Geologicheskii Vestnik

For the first time, conodonts from the Middle — Upper Carboniferous and Lower Permian deposits were studied in the joint zone of the Pre — Ural’sforedeep and the West Ural megazone. Two sections were studied. The section in the siliceous — carbonate depositsis common in Belsk — Eletstectono — stratigraphic zone (West Ural’s megazone) and the clastic (olistostrome) section located in the southern part of the Karatau sallent (The Pre –Ural’s Foredeep) adjacent with the West Ural’s. Under field research 30 samples were taken in order to identify conodont fauna. Conodonts were found in 16 samples. Studed conodont complexes contain numerous cosmopolitan forms that determine the stratigraphic position of deposits as the Middle Carboniferous in the volume of Tashasty Horizon of the Bashkirian Stage — the Podolian Horizon of the Moscovian Stage. As result, a biostratigraphic sequence in the rank of beds with fauna was outlined: the beds with Declinognathodus marginodosus, Swadelina suberecta, the beds with Idiognathodus postsulcatus, Id. volgensis, the beds with Sw. dissecta and the beds with Id. podolskensis. The presence of the Bashkirian and Moscovian boundary depositsis proposed. The siliceous — carbonate (olistostrome)section containsthe Middle, Upper Carboniferous, and Lower Permian olistoliths with conodonts, fusulinids and brachiopods. Conodonts and foraminifers of Early Permian age were identified in the matrix.

Karatau salient, conodonts, Middle Carboniferous, Bashkirian and Moscovian stages, limestones, olistostrome

• Aretz M., Herbig H.G. and Wang X.D. The Carboniferous Period // [Geologic Time Scale] / Eds. by Gradstein F.M., Agterberg F.P. and Ogg J.G. — Amsterdam: Elsevier, 2020. V. 2 (23). P. 811–855.
• Barskov I.S., Alekseyev A.S., Kononova L.I., Migdisova A.V. Opredelitel’ konodontov verkhnego devona i karbona [Treatise on conodonts of the Upper Devonian and Carboniferous]. M.: Izd — vo MGU, 1987. 144 р. (In Russian)
• Makhlina M.Kh., Alekseev A.S., Goreva N.V., Goryunova R.V., Isakova T.N., Kossovaya O.L., Lazarev S.S., Lebedev O.A., Shkolin A.А. Middle Carboniferous Moscow Syneclise (southern part). M.: Scientific World, 2001. Vol. 2, 328 p.
• Nemyrovska T.I. Bashkirian conodonts of the Donets Basin, Ukraine // [Scripta Geologica]. 1999. №119, P. 1–115.
• Postanovleniya Mezhvedomstvennogo stratigraficheskogo komiteta i yego postoyannykh komissiy. Otv.red. Zhamoyda A.I., Petrov O.V. Vyp.38. SPb: Izd — vo VSEGEI, 2008. 131 р. (In Russian)
• Puzhakov B.A., Shokh V.D., Schulkina N.E. Report on the results of work on the object “Performance of geologicalsurvey work within sheet N — 40 — X (Ashinsky area)”. Аs part of the object of the FS B I “VSEGEI” “Conducting in 2017–2019 regional geologicalsurveys at a scale of 1: 200.000 for a group of sheets within the Ural and Volga Federal Districts” (Rosgeolfond; TFGI Chelyab. region), 2019. (In Russian, unpublished)
• Resheniyа Mezhvedomstvennogo regional’nogo stratigraficheskogo soveshchaniya po srednemu i verkhnemu paleozoyuRusskoy platformy sregional’nymi stratigraficheskimi skhemami. Leningrad, 1988. Kamennougol’naya sistema / Red. A. Kh. Kagarmanov, L. M. Donakova. L.: Izd — vo VSEGEI, 1990. 41 р. (In Russian)