History of stratigraphy partition of Devonian sediments in Middle Timan

The article provides a history of stratigraphic partition of the Devonian sediments on Middle Timan over the past 150 years. The main milestones of the local stratigraphic scheme development are described in chronological order. A retrospective analysis is aimed, first of all, at analyzing the evolution of the views of the stratigraphic partition of the Devonian sediments, which, in turn, is the basis for identifying the most problematic and relevant aspects of the geology of Middle Timan.