In situ X-ray diffraction of silicate liquids and glasses under dynamic and static compression to megabar pressures - Université Clermont Auvergne Accéder directement au contenu
Article Dans Une Revue Proceedings of the National Academy of Sciences of the United States of America Année : 2020

In situ X-ray diffraction of silicate liquids and glasses under dynamic and static compression to megabar pressures

Denis Andrault

Résumé

Properties of liquid silicates under high pressure and high temperature conditions are critical for modeling the dynamics and solidification mechanisms of the magma ocean in the early Earth, as well as for constraining entrainment of melts in the mantle and in the present-day core-mantle boundary. Here, we present in situ structural measurements by X-ray diffraction of selected amorphous silicates compressed statically in diamond anvil cells (up to 157 GPa at room temperature) or dynamically by laser-generated shock compression (up to 130 GPa and 6000 K along the MgSiO3 glass Hugoniot). The X-ray diffraction patterns of silicate glasses and liquids reveal similar characteristics over a wide pressure and temperature range. Beyond the increase in Si coordination observed at 20 GPa, we find no evidence for major structural changes occurring in the silicate melts studied up to pressures and temperatures exceeding Earth's core mantle boundary conditions. This result is supported by molecular dynamics calculations. Our findings reinforce the widely-used assumption that the silicate glasses studies are appropriate structural analogs for understanding the atomic arrangement of silicate liquids at these high pressures.
Fichier principal
Vignette du fichier
2019-20470RRR_Merged_PDF-1.pdf (646.68 Ko) Télécharger le fichier
SI Appendix_AKS.pdf (1.04 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-02668606 , version 1 (31-05-2020)

Identifiants

Citer

Guillaume Morard, Jean-Alexis Hernandez, Marco Guarguaglini, Riccardo Bolis, Alessandra Benuzzi-Mounaix, et al.. In situ X-ray diffraction of silicate liquids and glasses under dynamic and static compression to megabar pressures. Proceedings of the National Academy of Sciences of the United States of America, 2020, 117 (22), pp.11981-11986. ⟨10.1073/pnas.1920470117⟩. ⟨hal-02668606⟩
311 Consultations
207 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More