安徽巢湖北部地区下三叠统和龙山组微生物岩及其意义

Microbialites and its significances from the Lower Triassic Helongshan Formation in Chaohu area, Anhui Province, south China

巢湖北部地区下三叠统和龙山组(Smithian亚阶中上段)含有特征明显的微生物岩。微生物岩包含微生物席和叠层石两种类型,其中最为丰富的类型是以蓝藻为主。该组微生物岩的普遍发育以及宏体化石组合的分布特征表明,和龙山组微生物岩可能是早三叠世生态环境开始改善、生物开始复苏的标志。微生物岩及微生物群落特征表明,该组很可能沉积于低能浅水环境中。

Microbialites,such as microbial mats and stromatolites, have been iound in the Lower Triassic Helongshan Formation （middle-upper Smithian）recently in Chaohu area, Anhui Province,east China. Microbial mats mainly consist of cyanobacteria and simpler green algae. Stromatolites, predominating with cyanobacteria, contain a lot of microorganism types. Microbialites,sedimentary features and special minerals suggest that the Helongshan Formation was deposited in quiet shollow environments,the characteristics of biologic evolution during the early Triassic in Chaohu area and other areas of south China indicate that the development of microbialites in Helongshan Formation might be a signature of the better beginning of environments and biological recovery in the Early Triassic.