MANIFESTATION FEATURES OF DIFFERENT RANK EXTENSION ZONES IN THE RELIEF OF EXPERIMENTAL MODELS AND THEIR NATURAL ANALOGUES

The Purpose of the work is to study the reflection patterns of the interblock tension zones structure in relief at various scale levels of the Earth's crust tectonic divisibility in the Baikal rift. Methods. The study involves the analogue modeling on elastic-plastic material (clay paste) with the following construction of digital models of the control sample surface relief. The resulting digital terrain models are analyzed by constructing the distributions of vertical motion gradient. The similar method is used to study the readily available digital terrain models of the natural analogue of the experimental models of the Baikal rift. The data obtained in the analysis of the two types of digital models are compared. Results. Distributions of the gradient of vertical motions for the experiment and the relief gradient of the north-west and south-east flanks of the Baikal rift have been obtained and analyzed. Sections reflecting the extension zones of different ranks and their internal structure have been distinguished in the gradient field. A procedure has been proposed to identify the interblock zones of different hierarchical levels based on the relief gradient of Earth’s fault zones. Conclusions. The fault zones and their structure formed under extension are reflected in gradient distribution by the increased parameter values. The maximum values of the parameter are characteristic of the main fault of the zone, smaller values are referred to second-order cracks. Strike-slip cracks formed under extension are not demonstrated by special gradient values but they can be traced by the displacement of local maxima associated with other cracks. In most cases, found regularities are valid for experimental and natural extension zones.

interblock zone, fault zone, analogue modeling, digital elevation models, gradient of vertical motions, relief gradient

1. Seminskii K.Zh. Vnutrennyaya struktura kontinental'nykh razlomnykh zon. Tekto-nofizicheskii aspect [Internal structure of continental fault zones. Tectonophysical aspect]. Novosibirsk: Geo Publ., 2003, 244 p. (In Russian).

2. Seminskii K.Zh., Kozhevnikov N.O., Cheremnykh A.V., Pospeeva E.V., Bobrov A.A., Olenchenko V.V., Tugarina M.A., Potapov V.V., Zaripov R.M., Cheremnykh A.S. Interblock zones in the crust of the southern regions of East Siberia: tectonophysical interpretation of geological and geophysical data. Geodinamika i tektonofizika [Geodynamics & Tectonophysics], 2013, vol. 4, no. 3. pp. 203–278. (In Russian).

3. Lamakin V.V. Neotektonika Baikal'skoi vpadiny [Neotectonics of the Baikal basin]. Moscow: Nauka Publ., 1968, 247 p. (In Russian).

4. Levi K.G. Vertical movements of the earth crust in the Baikal rift zone. Problemy razlomnoi tektoniki [Problems of fault tectonics]. Novosibirsk: Nauka Publ., 1981, pp. 142–167. (In Russian).

5. Levi K.G., Sherman S.I. Aktual'nye voprosy sovremennoi geodinamiki Tsentral'noi Azii [Topical issues of modern geodynamics of Central Asia]. Novosibirsk: Siberian branch of the Russian Academy of Sciences Publ., 2005, 294 p. (In Russian).

6. Levi K.G., Sherman S.I., Plyusnina L.V. Karta neotektoniki Pribaikal'ya i Zabaikal'ya. Masshtab 1:2500000 [Map of Baikal and Transbaikal area neotectonics. Scale 1:2500000]. Irkutsk, 1982. (In Russian).

7. Logachev N.A. History and geodynamics of the Baikal rift. Geologiya i geofizika [Russian Geology and Geophysics], 2003, vol. 44, no. 5, pp. 391–406. (In Russian).

8. Logachev N.A. Florensov N.A. Baikal system of rift valleys. Rol' riftogeneza v geologicheskoi istorii Zemli [The role of rifting in geological history of the Earth]. Novosibirsk: Nauka Publ., 1977, pp. 19–30. (In Russian).

9. Lunina O.V., Gladkov A.S., Sherstyankin P.P. A new electronic map of active faults for southeastern Siberia. Doklady Akademii Nauk [Doklady Earth Sciences], 2010, vol. 433, no. 5, pp. 662–667. (In Russian).

10. Lukhnev A.V., San'kov V.A., Miroshnichenko A.I., Ashurkov S.V. Tectonic deformations of the Mongolian-Baikal region according to GPS geodesy data. Interekspo Geo-Sibir' [Interekspo Geo-Siberia], 2006, vol. 3, no. 2, pp. 42–51. (In Russian).

