The uninterrupted succession of the Mississippian–Pennsylvanian boundary beds in the Muradymovo section in the South Urals contains diverse fossils and has a high correlative potential. The Muradymovo section is located in the Zilair Megasynclinorium (ZM), which belongs to the West Uralian Subregion and displays carbonate-siliciclastic deep-water facies of the Bukharcha Formation, which is partly Serpukhovian (Kosogorian, Protvian and Yuldybaevian) and partly Bashkirian (Syuranian). In the southern ZM, the lower part of the formation contains argillaceous carbonates with beds of shale and siltstone, subordinate clastic limestones and limestone breccia, while the upper part is mostly limestone with cherty interbeds. In the north of the ZM, the formation mainly consists of limestone. The Muradymovo succession contains no identifiable gaps in the Mid-Carboniferous Boundary (MCB) portion and has a succession of foraminiferal, conodont, ammonoid and ostracod zones. The MCB in this section coincides with the base of the Bogdanovkian and is defined by the entry of Declinognathodus noduliferus. This level falls within the upper part of the foraminiferal Monotaxinoides transitorius Zone, is near the base of the ammonoid Homoceras–Hudsonoceras Genozone and can be correlated worldwide.

No abstract

The taxonomic diversity of foraminifers from the Devonian-Carboniferous boundary beds was studied in the key sections on the western slope of the South Urals in Russia and from Mugodzhary in Kazakhstan. These sections are mainly composed of marine carbonates, apparently deposited in a shallow-water environment. The boundary interval contains 111 species belonging to 30 genera within the foraminiferal zones Quasiendothyra communis, Q. kobeitusana, Tournayellina beata pseudobeata, Earlandia minima, and Chernyshinella disputabilis of the Russian General Stratigraphic Scale. Maximum diversification is recorded in the Q. kobeitusana Zone, and minimum species diversity is observed in the Earlandia minima Zone

No abstract