Geologicheskii Vestnik

The article discusses the sedimentation conditions at the beginning of the Bashkirian Age within the Lower Carboniferous carbonate platform on the Middle Urals’ eastern slope. Data on six most representative sections of the East Ural megazone territory (Sosvinsko — Techenskaya and Makhnevskaya — Bredinskaya zones) are generalized in order to clarify the influence of the global geological event timed to the Lower / Middle Carboniferous boundary on the formation of sedimentary strata. The characteristics of lithological features of these sections are given. The data obtained confirm that at the beginning of the Bashkirian Age, the situation in the east of the Urals changed dramatically, the sedimentation conditions became much more complex. The Lower Carboniferous shelf limestones were replaced by deposits of several deep — sea troughs, which were formed at the beginning of the Bashkirian Age, but, apparently, not simultaneously. All this was due to a local increase in tectonic activity. There was no significant break in sedimentation at the very turn of the Lower / Middle Carboniferous boundary.

Middle Urals, Eastern slope, Bashkirian Stage, Lower/Middle Carboniferous boundary, depositional environments, deep-sea troughs, shelf basin, limestones, debris

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