第157回ジオダイナミクスセミナー
　　　Geodynamics Seminar

　
　　　　　　　　　　　"P-V-T relation of phase D"

　　　　　　　　　講師：新名　亨（研究推進研究員）


　　　　　 主催　：　愛媛大学地球深部ダイナミクス研究センター
　　　　　 日時　：　２００６年６月２３日（金）17：00〜
　　　　　 場所　：　愛媛大学理学部講義棟　

　　

要　旨
　 Water affects the mineral constitution, melting temperature, rheological properties and seismic wave velocity structure of the mantle. The existence of water and its forms in the subducting slabs hence have been the focus of interest in many previous investigations. Many experiments have shown that water could be transported from the surface to deep earth's interior via subducting slabs through hydrous or nominally anhydrous minerals such as wadsleyite and ringwoodite. In hydrous minerals, dense hydrous magnesium silicate (DHMS) phases would be important water carriers because these phases are stable under the mantle transition zone conditions.
　 It has been experimentally reported that phase D is stable under upper part of the lower mantle conditions along cold slab geotherms and the highest pressure mineral in the DHMS phases. Therefore, phase D is the most important candidate to transport water into the lower mantle.
　 Recently, possibility of the phase transition of Phase D was reported and large change of the compressibility was predicted by first-principles study (Tsuchiya et al., 2005). In order to clarify the phase transition and compressional behavior of phase D under high pressure conditions, we have conducted in situ X-ray diffraction experiments using a combination of multianvil apparatus and synchrotron radiation at SPring-8.


　　　　　　　　問い合わせ先：土屋　卓久　　TEL　　　（089）927-8198
　　　 　　　　　　　　　　　　　　　　　　 E-mail　　takut@sci.ehime-u.ac.jp