Geologicheskii Vestnik

The Kyshtym (PR1 kš), Saitovo (RF2st), Igish (RF2ig), and Kundravi (Vkn) Formations are distributed within the framework of the Ilmen metamorphic complex and envelop the Chashkov granite massif and the Elanchik antiform structure in a narrow strip. Geological, petrochemical, and thermobarometric data on biotite-garnet and amphibole-garnet parageneses and carbonaceous shales made it possible to conclude that the black shale deposits of the above formations were formed in the distal deep-water environment and remote from the coastline area of the sedimentary basin. They belong to the low-carbonaceous and carbonaceous types, as well as the siliceous-carbonaceous formation, which has a minimum amount of terrigenous impurities in its composition. At the boundary between the Riphean and Vendian, when a major structural transformation occurred in the Southern Urals, volcanogenic-sedimentary rocks of the above formations experienced regional metamorphism under conditions of the epidote-amphibolite facies (T = 470–580°C, P = 2.0–7.2 kbar , abyssal depth zone). Later, during the formation of the large Argazi, Kisegach, Elanchik and Chashkov granitoid massifs, the deposits of the Ilmen-Sysert anticlinorium underwent zonal contact metamorphism. Depending on the distance to acidic intrusions, they underwent transformation under conditions from the facies of almandine amphibolites (T = 750–770°C, P = 8.8–9.0 kbar) to cummingtonite amphibolites (T = 530–550°C, P = 2.1–3.6 kbar).

Ilmen-Sysert anticlinorium, Saitovo Series, Kyshtym Series, Kundravi Series, Igish Series, temperature, pressure, paleogeography, paleogeodynamics

• Bluman B.A., Dyakonov Yu.S., Krasavina T.N., Pavlov M.G. (1974) The use of thermal and X-ray characteristics of graphite to determine the level and type of metamorphism. Zapiski Vsesoyuznogo Mineralogicheskogo obshchestva – Notes of the AllUnion Mineralogical Society, 103(1), 95-103. (In Russian).
• Borneman-Starynkevich I.D. (1964) Rukovodstvo po raschetu formul mineralov [Guidelines for the calculation of mineral formulas]. Moscow, Nauka Publ., 224 p. (In Russian).
• Buseck P.R., Beyssac O. (2014) From organic matter to graphite: graphitization. Elements, 10(6), 421-426. DOI: 10.2113/gselements.10.6.421
• Gorbachev O.V., Sozinov N.A. (1985) Some petrochemical and geochemical aspects of the typi cation of carbonaceous deposits of the Precambrian. Problemy osadochnoy geologii dokembriya [Problems of sedimentary geology of the Precambrian]. Moscow, Nauka Publ., 55-62. (In Russian).
• Knyazev Y.G., Knyazeva O.Y., Snachev V.I., Zhdanov A.V., Karimov T.R., Aydarov E.M., Masagutov R.K., Arslanova E.R. (2013) Gosudarstvennaya geologicheskaya karta Rossiyskoy Federatsii. Masshtab 1:1 000 000 (3 pocolenie). Seriya Ural’skaya. List N–40 (Ufa). Ob”yasnitel’naya zapiska [State Geological Map of the Russian Federation. Scale 1: 1,000,000 (3rd Generation). Ural Series. Sheet N–40 (Ufa). Explanatory letter]. Saint Petersburg: VSEGEI Publ., 512 p. (In Russian).
• Krupenin M.T., Maslov A.V., Rykus M.V., Snachev V.I. (1993) New data on Corg content in shales of the Lower and Middle Riphean of the South Urals. Trudy Instituta geologii i geokhimii [Proceedings of the Institute of Geology and Geochemistry UrO RAN], (140), 19-20. (In Russian).
• Permyakov B.N. (2000) Chashkovsko-Yelanchikovskiy migmatit-gneysogranitnyy massiv (Yuzhnyy Ural) [Chashkovsko-Elanchikovsky migmatite-gneiss-granite massif (South Urals. Miass, IGZ UrO RAN, 187 р. (In Russian).
• Perchuk L.L., Ryabchikov I.D. (1976) Fazovoe sootvetstvie v mineral’nyh sistemah [Phase matching in mineral systems]. Moscow, Nedra Publ., 287 p. (In Russian).
• Petrov V.I., Shalaginov A.E., Punegov B.N. (2003) Gosudarstvennaya geologicheskaya karta Rossiyskoy Federatsii. Masshtab 1:200 000. 2-ye izd. Seriya Yuzhno-Ural’skaya. List N-41-VII (Miass). Ob”yasnitel’naya zapiska [State geological map of the Russian Federation. Scale 1:200,000. 2nd ed. Series South Ural. Sheet N-41-VII (Miass). Explanatory letter]. Moscow, VSEGEI Publ., 167 p. (In Russian).
• Rykus M.V., Snachev V.I. (2000) Features of Paleozoic carbonaceous sedimentation of the Sysertsko-Ilmenogorsk zone of the Southern Urals. Osadochnyye basseyny: Zakonomernosti stroyeniya i evolyutsii, minerageniya [Sedimentary basins: Patterns of structure and evolution, minerageny]. Yekaterinburg, IGiG UrO RAN, 112-114. (In Russian).
• Saveliev D.E., Snachev A.V., Puchkov V.N., Snachev V.I. (2006) Petrogeochemical and geodynamic features of the formation of Ordovician-Early Silurian basalts on the eastern slope of the Southern Urals. Geologicheskiy sbornik – Geological Digest, (5), 86-104. (In Russian).
• Silaev V.I., Smoleva I.V., Antoshkina A.I., Tchaikovsky I.I. (2012) Experience of conjugated analysis of the isotopic composition of carbon and nitrogen in carbonaceous substances of different origin. Problemy mineralogii, petrografi i i metallogenii. Materialy nauchnykh chteniy pamyati P.N. Chirvinskogo [Problems of mineralogy, petrography and metallogeny: Materials of scienti c readings in memory of P.N. Chirvinsky]. Perm, PGU Publ., (15), 342-366. (In Russian).
• Snachеv A.V. (2021) Paleogeogra cheskiye usloviya obrazovaniya i metamor zm uglerodistykh otlozheniy saitovskoy i igishskoy svit (Il'menogorsko-Sysertskiy antiklinoriy) [Paleogeographic conditions of formation and metamorphism of carbonaceous deposits of the Saitovskaya and Igishskaya formations (Ilmenogorsk-Sysertskiy anticlinorium)]. Neftegazovoe delo – Oil and Gas Business, (3), 17-25. (In Russian).
• Snachev A.V., Puchkov V.N., Snachev V.I., Savelyev D.E., Bazhin E.A. (2009) Bol'shakovsky gabbro massif, fragment of the South Ural zone of the Early Carboniferous rift. Dokl. Akad. Nauk, 429(1), 79-81. (In Russian).
• Snachеv V.I., Snachеv A.V. (2019) Conditions of metamorphism of rocks of the Kyshtym sequence (IlmenogorskoSysertsky meganticlinorium). Izvestiya UNTS RAN, (3), 24-31. (In Russian).
• Termo- i barometriya metamor cheskih porod (1977) [Thermo- and barometry of metamorphic rocks]. Leningrad, Nauka Publ,, 207 p. (In Russian).
• Yudovich Yа.E., Ketris M.P. (2015) Geokhimiya chernykh slantsev [Geochemistry of black shale]. Moscow-Berlin, DirektMedia Publ., 272 р. (In Russian).