The stratigraphic and paleontological substantiation of the Upper Devonian–Tournaisian oil-bearing formations of the Kama-Kinel trough system axial zones are considered in the typical section of the Melekesskaya-1 key well. The Upper Devonian sediments represented mainly by high-carbonaceous carbonate-siliceous Domanik-type deposits compose the Alkeevo Group that includes the Kuznechikha, Mogutovo, Domanik, Mendym, Askyn (Frasnian) and Maly Cheremshan (Famenian) formations. The Lower Carboniferous (Tournaisian) high-carbonaceous clay-siliceous-carbonate deposits comprise the Zolotoe Ozero and Erykla formations. The Elkhovka Formation is part of the Upper Tournaisian – Visean terrigenous play together with the Visean Dimitrovgrad, Malyklinka and Mullovka formations. The Melekesskaya-1 key well represent a typical section for Upper Devonian Kuznechikha and Maly Cheremshan formations, and also for Tournaisian Zolotoe Ozero, Erykla, and Elkhovka formations. The comprehensive biostratigraphic characterization of the formations according to conodonts, foraminifers, radiolarians, and miospores presence is presented. In the Upper Devonian, series of the Standard Conodont scale zones for deep-water deposits are determined. The Upper Devonian Kuznechikha and Mogutovo formations are characterized by miospores of the Raistrickia bucera – Archaeozonotriletes variabilis insignis Zone. The Maly Cheremshan Formation is characterized by foraminifers of the Septaglomospiranella primaeva – Quasiendothyra communis and Q. kobeitusana zones. Radiolarians in the Middle Maly Cheremshan Member were identified in the Natgorella hirsuta – Spinoalium melekessensis Ecozone. In the Tournaisian sediments, six units in the rank of beds with conodonts were determined and compared with Standard Conodont zones. The Zolotoe Ozero Formation comprises the units of two foraminiferal zones: Tournayellina pseudobeata – remnant Quasiendothyra and Earlandia minima, as well as associations of two radiolarian ecozones: Provisocyntra kononovae and Spongentactinia oraia. The Tournaisian Elkhovka Formation contains miospores of the Tuberculispora exigua – Triquirtites batillatus (EB) and Monilospora variomarginata – Euryzonotriletes macrodiscus (VM) zones.

Natalya K. Fortunatova ORCiD  Scopus
Doctor of Geological and Mineralogical Sciences,
Deputy Director General
All-Russian Research
Geological Oil Institute,
36, Shosse Entuziastov, Moscow, 105118, Russia
e-mail: fortunatova@vnigni.ru

​Elena L. Zaytseva  ORCiD
Candidate of Geological and Mineralogical Sciences
Senior Researcher
Lomonosov Moscow State University
Leninskie Gory 1, Moscow, 119991, Russia
e-mail: ezaitseva@vnigni.ru
AuthorID: 324326

Anna V. Baranova
Leading researcher
All-Russian Research
Geological Oil Institute,
36, Shosse Entuziastov, Moscow, 105118, Russia
e-mail: baranova@vnigni.ru

Marina А. Bushueva
Head of Sector
All-Russian Research
Geological Oil Institute,
36, Shosse Entuziastov, Moscow, 105118, Russia
e-mail: bushueva@vnigni.ru

Lyudmila I. Kononova
Candidate of Geological and Mineralogical Sciences
Senior Researcher
Lomonosov Moscow State University
Leninskie Gory 1, Moscow, 119991, Russia
e-mail: mvasil69@list.ru

Marina S. Afanasieva
Doctor of Geological and Mineralogical Sciences,
Leading researcher
Borissiak Paleontological Institute, RAS
123, ul. Profsoyuznaya, Moscow, 117647, Russia
e-mail: afanasieva@paleo.ru

Svetlana I. Kharchenko
Researcher
All-Russian Research
Geological Oil Institute,
36, Shosse Entuziastov, Moscow, 105118, Russia
e-mail: kharchenko@vnigni.ru

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