An experimental study of phase transformations in olivine under pressure and temperature conditions corresponding to the mantle transition zone

Wu, Yao; Wang, Yanbin; Zhang, Yanfei; Zhang, Jin; Wang, Chao; Zhou, Chunyin

doi:10.1007/s11434-011-4884-2

Cited by 8 publications

(2 citation statements)

References 37 publications

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“…GPa [Katsura and Ito, 1989;Fei and Bertka, 1999;Katsura et al, 2004]) and wadsleyite-ringwoodite transitions (20 GPa [Katsura and Ito, 1989;Suzuki et al, 2000]) in Mg 2 SiO 4 at 1673 K, as well as the phase transition of coesite-stishovite in SiO 2 at 1473 K (9.2 GPa [Zhang et al, 1996]). For details of the cell assembly and pressure calibration see Wu et al [2011]. For the 8/3 assembly (Figure 1b), pressure calibration was made according to the olivine-wadsleyite transition (14.6 GPa [Katsura and Ito, 1989;Fei and Bertka, 1999;Katsura et al, 2004]) in Mg 2 SiO 4 at 1673 K, wadsleyite-ringwoodite (21.3 GPa [Suzuki et al, 2000]) and the ringwoodite to perovskite+periclase transformations (23.1 GPa [Fei et al, 2004]) in Mg 2 SiO 4 and akimotoiteperovskite in MgSiO 3 (22.3 GPa [Hirose et al, 2001;Fei et al, 2004]), all at 1873 K. The calibration curves appear temperature independent between 1473 and 1873 K, and reproducibility of pressure in the present experiments was estimated to be about AE0.3 GPa and AE0.5 GPa, respectively, for the 10/5 and 8/3 assemblies.…”

Section: High-pressure High-temperature Experimentsmentioning

confidence: 99%

Phase transitions of harzburgite and buckled slab under eastern China

Zhang

Wang

et al. 2013

Geochem Geophys Geosyst

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[1] Phase relations in harzburgite have been determined between 14 and 24 GPa and 1473 and 1673 K. At 1673 K, harzburgite transformed to wadsleyite + garnet + clinopyroxene below 19 GPa and decomposed into an assemblage of ringwoodite + garnet + stishovite above 20 GPa. Certain amounts of akimotoite were produced at still higher pressures (22)(23). Finally, perovskite and magnesiowüstite were found to coexist with garnet at 24.2 GPa. Compositions of all the phases were analyzed and elemental partitioning coefficients were determined among coexisting phases. Combining our experimental data with available thermoelastic properties of major minerals in the earth's mantle, we modeled the velocity and density signatures of the stagnated oceanic slab in the mantle transition zone (MTZ) under eastern China, based on kinematic slab thermal structure analysis. We examined two end-member slab models: a conventional straight slab with deformation thickening and an undulate slab with an oscillating wavelength of 200 km. We found that an undulated (buckled) slab model yields velocity anomalies (about 1-2% for Vp) that are consistent with seismic tomography models, taking into account low-pass filtering effects in seismic tomography studies. On the other hand, straight slab models yield velocity anomalies that are too high compared with seismic tomography models. Our models provide important constraints on the thermal structure, mineralogy, composition, density, and velocities of slab materials in the MTZ.

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Section: High-pressure High-temperature Experimentsmentioning

confidence: 99%

Phase transitions of harzburgite and buckled slab under eastern China

Zhang

Wang

et al. 2013

Geochem Geophys Geosyst

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“…High-temperature pressure calibration was performed using the olivinewadsleyite transition (14.6 GPa, Katsura et al 2004), wadsleyite to ringwoodite transition (20 GPa, Suzuki et al 2000) at 1673 K and the phase transition of coesite to stishovite at 1473 K (9.2 GPa, Zhang et al 1996). For details of the cell assembly and pressure calibration, see Wu et al (2012). A type C thermocouple was used to measure the temperature at the center of the furnace.…”

Section: Methodsmentioning

confidence: 99%