【摘要】 扬子地块西北缘二叠系-中三叠统以大套碳酸盐岩地层为主。本文应用碳酸盐岩层序地层学理论和方法,通过地震、露头、岩心和测井资料分析,在二叠系-中三叠统识别出升隆侵蚀不整合面、海侵上超层序不整合面、水下沉积间断层序不整合面、局部暴露层序不整合面等4种沉积层序界面,并将二叠系-中三叠统划分为11个三级层序23个体系域。通过层序地层对比,建立了研究区层序地层格架,在格架内分析了不同体系域的沉积相特征,认为台缘礁滩相和台内滩相为有利储集相带,且前者主要发育于层序Ⅰ的高位体系域(栖霞组),以及层序Ⅴ和层序Ⅵ的海浸体系域(长兴组和飞仙关组)。更多还原

【Abstract】 The Permian-Middle Triassic is mainly composed of carbonate rocks in the northwestern margin of the Yangtze block. In this paper, based on the application of theories and methods of carbonate sequence stratigraphy and the analysis of seismic data, outcrop, drill core and log information, we identify in the Permian-Middle Triassic strata four depositional sequence surfaces, i.e., erosional unconformity, transgression onlap sequence unconformity, subaqueous depositional break sequence unconformity and local exposure sequence unconformity. We also divide the strata into 11 third-level sequences and 23 system tracts. By the contrast of stratigraphic sequence, the sequence stratigraphic framework is established, within which characteristics of sedimentary facies of different system tracts are analyzed. And it’s concluded that platform edge reef and beach facies and platform inside beach facies are the best reservoir facies belts, and the former is mainly located in highstand systems tract of sequence I (Qixia Formation), and transgressive systems tract of sequence V (Changxing Formation) and sequence VI (Feixianguan Formation).更多还原