| The paper picks Huimin sag up as object for study which combine the inner faults inderpression with fastigiate faults in the north of the Western Shandong uplift, and researchsthe faults’ geometry and kinematics characteristics by geological surveys, structural geologyand geophysical methods.During the Paleocene-early Eocene, there were mainly two fault systems: extensionalfaults and strike-slip faults. The extensional faults, with diverse geometry, extend to NE orNEE and include strike-parallel，fastigiate，feather pattern in the plane; correspondingly, theypresent planar，listric，sloping floor type in the section and form step-shaped， Y·-shapedfaults and graben，horst. The strike-slip faults, extending to NNW and intersecting withextensional faults in large angle, have transtensional characteristics indicated by the negativeflower structure and wave-like form in the section—Baiqiao fault for example. Aftercalculating the elongation of geological section and the main faults’ activity rate, we concludethat most of the extensional movement occurred in Ek and Mz, coupling with fact that themiddle of sag extend larger than both the east and west side; Xiakou fault, Ningnan fault,Linnan and qudi faults acted intensively in this time. Strike-slip faults were formed as transferfault in order to adjust the variation produced during the extending process. Under thisassumption, the sinistral strike-slip displacement of Baiqiao fault was about5km. Physicalsimulation of Huimin sag simulated the evolution process of main faults in the Paleocene-early Eocene. With the development of Xiakou fault, the Qudi fault gradually developedbetween Xiakou fault and Qiguang fault. Qudi fault played a significant role in regulation.Linyi fault started at the end of the period.Using the optimum estimation by porosity data to calculate the erosion amount during Paleocene-early Eocene, the study finds that the northern salient and the southern slopeeroded most. After composing original stratigraphic thickness contour map and erosionstratigraphic thickness contour map, combining the investigation about palaeostructure, werestored the prototype basin in Es4. After analysing the prototype basin, we find that thedepocenters distribute along the faults; compared with residual basin, the prototype basin hasa wider range. |
