Filling process and evolutionary model of sedimentary sequence of Middle-Upper Yangtze craton in Hercynian-Indosinian(Devonian-Middle Triassic)
中上扬子克拉通海西-印支期(泥盆纪-中三叠世)沉积层序充填过程与演化模式

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 Hercynian-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-sequen