Results 31 to 40 of about 406 (161)

Valence and spin states of iron are invisible in Earth’s lower mantle

Nature Communications, 2018
Bridgmanite is the most abundant mineral in the lower mantle and therefore is crucial to interpreting geophysical observations and models. Here, the authors show that ferric-iron-only bridgmanite Fe3+ undergoes a spin transition at 43–53 GPa at 300 K and
Jiachao Liu, Susannah M. Dorfman, Feng Zhu, Jie Li, Yonggang Wang, Dongzhou Zhang, Yuming Xiao, Wenli Bi, E. Ercan Alp   +8 more
doaj   +1 more source

Formation of large low shear velocity provinces through the decomposition of oxidized mantle

Nature Communications, 2021
Dense Fe3+-rich bridgmanite can explain the seismic features of Large Low Shear Velocity Provinces, as it can form large-scale thermochemical piles in the deep mantle that remain stable throughout Earth’s history.
Wenzhong Wang, Jiachao Liu, Feng Zhu, Mingming Li, Susannah M. Dorfman, Jie Li, Zhongqing Wu   +6 more
doaj   +1 more source

Mantle dynamics inferred from the crystallographic preferred orientation of bridgmanite [PDF]

Nature, 2016
Seismic shear wave anisotropy is observed in Earth's uppermost lower mantle around several subducted slabs. The anisotropy caused by the deformation-induced crystallographic preferred orientation (CPO) of bridgmanite (perovskite-structured (Mg,Fe)SiO3) is the most plausible explanation for these seismic observations. However, the rheological properties
Tsujino, Noriyoshi, Nishihara, Yu, Yamazaki, Daisuke, Seto, Yusuke, Higo, Yuji, Takahashi, Eiichi   +5 more
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Natural Fe-bearing aluminous bridgmanite in the Katol L6 chondrite

Proceedings of the National Academy of Sciences, 2021
Significance Bridgmanite is the most volumetrically abundant mineral of the Earth’s interior, and it is important to understand its formation mechanism to better comprehend the origin and evolution of planetary interiors.
Sujoy Ghosh, Kishan Tiwari, Masaaki Miyahara, Arno Rohrbach, Christian Vollmer, Vincenzo Stagno, Eiji Ohtani, Dwijesh Ray   +7 more
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Oxygen Vacancy Substitution Linked to Ferric Iron in Bridgmanite at 27 GPa [PDF]

Geophysical Research Letters, 2020
AbstractFerric iron can be incorporated into the crystal structure of bridgmanite by either oxygen vacancy substitution (MgFeO2.5 component) or charge‐coupled substitution (FeFeO3 component) mechanisms. We investigated the concentrations of MgFeO2.5 and FeFeO3 in bridgmanite in the MgO‐SiO2‐Fe2O3 system at 27 GPa and 1700–2300 K using a multianvil ...
Fei, Hongzhan, Liu, Zhaodong, McCammon, Catherine, Katsura, Tomoo   +3 more
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Melting phase relations in the MgSiO3–CaSiO3 system at 24 GPa

Progress in Earth and Planetary Science, 2017
The Earth’s lower mantle is composed of bridgmanite, ferropericlase, and CaSiO3-rich perovskite. The melting phase relations between each component are key to understanding the melting of the Earth’s lower mantle and the crystallization of the deep magma
Ryuichi Nomura, Youmo Zhou, Tetsuo Irifune   +2 more
doaj   +1 more source

Shear deformation of bridgmanite and magnesiowüstite aggregates at lower mantle conditions [PDF]

Science, 2016
Mantle minerals won't share the strain The deformation of a mixed block of material depends on the strength of the components of which it is made. Weak materials will deform more than the strong ones in a mixture that is squished or stretched. Girard et al.
Jennifer, Girard, George, Amulele, Robert, Farla, Anwar, Mohiuddin, Shun-ichiro, Karato   +4 more
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Iron partitioning between ferropericlase and bridgmanite in the Earth's lower mantle [PDF]

Journal of Geophysical Research: Solid Earth, 2017
AbstractEarth's lower mantle is generally believed to be seismically and chemically homogeneous because most of the key seismic parameters can be explained using a simplified mineralogical model at expected pressure‐temperature conditions. However, recent high‐resolution tomographic images have revealed seismic and chemical stratification in the middle‐
Shenzhen Xu, Jung‐Fu Lin, Dane Morgan
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Aluminum Components in Bridgmanite Coexisting With Corundum and the CF‐Phase With Temperature

Journal of Geophysical Research: Solid Earth, 2023
AbstractPhase relations in the MgSiO3–MgAl2O4–Al2O3 system are investigated at 27 GPa and 2000–2600 K using a multi‐anvil apparatus. The AlAlO3 content in the bridgmanite increases from 8.6 to 20.0 mol% with increasing temperature from 2000 to 2600 K, while the MgAlO2.5 content remains nearly constant, that is, 3–4 mol% at these temperatures. Therefore,
Wang, Lin, Liu, Zhaodong, Koizumi, Sanae, Ballaran, Tiziana Boffa, Katsura, Tomoo, Liu, Zhaodong; 3 State Key Laboratory of Superhard Materials Jilin University Changchun China, Koizumi, Sanae; 4 Earthquake Research Institute University of Tokyo Tokyo Japan, Ballaran, Tiziana Boffa; 1 Bayerisches Geoinstitut University of Bayreuth Bayreuth Germany, Katsura, Tomoo; 1 Bayerisches Geoinstitut University of Bayreuth Bayreuth Germany   +8 more
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Density functional theory calculations and thermodynamic analysis of bridgmanite surface structure [PDF]

Physical Chemistry Chemical Physics, 2019
Bridgmanite surface structure variations as a function of chemical potentials of Mg and O at the upper most of the Earth's lower mantle condition (∼660 km).
Ming Geng, Hannes Jónsson
openaire   +4 more sources