The Minle manganese (Mn) deposit is a typical Mn-bearing deposit in the Datangpo Formation in southern China. The metallogenic environment and associated changing processes directly determine the migration, enrichment, and precipitation of Mn. To have a better understanding of the metallogenic structure, magnetotelluric (MT) method was performed to explore the Minle deposit. Electrical spindle analysis of MT data was conducted based on the Swift decomposition and the phase tensor decomposition, and inversion of the transverse-electric (TE) and transverse-magnetic (TM) models was carried out using the Occam inversion method. The results revealed that the main structural strike of the MT section was approximately 37° north to east and obtained the distribution characteristics of the deep electrical properties in the study area. The “concave structure” in the resistivity model is the main geophysical marker for delineating the Mn-ore body. In the metallogenic structure of Mn ore, a “funnel-shaped structure” of the strata was found, which provided favorable space for the percolation and enrichment of Mn deposits. The results of this study will be helpful in improving geophysical prospecting techniques for sedimentary Mn deposits in southern China.

民乐锰矿床是我国南方大塘坡组典型的含锰矿床。成矿环境及变化过程直接决定锰的运移、富集和沉淀。为了更好地了解成矿结构，采用大地电磁（MT）方法对民乐矿床进行了勘探。基于Swift分解和相张量分解对MT数据进行电主轴分析，并利用奥卡姆反演方法对横电（TE）和横磁（TM）模型进行反演。结果表明，MT剖面主构造走向约为北向东37°，获得了研究区深部电性分布特征。电阻率模型中的“凹状构造”是圈定锰矿体的主要地球物理标志。在锰矿成矿结构中，发现了地层的“漏斗状结构”，为锰矿床的渗滤富集提供了有利的空间。本研究成果将有助于提高我国南方沉积锰矿地球物理找矿技术。