尼泊尔喜马拉雅山脉中央丘里亚冲断层的电子自旋共振测年  

Electron spin resonance dating for the Central Churia Thrust of the Nepal Himalaya

作　　者：NEUPANE Bhupati ZHAO Junmeng LIU Chunru PEI Shunping MAHARJAN Bishal DHAKAL Sanjev 

机构地区：[1]State Key Laboratory of Tibetan Plateau Earth System,Environment and Resources,Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China [2]Department of Civil Engineering,Sagarmatha Engineering College,Lalitpur 44600,Nepal [3]Institute of Fundamental Research and Studies(InFeRS),Kathmandu 44600,Nepal [4]Tibet University,Lhasa 850000,China [5]State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029,China [6]Earth Science Research Centre,Kathmandu 44600,Nepal

出　　处：《地学前缘》2023年第4期260-269,共10页Earth Science Frontiers

基　　金：The Chinese Academy of Sciences President's International Fellowship Initiative (PIFI) for Visiting Scientist (Grant No.2023VMC0003);The National Science Foundation of China (Grant No.42230307);The Strategic Priority Research Program (A) of the Chinese Academy of Sciences (Grant No.XDA20070302)。

摘　　要：利用断层泥样品中石英颗粒的ESR信号,研究尼泊尔喜马拉雅山脉南段中央丘里亚冲断层(CCT)第四纪断层活动的时间模式。为了更好地理解重置过程,分析了不同石英粒度的ESR信号、累积剂量和年龄的变化。样品CCT3的E1’中心(ESR定年的一种信号)的ESR强度结果显示,大块、粗粒(200~250 μm)和细粒(40~80 μm)粒度组分存在显著的空间变化。第四纪断层的ESR数据,粗年龄为(5±0.5) ka,细分数平均年龄为(50±10) ka,显示了西瓦利克地区最近的伸展事件。A temporal pattern of Quaternary fault activity of the Central Churia Thrust(CCT)in the southern Nepal Himalaya has been investigated using Electron Spin Resonance(ESR)signals of quartz grains in fault gouge samples.In order to better understand the reset process,the study of the variations in ESR signal,accumulated dose,and age in various quartz grain sizes was analysed.The results of the E1’center(a type of signal for ESR dating)of sample CCT3 show a significant spatial variation in the bulk,coarse(200250μm),and fine(4080μm)grain-size fractions.The ESR date of Quaternary faults,coarser age of(5±0.5)ka and finer fraction mean age of(50±10)ka,demonstrates the latest extension event in the Siwalik region.

关 键 词：大地构造 地质年代学 中央丘里亚冲断层(CCT) ESR测年 断层泥 第四纪断层 

分 类 号：P597[天文地球—地球化学] P542[天文地球—地质学]