According to the latest ideas, the Dnieper-Donets Depression is a transverse avlacogen that arose in the late stages of the Russian Platform development in the Middle Devonian, when not only the platform basement but also a significant part of the platform cover had already been formed...

The main ideas about the tectonics of the Mountain Crimea were obtained as a result of the works of K. K. Focht, A. A. Borisyak, A. S. Moiseev, V. F. Pchelintsev, M. V. Muratov, G. A. Lychagin, G. X. Dickenstein and many other researchers.The material presented in this article was collected by the author during ten years of research in the Mountain Crimea and route thematic works in the Western Caucasus.About tectonic zoning of the Crimea. The mountainous Crimea is a fragment of a large inherited vaulted uplift of Neogene age. The southeastern part and southwestern pericline of this uplift are cut off by northeastern and northwestern strike-slip faults and are submerged in the Black Sea. The northwestern wing of the Neogene uplift dips gently towards the Plain Crimea and, judging by the occurrence of Upper Cretaceous and Tertiary sediments, is associated with the marginal structures of the platform part of the peninsula - the Alma Syneclise and the Simferopol uplift - without significant disjunctive faults....

Paleocene and Eocene sediments participate in the structure of the northwestern wing of the Crimean meganticlinorium. Nummulitic clays, marls and limestones of the Eocene crown the Second Ridge of the Crimean Mountains almost all along its length from Sevastopol Bay to Simferopol. Eocene sediments in the southwestern part of the Second Ridge lie on Paleocene sediments, and towards Simferopol they pass to more and more ancient sediments of the Upper Cretaceous. In the immediate vicinity of Simferopol, in the left side of the Salgir valley, the Eocene rocks lie already on the Turonian and Cenomanian marls, and at the watershed of the Salgir and Little Salgir - even on the Middle Jurassic sediments.

In 1955-1959 we studied the stratigraphy, lithology and tectonics of the flysch Taurian series in the southwestern part of the Mountainous Crimea. A detailed geologic survey was made over a large area of the Salgir-Alma and Alma-Bodrak interfluves. In addition, routes, accompanied by documentation of sections, were carried out in all the main valleys of southwestern Crimea. Numerous faunal remains were collected in the course of the work, allowing us to clarify the age of the individual stratigraphic elements that make up the series.

The methodology of tectonic analysis of complex geological structures is still not exhaustively developed. Deciphering the geological structure and analyzing its development in time often cause difficulties for geologists not only in the course of geological survey, but also in the process of final interpretation of the totality of the actual material in the desk period. In practice there were and still are cases when the structure of the area, for which a conditional geological map was made, was interpreted inaccurately or even erroneously only because of the researcher's insufficiently clear idea of the tasks and content of tectonic analysis.