Numerical Simulation on Filling Process of Faulted Basin in Response to Lake-Level Change

Understanding the filling process in response to variation of lake-level is important in faulted basin. In this paper, numerical simulation has been applied to analyze the filling characteristics of the Songliao faulted basin. To assess the effect of different parameters on the filling characteristics, lake-level change, tectonic subsidence and sediment supply are taken into consideration. Based on the filling features of the Songliao faulted basin, we simulated filling characteristics of this faulted basin during 3 lake-level fluctuated periods, in which tectonic subsidence and sediment supply are supposed as constants, and the lake-level change follows a sin-function. The modeling results indicated that: ① Variation of lake-level in the faulted basin is well compared with the global sea-level change. One cycle of lake-level change results in formation of a corresponding sequence, in which a sequence boundary formed at the lowstand period of lake-level; ② Amplitude of lake-level change controlled the distribution of corresponding sequence unit, the larger the lake-level change is, the larger the distribution area and the thicker the sedimentary thickness of the corresponding sequence are; ③ The sequence units due to lake-level change are well reserved at following favorable conditions, such as the subordinate lake-level change under the background of a continuous rise of lake-level or tectonic subsidence. The numerical modeling results in agreement with measured sequences have demonstrated the architecture of sequence units and filling processes in the Songliao faulted basin.