About SHIMOKAWA K
About Geological Survey of Japan, Ibaraki
About IMAI N
About Geological Survey of Japan, Ibaraki
About HIROTA M
About Meteorological Research Inst., Ibaraki
About Chemical Geology. Isotope Geoscience Section
About volcanic rock
About Dating
About 電子スピン共鳴
About 火山岩
About 年令