谭庄—沈丘凹陷位于华北克拉通南部,大别山北缘与华北克拉通接壤部位的周口坳陷内。区内下白垩统地层厚度巨大,沉积和沉降中心偏于盆地南侧。沉积物以细粒陆源碎屑砂岩、粉砂岩和泥岩为主;岩石中富含火山碎屑,成分成熟度和结构成熟度中等;发育一系列牵引流成因的沉积构造,属于与河流三角洲——滨浅湖沉积体系及其沉积相的组合,早白垩世沉积物源供给主要来自南部。盆地的发育和演化及早白垩世沉积主要受南部边界的叶鲁断裂控制,属于张性正断层,后期该断层发生明显地向盆地方向的逆冲。依据下白垩统砂岩组分构造属性、砂岩岩屑组分、沉积物常量元素和稀土元素地球化学特征分析以及与南部大别山造山带火山岩发育年代的对比等综合分析认为,谭庄—沈丘凹陷形成于早白垩世伸展大地构造背景,是受大别山北缘山盆耦合作用影响形成的断陷型沉积盆地。 Tanzhuang - Shenqiu depression is located in the northern part of North China Craton, the northern edge of the Dabie Mountains and North China Craton in the vicinity of the Zhoukou depression. The Lower Cretaceous strata in this area are huge in thickness, with sedimentary and subsidence centers on the south side of the basin. The sediments are mainly composed of fine-grained terrigenous clastic sandstone, siltstone and mudstone. The rocks are rich in volcaniclastic debris with moderate maturity and structural maturity. A series of depositional structures are formed that are responsible for the formation of traction flow, The combination of foreland shallow lake sedimentary system and its sedimentary facies, the source of sediments in the Early Cretaceous comes mainly from the south. The development and evolution of the basin and the deposition of the Early Cretaceous are mainly controlled by the Yelu fault on the southern boundary, which belongs to the Zhangxingzheng fault. In the later period, the fault of this fault was obviously thrust to the basin. According to the structural characteristics of the Lower Cretaceous sandstone components, the analysis of the lithofacies components, the sedimentary elements and the REE geochemical characteristics and the comparison with the volcanic age of the Dabie orogen in the southern part of the country, it is concluded that the Tanzhuang-Shenqiu depression Extending the tectonic setting during the Early Cretaceous, it is a fault-depression sedimentary basin formed by the coupling of the mountain basin in the northern margin of the Dabie Mountains.