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Izvestiya, Physics of the Solid Earth

, Volume 51, Issue 1, pp 26–37 | Cite as

The pattern of deep structure and recent tectonics of the Greater Caucasus in the Ossetian sector from the complex geophysical data

  • A. V. Gorbatikov
  • E. A. Rogozhin
  • M. Yu. Stepanova
  • Yu. V. Kharazova
  • N. V. Andreeva
  • F. V. Perederin
  • V. B. Zaalishvili
  • D. A. Mel’kov
  • B. V. Dzeranov
  • B. A. Dzeboev
  • A. F. Gabaraev
Article

Abstract

Microseismic sounding along the profile in the Ossetian sector of the Greater Caucasus revealed two domains with characteristic properties and morphology deep beneath the mountain system. One subvertical domain is marked with low velocities and the other, also subvertical, has high velocities. The high-velocity zone is largely located beneath the northern limb and axial part of the Greater Caucasus mega-anticlinorium, whereas the low velocity zone projects on the southern limb. Almost throughout the entire structure of the block part of the northern limb of mega-anticlinorium, the top of the high-velocity zone beneath it is consistently horizontal at a depth of ∼10 km. This pattern is violated by the apparent steep rise of the top of the high-velocity zone to the surface in the southern direction, which starts approximately from the main thrust. Beneath the southern limb, the top boundary can also be guessed at a depth of ∼10 km, although less reliably. The roots of the low-velocity zone stretch to a depth of ∼50–60 km and narrow with the depth. The weak regional seismicity quite distinctly maps onto the high-velocity zone. In the depth interval of 10 to 25 km, weak seismicity abruptly drops northwards at the transition to the low-velocity zone. The independent magnetotelluric data show that electric resistivity of the low-velocity zone significantly exceeds the resistivity of the hosting rocks. The model of a medium filled with isolated fractures with mineralized fluid is suggested for the low-velocity zone. According to a series of features, the low-velocity zone tends to float up; in particular, there is a high lateral correlation between the most elevated part of the mountain relief, morphology, and age of the rocks, on one hand, and the position of the low-velocity zone, on the other hand.

