Yamansu Fm

The type section is located at Dagou, Yamansu District, Xinjiang. It was named by Zhang Quanhui in 1958.

Limestone, Sandstone and Volcaniclastics. A suite of neritic terrigenous clastic rock, carbonate rock and pyroclastic rock. Dominantly dark-gray to gray thick-bedded limestone, bioclastic limestone, reef limestone, oolitic limestone, sandy limestone, clayey limestone, gray-green thick-bedded calcareous sandstone, greywacke-cobblestone, pebbly grit, calcareous siltstone, light-gray-green thin-bedded tuff, purple-gray tuff, tuffaceous sandstone and siltstone, occasionally intercalated with lava. Exposed thickness 2237 m. Westward to Aqi Mt., lavas increase, containing fusulinid Eostaffella sp., and regionally from east to west carbonate rocks decrease while volcanic rocks increase, 1826−2887 m in thickness.

Contains abundant Corals Yuanophyllum sp., Clisiophyllum sp., Gangamophyllum sp., Lithostrotion sp., Palaeosmilia sp., Hexaphyllia sp., Rotiphyllum sp., Dibunophyllum sp. and Cystodendropora sp.; Brachiopods Gigantoproductus sp., Striatifera striata, Linoproductus sp. and Chonetipustula sp.; Ammonoids Platygoniatites molaris, Proshumardites sp., Irinoceras sp., Dombarites paratectus and Syngastrioceras sp., as well as gastropods, bivalves, bryozoans, algae, etc.

It is interpreted as a neritic facies with volcanism.