关键词: 活动断裂, 晚更新世, 地表断错, 最大潜在地震

Abstract: The Haiyang fault of 115km length is a larger scale fault in the east of the NE striking Mu ping Jimo Fault zone in Jiaodong Peninsula, Shandong Province. This fault showed intense surface faulting during middle Pleistocene, while dip slip reverse displacement of larger than 1m on the fault can be identified in the field. Although the surface faulting along the fault has generally ceased since late Pleistocene, late Pleistocene surface faulting still occurred on the Dongshilangou segment of the fault. The Length of the Dongshilangou segment is about 8km. Detailed investigation along the segment shows that the latest surface faulting event occurred at 37～12ka B.P., and most possibly near 12ka B.P. The surface faulting has a total length of 6.5km or more, and is dominated by right lateral strike slip with small amount of dip slip reverse component. The observable maximum dip slip displacement is about 0.2m, and the right lateral displacement is about 1.13m as deduced from the plunge of fault striae. The average right lateral strike slip rate is estimated to be 0 094mm/a and the dip slip rate to be 0.017mm/a, with the assumption that the latest surface faulting event occurred at 12ka B.P. The geologic profile of this active segment indicates that the late Pleistocene surface faulting on this fault was an abrupt faulting event. According to the relationship between the parameters of seismic surface faulting and the rupture length, it is estimated that the maximum magnitude of the potential earthquake on this segment may reach 6 1/4.

Key words: Active fault, Late Pleistocene, Surface faulting, Maximum potential earthquake