Application of BEMD in Extraction of Magnetic Anomaly Components Associated with Sn-W Polymetallic Mineralization in SE Yunnan,SW China  

作　　者：Chen Chen Xu Zhu Yongqing Chen Shouting Zhang Pengda Zhao 

机构地区：[1]School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China

出　　处：《Journal of Earth Science》2021年第2期318-326,共9页地球科学学刊（英文版）

基　　金：jointly funded by the National Key Research and Development Project of China(No.2016YFC0600509);the National Natural Science Foundation of China(Nos.41972312,41672329,41272365);the China Geological Survey(No.1212011220922)。

摘　　要：The tin(Sn)-tungsten(W)polymetallic ore concentrated district in SE Yunnan is distributed at the junction region of the Yangtze Block,the Cathaysian Block and the Indosinian Block,where there are several giant deposits of tin,tungsten,copper,silver,lead,zinc and indium closely associated with a large scale Late Cretaceous magmatism.Bi-dimensional empirical mode decomposition(BEMD)is used to extract aeromagnetic anomalous components at the survey scale of 1:200000 from the original aeromagnetic data of SE Yunnan.Four intrinsic mode functions(IMFs)and a residues component are obtained,which may reflect the geological structures and geological bodies at different spatial scales from high frequency to low frequency.The results are shown as follows:(1)Two different types of Precambrian basement in the study area were recognized:one is the Yangtze Block basement characterized by a strong positive magnetic anomaly,the other is the Cathaysian Block basement with a weak negative magnetic anomaly.The former consists of high grade metamorphic rocks including metamorphosed basic igneous rocks,while the latter consists of low grade metamorphosed sedimentary rocks.(2)The aeromagnetic anomalies associated with Sn-W polymetallic mineralization and related to granites in the study area illustrate a pattern of a skarnized alteration-mineralization zone with a positive ring magnetic anomaly enclosing a granitic intrusion with negative magnetic anomaly;(3)The ring positive magnetic anomaly zones enclosing the negative magnetic anomaly are defined as the SnW polymetallic ore-searching targets in the study area.

关 键 词：BEMD intrinsic mode function(IMF) magnetic anomalous components Sn-W polymetallic deposits Late Cretaceous granites SW China 

分 类 号：P618.2[天文地球—矿床学] P631.2[天文地球—地质学]