Ledoux, Estelle Krug, Matthias Gay, Jeffrey Chantel, Julien Hilairet, Nadège Bykov, Maxim Bykova, Elena Aprilis, Georgios Svitlyk, Volodymyr Garbarino, Gaston
...
Published in
American Mineralogist
The olivine-wadsleyite transformation is believed to occur at depths of about 410 km in the Earth, producing a major seismic discontinuity in this region of the Earth’s mantle. The mechanism of this phase transition controls the microstructures of the newly nucleated wadsleyite, the major phase of the upper part of the mantle transition zone, and t...
Tauber, Michael J. Saxena, Suryansh Bullock, Emma S. Ginestet, Hélène Pommier, Anne
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American Mineralogist
The detection and quantification of metal sulfides in host rocks by electrical measurements have been priorities for field and laboratory studies, motivated by mineral prospecting and fundamental interest in the mantle structure or core/mantle differentiation, among other reasons. Here, we reanalyze electrical data for a dunite host with added FeS ...
Qin, Fei Wu, Ye Xue, Shengchao Zhang, Dongzhou Wu, Xiang Jacobsen, Steven D.
Published in
American Mineralogist
Alkali-rich aluminous high-pressure phases including calcium-ferrite (CF) type NaAlSiO4 are thought to constitute ~20% by volume of subducted mid-ocean ridge basalt (MORB) under lower mantle conditions. As a potentially significant host for incompatible elements in the deep mantle, knowledge of the crystal structure and physical properties of CF-ty...
Insixiengmay, Leslie Stixrude, Lars
Published in
American Mineralogist
We focus on the ferric end-member of phase H: ε-FeOOH using density functional theory at the PBEsol+U level. At 300 K, we find that ε-FeOOH undergoes a hydrogen bond symmetrization at 37 GPa and a sharp high-spin to low-spin transition at 45 GPa. We find excellent agreement with experimental measurements of the equation of state, lattice parameters...
Matsumoto, Kazuhisa Okumura, Satoshi Tomiya, Akihiko
Published in
American Mineralogist
Decompression-induced crystallization is an important process that controls the behavior of volcanic eruptions because it strongly affects magma rheology and degassing behavior in the shallow parts of volcanic conduits. Several decompression experiments have been performed to understand and model the crystallization processes; however, the effect o...
Farsang, Stefan Caracas, Razvan Adachi, Takuji B.M. Schnyder, Cédric Zajacz, Zoltán
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American Mineralogist
Taking advantage of the Raman resonance effect, we employed 405 and 532 nm excitations to (1) identify sulfur species present in lazurite, haüyne, and synthetic ultramarine blue pigments and (2) investigate the enigmatic ~485 cm–1 band found previously in Raman spectra of lazurite and haüyne collected with 458 nm excitation. In spectra of lazurite ...
Zhao, Kai Xu, Xisheng He, Zhenyu Xia, Yan
Published in
American Mineralogist
The current debate on volcanic-plutonic connection is centered on whether eficient liquid-crystal segregation dominates the evolution of a mushy reservoir to produce evolved, crystal-poor rhyolite and cumulate leftover. However, magma recharge may remarkably influence the evolution of a mushy reservoir and obscure the evidence of liquid-crystal seg...
Spano, Tyler L. Olds, Travis A. McDonnell, Marshall Smith, Robert Niedziela, Jennifer L. Miskowiec, Andrew Kapsimalis, Roger Shields, Ashley E.
Published in
American Mineralogist
Identification of radioactive materials is a critical goal of resource exploration, basic actinide science, and nuclear forensics, and we provide here new insights toward rapid, nondestructive analysis of uranium-containing minerals and technogenic phases. Raman and infrared spectroscopic data are powerful indicators of solid-phase U(VI) coordinati...
Huang, Yongsheng Nakatani, Takayuki Sawa, Sando Wu, Guoji Nakamura, Michihiko McCammon, Catherine
Published in
American Mineralogist
Grain-scale pore geometry primarily controls the fluid distribution in rocks, affecting material transport and geophysical response. The dihedral angle (θ) in the olivine-fluid system is a key parameter determining pore fluid geometry in mantle wedges. In the system, curved and faceted olivine-fluid interfaces define θ, resulting in faceted-faceted...
Chatterjee, Somdipta Karmakar, Shreya Mukherjee, Subham Sanyal, Sanjoy Sengupta, Pulak
Published in
American Mineralogist
In this manuscript, we report a rare occurrence of rod-like intergrowths of clinopyroxene-ilmenite that variably replace titanite in a suite of high-pressure mafic granulites from the Chotanagpur Granite Gneissic Complex, Eastern Indian Shield. Garnet proximal to the clinopyroxene-ilmenite intergrowth is invariably replaced with symplectic clinopyr...
