Detailed reconstructions of Holocene climate and environmental changes in the Taman Peninsula (Kuban River delta region) and their correlation with rapid sea-level fluctuations of the Black Sea

Abstract

The paper presents results of a detailed subdivision of Holocene sediments in the region of the Kuban River delta into climate-stratigraphic units and reconstructions of the vegetation, climate and depositional environment changes on the Taman Peninsula (NE Black Sea region) during the last 7400 years. The reconstructions are based on data from geological-geomorphological and lithological-facies analysis, palynological studies and radiocarbon dating of six sections penetrated by boreholes in various parts of the Kuban River delta. The studied lithological sequences present an assortment of liman, fluvial, lacustrine and marsh sediments, as well as subaerial deposits that accumulated in the course of the delta development.The factual materials thus obtained provided the basis for reconstructing changes in zonal vegetation types and transformations of zonal and intra-zonal formations in the Holocene landscapes of the Taman Peninsula, induced by changes in edaphic conditions and regional climate. Seventeen phases (stages) have been recognized in the evolution of vegetation and climate through the Middle and Late Holocene, and a detailed description is given to every phase. A detailed pollen-climate-chronostratigraphic scheme of the Black Sea level fluctuations over the last 7400 years is proposed.Steppe and forest-steppe landscapes were dominant on the Taman Peninsula over the greater part of the studied period of the Holocene. The warmest and most arid conditions were typical of the phases dominated by steppes with grass, herb and grass, and pigweed-wormwood (Chenopodiaceae-Artemisia) plant communities. Such phases were dated to intervals ∼4660–4400, 3780–3430, 2910–2280, 1540–1230 and 900–830/730 cal yr BP. The most humid intervals within the studied period are dated at ∼5160–4900, 4400–3780, 2280–1540 cal yr BP. They were distinct because of the dominance of broadleaf (mostly beech-oak-hornbeam) forests. Those humid intervals most likely correspond to the maxima of the Kalamitian, Dzemetinian, and Nimphaean Black Sea transgressions.The climatic indexes and zonal attribution of the dominant plant communities can be matched with six transgressive and seven regressive sea level fluctuations of various ranks over the last 7400 years. Of the six transgressive stages, one stage was marked by a relatively cool and humid climate, whereas five others occurred under warm and wet conditions. The regressive stages include four phases of relatively warm and dry climate and three periods of dry and relatively cold (or cool) climate.