Geologicheskii Vestnik

In the southern part of the Ishimbay region of the Bashkortostan Republic attention is drawn to the outcrops of the Biarmian and Tatarian series of the Permian system. They are represented by molasse composed of red and gray-colored polymictic sandstones, conglomerates, siltstones, mudstones with interlbeds of marls and limestones. They are traced along the banks of the Belaya, Tor, and Yurgabashka rivers, in the slopes of gullies and ravines, and distinguished by a peculiar red-brown color. The article provides a brief overview of studies of the Permian deposits of this territory, the characteristics of the underlying Priuralian (lower Permian) deposits. The Cisuralian Series (lower Permian) is represented by all stages. The Asselian and Sakmarian are composed of a small thickness carbonates. The Artinskian is composed of carbonate and clay-carbonate deposits up to 750 m thick. The Kungurian is represented by an unit of evaporites with a thickness of up to 1500 m. The Ufi mian is composed of terrigenous red rocks with rare intercalations of limestone, the thickness of up to 900 m. The Biarmian Series (Kazanian and Urzhumian stages) is composed of terrigenous-carbonate member, its thickness reaches more than 900 m. The Tatarian Series is represented by the Severodvinian Stage, that is composed mainly of terrigenous rocks with intercalations of copper sandstones and conglomerates, its thickness is more than 1400 m. The age of the Biarmian and Tatarian deposits is justifi ed by non-marine ostracods.

Pemian System, Tatarian Series, Biarmian Series, type sections, paleontological characteristics

• Alksne A.E., Kochetkova N.M. Osnovnye tipy razrezov ufi mskogo yarusa v Bashkirskom Priural'e [The main types of sections of the Ufa layer in the Bashkir Urals] // Ye.V. Chibrikova (ed.). Voprosy geologii vostochnoi okrainy Russkoi platformy i Yuzhnogo Urala [The questions of the Eastern part of the Russian Platform and the Southern Urals]. Ufa, 1969. Is. 9: Stratigrafiya i paleontologiya. P. 123–133. (In Russian).
• Henderson C.M., Davydov V.I., Wardlaw B.R., Gradstein F.M., Hammer O. The Permian Period // The Geologic Time Scale. 2012. Vol. 1–2. P. 653–679.
• Klimenko T.V. Seleuk Section // Kozlov V.I., Sinitsyna Z.A., Kulagina E.I., Pazukhin V.N., Puchkov V.N., Kochetkova N.M., Abramova A.N., Klimenko T.V., Sergeeeva N.D. Putevoditel' geologicheskoi ekskursii po razrezam paleozoya i verhnego dokembriya zapadnogo sklona Yuzhnogo Urala i Priural'ya [Guidebook of excursion for the palaeozoic and upper Precambrian sections of the western slope of the Southern Urals and Preuralian Regions] / RAS, Ufa Scientifi c Centre, Institute of Geology. Miass, 1995. P. 97–105.
• Kochetkova N.M. Stratigrafi ya i ostrakody verkhnepermskikh otlozhenii yuzhnykh raionov Bashkirii i prilegayushchikh chastei Orenburgskoi oblasti [Stratigraphy and ostracods of the Upper Permian deposits of the southern regions of Bashkiria and adjacent parts of the Orenburg region]. M.: Nedra, 1970. 131 p. (In Russian).
• Kotlyar G.V., Golubev V.K., Silant'yev V.V. Obshchaya stratigrafi cheskaya shkala permskoi sistemy: sovremennoe sostoyanie [General stratigraphic scale of the Permian system: current status] // M.A. Fedonkin (ed.). Obshchaya stratigrafi cheskaya shkala Rossii. Sostoyanie i perspektivy obustroistva: Vserossiyskoe soveshchanie [General stratigraphic scale of Russia. Status and prospects of the arrangement: All-Russian meeting], 23–25 may 2013, GIN RAN, Moscow. M., 2013. P. 187–195. (In Russian).
• Kotlyar G.V., Kosovaya O.L., Amon E.O., Golubev V.K., Konovalova M.V., Oshurkova M.V. Permskaya sistema [Permian system] // T.N. Koren' (ed.). Zonal'naya stratigrafi ya fanerozoya Rossii [Zonal stratigraphy of the Phanerozoic of Russia]. SPb: VSEGEI Press, 2006. P. 91–102. (In Russian).
• Mizens G.A. Verkhnepaleozoiskii fl ish Zapadnogo Urala [Upper Paleozoic fl ysch of the Western Urals]. Ekaterinburg: UrO RAS, 1997. 229 p. (In Russian).
• Naumcheva M.A. Istoriya izucheniya pozdnepermskikh i rannetriasovykh presnovodnykh ostrakod Vostochno-Evropeiskoi platformy [Research history of the late Permian and early Triassic non-marine ostracods from East European Platform] // Bulletin of the Moscow Society of Naturalists. Geological Series. 2017. Vol. 92, Is. 1. P. 21–37. (In Russian).
• Postanovleniya Mezhvedomstvennogo stratigrafi cheskogo komiteta i ego postoyannykh komissii [Decisions of the Interdepartmental Stratigraphic Committee and its standing commissions]. Is. 36. SPb: VSEGEI Press, 2006. 63 p. (In Russian).
• Puchkov V.N. Paleogeodinamika Yuzhnogo i Srednego Urala [Paleogeodynamics of the South and Middle Urals]. Ufa: Dauriya, 2000. 146 p. (In Russian).
• Stratigraphicheskie schemy Urala (Dokembrii, Paleozoi) [Stratigraphic schemes of the Urals (Precambrian, Paleozoic)]. Ekaterinburg, 1993. 51 schemes. (In Russian).