STRUCTURAL-GEODYNAMIC CONTROL OF KIMBERLITE PIPES OF THE YAKUT DIAMOND PROVINCE ACCORDING TO THE DATA OF GRAVISTRUCTURAL ANALYSIS

The article deals with the fundamental concepts of a new method of interpretation of regional gravimetry (scale 1:1000000) based on the idea of the deformational nature of low-frequency gravity anomalies. The method provided an opportunity to identify the direction of tectonic compression in the Yakut diamond-bearing province, to localize segments and axes of inter-shear compression and extension of different kinematics and on that basis to distinguish the shear interaction zones spatially correlating with the location of kimberlite pipes. Particularly, the whole area is characterized by four transpressive compression directions: a pair of orthogonal (dextral with azimuth 8° and sinistral with azimuth 98°) and a pair of diagonal (dextral with azimuth 38° and sinistral with azimuth 128°). These data correlate to those from the regional tectonophysical studies not only within the compression direction azimuths but also within kinematics of transpressive motions for two main phases in geodynamical evolution of the Yakutsk diamond-bearing province (YDP) - predominantly dextral for the first phase of the northeastern compression and sinistral for second phase of the northwestern compression. The article also shows that the Alakit-Olenek mineragenic zone is an extensive (~500 km) area of plastic deformation of rocks ~90 km in width with the right-lateral kinematics of apparent motions of the rocks along its northern and southern boundaries. The southern boundary of the mineragenic zone exhibits the northeaststriking continuity whereas its northern boundary is discontinuous. The boundaries of the Alakit-Olenek mineragenic zone are controlled by the zones of shear interaction of different dynamics and kinematics, which are spatially related to kimberlite pipes and diamond placer deposits. The results of this study imply that the method proposed for interpretation of gravity field can predict the occurrence of structures of geodynamic control of kimberlite magmatism of the Yakut diamond-bearing province.

1. Bornyakov S.A., 1981. Tectonophysical Analysis of the Process of Formation of the Transform Zone in an Elastic-Viscous Model. In: N.A. Logachev, S.I. Sherman (Eds), Problems of Fault Tectonics. Nauka, Novosibirsk, p. 26–44 (in Russian)

2. Cowgill E., Yin A., Feng W.X., Qing Zh., 2000. Is the North Altyn Fault Part of a Strike-Slip Duplex along the Altyn Tagh Fault System? Geology 28 (3), 255–258. https://doi.org/10.1130/0091-7613(2000)28<255:ITNAFP>2.0.CO;2.

3. Gladkov A.S., Bornyakov S.A., Manakov A.V., Matrosov V.A., 2008. Tectonophysical Studies for Diamond Prospecting. Guidelines. Nauchny Mir, Moscow, 175 p. (in Russian)

4. Gol’din S.V., 2002. Lithosphere Destruction and Physical Mesomechanics. Physical Mesomechanics 5 (5), 5–22 (in Russian)

5. Ignatov P.A., Novikov K.V., Zaripov N.R., Khodnya M.S., Shmonov A.M., Razumov A.N., Kilizhekov O.K., Kovalchuk O.E., Kryazhev S.G., 2017. A Complex of Nontraditional Prospecting Indicators of Primary Diamond Deposits Used in Closed Areas. In: Problems of Minerageny, Economic Geology and Mineral Resources. Smirnov Collection-2017. MAKS Press, Moscow, p. 207–228 (in Russian)

6. Kheraskova T.N., Kaplan S.A., Galuev V.I., 2009. Structure of the Siberian Platform and Its Western Margin in the Riphean – Early Paleozoic. Geotectonics 43 (2), 37-56 (in Russian)

7. Krainov S.R., Ryzhenko B.N., Shvets V.M., 2004. Geochemistry of Groundwater. Theoretical, Applied and Environmental Aspects. Nauka, Moscow, 677 p. (in Russian)

8. Likhachev A.P., 2017. The Conditions of Magnetite and Its Ore Clusters Formation. Otechestvennaya Geologiya 4, 44–53 (in Russian)

9. Makarov P.V., 2007. Evolutionary Nature of Destruction of Solids and Media. Physical Mesomechanics 3 (10), 23–38 (in Russian)

10. Makeev S.M., 2016. Solving of Two Problems of Geodynamics with the Gravity Structure Method. Geology and Mineral Resources of Siberia 4, 63–74 (in Russian)

11. Milashev V.A., 1979. The Structure of Kimberlite Fields. Nedra, Leningrad, 183 p. (in Russian)

12. Molchanov Yu.D., Savrasov D.I., 1981. Physico-Geological Characteristics of Faults of the Vilyui-Markha Tectonic Zone within the Mirny Kimberlite Field. In: Geology, Diamond Content and Metallogeny of the Siberian Platform and Its Margins. IEC SB AN USSR, Irkutsk, p. 37–39 (in Russian)

13. Nikolaevsky V.N., 2010. Geomechanics. Collection of Works. Vol. 1. Institute for Computer Research, Izhevsk, 640 p. (in Russian)

14. Odintsov M.M., 1957. Main Geological Features of the Siberian Diamond-Bearing Province. Bulletin of the Eastern Division of the USSR Academy of Sciences 1, 27–34 (in Russian)

15. Panin V.E., 1998. Foundations of Physical Mesomechanics. Physical Mesomechanics 1 (1), 5–22 (in Russian)

16. Rodionov V.N., 2006. The Doctrine of Geomechanics. Geophysics 5, 61–64 (in Russian)

17. Sadovsky M.A., 1979. Natural Lumpiness of Rocks. Doklady of the USSR Academy of Sciences 247 (4), 829–831 (in Russian)

18. Sarkarinejad K., Azizi A., 2008. Slip Partitioning and Inclined Dextral Transpression along the Zagros Thrust System, Iran. Journal of Structural Geology 30 (1), 116–136. http://dx.doi.org/10.1016/j.jsg.2007.10.001.

19. Seminsky K.Zh., 2003. Internal Structure of Continental Fault Zones. Tectonophysical Aspect. GEO, Novosibirsk, 244 p. (in Russian)

20. Sherman S.I., Bornyakov S.A., Buddo V.Yu., 1983. Areas of Dynamic Influence of Faults (Modelling Results). Nauka, Novosibirsk, 112 р. (in Russian)

21. Sherman S.I., Seminsky K.Zh., Bornyakov S.A., Buddo V.Yu., Lobatskaya R.M., Adamovich A.N., Truskov V.A., Babichev A.A., 1991. Faulting in the Lithosphere. Strike-Slip Zones. Vol. 1. Nauka, Novosibirsk, 261 p. (in Russian)

22. Trushkov Yu.N. (Ed.), 1974. Structural Control of the Manifestations of Kimberlite Magmatism in the Northeast of the Siberian Platform. Nauka, Novosibirsk, 98 p. (in Russian)

23. Twiss R.J., Moores E.M., 1992. Structural Geology. W.H. Freeman and Company, New York, 532 p.

24. Vaganov V.I., Golubev Yu.K., Minorin V.E., 2002. Evaluation of the Inferred Resources of Diamonds, Precious and Non-Ferrous Metals. Guidelines. Iss. "Diamonds". TSNIGRI, Moscow, 76 p. (in Russian)

25. Woodcock N.H., Fischer M., 1986. Strike-Slip Duplexes. Journal of Structural Geology 8 (7), 725–735. http://dx.doi.org/10.1016/0191-8141(86)90021-0.