Hongluoxian Fm

The type section is lies around Hongluoxian, about 20 km north of Jingxi City, Liaoning. It was named by Song Zexun in 1935.

Claystone, Coal and Sandstone. It is formed by gray-white, gray and black shale, sandstone and conglomerate, intercalated with coal seams, and with irregular bauxite shale at bottom. 90−120 m thick.

The shales contain Plants Calamites cistii, C. suckowii, Lobatanularia sinensis, Sphenophyllum oblongifolium, Cladophlebisnystroemii, Alethopteris scendens, Cathaysiodendron chuseni, C. nanpiaoense, Odontopteris chui, Neuropteris wutaotingensis, Emplectopteris alatus, etc. To the southwest of Yushu Village, Yangjiazhazi, the black slaty shale in the middle formation yields Brachiopods Chonetes cf. latesinuata, Dictyoclostus taiyuanfuensis, D. grauenwaldti, Schellwienella sp., Streptothynchus kayseri, etc.; bivalve Sangusinolites cf. olseni, etc.

It is interpreted as neritic terrigenous clastic deposits, locally changed into marine-continental deposits.

In the areas bordering Liaoning and Hebei, nomination of this formation and some corresponding strata is confused, including the Wudaoling bed of the formation. Those corresponding to the formation include the Liuhe coal containing bed and the Jinxi Series, and those partly corresponding include the Nanpiao Series, Sanjiazi Series, Yinwo conglomerate bed and Laoqiangda conglomerate, and also Maquanzi, Beishan, Zhangjiazhuang, Labagou and Huangshenshan beds. There still lacks a representative stratigraphic cross-section for the strata named after Hongluoxian. In the Regional Stratigraphical Scale of Liaoning, this formation was divided into two, and attributed into the Taiyuan Fm and Shanxi Fm respectively.