Study on Fault Activity in Linnan Area of Huimin Depression, Bohai Bay Basin

摘要

Based on the analysis of growth index, fault throw and fault activity rate, we find the method of fault activity rate integrates advantages of other methods which avoids the influence of erosion and could carry out comparison among fault activities of different geological times. We optimize the method of fault activity rate to analyze the characteristics of fault activities in Linnan area and the results show: the main direction of the faults in Linnan area is nearly NEE-trending and most of the faults have two larger activity periods. It acts intensively in the period of Es2 and Ed and weakens in the period of Es1 and Ng. There is a small comeback in the period of Nm at last. We conduct the force analysis of this area based on stress ellipsoid and find that the stress state agrees well with the regional geological background. The evolution of faults is impacted by the subduction of the Pacific plate and the compression of the Indian Ocean plate.