The Cretaceous period
The Cretaceous period
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DOI：
10.1144/gsl.sp.1964.001.01.17
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发表时间：
1964
期刊：
影响因子：
--
通讯作者：
R. Casey
中科院分区：
文献类型：
--
作者：
R. Casey
综述了白垩纪大量放射性测量数据中的50个重要项目，并接受以下日期作为讨论的基础：侏罗纪-白垩纪（Volgian-Ryazanian）边界：1.36亿年;下白垩纪-上白垩纪（阿尔比亚-塞诺曼阶）界线：1亿年;上白垩纪-第三纪（Maestrichtian-Danian）界线：64百万年这一时期的精确地质年代学规模受到以下因素的阻碍：火成岩事件的地层测年不足、沉积物来源（碳酸盐岩）的结果不可靠，以及国际上对白垩系的界限缺乏一致意见。
Summary Fifty significant items from the large body of radiometric data on the Cretaceous period are reviewed and the following dates are acceptedas a basis for discussion: Jurassic-Cretaceous (Volgian-Ryazanian) boundary: 136 m.y.; Lower Cretaceous-Upper Cretaceous (Albian-Cenomanian) boundary: 100 m.y.; Upper Cretaceous-Tertiary (Maestrichtian-Danian) boundary: 64 m.y. A precise scale of geochronology for this period is impeded by inadequate stratigraphical dating of igneous events, unreliability of results from sedimentary sources (glauconite), and lack of international agreement on the limits of the Cretaceous System.