Geologicheskii Vestnik

The structure and kinematics of the Yalchigulovsky fault, which relates to the longitudinal faults of the second order of the zone of the Main Ural Fault in the Southern Urals, are characterized. The results of the structural-paragenetic and tectonophysical analysis of small structural forms (duplexes, fractures, drag folds) developed in the Yalchigulovsky fault zone are given. The structural constructions are based on the data of detailed mapping of the surface of the fault zone. It was established that the Yalchigulovsky fault is a transpressive right strike-slip fault, which has a positive flower structure at the latitude of Karagaykul Lake. The axial part of the flower structure is formed by subvertical reverse faults with dextral strike-slip component. On the flanks, packages of tectonic plates are developed, which are bounded by thrusts with dextral strike-slip component and a gentle dip toward the center of the fault zone. According to the results of tectonophysical reconstructions, two phases of right-sided movements along the Yalchigulovsky fault were identified, which occurred under conditions of near-horizontal compression of the north-east–southwest direction. It is shown that a transressive right strike-slip fault was formed in the Late Paleozoic at the collisional stage of development of the zone of the Main Ural Fault.

the Main Uralian fault, transpressive strike-slip fault, positive flower structure, duplex, drag folds, tectonic plate

• Cowan D.S., Brandon M.T. A symmetry-based kinematic analysis of large-slip brittle fault zones // American J. of Science. 1994. V. 294. P. 257–306. doi.org/10.2475/ajs.294.3.257.
• Gzovskiy M.V. Osnovy tektonofiziki [Basics of tectonophysics]. M.: Nauka, 1975. 536 p. (in Russian). Harland W.B. Tectonic transpression in Caledonian Spitsbergen // Geological Magazin. 1971. V. 108. P. 27–42. doi.org/10.1017/s0016756800050937.
• Kano K.-J., Nakaji М., Takenchi S. Asimmetrical mélange fabrics as possible indicators of the convergent direction of plates: a case study from Shimanto Belt of the Akaishi Mountains, central Japan // Tectonopysics. 1991. V. 185, No. 3–4. P. 375–388. doi.org/10.1016/0040-1951(91)90455-2.
• Kazantsev YU.V., Kazantseva T.T., Kamaletdinov M.A. Strukturnaya geologiya Magnitogorskogo sinklinoriya Yuzhnogo Ural [Structural geology of the Magnitogorsk synclinorium of the Southern Urals]. M: Nauka, 1992. 190 p. (in Russian).
• Lowell J.D. Spitsbergen Tertiary orogenic belt and the Spitsbergen fracture zone // Geologial Society of America Bulletin. 1972. V. 83. P. 3091–3102. doi.org/10.1130/0016-7606(1972)83[3091:stobat]2.0.co;2.
• McClay K. The mapping of geological structures. London: Open University press, 1995. 161 p.
• Savel’yev A.A., Astrakhantsev O.V., Knipper A.L. Stroyeniye i fazy deformatsii severnogo okonchaniya Magnitogorskoy zony Urala [Structure and phases of deformation of the northern end of the Magnitogorsk zone of the Urals] // Geotektonika. 1998. No. 3. P. 38–50 (in Russian).
• Sylvester G. Strike-slip faults // Geological Society of America Bulletin. 1988. V. 100, No. 11. P. 1666–1703.
• Wilcox R.E., Harding T.R., Seely D.R. Basic wrench tectonics // Geological Society of America Bulletin. 1973. V. 57. P. 74–96. doi.org/10.1306/819a424a-16c5-11d7-8645000102c1865d.
• Znamensky S.E. The Late Paleozoic Structural Evolutionof the Magnitogorsk Megazone in the Southern Urals // Doklady Earth Sciences. 2008. V. 420,Is. 1. P. 547–550. doi.org/10.1134/S1028334X08040041.
• Znamenskii S.E., Svetlakova A.N., Puchkov V.N. The Structural Peculiariaties of the Dzhetygara-Troitsk Zone, Southern Urals (Based on the URSEIS-95 Profile) // Doklady Earth Sciences. 2013. V. 448, Is. 1. P. 31–34. doi.org/10.1134/s1028334x12110177.