Ziliujing Fm

It was named by Arnold Heim as the Ziliujing System in 1930. The naming locality is situated in the vicinity of Zigong City, Sichuan Province; with the Xintiangou section at the Beibei District of Chongqing City serving as its reference section.

Synonym: （自流井组）

The formation can be subdivided into five members in ascending order as follows: 1) The Qijiang Member, the lower part of which is composed mainly of quartz-sandstones and mudstones, intercalated with carbonaceous shales and thin coal beds, occasionally with siderites; and the upper part of which is composed largely of hematites, siderites, quartz-sandstones, siltstones and mudstones, with a thickness varying from 5 m to 6 m, with the maximum thickness being of over 10-20 m; 2) the Zhenzhuchong Member, consisting of dark-purple mudstones, intercalated with grey-green siltstones lenses or thin layers, with a thickness of 50-75 m; 3) the Dongyuemiao Member, the lower part of which is composed of calcareous mudstones, being rich in calcareous concretions or limestone aggregates, and the upper part of which is composed of light-grey marl and shelly limestones, intercalated with shales, with a thickness of 6-9 m, its thickness being commonly of 10-30 m in other areas; 4) the Ma’anshan Member, the lower part of which is composed of purple mudstones, with its middle part consisting of dark-grey sandstones, and with its upper part consisting of purple mudstones and sandy mudstones, with a total thickness of 120-140 m, and being of 100-180 m in other regions; and 5) the Da’anzhai Member, which represents an alternating layer of blue-grey and light-grey limestones and crystalline limestones in association with dark-purple calcareous mudstones, with a thickness of 46 m.

The Zhenzhuchong Member yields Lufengosaurus sp. in the Chengyuan region. The Dongyuemiao Member yields abundant bivalves such as Pseudocardinia kweichouensis, Cuneopsis johannisboehmi, and reptiles as represented by Bishanopliosaurus youngi in other areas. The Ma’anshan Member yields vertebrates as represented by Sanpasaurus yaoi, Sinopliosaurus weiyuanensis and Peipehsuchus teleorhinus, in addition to bivalves and clam shrimp. And the Da’anzhai Member yields bivalves as represented by Apseudocardinia spp. and Lamprotula (Eolamprotula) spp., as well as fish as represented by Lepidotes luchowensis and L. chungkingensis.