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Sound velocities and elasticity of aluminous MgSiO_3 perovskite: Implications for aluminum heterogeneity in Earth's lower mantle

Jackson, Jennifer M. and Zhang, Jianzhong and Bass, Jay D. (2004) Sound velocities and elasticity of aluminous MgSiO_3 perovskite: Implications for aluminum heterogeneity in Earth's lower mantle. Geophysical Research Letters, 31 (10). Art. No. L10614. ISSN 0094-8276. https://resolver.caltech.edu/CaltechAUTHORS:20130501-155506457

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Abstract

Aluminum has been reported to have a remarkably strong effect on the thermoelastic properties of MgSiO_3 perovskite. However, the sound velocities of aluminous MgSiO_3 perovskite have not been previously measured, even though this phase likely dominates most of the chemistry in Earth's lower mantle. Here we report the first sound velocity measurements on aluminous MgSiO_3 perovskite using Brillouin spectroscopy and obtain the following values for the room-pressure room-temperature adiabatic bulk and shear moduli: K_S = 252 ± 5 GPa and μ = 165 ± 2 GPa, respectively. The presence of 5.1 ± 0.2 wt.% Al_(2)O_3 in MgSiO_3 perovskite decreases the shear modulus by 5.6%. However, within experimental uncertainties, there is no discernable effect of aluminum on the bulk modulus. We find that variations in the aluminum content of MgSiO_3 perovskite may provide an explanation for some observed lateral heterogeneity in Earth's lower mantle.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1029/2004GL019918DOIArticle
http://onlinelibrary.wiley.com/doi/10.1029/2004GL019918/abstractPublisherArticle
ORCID:
AuthorORCID
Jackson, Jennifer M.0000-0002-8256-6336
Additional Information:© 2004 American Geophysical Union. Received 8 March 2004; revised 12 April 2004; accepted 19 April 2004; published 27 May 2004. We are grateful to Ian Steele for the microprobe analyses and to Wolfgang Sturhahn, Ian Steele, S. V. Sinogeikin, and I. Daniel for helpful discussions. This research was supported by NSF grant EAR 0003383 and 0135642. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
Group:Seismological Laboratory
Funders:
Funding AgencyGrant Number
NSFEAR-0003383
NSFEAR-0135642
Subject Keywords:Index terms: 3909 Mineral Physics: Elasticity and anelasticity; 3919 Mineral Physics: Equations of state; 5102 Physical Properties of Rocks: Acoustic properties; 8124 Tectonophysics: Earth’s interior—composition and state (1212).
Issue or Number:10
Record Number:CaltechAUTHORS:20130501-155506457
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20130501-155506457
Official Citation:Jackson, J. M., J. Zhang, and J. D. Bass (2004), Sound velocities and elasticity of aluminous MgSiO3 perovskite: Implications for aluminum heterogeneity in Earth's lower mantle, Geophys. Res. Lett., 31, L10614, doi:10.1029/2004GL019918.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:38220
Collection:CaltechAUTHORS
Deposited By: Jason Perez
Deposited On:01 May 2013 23:15
Last Modified:24 Jan 2020 18:45

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