重力水平梯度矢量法在琼东南盆地基底断裂划分上的应用  

Studying basement fault division in Southeast Hainan Basin of the South China Sea using gravity horizontal gradient vector method

作　　者：刘兵[1,2] 吴世敏[1,3] 龙根元[1,2] 郭翔艳[1,2] 曾广东 

机构地区：[1]中国科学院边缘海重点实验室,中国科学院南海海洋研究所,广东广州510301 [2]中国科学院研究生院,北京100039 [3]中山大学地球科学系,广东广州510275 [4]中国石油化工股份有限公司上海海洋油气分公司,上海200120

出　　处：《热带海洋学报》2011年第5期74-80,共7页Journal of Tropical Oceanography

基　　金：国家重点基础研究发展计划项目(2007CB411706-05);中国石油化工股份有限公司委托项目(5220292)

摘　　要：基底断裂与盆地是一对相互影响的伴生构造,断裂活动控制盆地内沉积填充和构造样式以及后期资源的分布。本文利用琼东南盆地2′×2′的自由空间重力异常,在进行地形校正、布格异常校正得到布格重力异常的基础上求得重力水平梯度矢量。尝试利用重力水平梯度矢量对基底断裂进行划分并取得良好效果:在盆地基底划分出48条断裂,并将其分为3个等级,其中一级断裂5条,二级断裂8条,三级断裂35条;将确定的断裂与其他地质、地球物理方法(地震剖面)确定的断裂进行比较,发现在主要格架上具有一致性;重力水平梯度矢量法与其他解释方法比较具有成本低廉、方法简单、结果直观的优点。Basement fault is an associated structure with the basin.The deposition in a basin and the tectonic style as well as the distribution of resources are determined by basement faults.On the basis of 2-minute Free Air Gravity anomaly database in the Southeast Hainan Basin of the South China Sea,the Bouguer anomaly is obtained after topography correction and Bouguer correction.The gravity horizontal gradient vector data are obtained from the analysis of the Bouguer anomaly.We are able to find 48 basement faults in the basin using the gravity horizontal gradient vector data,which are divided into three ranks,in-cluding five first rank faults,eight second rank faults,and 35 third rank faults.Comparing these findings with the results using other geological and geophysical methods such as seismic profiles,we find all results are consistent in terms of the main tec-tonic structure.However,the gravity horizontal gradient vector method has the advantages of being inexpensive,easy,and intuitive.

关 键 词：重力 水平梯度矢量 琼东南盆地 基底断裂 地震剖面 

分 类 号：P736[天文地球—海洋地质]