Keywords

Solid Earth Velocity Zone Elbrus Northern Limb Southern Limb 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Aleshin, I.M., Kosarev, G.M., Riznichenko, O.Yu., and Sanina, I.A., Velocity section of the Earth’s crust beneath the RUKSA seismic array, Kareliya, Geofiz. Issled., 2007, no. 7, pp. 3–13.Google Scholar
  2. Arbuzkin, V.N., Kompaniets, M.A., Shvets, A.I., Grekov, I.I., et al., Report on the Complex Geologic-Geophysical Study along the Cis-Elbrus Profile, Essentuki: Kavkazgeols’emka, 2002.Google Scholar
  3. Aref’ev, S.S., Rogozhin, E.A., Bykova, V.V., and Dorbat, K., Deep structure of the Racha earthquake source zone from seismic tomography data, Izv., Phys. Solid Earth, 2006, vol. 42, no. 1, pp. 27–40.CrossRefGoogle Scholar
  4. Baranov, G.I., Belov, A.A., and Dotduev, S.I., Rassloennost’ litosfery i regional’nye geologicheskie issledovaniya (Layering of the Lithosphere and Regional Geological Studies), Moscow: Nauka, 1990.Google Scholar
  5. Burov, E.B. and Diament, M., The effective elastic thickness (Te) of continental lithosphere: what does it really mean?, J. Geophys. Res., 1995, vol. 100, pp. 3905–3928.CrossRefGoogle Scholar
  6. Burov, E.B. and Watts, A.B., The long-term strength of continental lithosphere: “Jelly sandwich” or “crèmberûlé”?, GSA Today, 2006, vol. 16, pp. 4–10.CrossRefGoogle Scholar
  7. Gorbatikov, A.V., Stepanova, M.Yu., and Korablev, G.E., Microseismic field affected by local geological heterogeneities and microseismic sounding of the medium, Izv., Phys. Solid Earth, 2008, vol. 44, no. 7, pp. 577–592.CrossRefGoogle Scholar
  8. Gorbatikov, A.V., Larin, N.V., Moiseev, E.I., and Belyashov, A.V., The microseismic sounding method: application for the study of the buried diatreme structure, Dokl. Earth Sci., 2009, vol. 428, no. 7, pp. 1222–1226.CrossRefGoogle Scholar
  9. Gorbatikov, A.V., Stepanova, M.Yu., Tsukanov, A.A., Tinakin, O.V., Komarov, A.Yu., and Odintsov, S.L., A new technology of microseismic sounding for solving the problems of depth structure of oil and gas fields, Neft. Khoz., 2010, no. 6, pp. 15–17.Google Scholar
  10. Gorbatikov, A.V., Ovsyuchenko, A.N., and Rogozhin, E.A., Structure of the Vladikavkaz fault zone from the data of complex geologic-geophysical study, Geol. Geofiz. Yuga Ros., 2011, no. 2, pp. 23–32.Google Scholar
  11. Gorbatikov, A.V., Ovsyuchenko, A.N., Rogozhin, E.A., Stepanova, M.Yu., and Larin, N.V., Seismotectonics and depth structure of the active Vladikavkaz fault zone, Geofiz. Issled., 2011, no. 12, pp. 47–59.Google Scholar
  12. Gorbatikov, A.V. and Tsukanov, A.A., Simulation of the Rayleigh waves in the proximity of the scattering velocity heterogeneities. Exploring the capabilities of the microseismic sounding method, Izv., Phys. Solid Earth, 2011, vol. 47, no. 4, pp. 354–370.CrossRefGoogle Scholar
  13. Gorbatikov, A.V., Montesinos, F.G., Arnoso, J., Stepanova, M.Yu., Benavent, M., and Tsukanov, A.A., New features in the subsurface structure model of El Hierro Island (Canaries) from low-frequency microseismic sounding: An insight into the 2011 seismo-volcanic crisis, Surv. Geophys., 2013, vol. 34, no. 4, pp. 463–489.CrossRefGoogle Scholar
  14. Ivanov, S.N., An impermeable zone at the boundary between the upper and middle crust, Izv., Phys. Solid Earth, 1999, vol. 35, no. 9, pp. 779–784.Google Scholar
  15. Koronovskii, N.V., Kratkii kurs regional’noi geologii SSSR (Brief Course of USSR Regional Geology), Moscow: Mosk. Gos. Univ., 1976.Google Scholar
  16. Koulakov, I., Zabelina, I., Amanatashvili, I., and Meskhia, V., Nature of orogenesis and volcanism in the Caucasus region based on results of regional tomography, Solid Earth, 2012, vol. 3, no. 2, pp. 327–337.CrossRefGoogle Scholar
  17. Kovachev, S.A., Kaz’min, V.G., Kuzin, I.P., and Lobkovskii, L.I., New data on mantle seismicity of the Caspian Region and their geological interpretation, Geotectonics, 2009, vol. 43, no. 3, pp. 30–44.CrossRefGoogle Scholar
  18. Krasnopevtseva, G.V., Matushkin, B.A., and Shevchenko, V.I., New interpretation of the DSS data along the Stepnoe-Bakuriani profile, Caucasus, Sov. Geol., 1970, no. 8, pp. 113–120.Google Scholar
  19. Krasnopevtseva, G.V., Depth structure of the Caucasus, in Stroenie zemnoi kory i verkhnei mantii Tsentral’noi i Vostochnoi Evropy (Structure of the Earth’s Crust and Upper Mantle in Central and East Europe), Sollogub, V.B., Guterch, A., Prosen, D., et al., Eds., Kiev: Naukova dumka, 1978, pp. 190–199.Google Scholar
