Vol. 330 No. 6 (2019)
DOI https://doi.org/10.18799/24131830/2019/6/2129
OPPORTUNITIES OF VLF METHOD WHEN STUDYING THE TOP SECTION IN ORE AREAS
The relevance of the research is caused by the economic interest in using simple, efficient and high-performance geophysical technologies for prospecting and exploration of ore deposits. The main aim of the research is to evaluate the information content of geoelectrical sections, built on the impedance data of the Very Low Frequency (VLF) method, when studying the weathering crust and the bedrock in various geological conditions. Objects of the research are located in the Degtyarsko-Polevsky ore region of the Middle Urals, in the contact zone of the Serovsko-Mauksky Fault, separating the rock complexes of the Tagil trough and the East Ural uplift. Geophysical profiles were located on the territory of the Krylatovsky gold-quartz deposit, the Chusovskoe copper-pyrite deposit, the Kungursky and Volchikhinsky areas. Methods. Field measurements were carried out with a OMAR-2m wideband receiver with a creeping line and an inductive sensor of an alternating magnetic field. Observations of the orthogonal components of the very low frequency radio station signal field were made. As a comparison, we used the results of audio magnetotelluric and vertical electrical soundings, as well as information on the geological study of the territory. Quantitative processing of electrical data was carried out using software developed in various scientific institutions. Results. Studies have shown good comparability of the results of very low frequency inversion with the geoelectric sections obtained by other methods of electromagnetic sounding. A very low frequency method cannot display all the structural features of the upper part of the section, but makes it possible to single out the characteristic features of bedrock and to determine the main boundary between the loose sediments and the base of the section. The obtained results indicate that it is possible in principle to detect deep-laying ore objects using the very low frequency method. The method has a good performance, so you can achieve high detail observations at low cost. The geo-electric sections of the very low frequency can be used to quickly assess the total thickness of the weathering crust and select sounding points by other electromagnetic methods to clarify the geological situation.
Keywords:
Very Low Frequency method, , components of electromagnetic field, impedance, geoelectrical section, ore deposit


