Palaeoenvironments of the Delingha Basin in Qinghai during the Carboniferous

The analyses of 12 pieces of carbonate rock samples from the Carboniferous strata in the Delingha Basin, Qinghai have reflected that during the Carboniferous, the Delingha area was once in the marine saline water environments with saline and dysaerobic sea water, humid and highly evaporated conditions, and plenty of terrigenous supply. This type of humid and reducing environments may be favourable for the propagation of organisms and preservation of organic matter, and thus may be the ideal sites for the development of the Carboniferous source rocks. Vertically, higher salinity and stratification of sea water in the Keluke Formation suggest the relatively enclosed and salinized sea water in the restricted carbonate platform environment, while in the Huaitoutala and Zhabusagaxiu Formations, the sea water was well connected in the open carbonate platform environment. It can be seen that the total organic contents in the Keluke Formation are higher than those in the Huaitoutala and Zhabusagaxiu Formations in the Delingha Basin.