【摘要】 桐庐沈村剖面船山组,主体为深灰色泥晶灰岩,厚138.77m,与下伏地层黄龙组、上覆地层梁山组均呈整合接触,是一个跨系的岩石地层单位。在该组中划分出5个化石带:下部为①Streptognathoduselegantulus牙形刺带和②Triticitessubcrassulus带,归属逍遥阶;中部为③Sphaeroschwagerinasubrotunda带,归属紫松阶;上部为④Eoparafusulinapseudosimplex带和⑤Sweet-ognathusparaguizhouensis牙形刺带,归属隆林阶。石炭系与二叠系的界线位于Triticitessubcrassulus带与Sphaeroschwagerinasubrotunda带之间,即沈村剖面第15层与16层之间。船山组可划分出3个正层序(OS)和7个四级层序(SS),主要成岩环境为潮坪相、台地相和台地边缘相3种类型。对船山组中—上部高频旋回研究显示,每个米级旋回层时限约0.3Ma,主要受地球偏心率长周期400ka的控制。蜓蜓蜓更多还原

【Abstract】 The Chuanshan Formation exposed at the Shencun section, Tonglu County, consists predominantly of dark gray micritic limestone, 138.77 m in thickness. It is conformably underlain by the Huanglong Formation and overlain by the Liangshan Formation. Five fossil zones have been recognized in the formation; they are in ascending order:① the Streptog- nathodus elegantulus conodont zone,belonging to the Xiaoyaoan Stage;② the Triticites subcrassulus fusulinid zone,also be- longing to the Xiaoyaoan Stage;③ the Sphaeroschwagerina subrotunda fusulinid zone,belonging to the Zisongian Stage;④ the Eoparafusulina pseudosimplex fusulinid zone, belonging to the Longlinian Stage; and⑤ the Sweetognathus paraguizhouensis conodont zone,also belonging to the Longlinian Stage. The Carboniferous- Permian boundary lies between the Triticites sub- crassulus zone and Sphaeroschwagerina subrotunda zone, i.e. between bed 15 and bed 16 of the Shencun section. The Chuanshan Formation section may be divided into three 3rd- order sequences (Os)and seven 4th- order sequences (Ss),and three main diagenetic environments may be distinguished:tidal flat facies,platform facies and platform margin facies. The study of high- frequency sedimentary cycles in the middle and upper parts of the Chuanshan Formation indicates that the time range of every meter- scale cyclothem is 0.3 Ma,which is mainly controlled by the long cycle (400 ka)of the Earth’s eccentricity.更多还原