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Abstract: Sediments from the Black Sea, a region historically dominated by forests and steppe landscapes, are a valuable source of detailed information on the changes in regional terrestrial and aquatic environments at decadal to millennial scales. Here we present multi-proxy environmental records (pollen, dinoflagellate cysts, Ca, Ti and oxygen isotope data) from the uppermost 305cm of the core 22-GC3 (42°13.53′N, 36°29.55′E) collected from a water depth of 838m in the southern part of the Black Sea in 2007. The records span the last ~18kyr (all ages are given in cal kyr BP). The pollen data reveal the dominance of the Artemisia-steppe in the region, suggesting rather dry/cold environments ~18–14.5kyr BP. Warming/humidity increase during melt-water pulses (~16.1–14.5kyr BP), indicated by δ 18 O records from the 22-GC3 core sediment and from the Sofular Cave stalagmite, is expressed in more negative δ 13 C values from the Sofular Cave, usually interpreted as the spreading of C3 plants. The records representing the interstadial complex (~14.5–12.9kyr BP) show an increase in temperature and moisture, indicated by forest development, increased primary productivity and reduced surface run-off, whereas the switch from primary terrigenous to primary authigenic Ca origin occurs ~500yr later. The Younger Dryas cooling is clearly demonstrated by more negative δ13C values from the Sofular Cave and a reduction of pines. The early Holocene (11.7–8.5kyr BP) interval reveals relatively dry conditions compared to the mostly moist and warm middle Holocene (8.5–5kyr BP), which is characterized by the establishment of the species-rich warm mixed and temperate deciduous forests in the low elevation belt, temperate deciduous beech-hornbeam forests in the middle and cool conifer forest in upper mountain belt. The border between the early and middle Holocene in the vegetation records coincides with the opening of the Mediterranean corridor at ~8.3kyr BP, as indicated by a marked change in the dinocyst assemblages and in the sediment lithology. Changes in the pollen assemblages indicate a reduction in forest cover after ~5kyr BP, which was likely caused by increased anthropogenic pressure on the regional vegetation. [Copyright &y& Elsevier]

In this research, the crustal thickness (Moho depth) variations in the Black Sea and surrounding region were calculated from the regional gravity anomaly data using an empirical equation. The data were obtained from the open source of Bureau Gravimétrique International (BGI) in digitized form. The gravity anomaly values are changing from −80 mGal in the onshore Black Sea region in Turkey to 260 mGal in the deeper parts of the sea. Maximum gravity anomaly indicates a consistent pattern in the offshore Black Sea and anomaly pattern follows the shape of the shoreline. The pattern is consistent with the deeper parts in the marine area and the eastern anomaly extends into the Russian territory between NW of Georgia and SE of the Crimean Peninsula. The crustal thickness map indicates almost the same trends. In this map, the minimum crustal thickness is about 10 km around the mid of the Shatsky Ridge, close to the coastal regions of SE Russia and the second thinnest (12 km) place is located around the Western Black Sea Basin. The maximum thicknesses are represented with the 34–36 km contours in the onshore Eastern Black Sea region and east of Anatolia. On the other hand, the maximum crustal thickness to the north can reach up to 28 km around the Sea of Azov and to the east. The thickness variations are generally related with the main tectonic trends in this region. The Analytic Signal (AS) and maxima points of the horizontal gradients (maxspots) maps constructed from the gravity anomalies are also prepared in this research to see if these anomaly trends follow the tectonic lines. The regions of maximum and minimum crustal thicknesses are well-consistent with the AS anomalies and boundaries of the bifocal thin crustal sections coinciding with the Eastern and Western Black Sea basinal parts are surrounded with the maxspots. The northern thick crustal region around the southern margin of the Indolo-Kuban Basin is also surrounded by the maxspots. It is possible to claim that the maxspots map from the horizontal gradient of Bouguer anomalies reflects the boundaries of the main tectonic units in the Black Sea Region. Particularly, southern boundary of the Scythian Platform, southern boundary of the Shatsky Ridge and Great Caucasus thrust are distinctive and easy to follow in the maxspots map. Image 1 • Positive gravity anomalies in the Black Sea region follow the shorelines. • Thin crustal zones are about 10 km under the deeper parts of the sea. • Maximum thickness is about 36 km under the Pontides, onshore Turkey. • Analytic Signal and maxspots maps of the anomalies were also prepared in this study. • All produced maps are consistent to each other and main tectonic units in the area. [ABSTRACT FROM AUTHOR]