Experimental determination of N2 solubility in silicate melts and implications for N2–Ar–CO2 fractionation in magmas

NanoSIMS analysis of water content in bridgmanite at the micron scale: An experimental approach to probe water in Earth’s deep mantle

“…O 1 H − , 19 F − , 30 Si − , 31 P − , 32 S − , and 35 Cl − , they can be changed to measure other elements of interest, such as replacing the 31 P − with 14 N 16 O − and 30 Si − with 29 Si − (Gao et al, 2022), where either 30 Si or 29 Si serves as the normalized species. Considering that the partitioning behavior of any of the above-mentioned volatile elements may be affected by others (Iacono-Marziano et al, 2012;Li et al, 2015;Gaillard et al, 2022), simultaneous detection of several volatile elements is beneficial to a comprehensive evaluation of their likely interdependent partitioning behavior.…”

The origin and evolution of Earth's nitrogen

“…Knowledge of nitrogen solubility in silicate melts at the saturation of N 2 -rich gas ( \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} $S_N^{{melt}}$\end{document} ), nitrogen partitioning between mantle minerals and silicate melt, and nitrogen partitioning between fluid and silicate melt, is fundamentally important for understanding and quantifying the efficiency of mantle nitrogen degassing. Experimental studies focusing on determining \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} $S_N^{{melt}}$\end{document} were conducted on dry basaltic/chondritic melts [ 67 , 72 , 107 , 154 ], hydrous/anhydrous silicate melts in the simplified SiO 2 – Na 2 O ± FeO ± Al 2 O 3 systems [ 155–159 ], and on hydrous basaltic and granitic melts at conditions relevant for partial melting of Earth's upper mantle and crust [ 61 , 64 , 73 , 160 ]. The most important results of these studies reveal that \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} $S_N^{{melt}}$\end{document} depends on f O 2 , pressure and silicate melt composition (Fig.…”

“…Gao et al. (2022) [ 64 ] demonstrated that the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} $S_N^{{melt}}$\end{document} at f O 2 > IW is smaller than the argon and CO 2 solubilities at given conditions, indicating the fractionation of N 2 from Ar and CO 2 during the degassing of MORBs and arc magmas. Using all available nitrogen and argon solubility data obtained at f O 2 > IW, Gao et al.…”

“…Using all available nitrogen and argon solubility data obtained at f O 2 > IW, Gao et al. (2022) [ 64 ] developed an empirical solubility model that can be used to predict the solubilities of nitrogen and argon in the silicate melts of Earth's mantle to crustal magmas. In contrast, Dasgupta et al.…”

“…The experiments were conducted at conditions that are relevant for the early Earth magma ocean, mantle melting, subduction zone processes and magmatic degassing within the shallow crust. In combination with high-precision in situ analyses using an electron microprobe [ 62 , 63 ], Fourier-transform infrared (FTIR) and Raman spectroscopy [ 64 , 65 ], secondary ion mass spectrometry (SIMS) [ 63 , 66–68 ], and NanoSIMS [ 64 , 69 ], these experiments reveal a significant redox dependence of nitrogen behavior and the transition of nitrogen from a highly volatile element to a lithophile or a siderophile element in geological materials; its solubility in mantle minerals and melts [ 67–74 ], its partitioning between minerals, fluids and silicate melts [ 61 , 75–77 ], and its partitioning and isotope fractionation between metallic and silicate melts in planetary magma oceans [ 78–83 ] all depend on redox conditions. These experimental results, when considered alongside observations of natural samples, provide preliminarily constraints on the accretion processes of Earth's nitrogen [ 78 , 81 , 84 ].…”