广东郁南县连滩镇大尖山下志留统连滩组笔石动物群和地层对比

Graptolite Biostratigraphy of Liantan Formation of Lower Silurian of the Dajianshan in Liantan,Yunan County,Guangdong Province

广东省郁南县连滩镇大尖山的下志留统连滩组岩性主要为深灰色页岩,含丰富的笔石化石。通过对连滩组笔石化石的系统采集与研究,鉴定出6属12种,分别属于(1)Demirastrites triangulatus带;(2)Demirastrites convolutus带;(3)Monograptus sedgwickii带。研究区连滩组笔石化石组合与湖北宜昌龙马溪组、西秦岭南带安子沟组、陕南宁强龙马溪组、四川城口双河场组、北祁连山肮脏沟组和东秦岭东段张湾组的笔石化石组合可以进行对比,表明研究区连滩组的地质时代为早志留世埃隆期。

The Lower Sliurian Liantan Fro, consisting of shales, is well developed at Dajianshan, in Lian- tan,Yunan County, Guangdong Province. Based on detailed research on the graptolite of Liantan Fm, 6 genera and 12 species were found in the Dajianshan section. They respectively belong to 3 graptolite zones. ① Demirastrites triangulates ; ② Demirastrites convolutus ; ③ Monogra ptus sed gwickii. These graptolite as- semblages of Liantan Fm in the study area could be correlated with the graptolite assemblages of Longmaxi Fm in Yichang , Hubei Province, Anzigou Fm in the sounth of the West Qinling Mountains,Longmaxi Fm in Ningqiang, Shanxi Province,Shuangchanghe Fm in Chengkou, Sichuan Province, and Angzanggou Fm in the Northern Qilian Mountains and Zhangwan Fm in the east of the Eastern Qinling Mountains. Hence, the age of Liantan Formation in the stuy area should be Aeronian in the Early Sliurian.