1. Research Institute, The University of Tokyo, 1-15-1, Minamidai, Nakano-ku, Tokyo 164, Japan
2. Deep-sea Research Department, Japan Marine Science and Technology Center, Natsushima, Yokosuka, Kanagawa-Pref. 237 Japan
3. Laboratory for Earthquake Chemistry, The University of Tokyo, Hongo, Bunkyoku, Tokyo 113, Japan
4. Earthquake Research Institute, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113, Japan
5. Department of Chemistry, University of the Ryukyus, Senbaru, Nishihara-cho, Okinawa-Prefecture 903-01 Japan