@article{oai:niigata-u.repo.nii.ac.jp:00026801,
 author = {黒川, 勝己 and 樋口, 裕也},
 issue = {1},
 journal = {新潟大学教育人間科学部紀要 自然科学編, 新潟大学教育人間科学部紀要 自然科学編},
 month = {Oct},
 note = {In the Niigata region, hundreds of tephra beds are found in the Pliocene and the early Pleistocene Formations of marine and non-marine sediments. The framework of the tephro stratigraphy of these Formations has been established so far, and widearea correlations to the central Japan have been also documented. In this paper, further examinations of the stratigraphic relations and correlations of the tephras of the middle of the Pliocene (about 3.7-2.2Ma) in the Niigata region were carried out. The stratigraphic relations of the Nwg and Arg Tephra Beds of around 3.0Ma were clarified; that is Nwg-1, Nwg-2=identical to Arg-1, and Arg-2 in the accending order. Above the Arg-2 which is very important marker beds in central Japan, another useful marker bed in the Niigata region, namely the Mot Tephra Bed, was revealed. The Tsp Tephra Bed of around 2.25Ma has been widely detected in the fluvial to hemibathyal Formations in the Niigata region, and further it was correlated northwards to the Miyp Tephra Bed in the Niitsu Hill and to the Wzp and Kog Tephra Beds southwards in the northern Uonuma Hills. Chemical composition of the mafic minerals was also referred at the Tsp correlation. The YT1 and YT2 Tephra Beds in the Himi Group in the Toyama region are possibly correlated to the Ojw-2 and Ocg (Ojw-3) Tephra Beds, and the TY4 Tephra Bed is correlative to the Thw-3 Tephra Bed in the Niigata region respectively. The Ocg (Ojw-3) is situated about 5-2m above the Ymp (Ojw-1), which is widely detected in the Niigata region. The correlation of the Ymp Tephra Bed to the An112 Tephra Bed in the Anno Formation in the Boso Peninsula was also suggested. Considering the magnetostratigraphical studies in the Himi and Boso regions, the Ymp Tephra Bed is suspected to be around 3.7Ma in age.},
 pages = {13--78},
 title = {新潟地域の鮮新世中頃(4-2Ma)のテフラ層序の再検討と広域対比 : とくにNwgとArgテフラ層の層位関係,Tspテフラ層の分布と対比および氷見層群のYTテフラ層,安野層のテフラ層との広域対比の検討},
 volume = {7},
 year = {2004}
}