Piyaman Fm

The type section lies in the core of the Piyaman anticline and south of Langru, Xinjiang. It was named by Zhang Daole in 1972, and formally cited in The Paleozoic Erathem of Xinjiang in 1991.

Conglomerate to Claystone and Coal; and Limestone. It is divided into two members. Lower Member (south of Langru): the lower part, gray-yellow and gray-green clayey sandstone, siltstone, sandy mudstone intercalated with carbonaceous shale; the middle part is of gray-white quartzose conglomerate; the upper part is composed of brown-red sandy conglomerate, intercalated with clayey siltstone and coal seams. Upper Member (in the core of the Piyaman anticline): the lower part is of gray thick-bedded pebbly limestone and organic limestone; the middle part is of gray-white flaggy limestone and organic limestone intercalated with clayey-calcareous siltstone; the upper part is of gray-white thick-bedded pebbly organic limestone and moderately thick-bedded limestone. Total thickness 458.3 m.

Lower Member: lower part contains Brachiopods Dictyoclostus and Marginifera, Bivalve Annuliconcha, hornstone Michlinoceras, gastropods, etc.; upper part contain Plants Cardioneura, Sphenopteris and Calamites.

Upper Member: lower part contains Brachiopods Choristites and Avonia; Fusulinids Triticites, Schubertella, Boultonia and Parafusulina; coral Amplexus, as well as bivalves, gastropods, trilobites, etc; middle part contains Fusulinids Schubertella sp., Pseudofusulina and Hemifusulina; upper part contains Brachiopods Choristites and Notothyris, and Fusulinids Triticites and Hemifusulina

It is interpreted as marine-continental deposits