Institution: | aHokkaido Liaison, Geological Survey of Japan, Sapporo 060-0808, Japan;bFaculty of Education, Saitama University, Urawa 338-8570, Japan;cBureau of Geological Investigation, Ulaanbaatar 37-308, Mongolia;dRadiogenic Disposal Research Center, Geological Survey of Japan, Tsukuba 305-0808, Japan |