摘要
云南曲靖德泽剖面下寒武统梅树村组待补段底和晋宁梅树村剖面小歪头山段底粘土岩层的岩石、矿物和元素地球化学特征表明,这些粘土岩层是由酸性火山灰蚀变而成的变斑脱岩。它们是同期火山喷发事件沉积的标志,也是滇东地区下寒武统梅树村组底界等时对比的标志层。根据这个标志层以及小歪头山段和待补段沉积序列的对比,梅树村剖面小歪头山段仅相当于小江断裂以东地区的待补段下部白云岩层,缺失上部硅质岩层,因而它不能代表滇东地区下寒武统梅树村组下段的沉积序列。
Wuchiapingian conodont succession can not be subdivided into eight conodont zones as proposed by Mei et al. (1994),but five conodont zones are present.They are,in ascending order: C.postbitteri,C.niuzhuangensis C.liuchangensis,C.leveni.C.guangyuanensis C.transcaucasica and C.orientalis Zones.The age of Gallowayinella, based on coexisting conodont fauna,is Wuchiapingian.It can not be used as a marker for the lower limit of Changhsingian Stage.The lower limit of the Changhsingian may be marked by the first occurrence of Clarkina subcarinata and/ or C.wangi. The Qibaoshan section may be a boundary stratotype section for the Wuchiapingian Changhsingian.
出处
《地层学杂志》
CSCD
北大核心
1997年第2期91-99,155,共10页
Journal of Stratigraphy
基金
国家自然科学基金
关键词
变斑脱岩
火山喷发事件
下寒武统
沉积
含磷岩系
conodont zones, Gallowayinella , Wuchiapingian Stage, Changhsingian Stage, Permian, Jiangxi