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New windows on earth and planetary interiors

Published online by Cambridge University Press:  05 July 2018

R. J. Hemley  and
H. K. Mao
R. J. Hemley*
Affiliation:
Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road, NW, Washington, D.C. 20015, USA
H. K. Mao
Affiliation:
Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road, NW, Washington, D.C. 20015, USA
*
*E-mail: [email protected]
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Abstract

Recent diamond-anvil cell experiments are providing windows of unprecedented clarity on the interiors of the Earth, other planets, and their moons from high P-T studies of the materials that comprise these bodies. With recent advances in techniques, the component minerals can be examined with a growing array of in situ methods over an expanding range of conditions that extend to hundreds of gigaspascals in pressure and thousands of degrees in temperature. Such investigations reveal that major, if not profound, changes in physical and chemical properties of these materials occur with depth. This information is crucial for understanding the materials basis of regional to global structure and processes documented by a wealth of recent observational and geophysical data. This paper reviews selected recent studies of major planet-forming minerals, focusing on key examples that illustrate different microscopic origins of macroscopic behaviour. This comparative mineralogical approach provides insight into phenomena occurring over a wide range of length scales. For terrestrial planets, the high-pressure behaviour of representative silicates, oxides and sulphides is examined. This includes the silicate perovskite assemblages that form the bulk of the Earth's lower mantle, for which a number of new findings concerning effects of non-stoichiometry and defect properties, pressure-induced electronic and magnetic transitions, and rheology have been obtained. High P-T studies of Fe-Ni alloys, together with various light elements, provide constraints on the composition, structure and dynamics of terrestrial planet cores. Water is a key component of many planetary bodies; as ice it undergoes numerous high-pressure transformations and as a volatile component it is involved in potentially important high P-T mineral reactions and is incorporated in dense mineral phases. Striking behaviour is observed in other molecular systems, including CO2 and CH4 and their mixtures with H2O; these form new phases, some relevant at the relatively modest conditions of deep marine sediments, others at the extreme states found in the deepest planetary interiors. Additional high P-T interactions between rare gases and ices and silicates are also documented. For the large planets, the most abundant ‘mineral’ is hydrogen, which has been shown to undergo novel mineral/gas reactions, possibly in cloud decks deep within the dense atmospheres of these bodies.

Keywords

diamond anvilultra-high pressurelower mantlecoreplanetary coresvolatiles
Type
Research Article
Information
Mineralogical Magazine , Volume 66 , Issue 5 , October 2002 , pp. 791 - 811
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2002

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References

Alfè, D., Kresse, G. and Gillan, M.J. (2000) Structure and dynamics of liquid iron under Earth's core conditions. Physical Review B, 61, 132–142.CrossRefGoogle Scholar
Ancilotto, F., Chiarotti, G.L., Scandolo, S. and Tosatti, E. (1997) Dissociation of methane into hydrocarbons at extreme (planetary) pressure and temperature. Science, 275, 1288–1290.CrossRefGoogle ScholarPubMed
Anderson, O.L., Isaak, D.G. and Yamamoto, S. (1989) Anharmonicity and the equation of state for gold. Journal of Applied Physics, 65, 1534–1543.CrossRefGoogle Scholar
Andrault, D., Fiquet, G., Guyot, F. and Hanfland, M. (1998) Pressure-induced Landau-type transition in stishovite. Science, 282, 720–724.CrossRefGoogle ScholarPubMed
