著者

松本 達郎 西田 民雄

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.68, pp.1-12, 2000

参考文献数

35

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In connection with the global standard of the Albian-Cenomanian boundary which was proposed at Brussels in 1995 and has been under discussion, we are working on the biostratigraphy of the late Albianearly Cenomanian succession in selected areas of Hokkaido. In this paper a result of our study in the Shuparo Valley of central Hokkaido is presented. Although the clastic sedimentaries in the area are not necessarily prolific, some worldwide ammonoid species have been obtained at several horizons (see Figure 1), which are tentatively correlated with the subzones in West Europe (Table 1). The stage boundary can, thus, be placed approximately between the Members IIb 2 and IIc in this area. There is, however, a considerable difference in the faunules of successive subzones between Japan and West Europe. In comparison with the ammonite biostratigraphy, some comments are given on the previous results of the foraminiferal biostratigraphy in this area. There are layers of tuff at several levels in the succession of Hokkaido, which would be useful to supplement the biostratigraphic correlation.