High-pressure, temperature elasticity of Fe- and Al-bearing MgSiO3: Implications for the Earth's lower mantle

Zhang, Shuai and Cottaar, Sanne and Liu, Tao and Stackhouse, Stephen and Militzer, Burkhard (2016) High-pressure, temperature elasticity of Fe- and Al-bearing MgSiO3: Implications for the Earth's lower mantle. Earth and Planetary Science Letters, 434. pp. 264-273. ISSN 0012-821X DOI 10.1016/j.epsl.2015.11.030

[img]
Preview
Text
1-s2.0-S0012821X15007347-main.pdf

Download (1MB) | Preview
[img]
Preview
Image
1-s2.0-S0012821X15007347-gr001.jpg

Download (114kB) | Preview
[img] Text
mmc1.docx

Download (2MB)
[img] Archive
mmc2.zip

Download (1kB)
[img] Archive
mmc3.zip

Download (1kB)
[img] Archive
mmc4.zip

Download (1kB)
[img] Archive
mmc5.zip

Download (923B)
[img] Archive
mmc6.zip

Download (1kB)
[img] Archive
mmc7.zip

Download (928B)
[img] Archive
mmc8.zip

Download (1kB)
[img] Archive
mmc9.zip

Download (912B)
[img] Archive
mmc10.zip

Download (1kB)
[img] Archive
mmc11.zip

Download (911B)
[img] Archive
mmc12.zip

Download (1kB)
[img] Archive
mmc13.zip

Download (1kB)
[img] Archive
mmc14.zip

Download (1kB)
[img] Archive
mmc15.zip

Download (914B)
[img] Text
mmc16.csv

Download (28kB)
Official URL: http://www.sciencedirect.com/science/article/pii/S...

Abstract

Fe and Al are two of the most important rock-forming elements other than Mg, Si, and O. Their presence in the lower mantle's most abundant minerals, MgSiO3 bridgmanite, MgSiO3 post-perovskite and MgO periclase, alters their elastic properties. However, knowledge on the thermoelasticity of Fe- and Al-bearing MgSiO3 bridgmanite, and post-perovskite is scarce. In this study, we perform ab initio molecular dynamics to calculate the elastic and seismic properties of pure, Fe3+- and Fe2+-, and Al3+-bearing MgSiO3 perovskite and post-perovskite, over a wide range of pressures, temperatures, and Fe/Al compositions. Our results show that a mineral assemblage resembling pyrolite fits a 1D seismological model well, down to, at least, a few hundred kilometers above the core�mantle boundary, i.e. the top of the D � region. In D � , a similar composition is still an excellent fit to the average velocities and fairly approximate to the density. We also implement polycrystal plasticity with a geodynamic model to predict resulting seismic anisotropy, and find post-perovskite with predominant (001) slip across all compositions agrees best with seismic observations in the D � .

Item Type: Article
Uncontrolled Keywords: 2015AREP; IA70; weekly list
Subjects: 02 - Geodynamics, Geophysics and Tectonics
Divisions: 02 - Geodynamics, Geophysics and Tectonics
Journal or Publication Title: Earth and Planetary Science Letters
Volume: 434
Page Range: pp. 264-273
Identification Number: 10.1016/j.epsl.2015.11.030
Depositing User: Sarah Humbert
Date Deposited: 17 Jan 2016 02:57
Last Modified: 16 Feb 2016 12:28
URI: http://eprints.esc.cam.ac.uk/id/eprint/3545

Actions (login required)

View Item View Item

About cookies