11. Lukhnev A.V., San'kov V.A., Miroshnichenko A.I., Ashurkov S.V., Byzov L.M., San'kov A.V., Bashkuev Yu.B., Dembelov M.G., Kale E. GPS-measurements of recent crustal deformation in the junction zone of the rift segments in the central Baikal rift system. Geologiya i geofizika [Russian Geology and Geophysics], 2013, vol. 54, no. 11, pp. 1814–1825. (In Russian).

12. Mats V.D., Ufimtsev G.F., Mandel'baum M.M., Alakshin A.M., Pospeev A.V., Shimaraev M.N., Khlystov O.M. Kainozoi Baikal'skoi riftovoi vpadiny: stroenie i geologicheskaya istoriya [Cenozoic of the Baikal rift basin: structure and geological history]. Novosibirsk: Geo Publ., 2001, 252 p. (In Russian).

13. Florensov N.A. Mezozoiskie i kainozoiskie vpadiny Pribaikal'ya [Mesozoic and Cenozoic basins of the Baikal region]. Moscow – Leningrad: USSR Academy of Sciences Publ., 1960, 258 p. (In Russian).

14. Sherman S.I., Levi K.G., Ruzhich V.V., San'kov V.A., Dneprovskii Yu.I., Rasskazov S.V. Geologiya i seismichnost' zony BAM. Neotektonika [Geology and seismic activity of the BAM zone. Neotectonics]. Novosibirsk: Nauka Publ., 1984, 208 p. (In Russian).

15. Nekrasov A.I. Tektonofizicheskii podkhod k analizu dislokatsii dlya otsenki napryazhenno-deformirovannogo sostoyaniya ob"ekta v usloviyakh zakrytoi territorii [Tectonophysical approach to the dislocation analysis for object stress-strain state assessment in a closed area]. Tezisy dokladov Vserossiiskogo soveshchaniya s uchastiem priglashennykh issledovatelei iz drugikh stran “Razlomoobrazovanie v litosfere i soputstvuyushchie protsessy: tektonofizicheskii analiz” [Abstracts of the All-Russia conference with the participation of invited foreign researchers “Faulting in lithosphere and associated processes: tectonophysical analysis»]. Irkutsk, 11–16 August 2014. Irkutsk: Institute of the Earth’s crust SB RAS Publ., 2014, pp. 30. (In Russian).

16. Seminskii K.Zh., Gladkov A.S., Lunina O.V., Tugarina M.A. Vnutrennyaya struktura kontinental'nykh razlomnykh zon. Prikladnoi aspect [Internal structure of continental fault zones. Applied aspect]. Novosibirsk: Geo Publ., 2005, 293 pp. (In Russian).

17. Sherman S.I., Bornyakov S.A., Buddo V.Yu. Oblasti dinamicheskogo vliyaniya raz-lomov (rezul'taty modelirovaniya) [Areas of dynamic fault influence]. Novosibirsk: Nauka Publ., 1983, 112 p. (In Russian).

18. Sherman S.I., Seminskii K.Zh., Bornyakov S.A. Razlomoobrazovanie v litosfere: zony rastyazheniya [Faulting in lithosphere: extension zones]. Novosibirsk: Nauka Publ., 1992, 228 p. (In Russian).

19. Sherman S.I., Seminskii K.Zh. Destruction zones and fault-block structures of Central Asia. Tikhookeanskaya geologiya [Russian Journal of Pacific Geology], 1999, vol. 18, no. 2, pp. 41–53. (In Russian).

20. ASTER GDEM is a product of METI and NASA. Available at: http://www.jspacesystems.or.jp/ersdac/GDEM/E/index.html (accessed 27 September 2017).

21. Levi K.G. Primenenie kolichestvennykh metodov v geomorfologii [Application of quantitative methods in geomorphology]. Irkutsk: Irkutsk State University Publ., 1995, 54 p. (In Russian).

22. Cheremnykh A.S. Strike-slip fault zone in relief: analysis of experimental and natural objects numerical models. Vestnik Irkutskogo gosudarstvennogo tekhnicheskogo universiteta [Proceedings of Irkutsk State Technical University], 2014, no. 2 (85), pp. 92–103. (In Russian).

23. Hancock P.L. Brittle microtectonics: Principles and practice. Journal of Structural Geology, 1985, vol. 7, no. 3/4, pp. 437–457.