塔里木盆地下石炭统巴楚组岩相古地理特征及演化

Lithofacies Palaeogeography and Evolution of Bachu Formation of Lower Carbonniferous in Tarim Basin

在对塔里木盆地下石炭统巴楚组周缘野外露头剖面、钻井以及岩心观察,地层划分与对比的基础上,结合地震解释资料将巴楚组分为4个岩性段,识别出4种类型的沉积体系,即滨岸沉积体系、碳酸盐台地沉积体系、陆棚沉积体系和扇三角洲沉积体系。研究表明巴楚组岩相古地理具有4个主要的演化阶段,分别为初始海侵期盆地西部浅海陆棚与中部障壁海岸发育阶段,最大海泛期盆地西部开阔台地与中部局限台地发育阶段,海平面缓慢下降期盆地西部局限台地—蒸发台地与中部障壁海岸发育阶段,急速海侵期盆地西部开阔台地与中部局限台地发育阶段。塔里木盆地北部、东部以及中南部地区在整个早石炭世遭受隆起剥蚀,为盆地内部提供了稳定的物源。

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.