  20. Malovichko, A.A., Gabsatarova, I.P., Kashirgova, R.R., and Dolov, S.M., The current state of the seismic monitoring system in Kabardino-Balkaria, Seism. Instrum., 2012, vol. 48, no. 3, pp. 256–270.CrossRefGoogle Scholar
  21. Milanovskii, E.E., Geologiya Rossii i blizhnego zarubezh’ya (Severnoi Evrazii) (Geology of Russia and Neighboring Territories (North Eurasia)), Moscow: Mosk. Gos. Univ., 1996.Google Scholar
  22. Nikitin, M.Yu., Nikonov, A.A., Bolotov, S.N., and Belyakov, G.A., Paleoseismodislocations in the Ardon River Basin and their value for assessing the seismic potential of the Greater Caucasus, Dokl. Ross. Akad. Nauk, 1993, vol. 330, no. 6, pp. 740–744.Google Scholar
  23. Ovsyuchenko, A.N., Marakhanov, A.V., Novikov, S.S., and Lar’kov, A.S., Peculiarities of seismotectonics and the ancient earthquakes of South Ossetia, Part 2, Vestn. Vladikavkaz. Nauchn. Tsentra, 2011, vol. 2, no. 4.Google Scholar
  24. Pavlenkova, G.A., Crustal structure of the Caucasus from the Stepnoe-Bakuriani and Volgograd-Nakhichevan DSS profiles (reinterpretation of the primary data), Izv., Phys. Solid Earth, 2012, vol. 48, no. 5, pp. 375–384.CrossRefGoogle Scholar
  25. Proskuryakova, T.A., Novotny, O., and Voronina, E.V., Izuchenie stroeniya Zemli metodom poverkhnostnykh voln (Tsentral’naya Evropa) (Studing the Earth’s Structure by Surface Wave Method: A Case Study of Central Europe), Moscow: Nauka, 1981.Google Scholar
  26. Shankland, T.J. and Waff, H.S., Partial melting and electrical conductivity anomalies in the upper mantle, J. Geophys. Res., 1977, vol. 82, pp. 5409–5417.CrossRefGoogle Scholar
  27. Shempelev, A.G., Results of depth geophysical studies along the Genaldon profile, in Opasnye prirodnye i tekhnogennye geologicheskie protsessy na gornykh i predgornykh territoriyakh Severnogo Kavkaza. Trudy mezhdunarodnoi nauch.-prakt. konferentsii, Vladikavkaz, 2007 (Proceedings of the International Scientific Conference “Dangerous Natural and Anthropogenic Geological Processes in the Mountain and Foothill Territories of Northern Caucasus,” Vladikavkaz, 2007), Vladikavkaz, 2008, pp. 457–463.Google Scholar
  28. Shevchenko, V.I., Proiskhozhdenie struktur gorizontal’nogo szhatiya v skladchatom sooruzhenii (na primere Bol’shogo Kavkaza) (Origin of Horizontal Pressure Features in Folded Structures: A Case Study of the Greater Caucasus), Moscow: Nauka, 1985.Google Scholar
  29. Shevchenko, V.I., Guseva, T.V., Lukk, A.A., Mishin, A.V., Prilepin, M.T., Reilinger, R.E., Hamburger, M.W., Shempelev, A.G., and Yunga, S.L., Recent geodynamics of the Caucasus mountains from GPS and seismological evidence, Izv., Phys. Solid Earth, 1999, vol. 35, no. 9, pp. 691–704.Google Scholar
  30. Sholpo, V.N., Rogozhin, E.A., and Goncharov, M.A., Skladchatost’ Bol’shogo Kavkaza (Folding of the Greater Caucasus), Moscow: Nauka, 1993.Google Scholar
  31. Sobolev, S.V., Babeyko, A.Y., Koulakov, I., and Oncken, O., Mechanism of the Andean orogeny: insight from the numerical modelling, in The Andes: Active Subduction Orogeny, Oncken, O., Chong, G., Franz, G., Giese, P., Götze, H.-J., Ramos, V.A., Strecker, M.R., Wigger, P., Eds., Berlin: Springer, 2006, pp. 513–535.CrossRefGoogle Scholar
  32. Sobolev, S.V. and Babeyko, A.Y., What drives orogeny in the Andes?, Geology, 2005, vol. 33, pp. 617–620.CrossRefGoogle Scholar
  33. Somin, M.L., Structure of axial zones in the Central Caucasus, Dokl. Earth Sci., 2000, vol. 375A, no. 9, pp. 1371–1374.Google Scholar
  34. Tikhotskii, S.A., Fokin, I.V., Shur, D.Yu., and Arefiev, S.S., Structure of the 1991 Racha earthquake source zone from the local seismic tomography data with adaptive parameterization of the medium, Geofiz. Issled., 2011, vol. 12, no. 1, pp. 5–32.Google Scholar

Copyright information

© Pleiades Publishing, Ltd. 2015

Authors and Affiliations

  • A. V. Gorbatikov
    • 1
  • E. A. Rogozhin
    • 1
  • M. Yu. Stepanova
    • 1
  • Yu. V. Kharazova
    • 1
  • N. V. Andreeva
    • 1
  • F. V. Perederin
    • 1
  • V. B. Zaalishvili
    • 2
  • D. A. Mel’kov
    • 2
  • B. V. Dzeranov
    • 2
  • B. A. Dzeboev
    • 1
  • A. F. Gabaraev
    • 2
  1. 1.Schmidt Institute of Physics of the EarthRussian Academy of SciencesMoscowRussia
  2. 2.Center of Geophysical InvestigationsVladikavkaz Science Center of the Russian Academy of Sciences and the Government of Republic of North Ossetia-AlaniaVladikavkaz, Republic of North Ossetia-AlaniaRussia

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