Investigation of the magnetic characteristics of rocks of the Shchuchinsky ore region (Polar Ural)

Research subject . The studied area is located within the Shchuchinsk zone situated at the northern end of the East Ural megazone. The deposits and ore occurrences of the skarn-magnetite formation known in the Shchuchinsk ore region are grouped into two ore fields, Yunyaginskoe and Talbeyskoe. The Yunyaginskoe ore field is represented by an effusive sedimentary stratum composed of pyroxene porphyrites and pyroxene-plagioclase porphyrites and their tuffs. The Talbeyskoe ore field is located in the gabbroids of the Malyk block, on the contact with early Silurian volcanogenic rocks and is traced submeridionally along the Kharut deep fault. Aim . Analysis and comparison of the magnetic properties of rocks from the Yunyaginskoe and Talbeyskoe ore fields according to borehole magnetometry by the example of two wells of the Shchuchinsk ore region. Results . According to the diagrams of rock magnetic susceptibility and the horizontal and vertical components of the magnetic field, the geological section was subdivided, the elements of occurrence were determined and the vertical components of the natural total, residual and induced magnetization of rocks cut by the well were calculated. Conclusions. The results of borehole magnetometry revealed a wide differentiation of the magnetic properties of rocks of the Yunyaginskoe and Talbeyskoe ore fields. The sources of magnetic anomalies in the Yunyaginsky ore field are thin near-surface magnetic bodies with a high content of magnetite iron. In the Talbeyskoe ore field, the main source of the anomaly is poor magnetite ores (iron content 10–15 wt %) associated with basalt porphyrites filling the syncline formed by skarns. The study of the magnetic characteristics of ore sub-sections made it possible to identify differences in the mineralization types both within the same well and in different ore fields.