Deformations in the Upper Cretaceous — Neogene sediments of the South-Western Crimea on the base of new tectonophysical data

Abstract

Deformation structures (tectonic planes with slickensides, folds, parageneses fractures аre described) in the Upper Cretaceous—Neogene sediments of the south-western Crimea. The purpose of the study is to clarify the scope and sense of deformation in the Alpine orogeny stage. Strike-slip planes are dominated in the studied structures. Slickensides of reverse and thrust account for 25 % of all fractures. Deformations of various types are concentrated in the most plastic rocks and weak zones. The rest of the Upper Cretaceous and Cenozoic sediments have a gentle monoclinal bedding. It is shown that the part of the deformations in the rocks of the Tavrick series and of the rocks of Middle Jurassic—Lower Cretaceous age could occur during alpine period. Given geological data confirms compression structures for all the mountainous Crimea during Alpine stage. The orientation of the restored axes stress field shows that compression deformation is caused by pressure of the Black Sea microplate toward Crimea. The Strike-slip-type deformations, within the studied area, dominate over the reverse-type one. Folded-thrusted deformations are located more to the south — in the continental slope and shelf respectively, in the interaction area of the Black Sea microplate and the Crimea.