Characteristics of Sedimentary-Tectonic Evolution and High-Resolution Sequence Stratigraphy in Luanping Basin

In order to describe the spatial distribution and the size of all facies in fan-delta depositional system, and to compare with the same kind of system, the detailed analysis of crop sequence stratigraphy is taken in the Luanping basin. This basin underwent 5 evolution stages including volcanic irruptions and tectonic subsidences under the actions of episode tectonic movements. Based upon the analysis of high resolution stratigraphic sequence units, high-resolution sequence for the fan-delta system which was developed in late phase. The first flooding surface is taken as the fourth order sequence interface and many recognizable marks of the interface are set up. They also elaborate the principle of dividing fifth order sequence. According to the opinions and principles mentioned above, the high-resolution sequence is subdivided in Luanping basin, into 2 sequences, 15 fourth order sequences, and more than 40 fifth order sequences. In addition, the paper describes the model of fan-delta depositional composition. It dominantly was shallow and coarse fan-delta sedimentary system which was controlled by the synsedimentary fault. The system was composed of 3 depositional associations and 17 genetic facies. Furthermore, the paper generalizes three modes of fan-delta development under the control of tectonic activities. When tectonic movement is equable shallow water and slow fan-delta system is formed. During the basin sabsidence was dominated, the steep and subdeep-shallow water fan-delta system would be formed. When the tectonic movement was dominated by the uplift of the basin margin, the coarse fan-delta system was developed. The conclusions have a strong analogy and referring value to energy resources' exploration and exploitation in East China's similar basin.