上扬子区下志留统四射珊瑚组合带与层序地层序列的关系

根据动物群演替和层序地层的研究，厘定上扬子区下志留统（Ｌｌａｎｄｏｖｅｒｙ）四射珊瑚组合带序列：（１）香树园组Ｄｉｎｏｐｈｙｌｕｍ Ｒｈａｂｄｏｃｙｃｌｕｓ组合带，时限为Ａｅｒｏｎｉａｎ期；（２）雷家屯组下部Ｓｔａｕｒｉａ Ｂｒｉａｎｔｅｌａｓｍａ组合带；（３）雷家屯组上部Ｍａｉｋｏｔｉａ Ｋｏｄｏｎｏｐｈｙｌｕｍ组合带，它们对应于Ｔｅｌｙｃｈｉａｎ早期；（４）宁强组Ｇｙａｌｏｐｈｙｌｏｉｄｅｓ Ｉｄｉｏｐｈｙｌｕｍ组合带，相当于Ｔｅｌｙｃｈｉａｎ晚期。上扬子区下志留统可以划分为５个三级层序，四射珊瑚组合带分别位于三级层序的高水位体系域内

LOWER SILURIAN (LLANDOVERY)RUGOSE CORAL ASSEMBLAGE ZONES AND THEIR RELATION WITH DEPO SITIONAL SEQUENCE OF UPPER YANGTZE REGION, CHINA

The Lower Silurian (Llandovery) rugose coral assemblage zones of Upper Yangtze region is reviewed based on the study of rugose coral fauna succession and sequence stratigraphy. In ascending order they are: Dinophyllum Rhabdocyclus assemblage zone of Aeronian age, occurring in the Xiangshuyuan Formation; Stauria Briantelasma assemblage zone of the lower part of the Leijiatun Formation and Maikottia Kodonophyllum assemblage zone of the upper part of the Leijiatun Formation, both being early and middle Telychian in age; and Gyalophylloides Idiophyllum assemblage zone of the Ningqiang Formation, corresponding to late Telychian. Five third order sequences are recognized from the Lower Silurian of Upper Yangtze region. The rugose coral assemblages mentioned above are all present in the high systems tracks of the third order sequences.