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Published March 16, 2017 | Version Published
Journal Article Open

Sound velocity and density of magnesiowüstites: Implications for ultralow-velocity zone topography

Creators

  • 1. ROR icon California Institute of Technology
  • 2. ROR icon Princeton University
  • 3. ROR icon University of Hawaii at Manoa

Abstract

We explore the effect of Mg/Fe substitution on the sound velocities of iron-rich (Mg_(1 – x)Fe_x)O, where x = 0.84, 0.94, and 1.0. Sound velocities were determined using nuclear resonance inelastic X-ray scattering as a function of pressure, approaching those of the lowermost mantle. The systematics of cation substitution in the Fe-rich limit has the potential to play an important role in the interpretation of seismic observations of the core-mantle boundary. By determining a relationship between sound velocity, density, and composition of (Mg,Fe)O, this study explores the potential constraints on ultralow-velocity zones at the core-mantle boundary.

Additional Information

© 2017 American Geophysical Union. Received 15 SEP 2016; Accepted 31 JAN 2017; Accepted article online 2 FEB 2017; Published online 4 MAR 2017. We thank D.J. Bower and D.V. Helmberger for fruitful discussions. We thank E.E. Alp, T.S. Toellner, and J. Zhao for their assistance at Sector 3; V. Prakapenka at GSECARS; and J. Knight at the ALS. We are thankful to NSF-EAR-CAREER-0956166, NSF-CSEDI-EAR-1161046 for support of this research and to two anonymous reviewers for their thoughtful suggestions. Operations at Sector 3 (APS) and beamline 12.2.2 (ALS) are partially supported by COMPRES. FeO X-ray diffraction measurements were conducted at GSECARS (Sector 13, APS), supported by NSF EAR-1128799 and U.S. DOE, Geosciences (DE-FG02-94ER14466). Use of the APS is supported by the U.S. DOE, Office of Science (DE-AC02-06CH11357) and ALS by the U.S. DOE, Office of Science (DE-AC02-05CH11231). Original data corresponding to those shown in figures and tables are available upon request from the authors.

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Additional details

Identifiers

Eprint ID
74404
Resolver ID
CaltechAUTHORS:20170217-131316177

Funding

NSF
EAR-0956166
NSF
EAR-1161046
COMPRES
NSF
EAR-1128799
Department of Energy (DOE)
DE-FG02-94ER14466
Department of Energy (DOE)
DE-AC02-06CH11357
Department of Energy (DOE)
DE-AC02-05CH11231

Dates

Created
2017-02-24
Created from EPrint's datestamp field
Updated
2021-11-11
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Seismological Laboratory, Division of Geological and Planetary Sciences (GPS)