龙门山断裂带横断层成因类型及地质意义  

Genetic Types and Geological Significances of Transverse Faults at Longmenshan Fault Zone

作　　者：王伟锋 朱传华 张晓杰 卿艳彬 单新建[3] 

机构地区：[1]中国石油大学地球科学与技术学院,山东青岛266580 [2]湖南省煤炭地质勘查院,湖南长沙410014 [3]中国地震局地质研究所地震动力学国家重点实验室,北京100029

出　　处：《地球科学（中国地质大学学报）》2016年第5期729-741,共13页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金项目(No.41340008);中央高校基本科研业务费专项资金(No.247201501024A)

摘　　要：目前,对龙门山冲断带内横断层研究较为薄弱.在综合分析区域地质和地球物理资料的基础上,利用野外考察和构造物理模拟等方法,对龙门山冲断带横断层成因类型及地质意义进行了探析.研究表明:(1)龙门山断裂带中北段主要发育6条横向断层,其中虎牙横断层为中段与北段的分界,卧龙-怀远横断层为中段与南段的分界;(2)横向断层主要有3种成因类型:先存北西向断裂或薄弱带再活化、主断裂带差异逆冲产生的撕裂(调节)断层、X共轭剪切断层和横张断裂;(3)横断层调节了冲断带各段构造活动性、构造变形强度等多方面的差异,其可以独立发震、使龙门山主断裂带分段发震、与主逆冲断裂联合发震、在主震发生后控制余震分布、引发余震等.Study on transverse faults in the Longmenshan fault zone is inadequate so far.Based on the regional geology,gravity data,magnetic data,distribution of earthquake and velocity data,combined with field study and structural modeling,the genetic types and geological significances of transverse faults at the Longmenshan fault zone were studied.It is found that：（1）There are 6 transverse faults in the northern and central Longmenshan fault zone,namely,the Bailongjiang,Nanba,Huya,Qingping,Xiaoyudong and Wolong-Huaiyuan transverse faults,where Huya fault is the boundary between the northern and central Longmenshan fault zones,while the Wolong-Huaiyuan fault is between the southern and central Longmenshan fault zone;（2）Transverse faults mainly have three genetic types,they are the transfer faults resulted from the reaction of the preexisting NW-trending faults or weak belts and the nonsynchronous movement of the thrust faults,X-type conjugate shear faults and transverse extensional faults;（3）Transverse faults cut the Longmenshan fault zone into several segments and transfer the differences of the stratum,the geomorphology,the movement intensity,width of the thrust belts,earthquake intensity and frequency of different segments,besides,transverse faults could be independent seismogenic faults which may trigger earthquakes with the Longmenshan major fault belts and restrict the spread of aftershocks.

关 键 词：龙门山断裂带 横断层类型 横断层特征 形成机制 构造 

分 类 号：P54[天文地球—构造地质学] P62[天文地球—地质学]