千葉県銚子地域, 名洗層群の下部層準に含まれる有孔虫化石群集

• Main Authors: 石川, 秀雄, 八田, 明夫, Ishikawa, Hideo, Hatta, Akio
• Format: Report
• Language: Japanese
• Published: 千葉大学教育学部 1984
• Subjects: NDC:370; Planktonic foraminifera
• Online Access: https://opac.ll.chiba-u.jp/da/curator/900025094/; https://opac.ll.chiba-u.jp/da/curator/900025094/KJ00004299371.pdf

The Naarai Formation, distributed in the southern part of Choshi Peninsula, is composed of tuffaceous sandstone containing many pumice and tuff. The thickness of the formation is about 120m, and the formation generally dips westward in 2 - 5 degrees. One of the horizon in the lower part of the formation, contains many balanus and foraminiferal fossils. The foraminiferal assemblage from the "Balanus horizon" in the Naarai Formation, is described and discussed in this paper from the stratigraphical and paleontological point of view. The results can be summarized as follows : (1) Juding from the ranges of the planktonic foraminifera, the age of the "Balanus horizon" may correspond with N.19 of Blow's zonation scheme (1969). (2) The planktonic ratio of the assemblage and the benthonic foraminiferal fauna indicate the paleo-enviroment of the middle bathyal condition.