摘要
天津隶属华北平原区,在大地构造位置上一级分区属于渤海湾裂谷盆地,为典型的多旋回盆地,受不同构造旋回期的发展演化控制,早期地质构造被掩盖,而研究深部构造有利于构造单元划分、资源评价、城市规划、地学研究等。笔者利用区域重磁资料,结合以往地质资料,通过小波变换有效的分离出重磁局部及区域异常信息并利用增强局部相位边界识别技术提取丰富线性构造信息,分析区内主要断裂构造特征,进行定性分析;根据分离出的大尺度重磁异常反演研究区莫霍面、磁性基低起伏特征,莫霍面起伏介于32.5~33.6 km之间,总体上具有西深东浅的特征,磁性基底深度介于7.9~12.4 km之间,为近东西向的带状分布,沧东断裂、宝坻断裂为研究区深部构造主要控制因素,反映了天津市平原区深部构造东西分带、南北分块的特征。
Tianjin is located on North China Plain,belonging to Bohai Bay Rift Basin in terms of the first grade of tectonic division..It is a typical multi-cycle basin which is controlled by the development and evolution of different tectonic cycles,with its early geological structures are covered up.The study of deep structures is conductive to the division of tectonic units,resource evaluation,urban planning,geoscience and so on.Based on the regional gravity and magnetic data and previous geological data,the local and regional anomaly information of gravity and magnetism can be effectively separated by wavelet transform.The enriched linear structure information can be extracted by using the enhanced local phase boundary recognition technology.The main fault structure characteristics in the area can be analyzed qualitatively.According to the separated large-scale gravity and magnetic anomaly inversion result,the Moho surface and magnetic basement in the study area can be obtained.The undulating characteristics of Moho surface range is from 32.5 km to 33.6 km.Generally,it display the characteristics of deep west and shallow east.The depth of near E-W zonal distributed magmatic basement ranges from 7.9 km to 12.4 km which is a zonal distribution in the near East-West direction.The Cangdong Fault and Baodi Fault are the main controlling factors of deep structure in the study area,reflecting the characteristics of belt distribution in East-West and blocky distribution in North-South of deep structure in Tianjin plain area.
作者
杨学明
李世斌
韩杰
林星
YANG Xue-ming;LI Shi-bin;HAN Jie;LIN Xing(Tianjin Geophysical Exploration Center,Tianjin 300180,China)
出处
《华北地质》
2021年第1期61-69,共9页
North China Geology
基金
天津市矿产资源补偿项目“天津市平原区1/5万重力调查(国土房任(2007)3号)”。
关键词
重磁异常
小波变化
线性构造
莫霍面
磁性基低
gravity and magnetic anomaly
wavelet transform
linear structure
Moho surface
magnetic basement
