evolution of the nitriding potential in gas mixtures between solar gas and an ice-derived gas with Hale-Bopp-like species composition.
    Figure 3: Kinetic evolution of the nitriding potential in gas mixtures between solar gas and an ice-derived gas with Hale–Bopp-like species composition.

    Shown are mixtures with 99 mol% (circles) and 90 mol% (squares) contributions of ice at 750 K/10 Pa total pressure (red), 750 K/1,000 Pa (green), 1,260 K/10 Pa (blue) and 1,260 K/1,000 Pa (orange). Coloured dashed lines indicate the corresponding equilibrium values. In a homogeneous gas the nitriding potential remains metastably above 3 × 10−4 Pa−1/2 at least for days. At this value rapid CrN formation has been demonstrated21.

  4. Gas mixing at 750 K between solar gas (diamonds) and an ice-derived gas of Hale-Bopp-like elemental composition (circles).
    Figure 4: Gas mixing at 750 K between solar gas (diamonds) and an ice-derived gas of Hale–Bopp-like elemental composition (circles).

    Elemental C/O = 0.29 (red) and C/O = 0.16 (blue, orange). Mixing trajectories at 10 Pa (solid lines) and 103 Pa (dashed lines) total pressure are calculated for full equilibration (blue, immediate reaction of NH3) and suppressed N2 (orange, maximum retention of NH3). The ratios of H2O/H2 and H2S/H2 trend towards the phase boundary of Fe-deficient pyrrhotite and magnetite for contributions of more than 90 mol% ice (squares).


