Mixed siliciclastic and carbonate sediments are distributed extensively in Carboniferous strain in Inner Mongolia and could be divided into five types. Their formation related to sediment sources

the openness of lagoon

coastal feature and the effect of events. The effect of events continued throughout the whole mixing process

and thus causing the mixed sediments that formed in beach-shallow marine environment

inner continental shelf and outer the shelf to differ from each other. The best one is the mixed sediment formed in inner continental shelf environment.