深圳横岗-罗湖断裂中南段活动特征及现今构造变形监测  

Monitoring of Tectonic Deformation and Activity of Middle-southern Segment of Henggang-Luohu Fault in Shenzhen

作　　者：雷东宁[1,2] 姚运生 但卫[3] 李雪[1,2] 蔡永建[1,2,4] 余松 LEI Dongning;YAO Yunsheng;DAN Wei;LI Xue;CAI Yongjian;YU Song(Key Laboratory of Earthquake Geodesy,Institute of Seismology,CEA,Wuhan 430071,Hubei,China;Institute of Earthquake Engineering of Wuhan,Wuhan 430071,Hubei,China;Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,Guangdong,China;School of Earth Sciences,China University of Geosciences,Wuhan 430074,Hubei,China)

机构地区：[1]中国地震局地震研究所地震大地测量重点实验室,湖北武汉430071 [2]武汉地震工程研究院,湖北武汉430071 [3]中国科学院广州地球化学研究所,广东广州510640 [4]中国地质大学(武汉)地球科学学院,湖北武汉430074

出　　处：《大地构造与成矿学》2018年第2期225-234,共10页Geotectonica et Metallogenia

基　　金：国家自然科学基金项目(41401428);中国地震局社会公益研究项目(1521401800062);中国地震局地震研究所基金(IS200856069);深圳市典型地质灾害点监测与示范研究项目(DZ2008001)联合资助

摘　　要：横岗-罗湖断裂是深圳断裂带的主干断裂,控制着深圳地区的地震构造环境。采用多种手段、方法对该断裂第四纪以来的活动性及现今构造变形进行研究十分重要。作者通过野外地质地貌调查、组合探槽开挖、断层带物质年龄测试(TL、ESR)等手段,分析了横岗-罗湖中南段第四纪活动期次、活动时代。初步认为,横岗-罗湖断裂在第四纪至少经历了4期构造活动,其最新活动时代在第四纪中更新世晚期,约0.14~0.31 Ma。为了定量监测该断裂现今构造变形量及变形速率,对断裂进行了动态形变监测、GPS形变监测、地应力及应变监测。监测数据表明,断裂现今变形速率在0.05~0.5 mm/a之间,属于中等偏下活动水平。断层活动方式以右旋正断与左旋逆冲交替进行,逆冲活动幅度较大,左旋活动略具优势,表明断裂现今变形具有螺旋式渐进的特征。同时,在监测时间段内,2010年11月19日深圳发生了MS2.8地震。通过分析应变仪和砂土应力仪记录的数据,发现在深圳MS2.8地震前后存在明显异常,这可能为地震前兆监测提供有效方法。The Henggang-Luohu fault is the main branch of the Shenzhen fault belt,which controls the seismo-tectonic activity in the Shenzhen area.To safeguard the healthy and sustainable development of this mega metropolis,it is critical to survey the Quaternary activity and present day deformation of the fault by using a variety of methods,including field survey and long-term monitoring.On the basis of field geologic and geomorphologic survey and geochronological study(including thermoluminescence and electron spin resonance),the active times and stages of the fault were analyzed.It is inferred that the fault experienced at least five-stages of tectonic deformation and the latest activity took place in the Late Middle Pleistocene of Quaternary,i.e.,approximately 0.14 Ma to 0.31 Ma.Monitoring ways such as dynamic deformation,GPS deformation,and stress and strain measurement are used to investigate the present day tectonic deformation and velocity of the fault.The monitoring results indicate that the present day deformation velocity is 0.05 mm/a to 0.5 mm/a,belonging to middle-low level deformation fault.The active pattern of the fault is alternatively dominated by right-lateral normal and left-lateral thrust.Moreover,abnormal response of stress and strain to the Shenzhen earthquake of MS2.8,19th November 2010 was recorded,which may provide an effective way for earthquake precursor monitoring.

关 键 词：横岗-罗湖断裂 动态形变监测 GPS监测 形变速率 应力应变异常 

分 类 号：P542[天文地球—构造地质学]