沂沭断裂带北段断层泥中石英颗粒微形貌特征分析  

Analysis of micromorphology of quartz in fault gouge of the northern segment of Yishu Fault zone

作　　者：黄静宜[1,2] 刘智荣 刘晓燕[1,2] HUANG Jingyi;LIU Zhirong;LIU Xiaoyan(Institute of Disaster Prevention,Sanhe 065201,China;Hebei Key Laboratory of Earthquake Dynamics,Sanhe 065201,China)

机构地区：[1]防灾科技学院,河北三河065201 [2]河北省地震动力学重点实验室,河北三河065201

出　　处：《自然灾害学报》2023年第5期197-207,共11页Journal of Natural Disasters

基　　金：中央高校基本科研业务费专项(ZY20180103)。

摘　　要：断层泥被公认是记录断层滑动和活动时间的重要信息来源。观测沂沭断裂沿线石英微形貌特征推断断层活动期次及活动方式。沂沭断裂是郯庐断裂向北的延伸,断层泥较为发育。在野外调查的基础上,在沂沭断裂北段的安丘-莒县断裂、昌邑-大店断裂选取了4个剖面,对石英颗粒进行了扫描电镜观察及光释光测年分析。结果表明,石英以中度溶蚀Ⅱ类和Ⅰb+Ⅰc型微形貌为主,也出现了Ⅲ型、Ⅳ型、Ⅰa型和Ru型,说明沂沭断裂北段具有多期活动的特征,最近一次较强的运动发生在早-中更新世,晚更新世以来活动过,但不强烈。由断层泥中石英的撞擦特征、破裂特征和形态特征等统计得出,该断裂晚更新世以来以蠕滑及过渡型为主,黏滑较弱。研究结果可为监测研究区的断层活动提供有力支持。The fault gouges have been worldwide proven sources of recording significant information on fault slippage and timing of activity.This paper presents the period and mode of fault activity inferred by observing the characteristics of quartz micromorphology along the Yishu Fault,Eastern China.Yishu Fault is the northward extension of Tanlu Fault where the fault gouge is well-developed.Based on the field investigation,four sections were selected in Changyi and Juxian.The quartz particles were observed by the scanning electron microscope(SEM)and analyzed by photoluminescence dating.The results show that the quartz is mainly composed of moderate dissolution type II and Ib+Ic micromorphology,and also type III,IV,Ia and Ru,indicating that the Yishu Fault has the characteristics of multi-stage activity.It is inferred from the obtained results that the last strong movement occurred in the early Middle Pleistocene and has been slightly active since the Late Pleistocene.According to the statistics of the collision,fracture and morphological characteristics of quartz in the fault gouge,the fault has been dominated by creep-slip and transition type since the Late Pleistocene,and the stick-slip was weak in general.The obtained results might provide strong support for monitoring the fault activity in the study.

关 键 词：断层泥 沂沭断裂带 石英 微形貌 断裂活动年代 

分 类 号：P542[天文地球—构造地质学] P694[天文地球—地质学]