重、磁异常的经验模态分解及其在鄂东张福山铁矿勘探中的应用  

EMD of gravity and magnetic anomalies and its application for iron deposit exploration in Zhangfushan, Eastern Hubei

作　　者：曾琴琴[1,2] 刘天佑[2] 

机构地区：[1]成都地质矿产研究所,成都610081 [2]中国地质大学(武汉),地球物理与空间信息学院,武汉430074

出　　处：《地球物理学进展》2011年第4期1409-1414,共6页Progress in Geophysics

基　　金：区域地球物理调查成果集成与方法技术研究(1212011120918)项目资助

摘　　要：由Norden E Huang提出的经验模态分解(Empirical Mode Decomposition,即EMD)是一种以信号板值特征尺度为度量的时空滤波过程,其利用信号的上、下包络得到多个分量.这些分量包含了信号从高到低不同频率段的成分,也称固有模态函数,最后的余量为趋势分量,代表信号的平均趋势,这与地球物理场中的区域异常具有相似的意义.根据这一思想,本文提出一种基于EMD的地球物理位场分离方法.与一些常规方法相比,EMD分解结果更接近理论值.鄂东张福山为多年的老矿山,区内标高-400 m以上的铁矿已探明并正在开采,由于人文干扰严重,有效地分离出深部未知铁矿体的异常是该区深部找矿的关键.将EMD用于张福山磁异常分离,并通过对分离后的异常进行2.5D正、反演解释,发现深部铁矿体,表明经验模态分解是一种能有效分离复杂位场的新方法.The Empirical Mode Decomposition （EMD） that proposed by Norden E Huang is a kind of spatial and temporal filtering process in terms of the signal extremum characteristic scales, which utilizes the upper and lower envelopes of the signal to produce many components. The components contain different frequency bands from high to low of signal, which is also called intrinsic mode functions （IMFs）, while the residue is the trend component represented the average trend of the signal, which is similar to the regional anomaly of geophysical potential field. According to this theory, we proposed a geophysical potential field separation method based on EMD in this article. Compared with some conventional methods, the EMD results closely approaches to the theoretical values, and it won＇ t bring any man-made influences. ZhangFuShan is an old iron deposit, and the ores above elevation --400 m have been confirmed and are being mined now. Because of the serious cultural interference, the key to the deep deposits exploration is to separate the anomalies caused by the unknown deep magnetites effectively. We applied the EMD method to separate ZhangFuShan magnetic anomalies, and then interpreted with 2. 5D forward and inverse for the separated anomalies. Finally, we found the magnetites in the deep, which indicated that EMD was an effective novel method for complicated potential field data separation.

关 键 词：经验模态分解(EMD) 固有模态函数(IMF) 位场分离 张福山铁矿 深部找矿 

分 类 号：P631[天文地球—地质矿产勘探]