THE CHARACTERISTICS AND SEDIMENTARY ENVIRONMENT OF THE MIDDLE CARBONIFEROUS CARBONATES OF EASTERN SICHUAN

The Middle Carboniferous series of Eastern Sichuan is composed of brecciated carbonate with moderate thickness. Its petrographic classification, sedimentary texture, biological fossils and diagenesis reveal that it is of tidal flat deposit formed under hot and semi-arid climate. The sedimentary environment which can be devided into six subtypes has been reconstructed and used to establish a sedimentation model for Middle Carboniferous series of Eastern Sichuan. The strata of the Middle Carboniferous of Eastern Sichuan can be divided into five members which make up a lower complete transgression-regression sequence and an upper incomplete transgression sequence. The sedimentation of these five members in different localities are analysed. Horizontal correlations between them are carried out. General aspects of the lithofacies change of different members are showed clearly on a diagram of lithofacies profile. In the case of the lacking biological fossils, individual beds are correlated according to facies cycles.