Abstract:

The Carboniferous System in Hetian River Gasfield was mainly formed of a set of interbedded clastic rocks,carbonate rocks as well as interbedded gypsum,mixed plateform shore clastic and shelf facies.The mixed plateform could be divided into tidal,limited plateform,beach,open plateform subfiacies.When the beach existed,all the subfacies would occur from the shore to sea direction;in reverse,the limited plateform and intraplateform subfacies would absent.But in early Carboniferous,it was formed by clastic shore shelf deposits.Carboniferous System in the area underwent the evolution of shore shelf to mixed plateform resulted from the middle late Hercynian tectonic movement,showing a large scale of ingression regression cycle from Bachu,Karashayi stages to Xiaohaizi stage in the Carboniferous Period.

Key words: sedimentary facies, shore shelf, mixed platform, evolution, Carboniferous System, Hetian River Gasfield