龙门山断裂带与龙日坝断裂带相互关系的物理模拟实验  

Physical Analogue Modeling Research on the Relationship Between Longmenshan Fault Zone and Longriba Fault Zone

作　　者：葛家成 贾东[1] 尹宏伟[1] 闫兵 陈竹新[3] 范小根 杨双 崔键[1] 钟城 GE Jiacheng;JIA Dong;YIN Hongwei;YAN Bing;CHEN Zhuxin;FAN Xiaogen;YANG Shuang;CUI Jian;ZHONG Cheng(School of Earth Sciences and Engineering,Nanjing University,Nanjing 210023,China;College of Oceanography,Hohai University,Nanjing 210098,China;Exploration and Development Research Institute,PetroChina,Beijing 100083,China)

机构地区：[1]南京大学地球科学与工程学院,南京210023 [2]河海大学海洋学院,南京210098 [3]中国石油天然气股份有限公司勘探开发研究院,北京100083

出　　处：《高校地质学报》2023年第4期617-629,共13页Geological Journal of China Universities

基　　金：国家自然科学基金项目(41927802);国家油气重大专项(2016ZX05003001和2017ZX05008001)联合资助。

摘　　要：在青藏高原东缘北东向龙门山断裂带西北约150 km的松潘—甘孜块体东部,存在一条北东向,具有右旋逆冲活动特征的龙日坝断裂带,由于其特殊的地理位置,目前已引起广泛关注。为了研究这两条性质相似断层带间的相互关系,文章根据该区域实际地质情况和相似性原理设计三组物理模拟实验,重点考虑碧口块体和底部滑脱层的影响,并运用粒子速度场成像技术监测表面变形。实验模型显示,在东西向挤压应力下发育了北东走向以逆冲为主兼右行走滑分量的龙门山断裂带和龙日坝断裂带以及南北走向的岷山隆起带。根据实验结果得出认识:只有在碧口块体的作用下,才会沿滑脱层边界发育断层,而不是在滑脱层内部形成弧形断层;龙门山断裂带与龙日坝断裂带在深部滑脱层相连,可能是一组同期发育的倾向相反的断层。该研究结果显示,在碧口块体影响下断裂带的发育过程,为理解龙门山断裂带和龙日坝断裂带相互关系提供了一种可能的构造模式。In the eastern part of Songpan-Ganzi block about 150 km northwest of Longmenshan fault zone in the eastern Tibetan Plateau,there is a NE-trending Longriba fault zone featured with dextral transpressive shearing.Due to its special geographical location,it has attracted widespread attention.In order to study the relationship between these two similar fault zones,three groups of physical analogue modeling are designed according to the actual geological conditions of the region and the similarity principles.The influence of the Bikou terrane and the bottom detachment is mainly considered,and the Particle Image Velocimetry is used to monitor the surface deformation.The experimental model shows that NE-trending Longmenshan fault zone and Longriba fault zone with thrust and right-lateral strike-slip component and Minshan uplift zone with north-south strike aredeveloped under EW compression stress. According to the experimental results, we conclude that only with the existence of theBikou terrane, faults develop along the boundary of the detachment, otherwise arc faults develop within the detachment layer. TheLongmenshan fault zone is connected with the Longriba fault zone in the deep detachment to form a pop-up structure.The resultsof this study show the development process of fault zone under the influence of Bikou terrane, and provide a possible structuralmodel for understanding the relationship between Longmenshan fault zone and Longriba fault zone.

关 键 词：青藏高原东缘 物理模拟 龙日坝断裂带 龙门山断裂带 碧口块体 

分 类 号：P542.3[天文地球—构造地质学]