Genetic types of Upper Maastrichtian sediments in the Mountainous Crimea

Abstract

The paper discusses sections of Upper Maastrichtian sediments in the Mountainous Crimea. It presents a detailed lithologic description of the sediments and describes their individual lithologic members and beds. We recognized seven lithotypes and three genetic types among the Upper Maastrichtian sediments, which allowed us to delineate facies zones that belong to the upper part of the continental slope, the deep shelf, and shallow-water shelf plains. We examined the alteration of genetic types of rocks down the sections and over the area, which resulted in constructing a detailed lithostratigraphic correlation of the Upper Maastrichtian beds. The differences between micro-and macrobiotic complexes, as well as differences between biostratigraphic subdivisions of the successions, were caused by the existence of different water masses within the shelf carbonate platform and within the pelagic zone of the marine basin in the Mountainous Crimea. Anoxic episodes were revealed in the Late Maastrichtian-Early Danian evolution of the relatively deep-water southeastern Crimean area, where tropical and subtropical planktonic foraminifers lived.