  1. Marty, B. The origins and concentrations of water, carbon, nitrogen and noble gases on Earth. Earth Planet. Sci. Lett. 313–314, 5666 (2012).
  2. Alexander, C. M. O D. et al. The provenances of asteroids, and their contributions to the volatile inventories of the terrestrial planets. Science 337, 721723 (2012).
  3. Kvenvolden, K. et al. Evidence for extraterrestrial amino-acids and hydrocarbons in the Murchison meteorite. Nature 228, 923926 (1970).
  4. Engel, M. H. & Macko, S. A. Isotopic evidence for extraterrestrial non-racemic amino acids in the Murchison meteorite. Nature 389, 265268 (1997).
  5. Nazarov, M. A. et al. Phosphorus-bearing sulfides and their associations in CM chondrites. Petrology 17, 101123 (2009).
  6. Devouard, B. & Buseck, P. R. Phosphorus-rich iron, nickel sulfides in CM2 chondrites: Condensation or alteration products? Meteorit. Planet. Sci. 32, A34 (1997).
  7. Kerridge, J. F. Carbon, hydrogen and nitrogen in carbonaceous chondrites: Abundances and isotopic compositions in bulk samples. Geochim. Cosmochim. Acta 49, 17071714 (1985).
  8. Pizzarello, S., Feng, X., Epstein, S. & Cronin, J. R. Isotopic analyses of nitrogenous compounds from the Murchison meteorite: Ammonia, amines, amino acids, and polar hydrocarbons. Geochim. Cosmochim. Acta 58, 55795587 (1994).
  9. Marty, B., Chaussidon, M., Wiens, R. C., Jurewicz, A. J. G. & Burnett, D. S. A. 15N-poor isotopic composition for the Solar System as shown by Genesis solar wind samples. Science 332, 15331536 (2011).
  10. Manfroid, J. et al. The CN isotopic ratios in comets. Astron. Astrophys. 503, 613624 (2009).
  11. Briani, G. et al. Pristine extraterrestrial material with unprecedented nitrogen isotopic variation. Proc. Natl Acad. Sci. USA 106, 1052210527 (2009).
  12. Sennour, M., Jouneau, P. H. & Esnouf, C. TEM and EBSD investigation of continuous and discontinuous precipitation of CrN in nitrided pure Fe–Cr alloys. J. Mater. Sci. 39, 45214531 (2004).
  13. Mittemeijer, E. J. & Slycke, J. T. Chemical potentials and activities of nitrogen and carbon imposed by gaseous nitriding and carburising atmospheres. Surf. Eng. 12, 152162 (1996).
  14. Lauretta, D. S., Lodders, K. & Fegley, B. Experimental simulations of sulfide formation in the solar nebula. Science 277, 358360 (1997).
  15. Fegley, B. Primordial retention of nitrogen by terrestrial planets and meteorites. J. Geophys. Res. 88, A853A868 (1983).
  16. Guo, W. & Eiler, J. M. Temperatures of aqueous alteration and evidence for methane generation on the parent bodies of the CM chondrites. Geochim. Cosmochim. Acta 71, 55655575 (2007).
  17. Lewis, J. S. & Prinn, R. G. Kinetic inhibition of CO and N2 reduction in the solar nebula. Astrophys. J. 238, 357364 (1980).
  18. Yamamoto, T., Nakagawa, N. & Fukui, Y. The chemical composition and thermal history of the ice of a cometary nucleus. Astron. Astrophys. 122, 171176 (1983).
  19. Bockelée-Morvan, D. & Crovisier, J. Lessons of comet Hale–Bopp for coma chemistry: Observations and theory. Earth Moon Planets 89, 5371 (2002).
  20. Maret, S., Bergin, E. A. & Lada, C. J. A low fraction of nitrogen in molecular form in a dark cloud. Nature 442, 425427 (2006).
  21. Hosmani, S. S., Schacherl, R. E. & Mittemeijer, E. J. Nitrogen absorption by Fe-1.04 at.% Cr alloy: Uptake of excess nitrogen. J. Mater. Sci. 43, 26182624 (2008).
  22. Ciesla, F. J., Lauretta, D. S., Cohen, B. A. & Hood, L. L. A nebular origin for chondritic fine-grained phyllosilicates. Science 299, 549552 (2003).
  23. Nuth, J. A., Johnson, N. M. & Manning, S. A self-perpetuating catalyst for the production of complex organic molecules in protostellar nebulae. Astrophys. J. 673, L225 (2008).
  24. Elsila, J. E., Charnley, S. B., Burton, A. S., Glavin, D. P. & Dwornik, J. P. Compound-specific carbon, nitrogen, and hydrogen isotopic ratios for amino acids in CM and CR chondrites and their use in evaluating potential formation pathways. Meteorit. Planet. Sci. 47, 15171536 (2012).
  25. Walsh, K. J., Morbidelli, A., Raymond, S. N., OBrien, D. P. & Mandell, A. M. A low mass for Mars from Jupiters early gas-driven migration. Nature 475, 206209 (2011).
  26. Lis, D. C., Wootten, A., Gerin, M. & Roueff, E. Nitrogen isotopic fractionation in interstellar ammonia. Astrophys. J. Lett. 710, L49 (2010).
  27. Aléon, J. Multiple origins of nitrogen isotopic anomalies in meteorites and comets. Astrophys. J. 722, 13421351 (2010).
  28. Hartogh, P. et al. Ocean-like water in the Jupiter-family comet 103P/Hartley 2. Nature 478, 218220 (2011).
  29. Brown, M. E., Schaller, E. L. & Fraser, W. C. A hypothesis for the color diversity of the Kuiper belt. Astrophys. J. Lett. 739, L60 (2011).
  30. Castillo-Rogez, J. C. & McCord, T. B. Ceres evolution and present state constrained by shape data. Icarus 205, 443459 (2010).

Download references

Author information


  1. Institut für Geowissenschaften, Friedrich-Schiller-Universität Jena, Carl-Zeiss-Promenade 10, 07745 Jena, Germany

    • Dennis Harries &
    • Falko Langenhorst
  2. Bayerisches Geoinstitut, Universität Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany

    • Dennis Harries
  3. Max-Planck-Institut für Chemie, Hahn-Meitner-Weg 1, 55128 Mainz, Germany

    • Peter Hoppe


D.H. and F.L. conducted the SEM and TEM work, P.H. and D.H. conducted the NanoSIMS work. D.H. contributed the modelling and wrote most of the paper with input from P.H. and F.L.

Competing financial interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to:

Author details

Supplementary information

PDF files

  1. Supplementary Information (4,200 KB)

    Supplementary Information

Additional data