乌海盆地岗德尔山西麓断裂晚更新世-全新世活动性  

Late Pleistocene-Holocene Activity of the Western Gangdeershan Fault in Wuhai Basin

作　　者：徐东卓[1] 尹海权[1] 李胜虎 朱传宝 XU Dongzhuo;YIN Haiquan;LI Shenghu;ZHU Chuanbao(The First Monitoring and Application Center,CEA,Tianjin 300180,China;Shandong Institute of Geological Sciences,Jinan 266071,China;Institute of Geology and Mineral Exploration of Qinghai Province,Xining 810029,China)

机构地区：[1]中国地震局第一监测中心,天津300180 [2]山东省地质科学研究院,山东济南250013 [3]青海省第三地质矿产勘查院,青海西宁810029

出　　处：《昆明理工大学学报（自然科学版）》2019年第3期26-32,40,共8页Journal of Kunming University of Science and Technology(Natural Science)

基　　金：中国地震局地震科技星火计划(XH18067Y);中国地震局震情跟踪定向工作任务(2019010229);科技部科技基础性工作专项(2015FY210400)

摘　　要：岗德尔山西麓断裂是桌子山断裂带的重要组成部分,同时也是乌海盆地的控盆边界断裂.关于该断裂晚第四纪以来活动性的研究成果很少.通过实地地质地貌调查、构造剖面分析以及OSL测年,综合分析研究该断裂晚第四纪活动性.综上所得,岗德尔山西麓断裂为晚更新世晚期至全新世有过明显活动的断裂.自观音庙至岗德尔山陵园,断裂整体走向近SN,倾向W,倾角80°左右,被切断的沉积层顶部或断裂上覆地层底部的OSL年龄样品测试结果分布在83.5~7.8 ka之间,最新活动时间集中在晚更新世晚期至全新世之间;自岗德尔山陵园至黄河村,断裂整体走向NNE,倾向NWW-NW,倾角60°~80°,被切断的沉积层顶部或断裂上覆地层底部的OSL年龄样品测试结果分布在86.9~2.7 ka间,最新活动时间集中在晚更新世晚期至全新世之间.根据岗德尔山西麓断裂野外调查所得的几何学特征,显示该断裂是一条由多条近平行的高角度断层组成的正断层系,整体表现出以拉张为主的运动特征.The Western Gangdeershan Fault is an important component of Zhuozishan Fault Zone, and is also a basin controlling fault of Wuhai Basin. Less research has been done on the Late Quaternary active characteristics of the fault. Based on the field geological and geomorphic survey, structure section analysis combined with OSL dating, the activity of the fault during the late Quaternary period are analyzed and studied. The conclusions show that the Western Gangdeershan Fault is a late Pleistocene to Holocene active fault. From Guanyin Temple to Gangdeershan Cemetery, the overall fault trend is near NS and dip W, the dip angle is about 80°. OSL dating results from the top of the cut deposit or the bottom of the deposit covering fault are distributed from 83.5~7.8 ka, and the latest active age is late Pleistocene to Holocene;From Gangdeershan Cemetery to Huanghecun, the overall fault trend is near NNE and dip NWW-NW, the dip angle is about 60°~80°. Its OSL dating results are distributed from 86.9~2.7 ka, and the latest active age is the late Pleistocene to Holocene. According to the geometric characteristics of the Western Gangdeershan Fault, the fault is a normal fault system composed of several near parallel high angle faults, and the whole fault shows the characteristics of extensional movement.

关 键 词：乌海盆地 岗德尔山西麓断裂 晚更新世晚期 全新世 活动性 

分 类 号：P546[天文地球—构造地质学]