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Science 11 June 1999:
Vol. 284. no. 5421, pp. 1788 - 1789
DOI: 10.1126/science.284.5421.1788
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Perspectives

Also see the archival list of Science's Compass: Enhanced Perspectives

MANTLE GEOCHEMISTRY:
Enhanced: A Lesson from Ceramics

Alexandra Navrotsky

Understanding the processes in Earth's lower mantle requires detailed knowledge of the composition, phase, and physical properties of the mantle minerals, chiefly magnesium silicates with a perovskite structure. Navrotsky (page 1788) argues that lessons can be learned from ceramic perovskites that have been studied in more detail than the silicate perovskites. A defect formation mechanism involving oxygen vacancy formation, coupled with facile hydration, may be operative in the mantle perovskites, with significant consequences for flow properties and water transport in the lower mantle.

The author is at the Thermochemistry Facility, Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616, USA. E-mail: anavrotsky{at}ucdavis.edu

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THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
High-pressure phase relations and crystal chemistry of calcium ferrite-type solid solutions in the system MgAl2O4-Mg2SiO4.
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Phase transitions of minerals in the transition zone and upper part of the lower mantle.
M. Akaogi (2007)
Geological Society of America Special Papers 421, 1-13
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Effect of water on the phase relations in Earth's mantle and deep water cycle.
K. D. Litasov and E. Ohtani (2007)
Geological Society of America Special Papers 421, 115-156
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Aluminum substitution in stishovite and MgSiO3 perovskite: High-resolution 27Al NMR.
J. F. Stebbins, L.-S. Du, K. Kelsey, H. Kojitani, M. Akaogi, and S. Ono (2006)
American Mineralogist 91, 337-343
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Thermodynamics of Water Solubility and Partitioning.
H. Keppler and N. Bolfan-Casanova (2006)
Reviews in Mineralogy and Geochemistry 62, 193-230
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Water in the Earth's mantle.
N. Bolfan-Casanova (2005)
Mineralogical Magazine 69, 229-257
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Formation of metastable cubic-perovskite in high-pressure phase transformation of Ca(Mg, Fe, Al)Si2O6.
Y. Asahara, E. Ohtani, T. Kondo, T. Kubo, N. Miyajima, T. Nagase, K. Fujino, T. Yagi, and T. Kikegawa (2005)
American Mineralogist 90, 457-462
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Aluminum substitution in MgSiO3 perovskite: Investigation of multiple mechanisms by 27Al NMR.
J. F. Stebbins, H. Kojitani, M. Akaogi, and A. Navrotsky (2003)
American Mineralogist 88, 1161-1164
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Water in Earth's Lower Mantle.
M. Murakami, K. Hirose, H. Yurimoto, S. Nakashima, and N. Takafuji (2002)
Science 295, 1885-1887
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