多宝山矿集区音频电磁剖面二维反演的多个软件处理对比

Comparison of Multiple Data Software Processing for 2D Inversion of Audio Electromagnetic Profile in Duobaoshan Ore Concentration Area

摘要: 宝山矿集区三合屯矿区位于我国黑龙江省嫩江县境内，是国内重要的多金属成矿远景区之一。随着研究区找矿工作逐渐转向深部，急需查明该地区的深部结构为深部找矿提供指引。因此，为了揭示研究区深部地层结构、控岩和控矿构造的空间展布特征，深化该地区的成矿作用认识，在多宝山矿集区南部的三合屯矿区开展了音频大地电磁(audio-frequency magnetotelluric, AMT)数据采集工作。通过采用SSMT2000、prMT和EMP软件对于野外实测数据进行预处理，对比分析了不同去噪处理技术的优缺点，获得了研究区较高质量的阻抗数据。在此基础之上，采用非线性共轭梯度法(nonlinear conjugate gradient, NLCG)对野外实测数据进行二维反演，得到了研究区横向分带、纵向分层的二维电性结构。结合区域地质和地球物理资料，揭示了研究区深部的导矿和容矿构造的展布特征，对该地区间接找矿具有重要指导意义。

Abstract: Located in Nenjiang County, Heilongjiang Province, the Dobaoshan mining area is an important polymetallic mineral formation area in China with complex subsurface structures. Many existing studies have been conducted to explore the mineralization factors in this area to facilitate the mineralization search work. In order to obtain the fine geological structure of the Sanhetun area in Nenjiang to guide the mineral search, audio-frequency magnetotelluric (AMT) data acquisition was carried out in the southern Sanhetun area of the Dobaoshan mine catchment, and the data processing method based on cross-reference and robust estimation (Robust) was adopted to improve the data quality, using phase After that, a two-dimensional inversion of the processed data is performed by the nonlinear conjugate gradient (NLCG) method to obtain a two-dimensional subsurface electrical structure with transverse zonation and vertical layered structure. Finally, the two-dimensional electrical structure model and other geological and geophysical data are combined to determine the distribution of deep geological bodies and tectonic spreading information under the profile, and to obtain the electrical response characteristics of magmatic-hydrothermal gold deposits in the area, and then infer the ore-conducting and ore-holding structures to achieve the purpose of indirect ore search.