Lithofacies Palaeogeography and Evolution of Bachu Formation of Lower Carbonniferous in Tarim Basin
塔里木盆地下石炭统巴楚组岩相古地理特征及演化

Based on comprehensive analysis of field section,drilling well data,well core,and the detailed stratigraphic division and correlation,combining with the seismic interpretation data,the Bachu Formation was divided into four lithologic members,and four depositional systems identified,which are littoral depositional system,carbonate platform depositional system,shelf depositional system and fan delta depositional system.Combining with the tectonic setting and the characteristics of sea-level change,the lithofacies palaeogeography of Bachu Formation was divided into four evolution stages.The stage of initial transgressive with shelf deposition in the western and tidal flat deposition in the central part of Tarim basin,the stage of maximum marine flooding with open platform deposition in the western and restricted platform deposition in the central part of Tarim basin,the stage of slow decline in sea level with evaporation platform deposition in the western and tidal flat deposition in the central part of Tarim basin,the stage of rapid transgression with open platform deposition in the western and restricted platform deposition in the central part of Tarim basin.In the early Carboniferous period,the northern,eastern and south-central part of Tarim basin in the uplift and erosion,and provide a stable source for sedimentation.