New data on sedimentation and biostratigraphy of ancient and New Azov Deposits (Sea of Azov)

Abstract

Applying the methods of absolute geochronology and lithology, it has been established that the average sedimentation rate in the Sea of Azov over the last 6000 years (Ancient and New Azov times) varied from 0.2 to 2.0 mm/year. Its minimum values are confined to transit and sediment-starved zones coinciding with the directions of the main marine currents. It has been indicated that changes in the water level of the Sea of Azov occur with lag relative to landscape–climate phases. The obtained data confirm the relation between marine and terrestrial processes occurring in the Sea of Azov region: transgressive phases are preceded by general humidification in adjacent regions, while regressive phases correlate with climate aridization. The biostratigraphic analysis of the Holocene sections examined reveals the unstable behavior of the sea level during their formation. The results of diatom analysis confirm development of the Phanagoria and Korsun Regressions and Nymphea Transgression. Frequent fluctuations of the Sea of Azov the level determined the rhythmical structure of the sedimentary sequence saturated with autochthonous and allochthonous organic matter.