Andrault, D., Bolfan-Casanova, N. and Guignot, N. (2001) Equation of state of lower mantle (Al,Fe)- MgSiO3 perovskite. Earth and Planetary Science Letters, 193, 501–508.CrossRefGoogle Scholar
Aoki, K., Yamawaki, H., Sakashita, M. and Fujihisa, H. (1996) Infrared absorption study of the hydrogen-bond symmetrization in ice to 110 GPa. Physical Review B, 54(22), 15,673–15,677.CrossRefGoogle ScholarPubMed
Badro, J., Struzhkin, V.V., Shu, J., Hemley, R.J., Mao, H.K., Kao, C.C., Rueff, J.P. and Shen, G. (1999) Magnetism in FeO at megabar pressures from X-ray emission spectroscopy. Physical Review Letters, 83, 4101–4104.CrossRefGoogle Scholar
Badro, J., Struzhkin, V.V., Goncharov, A.F., Hemley, R.J. and Mao, H.K. (in prep.).Google Scholar
Benedetti, L.R., Nguyen, J.H., Caldwell, W.A., Liu, H., Kruger, M. and Jeanloz, R. (1999) Dissociation of CH4 at high pressures and temperatures: diamond formation in giant planet interiors? Science, 286, 100–102.CrossRefGoogle ScholarPubMed
Bina, C.R. and Navrotsky, A. (2000) Possible presence of high-pressure ice in cold subducting slabs. Nature, 408, 844–847.CrossRefGoogle ScholarPubMed
Boehler, R. (1996) Melting temperature of the Earth's mantle and core: Earth's thermal structure. Annual Review of Earth and Planetary Sciences, 24, 15–40.CrossRefGoogle Scholar
Boss, A.P. (in press) Formation of gas and ice giant planets. Earth and Planetary Science Letters.Google Scholar
Brodholt, J.P. (2000) Pressure-induced changes in the compression mechanism of aluminous perovskite in the Earth's mantle. Nature, 407, 620–622.CrossRefGoogle ScholarPubMed
Brown, J.M., Fritz, J.N. and Hixson, R.S. (2000) Hugoniot data for iron. Journal of Applied Physics, 88, 5496–5498.CrossRefGoogle Scholar
Buffett, B.A. (2000) Dynamics of the Earth's core. Pp. 37–62 in: Earth's Deep Interior: Mineral Physics and Tomography from the Atomic to the Global Scale (Karato, S.-i., Forte, A.M., Liebermann, R.C., Masters, G. and Stixrude, L., editors). American Geophysical Union, Washington, D.C.CrossRefGoogle Scholar
Carpenter, M.A., Hemley, R.J. and Mao, H.K. (2000) High-pressure elasticity of stishovite and the P42/mnm → Pnnm phase transition. Journal of Geophysical Research, 105, 10807–10816.CrossRefGoogle Scholar
Cavazzoni, C., Chiarotti, G.L., Scandolo, S., Tosatti, E., Bernasconi, M. and Parrinello, M. (1999) Superionic and metallic states of water and ammonia at giant planet conditions. Science, 283, 44–46.CrossRefGoogle ScholarPubMed
Chou, I.-M., Blank, J., Goncharov, A.F., Mao, H.K. and Hemley, R.J. (1998) In situ observations of a high-pressure phase of H2O ice. Science, 281, 809–812.CrossRefGoogle ScholarPubMed
Chou, I.M., Sharma, A., Burruss, R.C., Shu, J., Mao, H.K., Hemley, R.J., Goncharov, A.F., Stern, L.A. and Kirby, S.H. (2000) Transformations in methane hydrates. Proceedings of the National Academy of Sciences, 97, 13484–13487.CrossRefGoogle ScholarPubMed
Chudinovskikh, L. and Boehler, R. (2001) High-pressure polymorphs of olivine and the 660-km discontinuity. Nature, 411, 574–577.CrossRefGoogle ScholarPubMed
Cohen, R.E., Mazin, I.I. and Isaak, D.G. (1997) Magnetic collapse in transition metal oxides at high pressure: implications for the Earth. Science, 275, 654–657.CrossRefGoogle ScholarPubMed
Collins, G.W., DaSilva, L.B., Celliers, P., Gold, D., Foord, M., Wallace, R.J., Ng, A., Weber, S.V., Budil, K.S. and Cauble, R. (1998) Measurements of the equation of state of deuterium at the fluid insulator-metal transition. Science, 281, 1178–1181.CrossRefGoogle ScholarPubMed
Conrad, P.G., Hemley, R.J., Mao, H.K., Hu, J., Shu, J., Finger, L.W. and Harte, B. (1997) In situ identification of crystalline inclusions in natural diamonds with synchrotron micro X-ray diffraction. Eos Transactions of the American Geophysical Union, 77, F7774.Google Scholar
Datchi, F., Loubeyre, P., LeToullec, R., Goncharov, A.F., Hemley, R.J. and Mao, H.K. (1996) Synchrotron Infrared spectroscopy of Ar(H2)2 to 220 GPa. Bulletin of the American Physical Society, 41, 564.Google Scholar
Datchi, F., Loubeyre, P. and LeToullec, R. (2000) Extended and accurate determination of the melting curves of argon, helium, ice (H2O), and hydrogen (H2). Physical Review B, 61, 6535–6546.CrossRefGoogle Scholar
