Abstract: The Carboniferous in Bashituo block of Tarim basin is divided into Bachu formation, Karrathayi formation and Xiaohaizi formation, with rock types of clastic rock, carbonate rock and laminated gypsolyte. The sedimentary facies is dominated by carbonate platform which includes three sub-facies of evaporation platform, restricted platform, open platform and six micro-facies. In the late Bachu the source area was retrograded towards north and northeast direction, and the terrigenous clastics trended towards rapid decrease, forming a set of bioclastic-enriched carbonate strata-restricted platform sub-facies deposit. The early-middle Karrathayi belongs to evaporation platform mixed with restricted platform sub-facies deposit, and the late Karrathayi to restricted platform environment. Xiaohaizi period was featured with open platform sub-facies deposit by the enlarging of transgression.

Key words: Tarim basin, Bashituo area, Carboniferous, sedimentary feature