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Research Group Division of Earth and Planetary Materials Science

 

Earth and Planetary Material Physics Research Group

http://epms.es.tohoku.ac.jp/minphys/index_e.html
•Assoc. Professor Akio Suzuki,
specializing in Magma generation and its nature, Phase transition, and Radiation of light
•Asst. Professor Tatsuya Sakamaki,
Magma, Glass, High temperature and high pressure
•Asst. Professor Seiji Kamada,
•Asst. Professor Yuki Shibasaki,
•Asst. Professor Shin Ozawa,

 

This group conducts research on the high-pressure physics of Earth and planetary materials, and the origin and evolution of Earth and the planets. Its current studies are of the partitioning of elements between metal and silicate at high pressure and its application to the core formation process of Earth, melting and phase relations of mantle materials, physical properties and equation of state of minerals and magmas at high pressure, and diffusion and kinetics of phase transition of mantle minerals. We are also conducting investigations of material transport from the surface to the core and the large-scale circulation of Earth materials including its volatiles.
 
 

(1) Exploration to the deep earth and planets:

(1) Exploration to the deep earth and planets: Seismic wave observations indicate that some discontinuity surfaces and heterogeneous materials exist in the deep earth. It is expected that they are due to phase transitions of minerals or the changes of properties in minerals. These discontinuities and heterogeneities are related with material circulations in the deep earth such as subducting slab and rising plume.
We are investigating a) melting and phase relations of materials, b) physical properties and equation of state of minerals and magmas, c) diffusion in minerals, d) kinetics of phase transition of minerals, e) material transportation from the earth`s surface to core, and f) large-scale circulation of materials including volatiles to clarify the formation, evolution and circulation of materials in the deep earth and planets (Moon, Mars, and Mercury).

 

(2) Origin of the earth:

The earth`s surface was covered with magma ocean 4.6 billion years ago. A small planet collided with the earth and subsequently, the moon was formed, which is so-called “Giant impact theory”. In addition, many meteorites hit the earth. We think that these dynamic event affected the formation of the earth`s mantle and core.
We are interested in how the magma ocean solidified and how the magma separated into mantle and core. We are investigating the partitioning of elements between metal and silicate at high-temperature and -pressure condition, and trying to apply the results to understand the core formation process of the earth.

 

(3) High-temperature and –pressure experiments:

(3) High-temperature and –pressure experiments: The interior of the earth is extreme conditions, high-temperature and high-pressure. The materials of the earth interior have different physical and chemical properties compared to materials of the earth`s surface. For example, former has higher density than later. It is well-known that graphite transforms to its high-pressure polymorph, diamond with increasing pressure.
In our laboratory, we can generate extreme condition corresponding to the earth`s surface to core using latest high-temperature and -pressure generating devices; a) Multi Anvil (MA) and a Diamond Anvil Cell (DAC). Thus, we can investigate materials of planet interior that we never obtain directly. We use synchrotron X-ray facilities, micro laser-Raman spectroscopy, and several electron microscopes (SEM, FE-SEM, EPMA, TEM, FE-TEM/STEM, and FIB) to analyzed samples recovered from MA and DAC experiments. We are also developing MA and DAC experiment techniques according to need.

 

(4) Planetary collisions:

Planetary collisions occur in the space. Some meteorites (ordinary chondrites, martian and lunar meteorites) record such dynamic events. High-temperature and –pressure conditions were generated by the dynamic events, leading to form high-pressure phases. The high-pressure phases mimic those of the earth`s interior. We are clarifying the phase transformation mechanisms of silicates with shocked meteorites, and also investigating the magnitude and ages of the dynamic events to elucidate the evolution of the solar system.