Dera, P., Prewitt, C.T., Boctor, N. and Hemley, R.J. (2002) Characterization of a high-pressure phase of silica from the Martian meteorite Shergotty. American Mineralogist, 87, 1018–1023.CrossRefGoogle Scholar
Dong, J., Tomfohr, J.K. and Sankey, O.F. (2000) Non-molecular carbon dioxide (CO2) solids. Science, 287, 11a.CrossRefGoogle Scholar
Dubrovinsky, L.S., Dubrovinskaia, N.A., Saxena, S.K., Tutti, F., Rekhi, S., Le Bihan, T., Shen, G. and Hu, J. (2001) Pressure-induced transformations of cristobalite. Chemical Physics Letters, 333, 264–270.CrossRefGoogle Scholar
Duffy, T.S. and Ahrens, T.J. (1995) Compressional sound velocity, equation of state, and constitutive response of shock-compressed magnesium oxide. Journal of Geophysical Research, 100, 529–542.CrossRefGoogle Scholar
Duffy, T.S. and Hemley, R.J. (1995) Temperature structure of the Earth. Reviews in Geophysics (US National Report to IUGG), 5-9.CrossRefGoogle Scholar
Duffy, T.S., Hemley, R.J. and Mao, H.K. (1995) Equation of state and shear strength at multimegabar pressures: Magnesium oxide to 227 GPa. Physical Review Letters, 74, 1371–1374.CrossRefGoogle ScholarPubMed
Fiquet, G., Andrault, D., Itie, J.P., Gillet, P. and Richet, P. (1996) X-ray diffraction of periclase in a laser-heated diamond-anvil cell. Physics of the Earth and Planetary Interiors, 95, 1–17.CrossRefGoogle Scholar
Fiquet, G., Badro, J., Guyot, F., Requardt, H. and Krisch, M. (2001) Sound velocities in iron to 110 gigapascals. Science, 291, 468–471.CrossRefGoogle ScholarPubMed
Goncharov, A.F., Struzhkin, V.V., Somayazulu, M., Hemley, R.J. and Mao, H.K. (1996) Compression of ice to 210 GPa: Evidence for a symmetric hydrogen bonded phase. Science, 273, 218–220.CrossRefGoogle Scholar
Goncharov, A.F., Gregoryanz, E., Hemley, R.J. and Mao, H.K. (2001) Spectroscopic studies of the vibrational and electronic properties of solid hydrogen to 285 GPa. Proceedings of the National Academy of Sciences, 98, 14234–14237.CrossRefGoogle ScholarPubMed
Goncharov, A.F., Struzhkin, V.V., Hemley, R.J., Mao, H.K. and Liu, Z. (2000) Advances in optical spectroscopy at multimegabar pressures. Pp. 90–95 in: Science and Technology of High Pressure (Manghnani, M.H., Nellis, W.J. and Nicol, M., editors). Universities Press, Hyderabad, India.Google Scholar
Goncharov, A.F., Struzhkin, V.V., Hemley, R.J., Mao, H.K. and Boctor, N. (in press) Raman scattering of metals at very high pressures. In High-Pressure Phenomena, Proceedings of the International School of Physics ‘Enrico Fermi’ (Hemley, R.J., Bernasconi, M., Ulivi, L. and Chiarotti, G., editors). IOS Press, Amsterdam.Google Scholar
Guthrie, M., Nelmes, R.J., Loveday, J., Mao, H.K., Xu, J., Hemley, R.J., Somayazulu, M., Klotz, S., Hamel, G., Keen, D.A., Francis, D.J. and Marshall, W.G. (2001) Recent advances in single-crystal neutron diffraction. Program of the International Workshop on Crystallography, Orsay, September 4–8, p. 85.Google Scholar
Heinz, D.L. (1990) Thermal pressure in the laser-heated diamond anvil cell. Geophysics Research Letters, 17, 1161–1164.CrossRefGoogle Scholar
Hemley, R.J. and Cohen, R.E. (1992) Silicate perovskite. Annual Review of Earth and Planetary Science, 20, 553–600.CrossRefGoogle Scholar
Hemley, R.J., Mao, H.K., Shen, G., Badro, J., Gillet, P., Hanfland, M. and Häusermann, D. (1997) X-ray imaging of stress and strain of diamond, iron, and tungsten at megabar pressures. Science, 276, 1242–1245.CrossRefGoogle Scholar
Hemley, R.J. and Mao, H.K. (1998) Static compression experiments on low-Z planetary materials. Pp. 173–183 in: Properties of the Earth and Planetary Materials at High Pressure and Temperature (Yagi, T., editor). American Geophysical Union, Washington, D.C.CrossRefGoogle Scholar
Hemley, R.J. and Mao, H.K. (2001) In situ studies of iron under pressure: new windows on the Earth's core. International Geology Review, 43, 1–30.Google Scholar
