Geologicheskii Vestnik

A mineralogical study of sandstones from the ore bed of the Sabantuy paleoplacer was completed. Using EDS scanning electron microscopy, the composition of grains of ore-bearing sandstones (chromitolites) and interbedded, conventionally barren sandstones (chert graywackes) was studied. Using EDS mapping, the ratios of ore minerals in the chromitolites and barren sandstones of the productive bed were estimated. Chromite was found to be the most quantitatively prevalent ore mineral (53 vol.%), followed by magnetite (25%, including chromium-magnetite – 29%) and ilmenite (12%). Variations in ore element contents were found to be related to the position of a particular sample within the section relative to the wave energy zones. Chromite preferentially accumulated in the supratidal zone along the line of relative energy dissipation of breaking waves. A combination of geological, lithological, and morphodynamic factors indicates distal sources of ore detritus for the Sabantuy paleoplacer. The primary sources of detrital material for the host sandstones could have been sedimentary and metamorphic complexes of the Bashkir Meganticlinorium and the Uraltau Zone, while additional (ore-bearing) material could have come from ultramafic-mafic massifs currently present in the axial Urals – ophiolitic allochthons (such as the Krakinsky and Khabarninsky) and tectonites of the Main Ural Fault. The source of cement was limestones from the overlying unit, which dissolve and redeposit.

Sabantuy chromite paleoplacer, graywackes, mineralogy, rock fragments, lithodynamics

• Kamaletdinov M.A. (1974) Nappe structures of the Urals. Moscow: Nauka Publ. 232 p. (In Russian).
• Knyazev Yu.G., Knyazeva O.Yu., Snachev V.I., Zhdanov A.V., Karimov T.R., Aydarov E.M., Masagutov R.Kh., Arslanova E.R. (2013) State geological map of the Russian Federation. Scale 1:1,000,000 (third generation). Ural series. Sheet N-40-Ufa. St. Petersburg: Cartographic Factory of VSEGEI. 512 p. (In Russian).
• Mizens G.A. (1997) Upper Paleozoic flysch of the Western Urals. Yekaterinburg: Ural Branch of RAS. 230 p. (In Russian).
• Rakhimov I.R. (2022а) Detrital clinopyroxene and amphibole from chromite-bearing sandstones of the Kazanian Stage in the Southern Pre-Urals as indicators of chromespinelid source. Proceedings of Voronezh State University. Series: Geology. (3), 41–51. (In Russian).
• Rakhimov I.R. (2022b) Register of chromite paleoplacers of the Southern Pre-Urals: certificate of database registration No. RU20222622457. (In Russian).
• Rakhimov I.R. (2021) Fedorovsky sections of the Kazanian Stage in the Southern Pre-Urals: geological and lithological characteristics of deposits. Geology. Proceedings of the Department of Earth Sciences and Natural Resources of the Academy of Sciences of the Republic of Bashkortostan. (28), 60–68. (In Russian).
• Rakhimov I.R., Pushkarev E.V., Chervyakovsky V.S., Dyakova S.A. (2024) U–Pb age of detrital zircon from the Sabantuy chromite paleoplacer of the Middle Permian (Southern Pre-Urals). Doklady of the Russian Academy of Sciences. Earth Sciences. 517 (1), 5–12. (In Russian).
• Rakhimov I.R., Saveliev D.E., Kholodnov V.V., Zamyatin D.A. (2020) The Unique Sabantuy Chromite Paleoplacer in the Sedimentary Cover of the Eastern European Platform. Geology of Ore Deposits. 62 (6), 542–546. (In Russian).
• Savko A.D. (2025) Evolution of the accumulation of titan-zircon placers in the Earth's history. Proceedings of Voronezh State University. Series: Geology. (4), 4–24. (In Russian).
• Samigullin A.A., Shabutdinov T.D., Gataullin R.A., Saveliev D.E. (2024) Detrital spinelids of the northern part of Bashkirian Urals region. Geology. Proceedings of the Department of Earth Sciences and Natural Resources. (4), 44–58. (In Russian).
• Sinitsyn I.M., Sinitsyna G.I. (1965) Explanatory note to the geological map of the USSR, scale 1:200,000, Sheet No. 40-XXVI. Ufa: BTGU. 1, 170 sheets. (In Russian).
• Tagarieva R.Ch., Rakhimov I.R., Naumcheva M.A., Semenov R.E., Urazaeva M.N. (2022) Organic fossils from carbonate-terrigenous chromite-bearing deposits of the Kazanian and Urzhumian stages of the Southern Pre-Urals. Geologicheskii Vestnik. 3, 79–92. (In Russian). https://doi.org/10.31084/2619-0087/2022-3-7
• Shutov V.D. (1967) Classification of sandstones. Lithology and Mineral Resources. (5), 86–102. (In Russian).
• Butler R.F. (1992) Paleomagnetism: Magnetic Domains to Geologic Terranes. Boston: Blackwell Scientific Publications. 319 p.
• Deer W.A., Howie R., Zussman J. (1992) An Introduction to the Rock-Forming Minerals. 2nd ed. London: Pearson Education Limited. 712 p.
• Dickinson W.R., Beard L.S., Brakenridge G.R., Erjavec J.L., Ferguson R.C., Inman K.F., Knepp R.A., Lindberg F.A., Ryberg P.T. (1983) Provenance of North American Phanerozoic sandstones in relation to tectonic setting. Geological Society of America Bulletin. 94, 222–235. https://doi.org/10.1130/0016-7606(1983)94%3C222:ponaps%3E2.0.co;2
• Dickinson W.R. (1988) Provenance and sediment dispersal in relation to paleotectonics and paleogeography of sedimentary basins. Kleinspehn K.L., Paola C. (Eds.). New Perspectives in Basin Analysis. New York: Springer. P. 3–25.
• Gujar A.R., Ambre N.V., Iyer S.D., Mislankar P.G., Loveson V.J. (2010) Placer chromite along south Maharashtra, central west coast of India. Current Science. 99 (4), 492–499.
• Mukherjee S., Ghosh K.K., Chanda A. (2023) Energy from the Ocean. Environmental Oceanography and Coastal Dynamics. Current Scenario and Future Trends Springer, Cham., 440 p. DOI: https://doi.org/10.1007/978-3-031-34422-0_13
• Rakhimov I.R., Pushkarev E.V., Gottman I.A. (2021) Chromite Paleoplacer in the Permian Sediments at the East Edge of the East European Platform: Composition and Potential Sources. Minerals. 11 (7), 691.
• Rakhimov I.R., Saveliev D.E., Rassomakhin M.A., Samigullin A.A. (2022) Chromian Spinels from Kazanian-Stage Placers in the Southern Pre-Urals, Bashkiria, Russia: Morphological and Chemical Features and Evidence for Provenance. Minerals. 12, 849.
• Scott R.A., Smyth H.R., Morton A.C., Richardson N. (Eds.) (2013) Sediment Provenance Studies in Hydrocarbon Exploration and Production. Geological Society of London, Special Publication. No. 386. DOI: 10.1144/SP386.8