Tephrostratigraphy of the Pliocene to Middle Pleistocene Series in Honshu and Kyushu Islands, Japan

摘要

The Pliocene to Pleistocene Series in each sedimentary basin or area of Japan has been investigated and described; however, their stratigraphic correlation is difficult because of complex geological structures. Regional stratigraphy has therefore been established using many intercalated tephra beds, i.e. by correlating tephra beds between distant areas. A standardized stratigraphic model of the Pliocene to Middle Pleistocene Series in Japan is put forward in this paper on the basis of tephrostratigraphy, magnetostratigraphy, and biostratigraphy. This stratigraphic model is important for studies of environmental changes and explosive volcanism in this period around the Japanese island-arc.