Geologicheskii Vestnik

The article examines the features of the material composition of sandstones of the Staropetrovskaya Formation of the Upper Vendian, discovered in well 4 Aslykul in the Volga-Uralian area. According to the results of petrographic studies, the sandstones of the Staropetrovskaya Formation correspond to feldspathic-quartz, mesomicto-quartz, feldspathic-quartz greywackes and quartz-feldspathic greywackes, less frequently to monomineral quartz and arkoses proper. The mineral composition of the heavy fraction indicates the dominance of metamorphic rocks in the source area, with fewer rocks of felsic, basic and ultrabasic composition. For the first time, for deposits of the Staropetrovskaya Formation, along with lithological and petrographic methods for studying rocks in thin sections and quantitative and mineralogical analysis of the heavy fraction of crushed samples, a study was carried out using scanning electron microscopy in polished sections. This made it possible to identify rare earth element minerals (monazite and xenotime) in sandstones. Additional information on the mineral and geochemical composition of the rocks of the Staropetrovskaya Formation will be further used to reconstruct the composition of the feeding provinces and the conditions of the sedimentary basin in the Vendian time.

Staropetrovskaya Formation, Vendian, Volga-Uralian area, mineralogy, petrography, geochemistry, electron microscopy

• Bashkova S.E., Subbotina N.B., Karaseva T.V. (2011) Regularities of the structure of the Riphean and Vendian deposits of the Volga-Uralian oil and gas basin. Vestnik Permskogo universiteta. Perm University Bulletin, (3), 8–17. (In Russian).
• Vendian system. Historical, geological and paleontological justification. T. 2. Stratigraphy and geological processes. M.: Nauka, 1985. 237 p. (In Russian).
• Kuharenko A.A. (1961) Mineralogiya rossypei [Mineralogy of placers]. М.: Gosgeolizdat,. 316 p. (In Russian).
• Kozlov V.I., Sergeeva N.D. (2011) Upper Proterozoic of the Volga-Uralian region. Stratigraphy and compositional features. Geologiya. Izvestiya Otdeleniya nauk o Zemle i prirodnyh resursov AN RB — Geology. Bulletin of the Department of Earth Sciences and Natural Resources of the Academy of Sciences of the Republic of Bashkortostan. (17), 58–80. (In Russian).
• Kozlova O.V., Solodova S.A., Ratov A.A. (2020) Novye dannye mineralogicheskikh issledovanii otlozhenii staropetrovskoi svity venda v razreze glubokoi skvazhiny 40 Krasnousol’skaya (Predural’skii kraevoi progib) [New data from mineralogical studies of the Vendian Staropetrovsk Formation in the section of 40 Krasnousolsk deep well (Preuralian Foredeep)]. Geologicheskii vestnik. 3, 68–75. DOI: 10.31084/2619–0087/2020-3-5 (In Russian).
• Lozin E.V. (2015) Geology and oil content of Bashkortostan. Ufa: BashNIPIneft. 704 p. (In Russian).
• Maslov A.V. (2010) Nekotorye petrokhimicheskie osobennosti peschanikov rifeya i venda platformennogo Bashkortostana [Some petrochemical features of Riphean and Vendian sandstones of platform Bashkortostan]. Proceedings of the conference “Geology, minerals and problems of geoecology of Bashkortostan, the Urals and adjacent territories”. Ufa: DizaynPoligrafServis. 2010. 42–45. (In Russian).
• Maslov A.V. (2011) Peschaniki verkhnego dokembriya platformennogo Bashkortostana: osnovnye cherty formirovaniya po litogeokhimicheskim dannym [Sandstones of the Upper Precambrian of platform Bashkortostan: main features of formation according to lithogeochemical data]. Bulletin of Perm University. Geology. 1 (10), 6–17. (In Russian).
• Maslov A.V., Isherskaya M.V., Krupenin M.T., Petrishcheva V.G., Gulyaeva T.Ya., Gorbunova N.P. (2010) Litogeokhimicheskie osobennosti tonkozernistykh terrigennykh porod rifeya Kamsko-Bel’skogo avlakogena i usloviya ikh formirovaniya [Lithogeochemical features of fine-grained terrigenous rocks of the Riphean Kama-Belsky aulacogen and the conditions of their formation]. Lithology and mineral resources. 2, 192–223. (In Russian).
• Ozhiganova L.D. (1960) Petrographic-Mineralogical studies of ancient deposits of Western Bashkiria // Ancient deposits of Western Bashkiria. M.: AN SSSR Publ. P. 28–87. (In Russian).
• Preobrazhenskii I.A., Sarkisyan S.G. Mineraly osadochnyh porod (primenitel’no k izucheniyu neftenosnykh otlozhenii) [Minerals of sedimentary rocks (applied to study of oil-bearing deposits)]. М.: Gostoptehizdat, 1954. 462 p. (In Russian).
• Sergeeva N.D., Puchkov V.N., Karaseva T.V. (2021) Verkhnii proterozoi (rifei i vend) Volgo-Ural’skoi oblasti v parametricheskikh i glubokikh skvazhinakh [Upper Proterozoic (Riphean and Vendian) of the Volga-Ural region in parametric and deep wells]. Ufa: KnigaPrint, 196 p. (In Russian).
• Solontsov L.F. (1963) K voprosu o peresmotre stratigraficheskoiskhemy otlozhenii pozdnego dokembriya tsentral’nykh i vostochnykh oblastei Russkoi platformy [On the issue of revising the stratigraphic scheme of Late Precambrian deposits in the central and eastern regions of the Russian Platform]. Izv. Kazan branch of the USSR Academy of Sciences. Geology. 10, 130–143. (In Russian).
• Stratigraphic scheme of Riphean and Vendian deposits of the Volga-Ural region: Explanatory note / Compiled by E.M. Aksenov, V.I. Kozlov. IG UNZ RAN, Ufa. 2000. 81 p. + diagram 2. (In Russian).
• Timergazin K.R. (1959) Dodevonskiye obrazovaniya Zapadnoy Bashkirii i perspektivy ikh neftegazonosnosti [PreDevonian formations of Western Bashkiria and prospects for their oil and gas potential]. GGI BFAN SSSR. Ufa. 311 P.
• Chepikova I.K. (1971) On the question of the stratigraphic position of the Upper Bavlinsky deposits of the Volga-Ural region // Reports of the Academy of Sciences. Т. 197 (3), pp. 671–673. (In Russian).
• Shutov V.D. (1967) Klassifikatsiya peschanikov [Classification ofsandstones]. Lithology and mineral resources. 5, 86–102. (In Russian).
• Cox R., Lowe D.R. (1995) A. Conceptual review of regional-scale controls on the composition of clastic sediment and the co-evolution of continental blocks and theirsedimentary cover // Journal of Sedimentary Research, 1, 1–12.
• Nesbitt H.W., Young G.M. (1982) Early Proterozoic climates and plate motions inferred from major element chemistry of lutites // Nature, 299, P. 715–717.
• Pettijohn F.J., Potter P.E., Siever R. (1972) Sand and sandstone. Springer, Berlin Heidelberg New York. 553 p.