基于重磁数据研究江苏岸外滨海断裂带及邻区构造特征  

Structural characteristics of the Binhai Fault Zone in Jiangsu offshore—implications from gravity and magnetic data

作　　者：尚鲁宁 潘军 曹瑞 周青春 孔祥淮[1] SHANG Luning;PAN Jun;CAO Rui;ZHOU Qingchun;KONG Xianghuai(Qingdao Institute of Marine Geology,China Geological Survey,Qingdao 266237,Shandong,China;Qingdao Geo-Engineering Surveying Institute,Qingdao 266101,Shandong,China;China Earthquake Disaster Prevention Center,Beijing,100029,China)

机构地区：[1]中国地质调查局青岛海洋地质研究所,山东青岛266237 [2]青岛地质工程勘察院,山东青岛266101 [3]中国地震灾害防御中心,北京100029

出　　处：《华东地质》2024年第1期101-114,共14页East China Geology

基　　金：中国地质调查局“南黄海西部1∶25万海洋区域地质调查(编号:DD20221710-2)”;山东省自然科学基金面上项目(编号:ZR2023MD047);中国地震局地震科技星火计划(编号:XH22014A)项目联合资助。

摘　　要：江苏岸外滨海断裂带是南黄海西部一条重要的活动断裂,孕育了多次M≥5.0的破坏性地震。该断裂带所在海域特殊的自然地理条件限制了海洋地质调查的开展,导致目前对其展布特征、断面结构、活动强度和力学性质等仍存在争议。文章基于重磁异常的定性分析和定量计算并结合前人研究成果,对滨海断裂带及邻区的构造特征进行研究,追踪了滨海断裂带可能的展布特征,并探讨了不同分段构造属性和活动性。结果表明,滨海断裂带在江苏岸外20~30 km处大致平行于岸线延伸,在废黄河口以北分叉为东、西两支。推测大致以射阳和如东海域为界,将断裂带分为3段。中段构成苏北盆地的东部边界,为长期继承性活动的深大断裂;南段为形成时代较新的平移断裂,构造活动性最强;北段的存在与否和活动性仍有待进一步调查确认。The Binhai Fault Zone in Jiangsu offshore is a prominent active fault zone in the western south Yellow Sea,which has undertaken multiple destructive M≥5.0 earthquakes.The local harsh offshore geographical and hydrodynamic conditions limit the marine geological and geophysical surveys,leading to ongoing controversies over its extension,fault-plane structure,kinematics and dynamic properties.Based on qualitative and quantitative analysis of gravity and magnetic data,this study focused on the structural characteristics of the Binhai Fault Zone and adjacent areas,traced the possible location and extension of the fault zone and explored the structural characteristics and kinematics in its different segments.The results show that the Binhai Fault Zone lies about 20~30 km offshore the Jiangsu Province and extends sub-parallel to the coastline.It bifurcates into two branches in the north area to the abandoned Yellow River estuary.The fault zone is roughly divided into three segments by the offshore boundaries of Sheyang city and Rudong city.Its middle segment standing as the eastern boundary of the Subei(North Jiangsu)Basin has deep-rooted faults with long-term inherited activities,the southern segment has younger and the most active strike-slip faults,while the existence and activity of the northern segment need to be further investigated and verified.

关 键 词：江苏岸外滨海断裂带 重磁异常 盆地结构 地震 海洋区域地质调查 

分 类 号：P31[天文地球—固体地球物理学] P54[天文地球—地球物理学] P65