Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5783282 | Geochimica et Cosmochimica Acta | 2017 | 25 Pages |
Abstract
Overall, we present thermodynamic evidence for nitrogen to be reconsidered as an extremely dynamic (chameleon) element whose speciation and therefore behavior is determined by a combination of temperature, pressure, oxygen fugacity, chemical activity, and pH. We show that altering the mineralogy in equilibrium with the fluid can lead to a pH shift of up to 4 units at 5 GPa and 1000 °C. Therefore, we conclude that pH imparts a strong control on nitrogen speciation, and thus N flux, and should be considered a significant factor in high temperature geochemical modeling in the future. Finally, our modelling demonstrates that pH plays an important role in controlling speciation, and thus mass transport, of Eh-pH sensitive elements at temperatures up to at least 1000 °C.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geochemistry and Petrology
Authors
Sami Mikhail, Peter H. Barry, Dimitri A. Sverjensky,