Paleontology and stratigraphy of the Middle–Upper Miocene of the Taman Peninsula: Part 1. Description of key sections and benthic fossil groups

The Taman sections, reference for the Neogene of the Eastern Paratethys, are investigated thoroughly paleontologically and stratigraphically, with level-by-level description of four sections, correlated in detail with each other; fossil remains coming from them are examined conjointly, with uniform binding to the sections. The composition of malacofaunas and foraminifers allowed the recognition of all regional stages and substages from the Upper Chokrakian to Middle Kimmerian, their boundaries, and correlation with the Kerch stratotypes. The study of the taxonomic composition of ostracods improved the boundaries of stratigraphic ranges of particular species. The complete and continuous sequence of Karaganian–Konkian deposits has provided the data improving the volume and boundaries of the Konkian Regional Stage and showing that it is divided into three units. Investigation of these groups provided the stratigraphical basis for pioneer studies of phytoplankton; the taxonomic composition and distribution in the sections of nannoplankton, diatoms, and organic-walled phytoplankton are investigated completely for the first time; the points of penetra- tion of marine water into the basin are recognized. The most reliable tool for correlation of deposits in a semiclosed basin is distribution of “ecologically plastic” groups that are able to tolerate a wide range of salinity and variation of the gas regime, such as mollusks, benthic foraminifers, and, among phytoplankton, diatoms and dinocysts. The appearance of stratigraphically significant diatom and nannoplankton species in Konkian, Sarmatian, and Maeotian deposits allowed the comparison of intervals of their presence with the oceanic zones where these index species are provided with absolute dating. The level-by-level palynological characteristics of the beds is reported, providing the basis for reconstruction of climatic changes in this region.