Geoelectric structure of the Tar Fault Zone in the Middle Urals according to audiomagnetotelluric soundings

Authors

  • V. A. Davydov Yu. P. Bulashevich Institute of Geophysics, Ural Branch of the Russian Academy of Sciences, Russian Federation

DOI:

https://doi.org/10.24028/gzh.0203-3100.v42i3.2020.204708

Keywords:

audiomagnetotelluric sounding, ore deposits, fault, geoelectric section, ore mineralization

Abstract

Currently, the reduction of reserves and forecast resources of ore minerals due to the development of previously discovered deposits continues. The reproduction of reserves is possible due to additional exploration of the flanks and deep horizons of known ore objects. To study the geoelectric structure of the Ural ore-bearing structures, audiomagnetotelluric soundings were carried out along sub-latitudinal profiles crossing the zone of the Degtyarsky fault near the largest pyrite deposit in the Middle Urals. Field observations were performed using the OMAR-2 universal broadband equipment developed at the Institute of Geophysics, Ural Branch of the Russian Academy of Sciences for electrometric studies of urbanized territories. The applied hardware-software measuring complex is designed to effectively suppress industrial noise with additional methods for digital filtering of network harmonics. The cameral processing of audiomagnetotelluric data consisted in transforming the obtained frequency sounding curves into deep sections of geoelectric parameters using an original transformation algorithm. Based on the materials of the work, lithological and tectonic boundaries of a complex rock complex adjacent to the Degtyarsky regional fault are identified. Electric prospecting methods confidently trace the surface of the bedrock base, and weakened zones are also traced. Studies have shown a good correlation of geoelectric sections with real geological conditions. Good identification of the fault-bearing and ore-controlling structures is noted, which makes it possible to identify areas of mineralization that are promising for mineralization that do not reach the surface. According to the results of the research, places of possible concentration of copper and nickel-cobalt mineralization are identified.

References

Davydov, V. A. (2014). Audio magnetotelluric motion capture. Geofizika, (2), 47—53 (in Russian).

Davydov, V. A. (2015). OMAR-2 measuring equipment for electromagnetic research methods. Ural’skiy geofizicheskiy vestnik, (1), 37—41 (in Russian).

Davydov, V. A. (2017). New electromagnetic sensors for mid-frequency electrical prospecting. Datchiki i sistemy, (11), 58—62 (in Russian).

Davydov, V. A. (2016). Audio magnetotelluric da¬ta transformation using a priori information. Geofizicheskie issledovaniya, 17(4), 57—66 (in Russian).

Davydov, V. A., Arzamastsev, E. V., Baydikov, S. V., Gorshkov, V. Yu., & Astafiev, P. F. (2019). Geophysical surveys in the Serov-Mauk fault zone. Ural’skiy geofizicheskiy vestnik, (1), 17—22. doi: 10.25698/UGV.2019.1.3.17 (in Russian).

Zhdanov, S. A., Pyzh’yanov, Yu. B. (2011). The results of the generalization of geological and geophysical materials in the Degtyarsko-Polevsky district. Lesa Rossii i hozyaystvo v nikh, (1), 19—26 (in Russian).

Ivanov, S. N., & Merkulov, M. I. (1937). Degtyarsky pyrite deposit. Мoscow-Leningrad: ONTI NKTP USSR, 124 p. (in Russian).

Kalugina, R. D., Kopanev, V. F., Storozhenko, E. V., et al. (2017a). State geological map of the Russian Federation. Scale 1:200 000. Second edition. Series Sredneuralskaya. Sheet O-41-XXV. Explanatory note. Moscow: Publ. of the Moscow branch of FSBI «VSEGEI», 156 p. (in Russian).

Kalugina, R. D., Kopanev, V. F., Storozhenko, E. V., et al. (2017b). State geological map of the Russian Federation. Scale 1:200 000. Second edition. Series Sredneuralskaya. Sheet O-41-XXXI. Explanatory note. Moscow: Publ. of the Moscow branch of FSBI «VSEGEI», 180 p. (in Russian).

Prokin, V. A., Buslaev, F. P., & Ismagilov, M. I. (1988). Copper pyrite deposits of the Urals: Geological structure. Sverdlovsk: Edition of the Ural Branch of the USSR Academy of Sciences, 241 p. (in Russian).

Prokin, V. A., Seravkin, I. B., & Vinogradov, A. M. (2011). Geological conditions of location and prospects for identifying large copper pyrite deposits in the Urals. Litosfera, (6), 123—133 (in Russian).

Rodionov, P. F., Zhdanov, S. A., Kozhevnikov, A. A., & Kononenko, I. I. (1972). Comparative characteristics of borehole electrical exploration methods (based on the materials of the Chusovsky pyrite deposit). In Theory and practice of electrometry (pp. 164—176). Sverdlovsk: Edition of the Editorial and Publishing Council of the Ural Scientific Center of the USSR Academy of Sciences (in Russian).

Sazonov, V. N., Ogorodnikov, V. N., Koroteev, V. A., & Polenov, Yu. A. (1999). Gold deposits of the Urals. Yekaterinburg: Publ. House of the Ural State Mining and Geological Academy, 570 p. (in Russian).

Smyvina, V. S., Kuzin, A. V., Nasedkin, A. P., & Papulov, N. B. (2000). Paleovolcanic reconstructions of the Polevsky ore district. Ural’skiy geologicheskiy zhurnal, (3), 107—117 (in Russian).

Sokolov, V. B., Averkin, Yu. P., & Silin, V. A. (1984). The structure of the section of the upper part of the earth’s crust in the region of development of the greenstone strata of the Urals and the structural position of the Degtyarsky copper ore region. Doklady AN SSSR, 276(5), 1185—1189 (in Russian).

Berdichevsky, M. N., & Dmitriev, V. I. (2009). Models and methods of magnetotellurics. Berlin: Springer, 563 p. doi: 10.1007/978-3-540-77814-1.

Cagniard, L. (1953). Basic theory of the magnetotelluric method in geophysical prospecting. Geophysics, (8), 605—635. doi: 10.1190/1.1437915.

Lahti, I. (2015). Audiomagnetotelluric (AMT) measurements: A new tool for mineral exploration and upper crustal research at the Geological Survey of Finland. Novel technologies for greenield exploration. Geological Survey of Finland, Special Paper 57, 155—172.

Lahti, I., Kontinen, A., & Nykänen, V. (2019). AMT survey in the Outokumpu ore Belt, Eastern Finland. Exploration Geophysics, 50(4), 351—363. doi: 10.1080/08123985.2019.1606200.

Lap, T. T., Xue, C., Wei, A., Liu, L., Li, W., Hu, Q., & Zhang, T. (2014). Application of Audio-magnetotelluric method for exploration the concealed ore-bodies in Yuele lead-zinc ore feild, Daguan County, NE Yunnan Province, China. Journal of Geoscience and Environment Protection, (2), 35—45. doi: 10.4236/gep.2014.23005.

Singh, S., Maurya, V. P., Singh, R. K., Srivastava, S., Tripathi, A., & Adhikari, P. K. (2018). Audio-magnetotelluric investigation of sulfide mineralization in Proterozoic-Archean greenstone belts of Eastern Indian Craton. Journal of Earth System Science, 127(3), 34. doi: 10.1007/s12040-018-0938-z.

Published

2020-06-10

How to Cite

Davydov, V. A. (2020). Geoelectric structure of the Tar Fault Zone in the Middle Urals according to audiomagnetotelluric soundings. Geofizičeskij žurnal, 42(3), 162–174. https://doi.org/10.24028/gzh.0203-3100.v42i3.2020.204708

Issue

Section

Articles