地面磁测异常分离及井中磁测处理在大乌苏南沟(M24)研究区的应用研究  

Application study on potential field separation of magnetic areal anomaly and three-component treatment in well in Dawusunangou(M24)iron ore area

作　　者：付东阳[1] 杨磊 沈志清 王晓东 马天航 付荣钦[1] FU Dongyang;YANG Lei;SHEN Zhiqing;WANG Xiaodong;MA Tianhang;FU Rongqin(The Fourth Geological Brigade of Hebei Bureau of Geology and Mineral Resources Exploration and Development,Chengde 067000,Hebei,China)

机构地区：[1]河北省地质矿产勘查开发局第四地质大队,河北承德067000

出　　处：《矿产勘查》2025年第2期309-326,共18页Mineral Exploration

基　　金：河北省地质勘查基金项目(冀地【2023】4号)资助。

摘　　要：大乌苏南沟(M24)研究区位于燕山台褶带北缘,受复杂构造控制,矿体群呈多层叠加分布,导致地表磁异常呈现多源叠加特征,严重制约深部矿体识别与定位。本研究针对叠加磁异常分离难题,以地面高精度磁测数据为基础,结合井中三分量磁测技术,通过化极、向上延拓(100 m、200 m、500 m及1000 m)及反演分析,实现了垂向叠加异常的逐层分离,揭示了不同空间矿体分布特征。研究通过化极处理消除斜磁化影响,采用向上延拓方法压制浅部干扰,分离出浅部铁磷矿体群((2)号)、中深部钒钛磁铁矿体((1)号Fe1)及深部辉石角闪岩型超贫铁矿体((3)号)。结果显示:(1)号Fe1矿体走向长度达1200 m,倾向延伸1800 m,平均厚度180 m,顶部埋深770 m,钻孔验证误差小于6%;(2)号矿体顶部埋深约200 m,叠加异常强度3000~6000 nT;(3)号矿体埋深593 m以下,水平模差矢量特征指示其侧向延伸潜力。井中三分量磁测数据进一步验证了矿体产状与空间展布规律,水平模差分析表明主矿体向东、向西延伸趋势显著。本研究将地面磁测异常分离与井中磁测三维解析结合,解决了复杂构造区多层叠加磁异常识别难题,定位精度提升约30%,勘探深度突破1500 m。成果为燕山地区深部隐伏铁矿勘查提供了可推广的方法体系,对同类矿区资源评价与开发具有重要实践意义。The M24 study area in the Dawusunangou is located on the northern margin of the Yanshan Fold-Thrust Belt.Controlled by complex structures,the orebody groups are distributed in multiple layers,resulting in the surface magnetic anomalies showing multi-source superimposition characteristics,which seriously restricts the identification and location of deep orebodies.This study,aiming at the problem of separating superimposed mag-netic anomalies,based on high-precision ground magnetic survey data and combined with in-bore three-component magnetic survey technology,achieved the layer-by-layer separation of vertically superimposed anoma-lies through pole transformation,upward continuation(100 m,200 m,500 m,and 1000 m),and inversion analysis,revealing the distribution characteristics of orebodies in different spaces.By pole transformation to eliminate the in-fluence of inclined magnetization and using upward continuation to suppress shallow interference,the shallow iron-phosphorus orebody group(No.2),the medium-deep vanadium-titanium magnetite orebody(No.1 Fe1),and the deep pyroxene amphibolite-type super-poor iron orebody(No.3)were separated.The results show that the No.1 Fe1 orebody has a strike length of 1200 m,a dip extension of 1800 m,an average thickness of 180 m,and a top burial depth of 770 m,with a verification error of less than 6%from drilling.The top burial depth of the No.2 orebody is about 200 m,and the superimposed anomaly intensity is 3000-6000 nT.The No.3 orebody is buried deeper than 593 m,and the horizontal modulus difference vector characteristics indicate its lateral extension poten-tial.The in-bore three-component magnetic survey data further verified the orebody occurrence and spatial distri-bution patterns.The horizontal modulus difference analysis indicated a significant eastward and westward extension trend of the main orebody.This study combined the separation of ground magnetic anomalies with the three-dimensional analysis of in-bore magnetic survey data,solving the problem of identifying mult

关 键 词：磁异常 叠加异常 向上延拓 异常分离 

分 类 号：P318.6[天文地球—固体地球物理学]