Ultrahigh-Pressure Acoustic Velocities of Aluminous Silicate Glass up to 155 GPa With Implications for the Structure and Dynamics of the Deep Terrestrial Magma Ocean

Title data

Saha, Pinku ; Murakami, Motohiko ; McCammon, Catherine ; Liebske, Christian ; Krymarys, Ewa:
Ultrahigh-Pressure Acoustic Velocities of Aluminous Silicate Glass up to 155 GPa With Implications for the Structure and Dynamics of the Deep Terrestrial Magma Ocean.
In: Geophysical Research Letters. Vol. 50 (2023) Issue 14 . - e2023GL103614.
ISSN 1944-8007
DOI: https://doi.org/10.1029/2023GL103614

Official URL:

Abstract in another language

Abstract We have carried out in situ high-pressure acoustic velocity measurements of (Fe2+, Al)-bearing MgSiO3 glass up to pressures of 155 GPa, which confirmed a distinct pressure-induced trend change in the transverse acoustic velocity (VS) profile around 98 GPa, likely caused by the Si-O coordination number (CN) change from 6 to 6+. Although it has been reported that the substitution of Fe2+ in MgSiO3 glass induces almost linear velocity reduction up to ∼160 GPa, we revealed that the VS profile of (Fe2+, Al)-bearing MgSiO3 becomes anomalously steeper above ∼100 GPa and eventually came to be equivalent to MgSiO3 glass above ∼125 GPa. This implies the incorporation of Al into Fe-bearing MgSiO3 glass significantly facilitates making it far elastically stiffer and thus the densification under pressures well within the Earth's lower mantle. Our results indicate the possible presence of stiff and highly dense silicate melts in deep MOs in the rocky terrestrial planets.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Additional notes:	e2023GL103614 2023GL103614
Keywords:	terrestrial magma ocean; silicate melt; Brillouin spectroscopy; acoustic velocity; diamond anvil cell; coordination number
Institutions of the University:	Research Institutions > Central research institutes > Bavarian Research Institute of Experimental Geochemistry and Geophysics - BGI
Result of work at the UBT:	Yes
DDC Subjects:	500 Science > 550 Earth sciences, geology
Date Deposited:	17 Oct 2024 07:12
Last Modified:	17 Oct 2024 07:12
URI:	https://eref.uni-bayreuth.de/id/eprint/90724