音频大地电磁测深在甲基卡深部找矿预测中的应用研究

Application of audio-frequency magnetotelluric sounding to deep prospecting and prediction of rare metal deposit in Jiajika area

近年随着找矿难度的不断加大,找矿重心已由早期的地表浅覆盖转向地下深部隐伏矿脉。川西甲基卡地区目前是我国乃至世界上规模最大的硬岩型稀有金属富集区之一,其深部找矿潜力巨大。基于多年野外实践工作成果笔者认为,音频大地电磁测深是解决当前甲基卡地区深部找矿预测的一种有效技术手段;通过与区域内的重磁资料综合对比解析,立足于地质基础,从面—线—点逐步深入分析研究;现基本查明,区内中深部地质构造格架,圈定出马颈子花岗岩等酸性岩体空间分布范围,推断勾绘出稀有金属伟晶岩脉体发育通道,为甲基卡矿区深部找矿工作指明了方向。

In the West Sichuan province is located Jiajika area where is one of the largest enrichment district of hard rock type rare metals in China,even in the world.It is still potential for prospecting to depth.Facing difficult situation of prospecting at surface the prospecting at prevent begins to focus on blind ore to depth.It is considered on basis of summary of field practice and results available in recent years that audio-frequency magnetotelluric is an effective technical means to prospect and predict blind ore to depth in the area.Based on basic geological data and analysis and comparison of magnetic and gravity survey data of Jiajika area with the regional ones and plane-line-point search are made clear the geological structural frame at medium-deep depth thus distribution of acidic intrusive bodies,such as Majingzi grantic body,are outlined,then the possible intruding conduits of pegmatite dykes.The future prospecting direction of the Jiajiika area and surrounding areas is pointed out according the outline.