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Yuguchi, Takashi; Tsuruta, Tadahiko; Nishiyama, Tadao*
no journal, ,
Hanamuro, Takahiro; Ninomiya, Atsushi; Umeda, Koji
no journal, ,
Helium isotope ratio is a profitable index to detect the contribution of the material derived from deep underground. In this study, isotope ratio of helium gas trapped in fluid inclusions within quartz vein are analyzed. Samples are collected from the mylonites of the Ryoke belt and black schists of the Sambagawa belt along the Median Tectonic Line (MTL) at Tsukide area. The result is that high 
He/
He ratio are observed along MTL, suggests that the fluid including helium derived from deep underground with high He/He value have risen along MTL when the quartz vein was formed.
Sano, Asami; Yagi, Takehiko*; Komatsu, Kazuki*; Otani, Eiji*
no journal, ,
Neutron diffraction experiments have been succeeded in determining of hydrogen position in many hydrous minerals. By contrast, little application to nominally anhydrous minerals has been done, despite its importance in the mantle. Wadsleyite, a high pressure polymorph of olivine, is a main constituent of shallower part of the mantle transition zone at the depth from 410 to 520 km. Ever since Smyth (1987) predicted that protonation of O1 site of wadsleyite results in significant amount of water content up to 3.3 wt%, hydration of wadsleyite and related change in physical properties has attracted much attention. However, several mechanisms of protonation have been proposed and the position of hydrogen in wadsleyite still remains controversial, because previous studies are based on X-ray diffraction and spectroscopic methods. To determin the hydrogen position precisely, we conducted neutron diffraction experiment on hydrated and deuterated wadsleyite at D20 in ILL, in France.