Two types of organogenic carbonate buildups (bryalgal and algal-microbialite) occurring for approximately 11 Ma from the Middle through to the Late Miocene in the Euxine-Caspian Basin are considered. Four main stages in the formation of these structures are established: Chokrakian-Karaganian, Early-Middle Sarmatian, Maeotian, and a specific Late Sarmatian one. Each of the first three stages began with bryalgal bioherms that, during the growing basins’ isolation, transformed into algal-microbialite buildups. Only bryalgal buildups are found in the Late Sarmatian Basin.

The first data on the cyclostratigraphy of Pontian deposits of the Eastern Paratethys were obtained by studying the magnetic susceptibility of Upper Miocene rocks of the Zheleznyi Rog section in the Taman Region. Based on statistical methods, using the Lomb-Scargle and REDFIT periodograms, cycles related to long-period insolation oscillations (precession of the Earth’s orbit and variations in Earth’s axial tilt) were revealed. It is proposed that a hiatus occurred (about 150000–200000 years) at the Novorossian/Portaferian boundary (Lower Pontian/Upper Pontian) due to the onset of the maximum Messinian Salinity Crisis.

C and O isotope composition of Middle-Upper Miocene and Lower Pliocene carbonates from Kerch-Taman Region (Eastern Paratethys) have been studied in order to reconstruct palaeoenvironmental variability and post-sedimentation changes. The δC and δО values of the Upper Sarmatian to Lower Pliocene organogenic carbonates reflect the desalinization of paleobasins, global Late Miocene Cooling, and increase in seasonal temperature fluctuations. Isotopic composition of the Middle Sarmatian organogenic carbonates was strongly influenced by evaporation processes, high bioproductivity, and local submarine methane emissions. Warm climate and low bioproductivity together with unstable hydrological regime during the Late Chokrakian and the Karaganian times influenced the isotope composition of primary carbonates. Calcite shell of . (δC =–0.4‰ and δО =–0.4‰) from Tarkhanian sediments was formed in warm marine environment. Dolomitization prevails over other secondary mineralization in the studied carbonate rocks. Two groups of secondary dolomites that are characterized by negative and positive δC values have been recognized. Lowe δC values (up to–31.4‰) in dolomites indicate the influence of both dissolved inorganic carbon (DIC) from oxidized organic matter (С) and methane. Dolomites with positive δC values (7.0 and 7.8‰) associat with migration of CO- and CH-containing saline groundwater.

The sequential accumulation of middle Sarmatian sediments in the Taman Trough in the terrigenous and carbonate settings is considered. Six facies of the shallow-water basin are identified. The first half of the middle Sarmatian was marked by the accumulation of dominant clayey sediments. The formation of small serpulid-microbial bioherms took place under relatively deep conditions (upper part of the lower sublittoral zone). The terminal middle Sarmatian was dominated by the deposition of carbonates with a wide development of bacterial-algal mats. Their formation in the upper sublittoral setting below the base level of ordinary waves was intermittently disturbed by the enhanced influx of terrigenous material and accumulation of clays, as well as by the storm-induced roiling and bioturbation.

Astronomically-tuned cyclicity in Upper Maeotian deposits of the Zheleznyi Rog section (Taman, Eastern Paratethys) was revealed first time using the methods of cyclostratigraphy. According to the spectral analysis of the data on the magnetic susceptibility of rocks and basing on the peaks of Lomb-Scargle and REDFIT periodograms, cyclicity with a length of 7.1–8.9 m was established in studied deposits. These cycles are comparable with the period of oscillations of the Earth’s axis angle to the plane of its orbit, which corresponds to 41000 years. The data we obtained confirm the idea of the correlation of Upper Maeotian deposits to the greater part of the Chron C3An and duration of the late Maeotian no longer than 700000–750000 years.

Results of the detailed study of Miocene volcanic ashes from Kerch and Taman peninsulas are presented. Based on the distribution of pyroclastics in the rocks under consideration, the Sarmatian and late Meotian stages of volcanic activity are distinguished. In close association with other geological data, results of the first microprobe analysis of the volcaniclastic materials are analyzed. It has been revealed that Sarmatian ashes are characterized by rhyolitic composition, whereas upper Meotian ashes correspond to dacites and rhyodacites. Decrease of silicate content and increase of alkalinity in the studied pyroclastic rocks are traced from ancient to younger sediments. The upper Meotian volcanics are noted for higher concentration of potassium. The predominantly vitroclastic Kerch-Taman ashes with a low content of calcium and high contents of potassium and sodium most likely belong to a single magmatic center. Stages of volcanic events and petrochemical similarity of composition of the magmatic products suggest that the studied ash material belongs to volcanic centers of the Lesser Caucasus.