Precise correlation of Miocene to early pleistocene in Japanese Islands by means of widespread tephra beds

在日本列岛，特别是在日本中部新潟地区，研究了中新世至早更新世温层标志层及其广域相关性。新潟地区Uonuna群早更新世SK110和SK100层与博索半岛Kiwada组Kd25和Kd24层相对应。新潟地区西山组晚上新世Thw-3层和Ftj层分别与富山湾附近Himi群YT4层和UN层相对应。此外，还尝试了中新世温层的对比，但几乎没有成功。即中新世Kdg， Gtm。柴田市Uchisugawa组Skhq和Jng Tephra层可以与seng， Stm相对应。津川地区野村组Tmhq层和Snsg层。这些结果不仅可用于地层记录的准确时间标记，也可用于环境史的进一步研究。

The Miocene to early Pleistocene tephra marker beds and their widearea correlation were examined in the Japanese Islands, especially based on the Niigata region, central Japan. The early Pleistocene SK110 and SK100 Tephra Beds in the Uonuna Group in the Niigata region were corralated to the Kd25 and Kd24 Tephra Beds in the Kiwada Formation in the Boso Peninsula. The late Pliocene Thw-3 and Ftj Tephra Beds in the Nishiyama Formation in the Niigata region were correlated to the YT4 and UN Tephra Beds in the Himi Group around Toyama Bay respectively. Furthermore, correlation of the Miocene tephra beds were attempted, which have been scarcely successful. Namely, the Miocene Kdg, Gtm. Skhq and Jng Tephra Beds in the Uchisugawa Formation in Shibata City can be correlated to the Sng, Stm. Tmhq and Snsg Tephra Beds in the Nomura Formation in the Tsugawa area respectively. These results will be made in use for not only the exact time marker in the stratigraphic records, but also for the further research of environmental history.