Hemley, R.J., Goncharov, A.F., Lu, R., Li, M., Struzhkin, V.V. and Mao, H.K. (1998 a) High-pressure synchrotron infrared spectroscopy at the National Synchrotron Light Source. II Nuovo Cimento D, 20, 539–551.CrossRefGoogle Scholar
Hemley, R.J., Mao, H.K. and Cohen, R.E. (1998 b) High-pressure electronic and magnetic properties of minerals. Pp. 591–638 in: Ultrahigh-Pressure Mineralogy (Hemley, R.J., editor). Reviews in Mineralogy, 37. Mineralogical Society of America, Washington, D.C.CrossRefGoogle Scholar
Hemley, R.J., Shu, J., Carpenter, M.A., Hu, J., Mao, H.K. and Kingma, K.J. (2000) Strain/order parameter coupling in the ferroelastic transition in dense SiO2 . Solid State Communications, 114, 527–532.CrossRefGoogle Scholar
Hemley, R.J., Eremets, M.I. and Mao, H.K. (2002) Progress in experimental studies of insulator-metal transitions at multimegabar pressures. Pp. 201–216 in: Frontiers of High Pressure Research II (Hochheimer, H.D., Kuchta, B., Dorhout, P.K. and Yarger, J.L., editors). Kluwer, Amsterdam.Google Scholar
Hirose, K., Fei, Y., Ma, Y. and Mao, H.K. (1999) Fate of subducted basaltic crust in the lower mantle. Nature, 397, 53–56.CrossRefGoogle Scholar
Hirose, K., Fei, Y., Ono, S., Yagi, T. and Funakoshi, K. (2001) In situ measurements of the phase transition boundary in Mg3Al2Si3O12: implications for the nature of the seismic discontinuities in the Earth's mantle. Earth and Planetary Science Letters, 184, 567–573.CrossRefGoogle Scholar
Hubbard, W.B. (1997) Neptune's deep chemistry. Science, 275, 1279–1280.CrossRefGoogle ScholarPubMed
Hubbard, W.B., Nellis, W.J., Michell, A.C., Holmes, N.C., Limaye, S.S. and McCandless, P.C. (1991) Interior structure of Neptune: comparison with Uranus. Science, 253, 648–651.CrossRefGoogle ScholarPubMed
Iota, V., Yoo, C.S. and Cynn, H. (1999) Quartz-like carbon dioxide: an optically nonlinear extended solid at high pressures and temperatures. Science, 283, 1510–1513.CrossRefGoogle Scholar
Irifune, T., Nishiyama, N., Kuroda, K., Inoue, T., Isshiki, M., Utsumi, W., Funakoshi, K., Urakawa, S., Uchida, T., Katsura, T. and Ohtaka, O. (1998) The postspinel phase boundary in Mg2SiO4 determined by in situ X-ray diffraction. Science, 279, 1698–1700.CrossRefGoogle ScholarPubMed
Ito, E. and Takahashi, E. (1989) Post-spinel transformations in the system Mg2SiO4-Fe2SiO4 and some geophysical implications. Journal of Geophysical Research, 94, 10637–10646.CrossRefGoogle Scholar
Ito, E., Akaogi, M., Topor, L. and Navrotsky, A. (1990) Negative pressure-temperature slopes for reactions forming MgSiO3 perovskite from calorimetry. Science, 249, 1275–1278.CrossRefGoogle Scholar
Jeanloz, R. and Kavner, A. (1996) Melting criteria and imaging spectroradiometry in laser-heated diamond-cell experiments. Philosophical Transactions of the Royal Society of London A, 354, 1279–1305.Google Scholar
Jeanloz, R. and Romanowicz, B. (1997) Geophysical dynamics at the center of the Earth. Physics Today, 50(8), 22–27.CrossRefGoogle Scholar
Jeanloz, R. and Williams, Q. (1998) The core-mantle boundary region. Pp. 241–259 in: Ultrahigh-Pressure Mineralogy (Hemley, R.J., editor). Reviews in Mineralogy, 37. Mineralogical Society of America, Washington, D.C.CrossRefGoogle Scholar
Karato, S.-i., Forte, A.M., Liebermann, R.C., Masters, G. and Stixrude, L. (2000) Earth's Deep Interior: Mineral Physics and Tomography from the Atomic to the Global Scale. p. 289. American Geophysical Union, Washington, D.C.CrossRefGoogle Scholar
Karki, B.B., Stixrude, L., Clark, S.J., Warren, M.C., Ackland, G.J. and Crain, J. (1999) Structure and elasticity of MgO at high pressure. American Mineralogist, 82, 51–60.CrossRefGoogle Scholar
Kingma, K.J., Cohen, R.E., Hemley, R.J. and Mao, H.K. (1995) Transformation of stishovite to a denser phase at lower-mantle pressures. Nature, 374, 243–245.CrossRefGoogle Scholar
Kleppner, H. (1996) The investigation of phase transitions by electronic absorption spectroscopy. Physics and Chemistry of Minerals, 23, 288–296.Google Scholar
Knudson, M.D., Hanson, D.L., Bailey, J.E., Hall, C.A., Asay, J.R. and Anderson, W.W. (2001) Equation of state measurements in liquid deuterium to 70 GPa. Physical Review Letters, 87, 225501, 1–4.CrossRefGoogle ScholarPubMed
