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Title: Exploring microstructures in lower mantle mineral assemblages with synchrotron x-rays
Understanding dynamics across phase transformations and the spatial distribution of minerals in the lower mantle is crucial for a comprehensive model of the evolution of the Earth’s interior. Using the multigrain crystallography technique (MGC) with synchrotron x-rays at pressures of 30 GPa in a laser-heated diamond anvil cell to study the formation of bridgmanite [(Mg,Fe)SiO 3 ] and ferropericlase [(Mg,Fe)O], we report an interconnected network of a smaller grained ferropericlase, a configuration that has been implicated in slab stagnation and plume deflection in the upper part of the lower mantle. Furthermore, we isolated individual crystal orientations with grain-scale resolution, provide estimates on stress evolutions on the grain scale, and report {110} twinning in an iron-depleted bridgmanite, a mechanism that appears to aid stress relaxation during grain growth and likely contributes to the lack of any appreciable seismic anisotropy in the upper portion of the lower mantle.  more » « less
Award ID(s):
2054951
PAR ID:
10420170
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
Science Advances
Volume:
7
Issue:
1
ISSN:
2375-2548
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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