晚二叠世初期上扬子盆地西部康滇古陆的隆升,是形成其东侧区域西高东低构造格局的首要因素,并控制了各期由陆到海沉积相带与富煤带随海侵向西超覆的抬升迁移.重庆市西部地区在龙潭期位于扬子盆地海陆过渡相区的东部,区内发育海陆过渡沉积相区-海湾潮坪沉积体系与浅海相沉积区,海湾潮坪沉积体系是本区主要聚煤场所.从层序地层分析,将二叠系上统划分为2个三级层序,其中层序1发育完整,主要煤层C25煤形成于海侵域之海侵初期,C18+19.煤形成于高位域内次级层序的海侵期.%The uplift of the Xikang-Yunnan old land in the upper Yangtze Basin during the early Late Permian Epoch, is the principal factor in the formation of high east and low west tectonic framework of the region on its east side, and controlled each stage sedimentary facies belts from terrestrial to marine and overlapping rising migration of coal rich zones along with the transgression westward. The western Chongqing region is situated in the eastern part of Yangtze Basin marine-terrestrial transitional facies belt during the Longtan stage. Marine-terrestrial transitional sedimentary facies region -embayment tidal flat depositional system and neritic depositional region were developed in the area, while the embayment tidal flat was the main coal accumulation site in the area. From sequence stratigraphic analysis, the Upper Permian Series can be subdivided into 2 third -order sequences, in which, the sequence I has integrally developed, main coal seam C25 was formed in transgression systems tract initial stage, while C18_19 coal in highstand systems tract second-order transgression stage.
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