Lebedev, S., Chevrot, S. and van der Hilst, R.D. (2002) Seismic evidence for olivine phase changes at the 410- and 660-kilometer discontinuities. Science, 296, 1300–1302.CrossRefGoogle ScholarPubMed
Li, J., Fei, Y., Mao, H.K., Hirose, K. and Shieh, S. (2001) Sulfur in the Earth's inner core. Earth and Planetary Science Letters, 193, 509–514.CrossRefGoogle Scholar
Li, J., Mao, H.K., Fei, Y., Gregoryanz, E., Eremets, M. and Zha, C.S. (2002) Compression of Fe3C to 30 GPa at room temperature. Physics and Chemistry of Minerals, 29, 166–169.CrossRefGoogle Scholar
Li, J., Mao, H.K., Fei, Y., Hadididiacos, C. and Hemley, R.J. (submitted) High Pressure Research.Google Scholar
Lin, J.F., Heinz, D.L., Campbell, A.J., Devine, J.M., Mao, W.L. and Shen, G. (2002 a) Iron-nickel alloy in the Earth's core. Geophysical Research Letters, 29, 1091–1093.CrossRefGoogle Scholar
Lin, J.F., Heinz, D.L., Campbell, A.J., Devine, J.M. and Shen, G. (2002 b) Iron-silicon alloy in the Earth's core? Science, 295, 313–315.CrossRefGoogle ScholarPubMed
Lobban, C., Finney, J.L. and Kuhs, W.F. (1998) The structure of a new phase of ice. Nature, 391, 268–270.CrossRefGoogle Scholar
Londono, D., Kuhs, W.F. and Finney, J.L. (1988) Enclathration of helium in ice II: the first helium hydrate. Nature, 332, 141–142.CrossRefGoogle Scholar
Loubeyre, P., Jean-Louis, M., Toullec, R.L. and Charon-Gerard, L. (1993) High pressure measurements of the He-Ne binary phase diagram at 296 K: Evidence for the stability of a stoichiometric Ne(He)2 solid. Physical Review Letters, 70, 178–181.CrossRefGoogle ScholarPubMed
Loubeyre, P., LeToullec, R. and Pinceaux, J.P. (1994) Compression of Ar(H2)2 up to 175 GPa: A new path for the dissociation of molecular hydrogen? Physical Review Letters, 72, 1360–1363.CrossRefGoogle ScholarPubMed
Loubeyre, P., Occeli, R. and LeToullec, R. (2002) Optical studies of solid hydrogen to 320 GPa and evidence for black hydrogen. Nature, 416, 613–617.CrossRefGoogle ScholarPubMed
Loveday, J.S., Nelmes, R.J., Guthrie, M., Klug, D.D. and Tse, J.S. (2001 a) Transition from cage clathrate to filled ice – the structure of methane hydrate III. Physical Review Letters, 87, 215501.CrossRefGoogle ScholarPubMed
Loveday, J.S., Nelmes, R.J., Guthrie, M., Klug, D.D., Tse, J.S. and Handa, Y.P. (2001b) Stable methane hydrate above 2 GPa and the source of Titan's atmospheric methane. Nature, 410, 661–663.CrossRefGoogle ScholarPubMed
Lunine, J.I. and Stevenson, D.J. (1985) Thermodynamics of clathrate hydrate at low and high pressures with application to the outer solar system. Astrophysics Journal Supplement Series, 58, 493–531.CrossRefGoogle Scholar
Manga, M. and Jeanloz, R. (1997) Thermal conductivity of corundum and periclase and implications for the lower mantle. Journal of Geophysical Research, 102(B2), 2999–3008.CrossRefGoogle Scholar
Mao, M.K. and Bell, P.M. (1970) Behavior of thermocouples in the single-stage piston-cylinder apparatus. Carnegie Institut e of Washing ton Yearbook, 69, 207–216.Google Scholar
Mao, H.K. and Hemley, R.J. (1998) New windows on the Earth's deep interior. Pp. 1–32 in: Ultrahigh-Pressure Mineralogy: Physics and Chemistry of the Earth's Deep Interior (Hemley, R.J., editor). Reviews in Mineralogy, 37. Mineralogical Society of America, Washington, D.C.Google Scholar
Mao, H.K., Bell, P.M. and England, J.L. (1971) Tensional errors and drift of thermocouple electromotive force in the single-stage, piston-cylinder apparatus. Carnegie Institute of Washington Yearbook, 70, 281–287.Google Scholar
Mao, H.K., Bell, P.M., Shaner, J. and Steinberg, D. (1978) Specific volume measurements of Cu, Mo, Pd, and Ag and calibration of the ruby R1 fluorescence pressure gauge from 0.06 to 1 Mbar. Journal of Applied Physics, 49, 3276–3283.CrossRefGoogle Scholar
Mao, H.K., Xu, J. and Bell, P.M. (1986) Calibration of the ruby pressure gauge to 800 kbar under quasihydrostatic conditions. Journal of Geophysical Research, 91, 4673–4676.CrossRefGoogle Scholar
