Dayanping Fm

Central-westernmost Hubei. The formation was named by the Party of Regional Geological Survey, Hubei Bureau of Geology in 1974. The type section is at Honghua-Dayanping area, Shennongjia Forest Region, Hubei Province. Synonyms: Yulongting Fm, Tianzhuping Member and Jiucaiyazi Fm. Lower formation (2 of 11 in Lexicon) of Shennongjia Gr.

Synonym: （大岩坪组）

The Dayanping Fm is of carbonate-flysch association, dominated by dark-grey, grey-black thin-bedded dolomitic siltstone, sandwiched with conglomerate dolo-arenite and muddy nodular limestone lenticules. The formation is roughly subdivided into three parts. Lower part consists of dark-grey to grey-black thick-bedded dolomitic siltstone intercalated with conglomerate and dolo-arenite. Middle part is thin-bedded dolomitic siltstone, with dolo-arenite bands and stromatolite limestone, nodular limestone and conglomerate lenses. Upper part consists of thin-bedded dolomitic siltstone and syngenetic breccia sandwiched with dolo-arenite, purple-red argillaceous dolomite. The scouring troughs and syngenetic clasts are seen in the strata. The formation is 1346 m thick. [Note: the term "dolomitic siltstone" was assumed here to be sugary-textured dolomite.]

Both the dolomite and marl yield stromatolites, the main taxa are Anabaria f., Jurusania f., Linella miaopingensis, Eucapsiphora emphysema, Dayanpingella microcolumnaris. The siltsone contains microplants, the main taxa are: Trematosphaerdium, Polyporata obsoleta etc.