Correlation of the Susg Tephra Bed in the Niitsu Hill to the Tephra Bed in the Nanaorezaka Formation in the Aizu region, northeast Japan and the corerlation of the Shirakawa Pyroclastic Flow deposits to the Niigata region

The Susg Tephra Bed in the Sugenosawa Formation in the Niitsu Hill in Niigata region was correlated to the Irt-A Tephra Bed in the Nanaorezaka Formation in the northwestern Aizu region on the basis of their horizon, petrography and chemical composition of glass shards (FeO^*=1.18-1.19%, CaO=1.14-1.15%). These Tephra Beds can be correlated to the Nishigo Pyroclastic Flow deposit in the Shirakawa area, erupted from the Narioka Caldera in the Aizu region at about 1.15Ma. Correlations of the thick-bedded Shirakawa Pyroclastic Flow Deposits erupted in the Aizu region in the early Pleistocene of about 1.55-0.95Ma to the tephras in the Niigata and Boso regions were also examined