Strike-Slipping Characteristics of the Cicun Fault,North of the Western Shandong Uplift and its Reservoir-Controlling Significance

Field observation around a basin is an important way to understand tectonic evolution of the basin. Moreover,the geological characteristics of the outcrops could be applied to the faults which are not directly observed in the basin. This paper focuses on the geological characteristics of the Cicun Fault in the western Shandong Uplift and its effect on the deposition. Furthermore,an analogy between the outcrop and the basin in regarding of the sedimentary responses to the fault activity is conducted. There are a variety of strike-slipping-related geological characteristics in the fault zone,such as scratches,steps,limestone cataclasites,drag folds,two types of boudins,rhombic structure. What's more,the boudinage and rhombic structure are controlled by the lithological changes and local change of tectonic stress field. The linear structure,together with other evidence indicates that the Cicun Faults is a right-lateral normal strike-slip fault. The activity model of the Cicun Fault and its sedimentary responses are summarized. The Cicun Fault is also characterized by several imbricate sedimentary facies along the obliquely-slipping faults in Jiyang Depression,as well as the inclined fan-folds. Consequently,the sand bodies distributing along the strike controlled the formation of oil reservoir. Based on the comprehensively study,the results indicate that the Cicun Fault developed under the trans-extension at the Late Mesozoic,and it was resulted from the adjustment of the differential extension between the sub-blocks in the western Shandong Uplift.