Logging of natural electromagnetic radiation in iron ore deposits by the example of Gusevogorskoye and Severo-Taratashskoye deposits
Research aim is to study the effect of natural electromagnetic radiation at various frequencies (45 kHz, 80 kHz, and 120 kHz) at the Gusevogorskoye titanomagnetite deposit and Severo-Taratashskoye iron ore deposit, and distinguish the most informative frequency range. Research relevance conditions in the first conducted studies of the connection between natural electromagnetic radiation (NEMR), measured in the drilling and blasting wells of the Gusevogorskoye deposit, and the strained state of the rock block and its rock jointing. Research methodology. The research was conducted in drilling and blasting wells of the Gusevogorskoye titanomagnetite deposit. It included primary point-to-point measurements when lowering a sonde, continuous measurements during lifting, and repeated measurements after technological explosion near the located block. At the North Taratashskoye iron ore deposit, investigations were carried out during one run. The presented measurement results were obtained using apparatus developed at the Institute of Geophysics of the Ural Branch of the Russian Academy of Sciences. Results. The results of testing the technique of point-to-point and continuous logging of natural electromagnetic radiation in wells at iron ore deposits of various types are presented. The data of the experiment on studying the zones of rockjointing, as well as tectonic disturbances detection in the wellbore space, are a reflection of the method practical implementation in the study of the ore field tectonics. Conclusions. Studies carried out in the quarry have shown that the distribution of the NEMR levels indicates the possibility of detecting tectonic disturbances in the wellbore space by their dynamic activity. The electromagnetic emission logging results analysis performed at the exploratory well of the Severo-Taratashskoye iron ore deposit, from the point of view of tectonic disturbance zones tie with NEMR high-amplitude anomalies, also allowed to explain the results obtained in the well.