关键词: 晚更新世, 最大潜在地震, 山东半岛, 东殿后断裂

Abstract: Late Quaternary tectonic movement in the northeast part of Shandong Peninsula was dominated mainly by integral uplift,while fault activity inside the peninsula was relatively weak. Late Pleistocene faults are limited to some local areas,and one of them is the newly discovered Dongdianhou Fault. The fault is located to the north of Taiboding Mountains,associated with a broad fracture zone of 100m wide. Outcrops of fault profile can be observed in many places along the fault strand. The fault has a general strike of nearly East-West and a total length of about 20km. Geomorphically,the fault appears as a straight fault valley consisting of 3 upper reaches of stream. The mountains on the southern side of the fault are obviously higher than those on the northern side. The cross section of the fault to the west of Xinshangzhuang Village shows that the fault displaces the unconsolidated rubble bed dated to be 84～75ka BP in age,resulting in a 1 8m high colluvial wedge,which is overlain by talus bed dated to be 64ka BP in age. The vertical slip rate of the fault is estimated roughly to be about 0.16mm/a. Soft fault gouges were observed on the fault planes exposed to the south of Diaoyushi Village and to the east of Taoyuan Village,and the age of the gouges is dated by thermoluminescent method to be 82ka BP. The characteristics of the fault and the age of overlying layers indicate that the latest faulting event occurred in early and middle stage of Late Pleistocene,while since the late stage of Late Pleistocene the fault has not ruptured the surface. According to the relation between surface rupture parameters and earthquake magnitude,it is estimated that the magnitude of the maximum potential earthquake on this fault is 6/2.

Key words: late Pleistocene, maximum potential earthquake, Shandong Peninsula, Dongdianhou Fault