基于卫星重力异常的渤海盆地秦南凹陷及邻区构造格局研究  

A study of tectonic framework of the Qinnan sag in Bohai Basin and its adjacent areas based on satellite gravity anomalies

作　　者：杨荣祥 王万银[1,2,3,4,5,6] 蔡梦轲 王丁丁 罗新刚 YANG Rong-Xiang;WANG Wan-Yin;CAI Meng-Ke;WANG Ding-Ding;LUO Xin-Gang(Institute of Gravity and Magnetic Technology,Chang'an University,Xi'an 710054,China;School of Geological Engineering and Geomatics,Chang'an University,Xi'an 710054,China;Key Laboratory of Western China's Mineral Resources and Geological Engineering of Ministry of Education,Chang'an University,Xi'an 710054,China;Key Laboratory of Marine Geology&Environment,Chinese Academy of Sciences,Qingdao 266071,China;Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;National Engineering Research Center of Offshore Oil and Gas Exploration,Beijing 100028,China;Department of Earth Sciences,University of Naples Federico II,Naples 80138,Italy)

机构地区：[1]长安大学重磁方法技术研究所,陕西西安710054 [2]长安大学地质工程与测绘学院,陕西西安710054 [3]长安大学西部矿产资源与地质工程教育部重点实验室,陕西西安710054 [4]中国科学院海洋地质与环境重点实验室,山东青岛266071 [5]中国科学院海洋研究所,山东青岛266071 [6]海洋油气勘探国家工程研究中心,北京100028 [7]Department of Earth Sciences,University of Naples Federico II,Naples 80138

出　　处：《物探与化探》2023年第3期584-596,共13页Geophysical and Geochemical Exploration

基　　金：中国海洋石油集团有限公司重大课题“中国近海盆地潜在富油凹陷资源潜力、成藏机制与突破方向”(YXKY-ZX01-2021)。

摘　　要：渤海盆地是我国目前发现海上油气田最多的地区,秦南凹陷作为渤海盆地中的潜在富油气凹陷,具有较高的勘探潜力,对凹陷及邻区的构造格局研究具有重要意义和应用价值。本文利用卫星重力异常,通过校正陆域地形和海水的影响得到布格重力异常,采用归一化总水平导数垂向导数(NVDR-THDR)、欧拉反褶积、最小曲率位场分离和双界面模型重力场快速反演等方法得到了断裂的平面分布和视深度、新生界厚度以及构造单元边界;结合地质及地球物理资料,分析了研究区内主要断裂和构造单元的分布特征及地球物理特征。研究表明秦南凹陷及邻区的断裂主要呈NE向、NEE向和NW向展布,断裂视深度以1~10 km为主,在控坳断裂的部分位置及众多断裂交汇处达到了15~25 km;新生界厚度在0~11 km,构造单元呈NE向和NEE向交替分布,其边界大多受断裂控制;通过进一步研究,将秦南凹陷西侧的洼陷划归为乐亭凹陷,对其他构造单元的边界也进行了调整。本次断裂分布和构造单元分布特征的研究结果能为秦南凹陷的油气勘探提供一定的地球物理支撑。The Bohai Basin has the most offshore oil and gas fields discovered in China.As a potential hydrocarbon-rich sag in the Bohai Basin,the Qinnan Sag is of high value in exploration.Therefore,the study of the tectonic framework of the sag and its adjacent areas is of great significance and application value.Based on satellite gravity anomalies,this study determined the Bouguer gravity anomalies by correcting the influences of land topography and seawater and obtained the planar distribution and apparent depths of faults,the thickness of Cenozoic strata,and the boundaries of tectonic units using methods such as the normalized vertical derivative of the total horizontal derivative(NVDR-THDR),the Euler deconvolution,the minimum curvature potential field separation,and the fast for the gravity field based in a dual interface model.Based on the geological and geophysical data,this study analyzed the distribution and geophysical characteristics of major faults and tectonic units in the study area.The results of this study are as follows:The faults in the Qinnan Sag and its adjacent areas mainly have NE,NEE,and NW strikes and an apparent depth of primarily 1~10 km,which is up to 15~25 km at some positions of the sag-controlling faults and the intersections of the faults;The Cenozoic strata have a thickness of 0~11 km.The Cenozoic tectonic units are distributed in alternating NE and NEE directions,and their boundaries are mostly controlled by faults;Through further investigation,this study classified the sub-sag on the west side of the Qinnan sag as the Laoting sag and adjusted the boundaries of other tectonic units.The results of this study on the distribution of the faults and tectonic units can provide geophysical data for hydrocarbon exploration in the Qinnan Sag.

关 键 词：卫星重力异常 秦南凹陷 构造单元 断裂 

分 类 号：P631[天文地球—地质矿产勘探]