Natural Sciences > Earth, Atmospheric, and Planetary Sciences > Phase Transitions in the Earth's Interior

Phase Transitions in the Earth's Interior posted by duggu on 1/29/2008

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Abstract/Syllabus

Courseware/Lectures

Test/Tutorials

Course Highlights

This course features assignments and detailed reading list.

Course Description

This course discusses phase transitions in Earth's interior. Phase transitions in Earth materials at high pressures and temperatures cause the seismic discontinuities and affect the convections in the Earth's interior. On the other hand, they enable us to constrain temperature and chemical compositions in the Earth's interior. However, among many known phase transitions in mineral physics, only a few have been investigated in seismology and geodynamics. This course reviews important papers about phase transitions in mantle and core materials.

Syllabus

Prerequisite

Permission of instructor

Overview

Phase transitions in Earth materials at high pressures and temperatures cause the seismic discontinuities and affect the convections in the Earth's interior. On the other hand, they enable us to constrain temperature and chemical compositions in the Earth's interior. However, among many known phase transitions in mineral physics, only a few have been investigated in seismology and geodynamics. This course reviews important papers about phase transitions in mantle and core materials.

The topics include:

Olivine-wadsleyite-ringwoodite, post-spinel, post-garnet, post-ilmenite, post-perovskite, coesite-stishovite, post-stishovite, and tetragonal-cubic Ca-perovskite transitions
Phase transitions in Fe, Fe-Ni, Fe-S, Fe-Si, and Fe-O systems
Melting of silicates and iron alloys
Spin transitions in (Mg, Fe)SiO3 perovskite and magnesiowustite.

This course focuses on physical property changes, depth, and Clapeyron slopes of these transitions and implications for seismology and geodynamics.

Format

This course is structured as a series of student presentations based upon the course topics. Two students give presentations each week. See the assignments section.

Grading

The course grade is based upon class participation, discussions and presentations.

Calendar

Course calendar.
WEEK #	Topics
1	Overview on the Transition Zone
2	Olivine-wadsleyite
3	Implications of the Olivine-wadsleyite Transition
4	Post-spinel Transition
5	Variability in Post-spinel Transition
6	Implications of the Post-spinel Transition
7	Implications of the Post-spinel Transition (cont.)
8	Mid-transition Zone Boundary
9	Relations among Different Phase Transitions and Post-stishovite
10	Post-perovskite
11	D" Discontinuity
12	D" Anisotropy and the Post-perovskite Transition and Spin Transition

Readings

Reading List

Fei, Y., and C. M. Bertka. "Phase transitions in the Earth's mantle and mantle mineralogy." Geochemical Society 6 (1999): 189-207.

Helffrich, G. R. "Topography of the transition zone seismic discontinuities." Reviews in Geophysics 38 (2000): 141-158.

Irifune, T., and M. Isshiki. "Iron partitioning in a pyrolite mantle and the nature of the 410-km seismic discontinuity." Nature 392 (1998): 702-705.

Wood, B. J. "The effect of H2O on the 410-kilometer seismic discontinuity." Science 268 (1995): 74-76.

Smyth, J. R., and D. J. Frost. "The effect of water on the 410-km discontinuity: An experimental study." Geophysical Research Letter 29, 10.1029/2001GL014418 (2002).

Gaherty, J. B., et al. "Testing plausible upper-mantle compositions using fine-scale models of the 410-km discontinuity." Geophysical Research Letter 26 (1999): 1641-1644.

Duffy, T. S., et al. "Elasticity of forsterite to 16 GPa and the composition of the upper mantle." Nature 378 (1996): 170-173.

Lebedev, S., et al. "Seismic evidence for olivine phase changes at the 410- and 660-kilometer discontinuities." Science 296 (2002): 1300-1302.

Shim, S. -H., et al. "The post-spinel transformation in Mg2SiO4 and its relation to the 660-km seismic discontinuity." Nature 411 (2001): 571-574.

Irifune, T., et al. "The postspinel phase boundary in Mg2SiO4 determined by in situ X-ray diffraction." Science 279 (1998): 1698-1700.

Katsura, T., et al. "Post-spinel transition in Mg2SiO4 determined by high P-T in situ X-ray diffractometry." Physics of the Earth and Planetary Interions 136 (2003): 11-24.

Higo, Y., et al. "Effect of water on the spinel-postspinel transformation in Mg2SiO4." Geophysical Research Letter 28 (2001): 3505-3508.

Wood, B. J., and D. C. Ruby. "The effect of alumina on phase transformations at the 660-kilometer discontinuity from Fe-Mg partitioning experiments." Science 273 (1996): 1522-1524.

Shearer, P. M., and M. P. Flanagan. "Seismic velocity and density jumps across the 410- and 660-kilometer discontinuities." Science 285 (1999): 1545-1548.

Tackley, P. J., et al. "Effects of an endothermic phase transition at 670 km depth in a spherical model of convection in the Earth's mantle." Nature 361 (1993): 699-704.

Christensen, U., and D. Yuen. "The interaction of a subducting lithospheric slab with a chemical or phase boundary." Journal of Geophysical Research 89 (1984): 4389-4402.

Deuss, and J. Woodhouse. "Seismic observations of splitting of the mid-transition zone discontinuity in Earth's mantle." Science 294 (2001): 354-357.

Shim, S. -H., et al. "Tetragonal structure of CaSiO3 perovskite above 20 GPa." Geophysical Research Letter 29 (2002): 2166.

Weidner, D. J., and Y. Wang. "Phase transformations: Implications for mantle structure. In Earth's deep interior: mineral physics and tomography from the atomic to the global scale." Geophysical Monograph 117 (2000): 215.

Shieh, S. R., et al. "Strength and elasticity of SiO2 across the stishovite-CaCl2-type structural phase boundary." Physical Review Letters 89 (2002): 255507.

Murakami, M., et al. "Post-perovskite phase transition and mineral chemistry in the pyrolitic lowermost mantle." Geophysical Research Letter 32, no. 3, CiteID L03304 (2005).

Mao, W. L., et al. "Ferromagnesian postperovskite silicates in the D' layer of the Earth." Proceedings of the National Academy of Sciences 101 (2004): 15867-15869.

Sidorin, et al. "Evidence for a ubiquitous seismic discontinuity at the base of the mantle." Science 286 (1999): 1326-1331.

Wysession, et al. "The D' discontinuity and its implications." In The Core-mantle Boundary Region. Edited by M. Gurnis, et al. Washington, DC: American Geophysical Union, 1998.

Stackhouse, S., et al. "The effect of temperature on the seismic anisotropy of the perovskite and post-perovskite polymorphs of MgSiO3." Earth and Planetary Science Letters 230 (2005): 1-10.

Badro, J., et al. "Electronic transitions in perovskite: possible nonconvecting layers in the lower mantle." Science 305 (2004): 383-386.