Back to Search Start Over

Mg-sursassite thermo-elastic parameters and its relevance as a water carrier in subducting slabs

Authors :
Milani S.
Fumagalli P.
Ziberna L.
Maurice J.
Lotti L.
Comboni D.
Pagliaro F.
Hanfland M.
Bais G.
Joseph B.
Merlini M.
Milani, S.
Fumagalli, P.
Ziberna, L.
Maurice, J.
Lotti, L.
Comboni, D.
Pagliaro, F.
Hanfland, M.
Bais, G.
Joseph, B.
Merlini, M.

Abstract

We report the synthesis, at 7 GPa and 923 K, and the thermoelastic characterization, up to 16 GPa and 850 K, of single crystal of Mg-sursassite, Mg5Al5Si6O21(OH)7. In-situ high-pressure and high-temperature single crystal diffraction allowed the study of structural variation at non-ambient conditions and the determination of bulk elastic properties. The refined parameters of a second order Birch-Murnagham Equation of State (BM-II EoS) are V0= 446.02(1) Å3 and KT0 = 135.6(7) GPa. The thermal expansion coefficients of a Berman-type EoS are α0=3.14 (5) x 10-5 K-1, α1=2.50(16) x 10-8 K-2 and V0=445.94(3). For comparison, the P-V Equation of State is determined for a natural sursassite sample, ideally Mn4Al6Si6O22(OH)6. The refined parameters of BM-II EoS (V0 = 470.2(3) Å3, KT0=128(4) GPa) indicate that composition has a minimal effect on elastic properties. The similarity of density and bulk properties of Mg-sursassite if compared to olivine and other anhydrous mantle minerals suggests that this phase could be overseen by geophysical methods.

Details

Language :
English
Database :
OpenAIRE
Accession number :
edsair.dris...01099..249e8f32118b6ca303f24f2a14f6ecba