以“构造控盆、盆地控相、相控组合”的思路和“过程-响应”原理为指导,即壳-幔耦合、板块活动和构造运动形成盆地,盆地沉积充填形成层序与相带组合的时空展布,而不同级别层序格架中层序结构、体系域叠加样式及相带的时空组合与盆地沉积充填过程密切相关.在前人对中上扬子克拉通盆地取得丰富的研究与勘探成果基础上,加强沉积环境、层序结构与沉积充填过程等方面的研究,对深化研究区认识以及油气资源勘探具有重要意义.因此,通过层序剖面结构、体系域叠加样式和相带组合的沉积响应记录,分析这些记录特征的时空变化规律来有效地揭示盆地沉积充填过程.具体以反映盆地整体特性的构造-层序(二级层序)为基础,以反映盆地充填格架的层序地层(三级层序)为单元,以反映层序沉积充填过程的层序结构、体系域叠置方式(四级以上层序)和相带分布规律为剖析对象”的技术路线,探讨和实践了中上扬子克拉通盆地海西-印支期沉积层序充填过程,剖析典型盆地的充填特征,与分阶段建立沉积演化模式.研究认为,中上扬子克拉通海西-印支期与加里东期的相似性是均由克拉通内和克拉通边缘两大沉积域组成,经历了克拉通边缘伸展和由伸展到挤压的2个盆地演化阶段,差异性是该期盆地类型与演化分异明显.典型盆地沉积充填特征表明,不同时期盆地充填特征的差异性决定于沉积充填控制因素的变化,各因素的控制作用因时因地而异.构造-层序充填过程的控制因素复杂多样,包括同沉积断裂、古地理格局、古隆起、碳酸盐生产率变化、相对海平面变化、基底构造特征和构造运动等,各种控制因素通过对层序沉积充填的边界条件、古地理背景、沉积环境、物源性质、层序结构和叠加样式等方面的影响来控制层序的发育,而且是造成沉积层序充填特征差异性的根本原因.各阶段沉积模式具有个性鲜明的充填背景、沉积建造类型、相带展布规律、演化过程和控制因素.海西-印支期中上扬子克拉通台地内保持隆坳相间,台缘以台盆相间为特征,优质储层发育于台地内和台缘高能礁滩环境,台内滞留环境和台盆区为有利盖层和烃源岩发育区.%Guided by the idea of "tectonic-controlled basin, basin-controlled sedimentary facies, sedimentary facies-controlled source-reservoir-cap assemblage" and the principle of "process-response" , namely that the basin is formed by crust-mantle coupling, plate activation and tectonic movement, and the space-time distribution of the sedimentary sequence and the facies zone association is formed by the sedimentary and filling processes of basin, while the configuration of sedimentary sequence of different orders, the superimposed pattern of system tract and the space-time association of facies zone are closely related with the sedimentary filling process of basin. On the basis of many research and exploration results of the Middle and Upper Yangtze cratonic basin made by previous research findings, it is thought that further study on sedimentary environment, sequence configuration and the filling process of sedimentary and so on are significantly important to deepening the understanding and oil and gas resources exploration of the researched area. Therefore, relied on the sedimentary response records of the profile configuration of sedimentary sequence, the superimposed pattern of system tract and facies zone association, the sedimentary filling process of basin can be effectively revealed by analyzing the temporal and spatial variation law of these records. Specific technical route is that the tectonic-sequence (second-order sequence) that indicates the overall characteristics of basin is considered as the basis, the sequence stratigraphy (third-order sequence) that indicates the filling framework of basin is taken as the research unit Meanwhile, the sequence configuration, superimposed modes (above fourth-order sequence) and the distribution pattern of facies belts are taken as the research objects. This paper has discussed the sedimentary filling process of Middle-Upper Yangtze cratonic basin in Hercynian-Indosinian period, analyzed the filling characteristics of sedimentary sequence and its difference in typical basin and established the sedimentary evolution model in stages. It is found by the study that both the Middle and Upper Yangtze craton in Hercyru'an-indosinian period and Caledonian period (see Huang et al. , 2011) are similarly composed of two sedimentary system tracts including intracraton and craton-margin and undergo two evolutionary phases composed of the extension phase of craton-margin and the phase changing from extension to compression, while the differences between them are the different basin types and obvious evolutionary differentiation. Generally, the sedimentary filling characteristics of typical basin indicate that the difference between the filling characteristics of the basins in different periods depends on the change of the controlling factors of sedimentary filling process, and the controlling effect of each factor varies with time and place. Consequently, the controlling factors for the filling process of tectonic-sequence are complicated and changeable, which are composed of synsedimentary fault, palaeogeographic pattern, palaeohigh, the change of productivity of carbonate, the change of relative sea level, the tectonic characteristics of basement, tectonic movement and so on. Additionally, all these controlling factors can control the development of the sedimentary sequence by influencing some aspects of the sedimentary filling process of sequence including the boundary condition, palaeogeographic background, sedimentary environment, provenance property, sequence configuration and superimposed pattern, which is the basic reason for the difference of the filling characteristics of sedimentary sequence. Basically, the sedimentary model of each phase has distinguishable filling background, sedimentary formation type, distribution law of facies zone, evolutionary process and controlling factors. Especially, the middle and upper Yangtze craton in hercynian-indosinian is characterized by the framework of uplift-depression in introplatform and platform-basin in platform edge, in which the high energy environment of introplatform and platform edge provide a good material basis for the development of the high-quality reservoirs, such as the reef-beach, and the low energy environment of introplatform and interplatform basin for the high efficiency seal rocks and the better source rocks.
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