Study on fault activities in Shahejie-Dongying period in Huimin Sag

The characteristics of the fault activities in Shahejie-Dongying period in Huiming Sag are researched by fault throw method.The results show that the sag goes through intensive extensional activities in Paleogene.The faults in the sag are mostly NE-trending,and the fault activities formed in different periods have segmentation.They have many kinds of geometrical morphologies.The fault activities in the border of the sag and within it form half-graben,half horst and graben-horst faulted blocks,and their combinational distribution makes Huimin Sag possess the structural character of north-south zonation and east-west blocking.During Es3 and the earlier period of Es2,Huimin Sag is rapidly extending faulted stage,its central anticlinal zone heaves and the fault activities in Linshang faulted zone and Xiakou faulted zone strengthen gradually.During Es2 and Ed periods,the extensional faulted activities weaken.The tectonic framework of Huimin Sag is basically formed by the tectonic evolution in Paleogene.