各向异性标准化方差计算重磁源边界  

Calculation of gravity and magnetic source boundary based on anisotropy normalized variance

作　　者：张恒磊[1,2] 刘天佑[1,2] 杨宇山[1] 

机构地区：[1]中国地质大学(武汉)地球物理与空间信息学院,武汉430074 [2]中国地质大学(武汉)构造与油气资源教育部重点实验室,武汉430074

出　　处：《地球物理学报》2011年第7期1921-1927,共7页Chinese Journal of Geophysics

基　　金：中国石油化工股份有限公司项目"华南关键构造运动对海相油气的控制作用研究"(P07014);国家自然科学基金项目(40374041);教育部高等学校博士学科点专项科研基金项目(20050491504)联合资助

摘　　要：在重磁源边界定位方法中,传统的梯度方法易受干扰的影响使计算的边界混乱,而且在弱异常处由于叠加异常的影响很难识别场源边界.本文首先利用坐标旋转构造了各向异性高斯函数,提出了各向异性标准化方差计算重磁源边界的方法.理论分析与模型实验详细阐明了该方法的数学含义,并通过干扰分析验证了方法的稳定性与有效性,结合中扬子地区航磁异常处理实例,表明通过计算各向异性标准化方差,可以有效地确定重磁源边界,尤其对微弱异常能够实现较好的边界定位,计算的边界分辨率高且信息丰富,有利于资料的综合解释.For the calculation of gravity and magnetic source boundary, the traditional gradient methods are vulnerable to disturbance and the resulting edges may be too cluttered when the field data are affected by noise. Besides, for the weak anomaly, sources tend to interfere with one another and consequently the edges of geological bodies may be impossible to detect. In this paper, we first construct anisotropic Gauss function based on coordinate rotation, then we propose the formula of calculating anisotropy normalized variance to detect source edge, and clarify its geological significance through theoretical analysis. The numerical experiment shows the method is stable and effective. Applications on both synthetic data and aeromagnetic data in mid Yangtze region indicate that anisotropy normalized variance can effectively determine the gravity and magnetic source boundaries, it also can get good results especially for weak anomaly, the results contain high-resolution and rich information, and these will facilitate the integrated interpretation.

关 键 词：位场勘探 各向异性标准化方差 梯度算法 重磁源边界 

分 类 号：P631[天文地球—地质矿产勘探]