Mao, H.K., Shu, J., Fei, Y., Hu, H. and Hemley, R.J. (1996) The wüstite enigma. Physics of the Earth and Planetary Interiors, 96, 135–145.CrossRefGoogle Scholar
Mao, H.K., Shen, G., Hemley, R.J. and Duffy, T.S. (1998) X-ray diffraction with a double hot plate laser-heated diamond cell. Pp. 27–34 in: Properties of Earth and Planetary Materials at High Pressure and Temperature (Manghnani, M.H., and Yagi, T., editors). American Geophysical Union, Washington, D.C.CrossRefGoogle Scholar
Mao, H.K., Kao, C.C. and Hemley, R.J. (2001 a) Inelastic scattering at ultrahigh pressures. Journal of Physics of Condensed Matter, 13, 7847–7858.CrossRefGoogle Scholar
Mao, H.K., Xu, J., Struzhkin, V.V., Shu, J., Hemley, R.J., Sturhahn, W., Hu, M.Y., Alp, E.E., Vocadlo, L., Alfè, D., Price, G.D., Gillan, M.J., Schwoerer-Böhning, M., Häusermann, D., Eng, P., Shen, G., Gieffer, H., Lübbers, R. and Wortmann, G. (2001 b) Phonon density of states of iron up to 153 GPa. Science, 292, 914–916.CrossRefGoogle Scholar
Mao, W.L., Mao, H.K., Struzhkin, V.V., Guo, Q., Hu, J., Goncharov, A.F., Shu, J., Hemley, R.J., Somayazulu, M. and Zhao, Y. (submitted) New hydrogen clathrates. Nature.Google Scholar
Matsuishi, K., Gregoryanz, E., Mao, H.K. and Hemley, R.J. (submitted) Equation of state and intermolecular potential of fluid hydrogen from Brillouin scattering measurements at high pressures and temperatures. Journal of Chemical Physics.Google Scholar
McDonough, W.F. (2001) Composition of the Earth. Pp. 3–23 in: Earthquake Thermodynamics and Phase Transformations in the Earth's Interior (Teisseyre, R. and Majewski, E., editors). Academic Press, San Diego.CrossRefGoogle Scholar
McMillan, P.F. and Hofmeister, A.M. (1988) Infrared and Raman spectroscopy. Pp. 99–159 in: Spectroscopic Methods in Mineralogy and Geology (Hawthorne, F.C., editor). Reviews in Mineralogy, 18. Mineralogical Society of America, Washington, D.C.CrossRefGoogle Scholar
McMillan, P.F., Hemley, R.J. and Gillet, P. (1996) Vibrational spectroscopy of mantle minerals. Pp. 175–213 in: Mineral Spectroscopy: A Tribute to Roger Burns (Dyar, M.D., McCammon, C. and Schaefer, M.W., editors). Geochemical Society, Houston, Texas.Google Scholar
Merkel, S., Goncharov, A.F., Mao, H.K., Gillet, P. and Hemley, R.J. (2000) Raman spectroscopy of iron to 152 gigapascals: implications for Earth's inner core. Science, 288, 1626–1629.CrossRefGoogle ScholarPubMed
Merkel, S., Wenk, H.R., Shu, J., Shen, G., Gillet, P., Mao, H.K. and Hemley, R.J. (in press) Deformation of polycrystalline MgO at pressures of the lower mantle. Journal of Geophysical Research.Google Scholar
Mishima, O. and Stanley, H.E. (1998) The relationship between liquid, supercooled and glassy water. Nature, 396, 329–335.CrossRefGoogle Scholar
Nellis, W.J., Ree, F.H., van Thiel, M. and Mitchell, A.C. (1981) Shock compression of liquid carbon monoxide and methane to 90 GPa (900 kbar). Journal of Chemical Physics, 75, 3055–3063.CrossRefGoogle Scholar
Nellis, W.J., Hamilton, D.C., Holmes, N.C., Radousky, H.B., Ree, F.H., Mitchell, A.C. and Nicol, M. (1988) The nature of the interior of uranus based on studies of planetary ices at high dynamic pressure. Science, 240, 779–781.CrossRefGoogle ScholarPubMed
Nellis, W.J., Holmes, N.C., Michell, A.C., Hamilton, D.C. and Nicol, M. (1997) Equation of state and electrical conductivity of “synthetic Uranus,” a mixture of water, ammonia, and siopropanol, at shock pressure up to 200 GPa (2 Mbar). Journal of Chemical Physics, 107, 9096–9100.CrossRefGoogle Scholar
Niemann, H.B., Atreya, S.K., Carignan, G.R., Donahue, T.M., Haberman, J.A., Harpold, D.N., Hartle, R.E., Hunten, D.M., Kasprzak, W.T., Mahaffy, P.R., Owen, T.C., Spencer, N.W. and Way, S.H. (1996) The Galileo mass spectrometer: composition of Jupiter's atmosphere. Science, 272, 846–849.CrossRefGoogle ScholarPubMed
Ohtani, E. and Maeda, M. (2001) Density of basaltic melt at high pressure and stability of the melt at the base of the lower mantle. Earth and Planetary Science Letters, 193, 69–75.CrossRefGoogle Scholar
