Nitrogen Isotopic Composition and Density of the Archean Atmosphere

Understanding the atmosphere’s composition during the Archean eon is a fundamental issue to unravel ancient environmental conditions.

We show from the analysis of nitrogen and argon isotopes in fluid inclusions trapped in 3.0-3.5 Ga hydrothermal quartz that the PN2 of the Archean atmosphere was lower than 1.1 bar, possibly as low as 0.5 bar, and had a nitrogen isotopic composition comparable to the present-day one. These results imply that dinitrogen did not play a significant role in the thermal budget of the ancient Earth and that the Archean PCO2 was probably lower than 0.7 bar.

Bernard Marty, Laurent Zimmermann, Magali Pujol, Ray Burgess, Pascal Philippot (Submitted on 24 May 2014)

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

Journal reference: Science 342,101 (2013), 101-104

DOI: 10.1126/science.1240971

Cite as: arXiv:1405.6337 [astro-ph.EP] (or arXiv:1405.6337v1 [astro-ph.EP] for this version)

Submission history From: Bernard Marty [v1] Sat, 24 May 2014 19:35:25 GMT (339kb)