西藏班戈西南地区中二叠统下拉组岩性特征及时代讨论

Lithological characteristic and age discussion of middle Permian Series Xiala Formation in southwest area of Ban,ge, Tibet

通过剖面测制,将下拉组地层由下到上分为三段:其岩性特征为,一段为生物碎屑粉晶灰岩段,二段为礁灰岩段,三段为含生物碎屑白云质灰岩段。一段和二段采珊瑚、腕足、等化石。经中国科学院南京古生物研究所专家鉴定时代为中二叠世。

Through the profile measuring, the Xiala Formation is divided into three Members from the bottom to the top. The lithologic characters of the first Member is bioclastic limestone powder, the second one is the reef limestone section, the third one is the bioclastic dolomite limestone section. We collected corals, brachiopods and fusulinids fossil in the first and second Member. Identification by the experts of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, shows that age is the middle Permian Epoch.