1. 1 Geology Unit, Science Division, Department of Science, Graduate School of Science and Technology, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
2. 2 Department of Geology, Faculty of Science, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
3. 3 Division of Earth and Planetary Sciences, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto, Kyoto 606-8502, Japan
4. 4 Department of Forest Science, Utsunomiya University, 350 Mincho, Utsunomiya Tochigi, 321-8505, Japan