Abstract:

Based on the detailed description of fault system, this paper established different types of fault structure patterns
and analyzed the distribution characteristics of faults in the study area of Bodong by using abundant seismic data and combined
analyses of sections and time slice characteristics. Furthermore, we carried out studies of the controlling role that fault system
played on basin structures. It is concluded that the development characteristics of fault system in Cenozoic age was in accordance
with the right lateral stress-field of Tanlu fault which is expressed as NNE-trending strike-slip faults for main branches, NEtrending
tensional faults for secondary ones and near EW-trending faults for the least abundant ones. Also, faults can be
subdivided into slip typed, tensional-slip, slip-tensional, and tensional types. Besides, different types of faults have different
structures due to the effects of property and activity intensity. Fault system in different ages showed tremendous differences
because of stress transition of Tanlu fault from left lateral to right lateral and intensity transition between tension and slip.
According to the dominant impact that fault acted on basin structures, Cenozoic basin can be classified into four revolutionary
stages, i.e., transitional stage from left lateral to right lateral, slip-tension faulted stage, tension-slip faulted stage, and slipdepression
stage. Therefore, the identification of temporal and spatial differences of faults could be used as an important guideline
for the oil and gas exploration in Dodong area.

Key words: Bodong area, fault system, basin structure, evolutionary stage