Back to Search Start Over

The Effect of Pulsed Laser Heating on the Stability of Ferropericlase at High Pressures

Authors :
Georgios Aprilis
Anna Pakhomova
Stella Chariton
Saiana Khandarkhaeva
Caterina Melai
Elena Bykova
Maxim Bykov
Timofey Fedotenko
Egor Koemets
Catherine McCammon
Aleksandr I. Chumakov
Michael Hanfland
Natalia Dubrovinskaia
Leonid Dubrovinsky
Source :
Minerals, Vol 10, Iss 6, p 542 (2020)
Publication Year :
2020
Publisher :
MDPI AG, 2020.

Abstract

It is widely accepted that the lower mantle consists of mainly three major minerals—ferropericlase, bridgmanite and calcium silicate perovskite. Ferropericlase ((Mg,Fe)O) is the second most abundant of the three, comprising approximately 16–20 wt% of the lower mantle. The stability of ferropericlase at conditions of the lowermost mantle has been highly investigated, with controversial results. Amongst other reasons, the experimental conditions during laser heating (such as duration and achieved temperature) have been suggested as a possible explanation for the discrepancy. In this study, we investigate the effect of pulsed laser heating on the stability of ferropericlase, with a geochemically relevant composition of Mg0.76Fe0.24O (Fp24) at pressure conditions corresponding to the upper part of the lower mantle and at a wide temperature range. We report on the decomposition of Fp24 with the formation of a high-pressure (Mg,Fe)3O4 phase with CaTi2O4-type structure, as well as the dissociation of Fp24 into Fe-rich and Mg-rich phases induced by pulsed laser heating. Our results provide further arguments that the chemical composition of the lower mantle is more complex than initially thought, and that the compositional inhomogeneity is not only a characteristic of the lowermost part, but includes depths as shallow as below the transition zone.

Details

Language :
English
ISSN :
2075163X
Volume :
10
Issue :
6
Database :
Directory of Open Access Journals
Journal :
Minerals
Publication Type :
Academic Journal
Accession number :
edsdoj.298db0c27a584dc4b54deb5d01493c57
Document Type :
article
Full Text :
https://doi.org/10.3390/min10060542