地面高精度磁测在信阳地区地质调查中的应用  

Application of high precision ground magnetic prospecting for geological survey in Xinyang area

作　　者：邵世威 郭贤培 张跃[1] 闫贺龙[1] 康晓涛 牛磊[1] SHAO Shi-wei;GUO Xian-pei;ZHANG Yue;YAN He-long;KANG Xiao-tao;NIU Lei(The First Geological Exploration Institute of Henan Bureau of Geo-exploration and Mineral Development,Zhengzhou 450001,China)

机构地区：[1]河南省地质矿产勘查开发局第一地质勘查院,郑州450001

出　　处：《地球物理学进展》2018年第4期1554-1565,共12页Progress in Geophysics

基　　金：河南省2009年度省级地质勘查基金项目"河南省境内游河幅;长台关半幅;浉河港幅;信阳市幅;五里店半幅;谭家河幅;李家寨幅;涩港幅;蔡家河幅;大新店幅;宣化店幅1:5万矿产地质调查"(任务书编号:豫国土资发[2011]75号)资助

摘　　要：信阳地区位于秦岭造山带东段,横跨华北板块与扬子板块.通过在该地区开展地面高精度磁法测量工作,以高精度磁测ΔT等值线平面图为基础,运用化极、向上延拓等技术手段提取与地质相关的磁场信息,缩小重点调查范围,提高了在该地区进行地质调查工作效率.本文详细介绍了在该地区进行地面高精度磁测的工作方法.对区内磁异常进行了分类和评价,本次工作以正磁异常为主圈定了28个磁异常,按其分布范围与地质单元的关系分为5类.研究区内磁场特征和磁异常的分布特征与地层、岩体及构造带的分布特征相吻合,区内磁场按磁场强度分为4个类型:平稳磁场区、弱磁场区、带状强磁场和零乱磁场区.根据磁场特征,结合野外地质调查,在研究区推测隐伏岩体3处;从灵山岩体中解体出李家寨岩体,并根据磁场形态完整性特征确定了两者侵入早晚关系.Xinyang area located in the eastern part of the Qinling Mountains orogenic belt is spanning the North China plate and the Yangtze plate. The high precision ground magnetic prospecting improves the efficiency of prospecting geological survey in this area by the way of narrow the scope of the key investigations,which based of high precision magnetic ΔT contour map pick up the magnetic field information related to geology by using of reductionto-the-pole and upward continuation. This paper introduces the working methods of ground high precision magnetic survey in this area. We classify and evaluate the 28 magnetic anomalies which were delineated mainly by positive magnetic anomalies,and dived them into five categories according to the relationship between the distribution range of magnetic anomalies and geological units. The characteristics of magnetic fields and the distribution characteristics of magnetic anomalies agree with the distribution characteristics of stratum,rock mass and tectonic zone. We divide the magnetic field into four types： stationary magnetic field,weak magnetic field,banded strong magnetic field,messy magnetic field. According to the characteristics of the magnetic field and field geological survey,We infer 3 hidden rock masses. We reassign a portion of Lingshan rock to Lijiazhai rock,and determine the intrusion relative date of them by the morphologic integrity of magnetic field.

关 键 词：高精度磁法 磁异常 东秦岭 地质调查 信阳 

分 类 号：P631[天文地球—地质矿产勘探]