About OKA SATOSHI
About TAKASHIMA REISHI
About NISHI HIROSHI
About ORIHASHI YUJI
About 日本地質学会学術大会講演要旨
About Hokkaido
About stratum
About Cretaceous Period
About planktonic foraminifera
About tuff
About carbon isotope
About animal fossil
About biostratigraphy
About chemostratigraphy
About uranium-thorium-lead dating
About Yezo group
About Mesozoic
About 北海道
About 下部白亜系
About 蝦夷層群
About 浮遊性有孔虫
About 化石
About 炭素同位体比
About 統合
About 層序
About 凝灰岩
About 放射
About 年代