基于浅层地震反射勘探技术的栟茶河断裂近地表构造特征研究  

Research on the near-surface tectonic characteristics of Benchahe fault based on shallow seismic reflection exploration technology

作　　者：顾勤平[1] 康清清[1] 杨浩[1] 胡利 许汉刚[1] 孟科[1] 于俊杰[3] 蒋新[1] 赵启光[1] 朱升初[1] 薛莹莹[1] 王金艳[1] 李金良[1] 张浩 徐烨 陈昊 GU QinPing;KANG QingQing;YANG Hao;HU Li;XU HanGang;MENG Ke;YU JunJie;JIANG Xin;ZHAO QiGuang;ZHU ShengChu;XUE YingYing;WANG JinYan;LI JinLiang;ZHANG Hao;XU Ye;CHEN Hao(Jiangsu Earthquake Agency,Nanjing 210014,China;Institute of Geochemical Exploration and Marine Geological Survey,East China Mineral Exploration and Development Bureau for Non-ferrous Metals,Nanjing 210007,China;Nanjing Center,China Geological Survey,Nanjing 210016,China)

机构地区：[1]江苏省地震局,南京210014 [2]江苏省有色金属华东地质勘查局地球化学勘查与海洋地质调查研究院,南京210007 [3]中国地质调查局南京地质调查中心,南京210016

出　　处：《地球物理学报》2025年第3期938-955,共18页Chinese Journal of Geophysics

基　　金：我国地震重点监视防御区活动断层地震危险性评价之“栟茶河断裂活动性鉴定”项目(1530601);中国地震局地震科技星火计划项目(XH18017Y,XH23018C、XH25019YC);江苏省地震局局长基金项目(202301);江苏省333高层次人才项目;国家自然科学基金项目(41704052)联合资助。

摘　　要：早期对栟茶河断裂的研究成果局限在深部发育特征,至今仍未对该断裂的空间展布、最新活动时代及其与近地表地层的切割关系等重要科学问题开展过系统性的勘探和研究工作.鉴于此,本文按照“由已知到未知、由深到浅、分步探测、由点到线、由疏到密”的工作思路,采用不同工作方法和技术参数的浅层地震勘探对其进行了系统的探测和研究,并结合小间距钻孔联合地质剖面及新年代学样品测试等,查明了目标断裂近地表的空间分布位置和最新活动习性.研究结果表明:(1)栟茶河断裂是海安凹陷和通扬隆起的分界断裂暨控制苏北盆地沉积的断裂之一.(2)并非前人认识的一条断层,而是由2条N倾正断层组成的断阶带.中间走向近东西向,西段北西向,东段北东东向;视倾角约为60°~75°,是上陡下缓的铲形生长断层.(3)平面上呈向东(隆起区)收敛、向西(凹陷区)撒开趋势;向东发育并未延伸至原来认定的南黄海,而是终止于Ⅱ测线以西;向西延伸可能穿越了海安市主城区,继续追踪其空间位置的科学探索和系统研究工作显得非常重要且尤为必要.(4)小间距钻孔联合地质剖面成功定位了主断面在BCL1测线和BCL3测线分别位于7765和3660桩号处.难能可贵的是,在新庄村场地ZK2-5孔内中更新统启东组下段砂层中揭露了断层面,倾角约为70°.(5)确定了最新活动时代为中更新世晚期至晚更新世早期.(6)在栟茶河断裂南侧新发现了丁家所南缘断裂,它与栟茶河断裂夹持构成了鼻状地垒式的丁家所古潜山.(7)查明了栟茶河断裂的空间展布,已探明的长度为26 km.本文研究成果不仅为江苏地区相关城市的规划与建设、重大工程的建设选址及减轻地震灾害风险提供科学依据,填补了目标断裂所在测区近地表浅层地震探测研究和空间发育特征研究的空白,而且探测思路和研究方法对其他城市(尤其是�Early research results on the Benchahe fault were limited to deep developmental features,and so far no systematic exploration and research has been carried out on such important scientific issues as the spatial spread of the fault,the age of its latest activity,and its cutting relationship with the near-surface strata.In view of this,in accordance with the working idea of“from known to unknown,from deep to shallow,step-by-step detection,from point to line,from sparse to dense”,this paper adopts different working methods and technical parameters of shallow seismic survey to systematically detect and study the target fault,and combines with the joint geologic profiles of the small spaced boreholes and the testing of new chronological samples,etc.,to find out the spatial distribution of the target fault near the surface of the location and the latest activity habits.The results of the study show that:(1)The Benchahe fault is one of the faults dividing the Haian depression and Tongyang uplift and controlling the sedimentation of Subei basin.(2)It is not a single fault as recognized by the predecessors,but a fault zone consisting of two N-dipping positive faults.The middle strike is nearly east-west,the western section is north-west,and the eastern section is north-east-east;the apparent dip angle is about 60°~75°,and it is a shovel-shaped growth fault with steep top and gentle bottom.(3)The plane shows a tendency of convergence to the east(uplift area)and spreading to the west(depression area);the development to the east does not extend to the South Yellow Sea as originally recognized,but terminates to the west of the survey lineⅡ;the extension to the west may have crossed the main urban area of Hai′an City,and scientific exploration and systematic research efforts to continue tracking its spatial location are important and particularly necessary.(4)The joint geological profile of small-spaced drill holes successfully located the main fault surface at the BCL1 and BCL3 survey lines at pile numbers 7765 and

关 键 词：栟茶河断裂 浅层地震勘探 多层次探测 钻孔联合地质剖面 活动断层 

分 类 号：P631[天文地球—地质矿产勘探] P315[天文地球—地质学]