Geological Survey of Japan, AIST, Tsukuba, Japan; College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, United States
College of Environmental Technology, Graduate School of Engineering, Muroran Institute of Technology, Muroran, Japan
Kyoto Fission-Track Co. Ltd., Kyoto, Japan
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, United States