摘要
新沂市作为郯庐断裂带山东段和苏皖段的分段节点,具有非常重要的地位。为研究郯庐断裂带新沂段地壳的浅部结构、活动性、空间展布以及深浅构造关系,文中采用了中深、浅层地震勘探及初至波层析成像相结合的工作方法,首先在新沂市南完成了1条长33km、覆盖次数>30次的中深层地震反射剖面,同时利用共炮集记录上的初至波开展地壳浅部结构的层析成像研究,之后给出了跨断裂的3条高分辨率浅层地震反射剖面和1条折射层析成像剖面。研究结果表明:郯庐断裂带新沂段是一条由5条隐伏主干断裂组成的断裂带,具有"两堑夹一垒"的构造样式。中深层和浅层地震反射剖面表明,郯庐断裂带新沂段各主干断裂具有上下一致的对应关系和明显的第四纪活动,对新生代地层厚度和堑-垒状构造特征具有明显的控制作用。浅层地震勘探结果揭示的地层界面形态和断裂浅部特征清楚,墨河-凌城断裂(F3)、新沂-新店断裂(F2)、马陵山-重岗山断裂(F5)及山左口-泗洪断裂(F1)不仅断错了基岩顶界面,且第四纪以来存在活动迹象,尤其是马陵山-重岗山断裂(F5)具有全新世的强活动特征。文中的研究结果可为深入理解新沂市及周缘的深部动力学过程、研究郯庐断裂新沂段的深浅构造组合关系及其活动性提供地震学依据。
The Tan-Lu fault zone is the largest active tectonic zone in eastern China,with a complex history of formation and evolution,and it has a very important control effect on the regional structure,magmatic activity,the formation and distribution of mineral resources and modern seismic activity in eastern China.Xinyi City has a very important position as a segmental node in the Shandong and Suwan sections of the Tan-Lu fault zone.Predecessors have conducted research on the spatial distribution,occurrence and activity characteristics of the shallow crustal faults in the Suqian section of the Tan-Lu belt,and have obtained some new scientific understandings and results.However,due to different research objectives or limitations of research methods,previous researches have either focused on the deep crustal structure,or targeted on the Suqian section or other regions.However,the structural style and deep-shallow structural association characteristics of Xinyi section of Tan-Lu belt have not been well illustrated,nor its activity and spatial distribution have been systematically studied.In order to investigate the shallow crustal structure features,the fault activities,the spatial distribution and the relationship between deep and shallow structures of the Xinyi section of the Tan-Lu Fault,we used a method combining mid-deep/shallow seismic reflection exploration and first-break wave imaging.Firstly,a mid-deep seismic reflection profile with a length of 33km and a coverage number greater than 30 was completed in the south of Xinyi City.At the same time,using the first arrival wave on the common shot record,the tomographic study of the shallow crust structure was carried out.Secondly,three shallow seismic reflection profiles and one refraction tomography profile with high resolution across faults were presented.The results show that the Xinyi section of Tan-Lu fault zone is a fault zone composed of five concealed main faults,with a structural pattern of“two grabens sandwiched by a barrier”.The five main faults reveal m
作者
顾勤平
许汉刚
晏云翔
赵启光
李丽梅
孟科
杨浩
王金艳
蒋新
马董伟
GU Qin-ping;XU Han-gang;YAN Yun-xiang;ZHAO Qi-guang;LI Li-mei;MENG Ke;YANG Hao;WANG Jin-yan;JIANG Xin;MA Dong-wei(Jiangsu Earthquake Agency,Nanjing 210014,China;Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;Xi'an Research Institute,China Coal Technology and Engineering Group Corp.,Xi'an 710077,China;Shanghai Shenfeng Institute of Novel Geological Techniques Co.,Ltd.,Shanghai 201107,China)
出处
《地震地质》
EI
CSCD
北大核心
2020年第4期825-843,共19页
Seismology and Geology
基金
2019年度“城市活断层探测与地震危险性评价”项目
新沂市活动断层探测与地震危险性评价项目
国家自然科学基金(41704052,41974066)
中国地震局地震科技星火计划项目(XY18017Y,XH20051)共同资助。
关键词
郯庐断裂带新沂段
初至波成像
地震反射剖面
地壳结构和构造
第四纪活动性
Xinyi section of Tan-Lu fault zone
first-break traveltime imaging
seismic reflection profile
crustal structure and tectonics
Quaternary activity
