摘要
可控源音频大地电磁法(CSAMT)是地球物理界在深部找矿工作中使用的主要方法之一,长期以来,人们一直采取CSAMT的标量测量方式。然而,标量测量仅适用于地下介质为一维的电性结构。张量CSAMT法满足二、三维地下介质的探测条件,开展张量CSAMT法深部找矿的试验工作、研究数据采集技术、考察它的地质勘探效果对深部找矿工作有着重要的指示意义。本文给出了一个在大型已知深部多金属矿床区张量CSAMT法三种不同激发方式场源的应用实例,展示了不同结构的发射场源的张量CSAMT法试验工作的效果。试验工作结果表明,根据地质构造走向或矿体走向采用不同方向交替发射的电偶极子场源,张量CSAMT法在对地层、岩体的划分以及圈定岩体内部的矿体分布等方面获得的地电异常特征不尽相同,在实际工作中需考虑发射场源的方向问题。
Controlled-source magnetotelluric （CSAMT） is the main method used in the field of geophysical prospecting. It has been used for a long time by scalar CSAMT measurement mode. Scalar measurement is only applicable to the one-dimensional electrical structure of the underground medium. Tensor CSAMT measurement satisfies the conditions of two and three dimensional underground medium, and testing of its abilities in deep ore exploration has important significance for further application. In this paper, as real-world-example, the tensor CSAMT method has been applied to a large-scale deep multi-metal mine area with the well-controlled geological structure and mine distribution, aiming to discriminate the ef- ficiencies of three different exciting sources and demonstrate its potentials in minerals exploration. The experiment results show that the efficiencies in imaging the strata, rock bodies division and ore bodies distribution are significantly dependent on coupling of field polarization directions and strikes of structure and ore deposits. And the direction of the emission source should be considered in practice.
出处
《工程地球物理学报》
2016年第4期435-442,共8页
Chinese Journal of Engineering Geophysics
基金
安徽省国土资源科技项目(编号:2013-k-4)
