MAGNETO-BIOSTRATIGRAPHY OF UPPER CRETACEOUS SYSTEM IN JAPAN

日本上白垩系地磁生物地层学

• 批准号: 08640592
• 负责人: KODAMA Kazuto
• 金额: $ 1.02万
• 依托单位: KOCHI UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640592/
• 关键词: MAGNETOSTRATIGRAPHY; UPPER CRETACEOUS; HOKKAIDO; KYUSHU; YEZO GROUP; POLARITY CHRON; BIOSTRATIGRAPHY

A line of magnetostratigraphic studies were done focusing on the upper Cretaceous Yezo Group in central Hokkaido. Four magnetozones of normal or reversed polarity were recognized from the upper part of the Osoushinai Formation distributed along the Abeshinai River and its tributaries in Teshio-Nakagawa area. In addition, a pair of normal and reversed polarity magnetozones were recognizable from the uppermost Haborogawa Formation in Haboro area. Comparison of these magnetozones with a geomagnetic polarity time scale led to a possible magnetic polarity interpretation that the four magnetozones could be correlated from top to bottom to the late Cretaceous magnetic polarity chrons C32r.1r, C32r.1n, C32r.2r, and C33n. In terms of macro-fossil stratigraphy, the Sphenoceramus schmidti zone is correlated to polarity chron C32r.1r, the Sphenoceramus orientalis zone to C32r.1n, and the upper part of the Polyptychoceras pseudogaultinum zone to C32r.2r.Paleomagnetic studies were also conducted for the upper Cretaceous strata in Kyushu including the Goshoura Group, the Mifune Group, the Ohnogawa Group, and the upper Konmon Group. All these strata are of normal polarity correlatable to the Cretaceous long normal polarity chron, C34n.

对北海道中部上白垩统叶佐群进行了一系列磁性地层学研究。在手盐-中川地区的大西内组上部，沿沿着阿贝志内川及其支流分布，识别出4个正极性或反极性的磁带。此外，在羽幌地区的羽幌川组最上部还可识别出一对正极性和反极性的磁带。这些磁带与地磁极性时间尺度的比较导致了一种可能的磁极性解释，即四个磁带可以从上到下与晚白垩世的磁极性年代C32r.1r，C32r.1n，C32r.2r和C33 n相关。在宏观化石地层学方面，将Sphenoceramusschmidti带与极性年代C32 r. 1 r相对比，将Sphenoceramusorientalis带与极性年代C32 r. 1 n相对比，将Polyptychoceraspseudogaultinum带上部与极性年代C32 r. 2 r相对比。这些地层均为正极性地层，与白垩纪长正极性地层C34 n相对应。

项目成果

Kodama, K.: "Visit to Sakhalin for studies of Cretaceous geomagnetism." National Science Museum News. 333. 8-9 (1997)

Kodama, K.：“访问萨哈林岛，研究白垩纪地磁。”

Kodama, K., Maeda, H., Shigeta, Y., Kase, T., and Takeuchi, T.: "Magnetostratigraphy of Upper Cretaceous strata in South Sakhalin, Russian Far East." Cretaceous Research. (in press). (1998)

Kodama, K.、Maeda, H.、Shigeta, Y.、Kase, T. 和 Takeuchi, T.：“俄罗斯远东地区南萨哈林岛上白垩纪地层的磁性地层学”。

小玉 一人, 武田 哲一: "御所浦島の地質-第6章" 御所浦町全島博物館構想推進協議会, 120 (1997)

Hitoshi Kodama、Tetsuichi Takeda：“Goshoura 岛的地质 - 第 6 章”Goshoura 镇岛屿博物馆概念促进委员会，120 (1997)

小玉一人・武田哲一: "御所浦島の地質(第6章)" 御所浦町全島博物館構想推進協議会, 120 (1997)

Hitoshi Kodama 和 Tetsuichi Takeda：“Goshoura 岛的地质（第 6 章）”Goshoura 镇岛屿博物馆概念促进委员会，120（1997 年）

Kodama, K., et al.: "Magnetostratigraphy of Upper Cretaceous strata in South Sakhalin,Russia" Cretaceous Research. (印刷中). (1998)

Kodama, K. 等人：“俄罗斯萨哈林岛南部上白垩纪地层的磁力地层学”白垩纪研究（1998 年）。