青海德令哈巴音郭勒河断裂带的新活动特征

STUDY ON THE NEW ACTIVE FEATURES OF BAYINGUOLE RIVER ACTIVE FAULT, DELINGHA, QINGHAI PROVINCE

摘要:

在青海德令哈巴音郭勒河北侧山前冲洪积扇上新发现了一条长约60km的逆断裂带,属于本区NNW-NWW向的柴达木盆地北缘活动断裂系内的一条次级挤压构造。断裂在地貌上表现为明显的挤压逆冲断层陡坎,晚更新世晚期以来的平均垂直滑动速率为0.41±0.27mm/a。探槽剖面确定了三次古地震事件,其年代分别为距今约32.7±1.45ka、15.54±1.32ka和3.2±0.33ka。

Abstract:

A new reverse fault zone,60 km long,was found on the alluvial and pluvial fan of the northern bank of Bayinguole river, Delingha, Qinghai Province. The fault is a sub-extrusion tectonics belongs to the northern margin of NNW-NWW oriented active fault system in Qaidam basin. Its tectonic geomorphology is characterized by clear linear fault scarps, the average vertical slip rate of the fault is about 0.41±0.27 mm/a since late period of the late Pleistocene. About three palaeo-earthquake events are found by trenching along the active fault zone, their ages are 32.7±1.45 ka, 15.54±1.32 ka and 3.2±0.335 ka, respectively.