LINK<\/strong><\/a><\/p>\n\n\n\n“Evolution of nitrogen (N), a life-essential volatile element, in highly reduced magmatic systems is a key for the origin of N on rocky planets formed via accretion of reduced chondritic parent body materials, planetesimals, and embryos that underwent partial or complete differentiation. However, the storage capacity of N in phases relevant for reduced silicate systems undergoing thermal processing is poorly known. To investigate the stability of N-bearing phases in partially molten silicate-rich systems as well as solubility of nitrogen in silicate melts and minerals, we performed laboratory experiments on a 80:20 synthetic basalt-Si3N4 mixture at 1.5-3.0 GPa and 1300-1600 \u00b0C in graphite capsules, yielding oxygen fugacity ranging from \u223cIW\u2013 3.0 to \u223cIW \u2013 4.0. All experiments produced silicate melt + nierite + Fe-rich alloy melt + N-rich vapor \u00b1 sinoite \u00b1 cpx. Sinoite was restricted to above while cpx was restricted below 1400-1500 \u00b0C. Nitrogen solubility and Nitrogen Concentration at Silicon-Nitride Saturation (NCNS) in silicate melts increases with increasing pressure and temperature and ranges between 3.6 and 9.5 wt %. Using our high pressure N solubility data and similar data at ambient and lower pressures, we derived a new N solubility model in silicate melts. Solubility of nitrogen in cpx was between 1.51 and 2.05 wt% and resulted in cpx\/silicate melt partition coefficients for nitrogen, of D epx\/silicatemelt\/N \u223c0.4 to \u223c0.2. These D epx\/silicatemelt\/N are distinctly higher than those previously estimated at more oxidizing conditions, suggesting N maybe much less incompatible during thermal processing of rocky reservoirs at highly reducing conditions. Partition coefficient of N between Fe-rich alloy melt and cpx, D Fe\/richalloymelt\/epx\/N was found to be between 1.6 and 2.1. The application of our N solubility data and model suggests that mobilization of N from the deeper, partially molten reservoirs to shallower reservoirs is possible in reduced planetesimals and internally differentiated meteorite parent bodies \u2013 leading to net loss of N via melt degassing or reprecipitation of N-bearing solid phases, depending on whether the surficial shell is oxidized or reduced, respectively. Similarly, comparison of the first measured D epx\/silicatemelt\/N values from our highly reducing experiments with those estimated at more oxidizing conditions suggest that N would be much less incompatible during internal and external magma ocean processing of rocky bodies under highly reducing conditions. Therefore, enrichment of N in the atmospheres of Earth and Venus is likely a result of more oxidizing penultimate phase of accretion, which would lead to N being more readily partitioned to residual liquid, which would also more readily degas at oxidizing conditions.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Rajdeep Dasgupta, Emily Falksen, Aindrila Pal, Chenguang Sun Geochimica et Cosmochimica ActaAvailable online 23 September 2022 LINK “Evolution of nitrogen (N), a life-essential volatile element, in highly reduced magmatic systems is a key for the…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[74,28,38,17,137,73],"tags":[3514,1826,1813,2336,654,1761,257,1206],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31298"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=31298"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31298\/revisions"}],"predecessor-version":[{"id":31299,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31298\/revisions\/31299"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=31298"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=31298"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=31298"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}