矿体地质-地球物理快速定位预测模型——以丰宁门营铜多金属矿床为例
Orebody Geology-Geophysics Fast Localization Prediction Model-A Case Study of Menying Cu Polymetallic Deposit in Fengning
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摘要: 随着矿产勘查实践的日益深入及找矿难度的增大,矿区大比例尺矿体定位预测已成为矿产勘查评价领域一项重要的研究课题.甚低频电磁法(VLF-EM)作为一种浅层物探技术,具有仪器轻便、方法简单、经济高效等优点,已经得到了国内外矿产勘查实践的检验,且勘查效果明显.简要叙述了甚低频电磁法及其数据处理的基本原理,并应用该方法对丰宁门营铜多金属浅地表隐伏-半隐伏矿体进行快速定位预测,建立了目标矿体的地质-地球物理模型;实践研究表明,在矿体地质研究的基础上,应用甚低频电磁法进行大比例尺地球物理数据采集,并应用磁倾角数据的Fraser滤波、线性滤波技术可以很好提取地球物理异常,揭示隐伏矿体的空间产状及延伸,为勘探工程的部署提供优选靶区.值得指出的是,由于地质噪声及外界电磁噪声的干扰,结合研究区地质特征的分析并对解译成果进行二维三维的表达和对比研究,是正确提取矿致异常的关键.Abstract: Following with the development of mineral exploration practices and the difficulties in prospect forores, mine area large -scale ore body fast locating prediction has became an important research topic in the domain of mineral exploration. The advan tages of VLF-EM method are portable, simple, economic and efficient. As a superficial-layer geophysical prospecting technology, its effect is good through practical check of mineral exploration in China and abroad. This paper briefly discusses the basic principle of VLF method and its data processing technology. On the basis of deposit geology research, this article establishes ageology-geophysics fast loca lization prediction model of the target ore body by using the verylow frequency elect romagnetic (VLF-EM) technology in Fengning Menying CU polymetallic deposit; practice shows that, utilizing this method to collectlarge-scale geophysical data and combined with studies of Fraser filtering and linear filtering. This method can be successfully applied to determine spatial occurrence and extension of buriedore bodies and can provideopt imaltarget area for the employment of exploration engineering. It is worth to pointout that, because of the in terference of geology noise and environment electromagnetic noise, geological characteristic analysis and comparative study of in terp retation results and their 2D、3D expression is the critical factor to extract ore induced anomaly.