Gravity and magnetic anomalies field characteristics in the South China Sea and its application for interpretation of igneous rocks  

南海重磁异常特征及火成岩分布(英文)

作　　者：李淑玲[1,2,3] 孟小红[2,3] 郭良辉[2,3] 姚长利[2,3] 陈召曦[2,3] 李和群[3] 

机构地区：[1]地质过程与矿产资源国家重点实验室(中国地质大学北京),北京100083 [2]地下信息探测技术与仪器教育部重点实验室(中国地质大学北京),北京100083 [3]中国地质大学(北京)地球物理与信息技术学院,北京100083

出　　处：《Applied Geophysics》2010年第4期295-305,399,共12页应用地球物理（英文版）

基　　金：the National 863 Projects(Nos.2006AA06Z111,2006AA06201-3,and 2006AA09A101-3);National Special Project(No.SinoProbe-01-05);Open Project of the National Key Laboratory for Geological Processes and Mineral Resources(No.GPMR0942).

摘　　要：Igneous rocks in the South China Sea have broad prospects for oil and gas exploration.Integrated geophysical methods are important approaches to study the distribution of igneous rocks and to determine and identify igneous rock bodies.Aimed at the characteristics of gravity and magnetic fields in the South China Sea,several potential field processing methods are preferentially selected.Reduction to the pole by variable inclinations in the area of low magnetic latitudes is used to perform reduction processing on magnetic anomalies.The preferential continuation method is used to separate gravity and magnetic anomalies and extract the gravity and magnetic anomaly information of igneous rocks in the shallow part of the South China Sea.The 3D spatial equivalent distribution of igneous rocks in South China Sea is illustrated by the 3 D correlation imaging of magnetic anomalies.Since the local anomaly boundaries are highlighted gravity and magnetic gradients,the distribution characters of different igneous rocks are roughly outlined by gravity and magnetic correlation analysis weighted by gradient.The results show the distribution of igneous rocks is controlled and influenced by deep crustal structure and faulting.南海火成岩油气藏具有广阔的勘探前景,综合利用地球物理方法圈划与识别火成岩体、研究火成岩分布是火成岩油气藏研究的基础。针对南海重磁场特征,采用低纬度、变倾角化极技术进行了磁异常化极处理,利用优选延拓方法实现重磁异常分离并提取南海海域浅部火成岩重磁异常信息,利用磁异常三维相关成像给出南海火成岩的三维空间等效分布,在重磁梯度突出局部异常边界信息的基础上,通过梯度加权的重磁相关分析勾画不同类型火成岩的平面展布,火成岩的分布特征显示出受地壳深部结构及断裂构造的控制与影响。

关 键 词：South China Sea gravity and magnetic fields reduction to the pole at low latitudes preferential continuation igneous rock distribution 

分 类 号：P631.2[天文地球—地质矿产勘探]