Skip to Main content Skip to Navigation
Theses

Solubilité, spéciation et diffusion de l'azote dans les verres et silicates fondus

Abstract : Nitrogen (N) belongs to the volatile elements (like hydrogen and carbon) that are essential for life on Earth. The behavior of N during high temperature geological processes, such as during magmatic processes, remains poorly understood. This study focuses on N solubility, speciation, and diffusion in silicate glasses and melts to better understand the N behavior during these processes. N solubility in silicate melts was studied for different melt compositions and for a wide range of fO₂ (IW –8 to IW +4.1) at 1425°C and 1 atm. The data obtained highlight the fundamental control of fO₂ and the degree of polymerization of the silicate melt on N solubility. These new data suggest that a mafic to ultra-mafic magma ocean could have incorporated a similar or higher amount of N compared to the actual bulk silicate Earth, suggesting that N may have been to the atmosphere and/or stored in Earth's deep interior (i.e., deep mantle, core). For the study of N diffusion in silicate glasses and melts, experimental and analytical developments were necessary. The first diffusion coefficient of N (as N³⁻) in silicate melts was determined from uni-axial diffusion experiments in a basaltic andesitic melt (4.2 × 10⁻⁸ cm².s⁻¹). The data highlight that N³⁻ diffusivity depends on melt composition. This dependence on the melt composition is more important than that of argon (Ar). Furthermore, N³⁻ diffusion is significantly slower than that of Ar in similar silicate melts, implying that N/Ar ratios can be fractionated during reducing magmatic processes (e.g., during Earth's magma ocean stage).
Document type :
Theses
Complete list of metadata

https://hal.univ-lorraine.fr/tel-03274674
Contributor : Thèses Ul <>
Submitted on : Wednesday, June 30, 2021 - 12:41:23 PM
Last modification on : Thursday, July 1, 2021 - 3:25:09 AM

File

DDOC_T_2020_0254_BOULLIUNG.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-03274674, version 1

Citation

Julien Boulliung. Solubilité, spéciation et diffusion de l'azote dans les verres et silicates fondus. Géochimie. Université de Lorraine, 2020. Français. ⟨NNT : 2020LORR0254⟩. ⟨tel-03274674⟩

Share

Metrics

Record views

40

Files downloads

40