The Recurrence of Parathuramminacea and Archaesphaeracea Representatives at the Tournaisian–Viséan Boundary of the Lower Carboniferous (the Kipchak Section, the Eastern Slope of the Southern Urals)

Abstract— The Tournaisian–Viséan boundary of the Lower Carboniferous was established in carbonate facies deposits of the “Kipchak” section (Southern Urals). There is a change in the facial settings at this boundary that is reflected in the variations in the composition of the foraminiferal assemblages. The recurrence of early Paleozoic genera and species of single-chamber foraminifera is observed in the deposits of the lower Viséan Stage that is associated with the specific ecological conditions of their habitat.