皖南某地磁法找矿效果分析

Analysis on the Effect of Magnetic Field Prospecting in Somewhere in Southern Anhui Province

皖南某地前期发现有多处金、银及铅锌锑等矿床,但规模均不大,成矿机制、远景等都不明确。后期省局在该地区开展了金及多金属找矿工作,采用地、物、化等多种方法同时进行,其中磁法勘探为其中之一。区内磁法工作在收集前期航磁资料基础上进行,分别在区调及普查找矿阶段开展了1∶2.5万及1∶1万地面高精度磁法测量,通过3个阶段磁法工作资料的整理及与地质、化探资料相结合后,对该地区地层、构造、岩浆岩分布特征进行了定性推断和分析,提出了该区金及多金属矿产为戴村岩体岩浆期后热液作用所致,为中—低温热液型矿产。该推论为后期找矿工作的布置提供了理论依据,并得到了较好的验证,取得了较好的经济效益,找矿效果明显。

A number of gold, silver, lead, zinc and antimony deposits were discovered in a certain area of southern Anhui in the early stage, but the scales are not large, the metallogenic mechanism and prospects are not clear. Later, the provincial bureau carried out gold and polymetallic prospecting work in this area, with simultaneous use of multiple methods of geological, geophysical and geochemical, of which magnetic prospecting was the focus among them. The regional magnetic work was carried out on the basis of collected the aeromagnetic data. The ground high-precision magnetic measurement on the scale of 1: 25,000 and 1: 10,000 were carried out in the survey and the prospecting stage separately.Through the compilation of working data by three stages of magnetic method and combination of the geology and geochemical data, qualitative inference and analysis are made on the distribution characteristics of strata, structures and magmatic rocks in this area.It is suggested that the gold and polymetallic minerals in this area are caused by post-magmatic hydrothermal processes of Daicun rock mass-medium-low temperature hydrothermal minerals. This inference provides a theoretical basis for the layout of prospecting work in the later stage, and has been well verified. It has achieved good economic benefits and obvious prospecting effect.