Magnetotelluric data from 104 new stations in northern Sweden together with previously available MaSca project data are analysed with respect to a hypothesised genetic relation between mineral occurrences and commonly reported deep crustal electrically conductive structures in Precambrian Shield areas. A total of 165 stations from the north-eastern part of the Norrbotten ore province are modelled from an area characterised as having an Achaean basement with later reworking during the Paleoproterozoic. The data cover an area of 200 × 250 km² and provide a significant improvement of spatial resolution compared to previously available data. The derived 3D model reveals the presence of strong crustal conductors with conductance of more than 3000 S at depth of tens of kilometres within a generally resistive crust. A subdivision into a central more conductive domain bounded towards north and south by resistive domains is revealed. The boundaries between these three domains are oriented NW-SE. The southern boundary coincides roughly with the boundary between Archaean and Paleoproterozoic crust defined by ε_Nd data. The northern boundary coincides with an interpreted 2.4–2.3 Ga coastline of a marine rift basin, which is spatially defined by the occurrence of the Kovo group rocks. The location of major conductors within the central domain correlates with the presence of mapped Paleoproterozoic metasupracrustal belts. A significant part of the middle crust conductors is elongated in directions that coincide with major deformation zones that have been mapped from airborne magnetic data and geological fieldwork. Some of these conductors have near-surface expression where they spatially correlate with the location of known mineralisation. In these cases, the conductive structures may mark the pathways for metal-bearing hydrothermal fluids. Interpretations involving enhanced quantities of magnetite or graphite in the middle crust are discussed but the magnetotelluric data alone are not conclusive with respect to cause of observed high conductivities.

瑞典北部前104个新站点的大地电磁数据以及以前可用的MaSca项目数据，针对前寒武纪盾构地区矿床与通常报道的深层地壳导电结构之间的假设遗传关系进行了分析。从北博滕矿石省东北部的总共165个站进行了建模，该站的特征是拥有Achaean地下室，随后在古元古代时期进行了重新加工。数据覆盖200×250 km ²与以前的可用数据相比，空间分辨率得到了显着改善。推导的3D模型揭示了在坚硬的地壳内数十公里深度处，电导大于3000 S的强地壳导体的存在。揭示了细分为一个中心的导电区域，该区域由电阻域界定为北向和南向。这三个域之间的边界是面向NW-SE的。南部边界重合大致与太古和古元地壳之间的边界由定义ε_钕数据。北边界与海洋裂谷盆地的经解释的2.4–2.3 Ga海岸线重合，该海岸线在空间上由科沃群岩石的出现确定。主要导体在中央区域内的位置与古元古代元上壳壳带的存在有关。中间地壳导体的很大一部分在与主要变形区域一致的方向上拉长，主要变形区域已从机载磁数据和地质野外工作中绘制出来。这些导体中的一些具有近地表层表达，它们在空间上与已知矿化的位置相关。在这些情况下，导电结构可能会标记出含金属热液的通道。