Pasternak, M.P., Rozenberg, G.K., Machavariani, G.Y., Naaman, O., Taylor, R.D. and Jeanloz, R. (1999) Breakdown of the Mott-Hubbard state in Fe2O3: A first order insulator-metal transition with collapse of magnetism at 50 GPa. Physical Review Letters, 82, 4663–4666.CrossRefGoogle Scholar
Porcelli, D. and Halliday, A.N. (2001) The core as a possible source of mantle helium. Earth and Planetary Science Letters, 192, 45–56.CrossRefGoogle Scholar
Ross, M. (1981) The ice layer in Uranus and Neptune – diamonds in the sky? Nature, 292, 435–436.CrossRefGoogle Scholar
Rossman, G.R. (1988) Vibrational spectroscopy of hydrous components. Pp. 193–206 in: Spectroscopic Methods in Mineralogy and Geology (Hawthorne, F.C., editor). Reviews in Mineralogy, 18. Mineralogical Society of America, Washington, D.C.CrossRefGoogle Scholar
Sanloup, C., Guyot, F., Gillet, P., Fiquet, G., Hemley, R.J., Mezouar, M. and Martinez, I. (2000) Structural changes in liquid Fe at high pressures and high temperatures from synchrotron X-ray diffraction. Europhysics Letters, 52, 151–157.CrossRefGoogle Scholar
Sanloup, C., Mao, H.K. and Hemley, R.J. (2002) Highpressure transformations in xenon hydrates. Proceedings of the National Academy of Sciences, 99, 25–28.CrossRefGoogle Scholar
Sanloup, C., Hemley, R.J. and Mao, H.K. (in press) Evidence for xenon silicates and high pressures and temperatures. Geophysics Research Letters.Google Scholar
Schindelbeck, T., Somayazulu, M.S., Hemley, R.J. and Mao, H.K. (1997) Breakdown of methane at high pressures and temperatures. MRS Fall 97 Meeting Abstract, 583.Google Scholar
Scott, H.P., Williams, Q. and Knittle, E. (2001) Stability and equation of state of Fe3C to 73 GPa: implications for carbon in the Earth's core. Geophysics Research Letters, 28, 1875–1878.CrossRefGoogle Scholar
Serra, S., Cavazzoni, C., Chiarotti, G.L., Scandolo, S. and Tosatti, E. (1999) Pressure-induced solid carbonates from molecular CO2 by computer simulation. Science, 284, 788–790.CrossRefGoogle ScholarPubMed
Sharma, A., Scott, J.H., Cody, G.D., Fogel, M.L., Hazen, R.M., Hemley, R.J. and Huntress, W.T. (2002) Microbial activity at gigapascal pressure. Science, 295, 1514–1516.CrossRefGoogle Scholar
Shen, G., Rivers, M.L., Wang, Y. and Sutton, S.R. (2000) Laser heated diamond cell system at the Advanced Photon Source for in situ X-ray measurements at high pressure and temperature. Review of Scientific Instruments, 72, 1273–1282.CrossRefGoogle Scholar
Shim, S., Duffy, T.S. and Shen, G. (2001) The post-spinel transformation in Mg2SiO4 and its relation to the 660-km seismic discontinuity. Nature, 411, 571–574.CrossRefGoogle ScholarPubMed
Sicardy, B., Ferri, F., Roques, F., Lecacheux, J., Pau, S., Brosch, N., Nevo, Y., Hubbard, W.B., Reitsema, H.J., Blanco, C., Carreira, E., Beisker, W., Bittner, C., Bruns, J.J., Denzau, H., Nezel, M., Riedel, E., Struckmann, H., Appleby, G., Forrest, R.W., Nicolson, I.K.M., Hollis, A.J. and Miles, R. (1999) Structure of Titan's stratosphers from the 28 Sgr occultation. Icarus, 142, 357–390.CrossRefGoogle Scholar
Singh, A.K., Mao, H.K., Shu, J. and Hemley, R.J. (1998) Estimation of single-crystal elastic moduli from polycrystalline X-ray diffraction at high pressure: application to FeO and iron. Physical Review Letters, 80, 2157–2160.CrossRefGoogle Scholar
Sobolev, N.V., Fursenko, B.A., Goryainov, S.V., Shu, J., Hemley, R.J., Mao, H.K. and Boyd, F.R. (2000) Fossilized high pressure from the Earth's deep interior: the coesite-in-diamond barometer. Proceedings of the National Academy of Sciences, 97, 11875–11879.CrossRefGoogle ScholarPubMed
Somayazulu, M.S., Finger, L.W., Hemley, R.J. and Mao, H.K. (1996) New high-pressure compounds in methane-hydrogen mixtures. Science, 271, 1400–1402.CrossRefGoogle Scholar
Somayazulu, M.S., Hemley, R.J., Goncharov, A.F., Mao, H.K. and Finger, L.W. (1997) High-pressure compounds in the methane-hydrogen system: X-ray, infrared and Raman studies on CH4(H2)2 . European Journal of Solid State Inorganic Chemistry, 34, 705–713.Google Scholar
