The solubility of N2 in silicate melts and nitrogen partitioning between upper mantle minerals and basalt

Abstract The solubility of N 2 in basaltic (MORB) and haplogranitic melts was studied at oxidizing conditions (oxygen fugacity about two log units above the Ni–NiO buffer). Under these conditions, is expected to be only significant nitrogen species present melt. Experiments were carried out from 0.1 GPa 1000–1450 ˚C using either an externally heated TZM pressure vessel, internally gas vessel or a piston cylinder apparatus. Nitrogen contents run product glasses quantified by SIMS (secondary ion mass spectrometry). To discriminate against atmospheric contamination, 15 N-enriched AgN 3 used as source experiments. According infrared Raman spectra, contain their dissolved species. Due interactions with matrix, molecule becomes slightly active. increases linearly over entire range studied; effect temperature on small. data may, therefore, described simple Henry constants K haplogranite = (1461 ± 26) ppm /GPa MORB (449 21) /GPa, recalculated weight (μg/g) isotopically normal samples. These equations describe during generation melting crust, we show thermodynamic analysis that environments. melt three times larger than for melt, ionic porosity considerations. If expressed molar basis, significantly lower argon solubility, accordance size molecule. Notably, felsic also much CO even basis. This implies exsolution may drive vapor oversaturation derived nitrogen-rich sediments. We measured partitioning between olivine, pyroxenes, plagioclase, garnet, slowly cooling sub-liquidus temperatures grow large crystals. mineral/melt partition coefficients 0.001 0.002, are similar coefficients. new data, support assumption there little fractionation mantle /Ar ratio basalts xenoliths is, representative source. essential assessing reservoir mantle. Our upper oxidation state one observed today, outgassing partial extremely efficient low fractions few percent extract nearly all