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Title: Strongly Anisotropic Magnesiowüstite in Earth's Lower Mantle

Here, the juxtaposition of a liquid iron-dominant alloy against a mixture of silicate and oxide minerals at Earth’s core–mantle boundary is associated with a wide range of complex seismological features. One category of observed structures is ultralow-velocity zones, which are thought to correspond to either aggregates of partially molten material or solid, iron-enriched assemblages. We measured the phonon dispersion relations of (Mg,Fe)O magnesiowüstite containing 76 mol% FeO, a candidate ultralow-velocity zone phase, at high pressures using high energy-resolution inelastic x-ray scattering. From these measurements, we find that magnesiowüstite becomes strongly elastically anisotropic with increasing pressure, potentially contributing to a significant proportion of seismic anisotropy detected near the base of the mantle.
Authors:
ORCiD logo [1] ; ORCiD logo [2] ;  [3] ; ORCiD logo [3] ;  [4] ; ORCiD logo [2] ;  [3]
  1. California Inst. of Technology (CalTech), Pasadena, CA (United States); Univ. of Hawai'i at Manoa, Honolulu, HI (United States)
  2. California Inst. of Technology (CalTech), Pasadena, CA (United States)
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
  4. Argonne National Lab. (ANL), Argonne, IL (United States); Miami Univ., Oxford, OH (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357; FG02-94ER14466; 1161046; 1600956; 1128799
Type:
Accepted Manuscript
Journal Name:
Journal of Geophysical Research. Solid Earth
Additional Journal Information:
Journal Volume: 123; Journal Issue: 6; Journal ID: ISSN 2169-9313
Publisher:
American Geophysical Union
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
National Science Foundation (NSF); Consortium for Materials Properties Research in Earth Sciences (COMPRES); USDOE
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; magnesiowüstite; high pressure; inelastic X‐ray scattering; elasticity; elastic anisotropy; periclase
OSTI Identifier:
1472128
Alternate Identifier(s):
OSTI ID: 1454624

Finkelstein, Gregory J., Jackson, Jennifer M., Said, Ayman, Alatas, Ahmet, Leu, Bogdan M., Sturhahn, Wolfgang, and Toellner, Thomas S.. Strongly Anisotropic Magnesiowüstite in Earth's Lower Mantle. United States: N. p., Web. doi:10.1029/2017JB015349.
Finkelstein, Gregory J., Jackson, Jennifer M., Said, Ayman, Alatas, Ahmet, Leu, Bogdan M., Sturhahn, Wolfgang, & Toellner, Thomas S.. Strongly Anisotropic Magnesiowüstite in Earth's Lower Mantle. United States. doi:10.1029/2017JB015349.
Finkelstein, Gregory J., Jackson, Jennifer M., Said, Ayman, Alatas, Ahmet, Leu, Bogdan M., Sturhahn, Wolfgang, and Toellner, Thomas S.. 2018. "Strongly Anisotropic Magnesiowüstite in Earth's Lower Mantle". United States. doi:10.1029/2017JB015349.
@article{osti_1472128,
title = {Strongly Anisotropic Magnesiowüstite in Earth's Lower Mantle},
author = {Finkelstein, Gregory J. and Jackson, Jennifer M. and Said, Ayman and Alatas, Ahmet and Leu, Bogdan M. and Sturhahn, Wolfgang and Toellner, Thomas S.},
abstractNote = {Here, the juxtaposition of a liquid iron-dominant alloy against a mixture of silicate and oxide minerals at Earth’s core–mantle boundary is associated with a wide range of complex seismological features. One category of observed structures is ultralow-velocity zones, which are thought to correspond to either aggregates of partially molten material or solid, iron-enriched assemblages. We measured the phonon dispersion relations of (Mg,Fe)O magnesiowüstite containing 76 mol% FeO, a candidate ultralow-velocity zone phase, at high pressures using high energy-resolution inelastic x-ray scattering. From these measurements, we find that magnesiowüstite becomes strongly elastically anisotropic with increasing pressure, potentially contributing to a significant proportion of seismic anisotropy detected near the base of the mantle.},
doi = {10.1029/2017JB015349},
journal = {Journal of Geophysical Research. Solid Earth},
number = 6,
volume = 123,
place = {United States},
year = {2018},
month = {5}
}