Speziale, S., Zha, C.S., Duffy, T.S., Hemley, R.J. and Mao, H.K. (2001) Quasi-hydrostatic compression of magnesium oxide to 52 GPa: Implications for the pressure-volume-temperature equation of state. Journal of Geophysical Research, 106, 515–528.CrossRefGoogle Scholar
Steinle-Neumann, G., Stixrude, L. and Cohen, R.E. (1999) First-principles elastic constants for the hcp transition metals Fe, Co, and Re at high pressure. Physical Review B, 60, 791–799.CrossRefGoogle Scholar
Stevenson, D.J. (1985) Cosmochemistry and structure of the giant planets and their satellites. Icarus, 62, 4–15.CrossRefGoogle Scholar
Stevenson, D.J. (1990) Fluid dynamics of core formation. Pp. 231–249 in: Origin of the Earth (Newson, H.E. and Jones, J.H., editors). Oxford University Press, New York.Google Scholar
Stretton, I., Heidelbach, F., Mackwell, S. and Langenhorst, F. (2001) Dislocation creep of magne siowüstite (Mg0.8Fe0.2O). Earth and Planetary Science Letters, 194, 229–240.CrossRefGoogle Scholar
Struzhkin, V.V., Mao, H.K., Hu, J., Schwoerer-Böhning, M., Shu, J., Hemley, R.J., Sturhahn, W., Hu, M.Y., Alp, E.E., Eng, P. and Shen, G. (2001) Inelastic X-ray scattering of FeO to 48 GPa. Physical Review Letters, 87, 255501.CrossRefGoogle ScholarPubMed
Teter, D.M., Hemley, R.J., Kresse, G. and Hafner, J. (1998) High pressure polymorphism in silica. Physical Review Letters, 80, 2145–2148.CrossRefGoogle Scholar
Tschauner, O., Somayazulu, M., Mao, H.K. and Hemley, R.J. (2001) Transitions to nonmolecular structures and decomposition of CO2 at high pressures. Bulletin of the American Physical Society, 46, K40.121.Google Scholar
Vos, W.L., Finger, L.W., Hemley, R.J., Hu, J., Mao, H.K. and Schouten, J.A. (1992) A high-pressure van der Waals compound in solid nitrogen-helium mixtures. Nature, 358, 46–48.CrossRefGoogle Scholar
Vos, W.L., Finger, L.W., Hemley, R.J. and Mao, H.K. (1993) Novel H2-H2O clathrate at high pressures. Physical Review Letters, 71, 3150–3153.CrossRefGoogle Scholar
Walker, D. (2000) Core participation in mantle geochemistry. Geochemical Society Ingersoll Lecture, GSA Denver, October 1999. Geochimica et Cosmochimica Acta, 64, 2897–2911.CrossRefGoogle Scholar
Weir, S.T., Mitchell, A.C. and Nellis, W.J. (1996) Metallization of fluid molecular hydrogen at 140 GPa (1.4 Mbar). Physical Review Letters, 76, 1860–1863.CrossRefGoogle Scholar
Wenk, H.-R., Matthies, S., Hemley, R.J., Mao, H.K. and Shu, J. (2000) The plastic deformation of iron at pressures of the Earth's inner core. Nature, 405, 1044–1047.CrossRefGoogle ScholarPubMed
Wood, B.J. and Rubie, D.C. (1996) The effect of alumina on phase transformations at the 660-kilometer discontinuity from Fe-Mg partitioning experiments. Science, 273, 1522–1524.CrossRefGoogle Scholar
Xu, J. and Mao, H.K. (2000) Moissanite: a window for high-pressure experiments. Science, 290, 783–785.CrossRefGoogle ScholarPubMed
Yagi, T., Mao, H.K. and Bell, P.M. (1978) Structure and crystal chemistry of perovskite-t ype MgSiO3 . Physics and Chemistry of Minerals, 3, 97–110.CrossRefGoogle Scholar
Yoo, C.S., Cynn, H., Gygi, F., Galli, G., Iota, V., Nicol, M., Carlson, S., Hausermann, D., and Mailhiot, C. (1999) Crystal structure of carbon dioxide at high pressure: “superhard” polymeric carbon dioxide. Physical Review Letters, 83, 5527–5530.CrossRefGoogle Scholar
Zerr, A., Diegler, A. and Boehler, R. (1998) Solidus of the Earth's deep mantle. Science, 281, 243–246.CrossRefGoogle ScholarPubMed
Zha, C.S., Mao, H.K. and Hemley, R.J. (2000) Elasticity of MgO and a primary pressure scale to 55 GPa. Proceedings of the National Academy of Science, 97, 13494–13499.CrossRefGoogle Scholar
Zhang, J. and Weidner, D.J. (1999) Thermal equation of state of aluminum-enriched silicate perovskite. Science, 284, 782–784.CrossRefGoogle ScholarPubMed
Zhang, K. and Schubert, G. (1996) Penetrative convection and zonal flow on Jupiter. Science, 273, 941–943.CrossRefGoogle ScholarPubMed
Zou, G., Ma, Y., Mao, H.K., Hemley, R.J. and Gramsch, S.A. (2001) A diamond gasket for the laser-heated diamond anvil cell. Reviews in Science Instruments, 72, 1298–1301.CrossRefGoogle Scholar