Miaochong Fm

The type section is located at Miaochong (gully), Yangshan Coal Mine, Gushi, Henan. It was named by Wang Deyou in 1977.

Siltstone, Sandstone and Conglomerate. Lower Member consists of clayey siltstone and moderately coarse-grained Fe-bearing clayey quartz sandstone, intercalated with silty mudstone, pebbly coarse-grained lithic quartz sandstone and gray-white thin-bedded clay shale, 712 m thick. For the Upper Member, the bottom is differentiated from the lower member with a conglomerate layer; the lower part is composed of mudstone and calcareous-silty mudstone, intercalated with thin-bedded sandstone, conglomerate and sedimentary quartzite; the middle part is of thick-bedded quartz conglomerate intercalated with moderately coarse-grained Fe-bearing clayey quartz sandstone; the upper part is of dolomitic fine-grained siltstone intercalated with limestone, dolomitic quartz sandstone, pebbly quartz sandstone, quartz conglomerate, etc., 716 m thick.

Lower Member yields Bivalves Parallelodon sp., Edmondia sp., Myalinella sp., Selenimyalina sp., Septimyalina sp. and Schizodus sp. as well as brachiopods and minor plant fragments. The mudstone in the lower part of the Upper Member contains abundant bivalves Dunbarella sp., Astartella sp., Palaeoneilo sp., Posidoniella sp., etc., fusulinids Pseudostaffella sp., etc., as well as brachiopods, gastropods, cephalopods, corals, crinoid stems, etc.

It is interpreted as piedmont-depression littoral facies of terrigenous clastics