Suchergebnisse

The work presents the results of paleogeographic study, including facies-lithological, malacofaunistic and luminescence analyses, of three boreholes core drilled in the central part of the Manych Depression, which made it possible to determine the time and stages of the existence of the Karangatian ingressive bay in the Manych Depression, and to correlate the latter with phases of the Karangatian transgression identified earlier on the basis of luminescence dating. Based on the results of the study it was found that: 1) the Karangatian Sea penetrated into the Manych Depression during the second phase of transgression in the time interval of ~120-110 ka years ago (MIS 5e-d). The salinity of the bay in the area of the modern Manych-Gudilo Lake reached 20-22‰; 2) the inflow of water of the Hyrcanian transgression of the Caspian into the bay in the central part of the Manych Depression took place 110-105 ka years ago, which corresponds to the third phase of the Karangatian transgression (MIS 5c). The brackish Caspian waters desalinated the Karangatian Bay in the area of the modern Manych-Gudilo Lake down to 14‰ and below; 3) the waters of the Karangatian Sea finally left the Manych Depression about 105 ka years ago (MIS 5c).

Biostratigraphic analysis of the cores from the Black Sea shelf in the northeastern part of the basin showed that the exposed Karangatian deposits contain shells of Didacna cristata and Didacna subcatillus mollusks in their upper part. The didacnae are of Caspian origin: they are characteristic species of the Hyrcanian transgressive basin that developed in the Caspian at the beginning of the Late Pleistocene. Mollusks migrated to the Karangatian Basin of the Black Sea through the strait that opened in the Manych Depression when the level of the Hyrcanian transgression overreached the threshold of the Manych runoff. The waters of the strait flowed into the Karangatian Basin in the final phase of its development when the sea level was lower than nowadays and salinity didn't exceed 18‰.

Palaeoecoligical reconstructions of predelta area of the North Caspian Sea were based on the multidisciplinary study of the core from the Rybachya borehole containing the Holocene deposits. Geochemical, grain size, mollusk fauna, diatom and ostracod analyses were performed, and the radiocarbon dating was carried out. The structure of deposits reflects palaeogeographic events of different scales including the inception of a palaeoincision in the Lower Khvalynian deposits, accompanied by erosion of the Upper Khvalynian deposits; its development during the Mangyshlak regression and gradual filling during the multistage Holocene Neocaspian transgression. The Holocene age of the deposits filling the palaeodepression is confirmed by radiocarbon dates - 8070 ± 110 and 7020 ± 140 cal. BP. The paleontological data indicate the interchange of tranquil and dynamic water regimes and the quasicyclical change in the conditions of the water basin, from brackish to freshwater and to marine during the stage of sedimentation, corresponding to the presentday conditions on the North Caspian shelf.

The article presents the results of interdisciplinary research at the Darvagchai- Zaliv-4 site. Long-term excavations at the site have revealed archaeological evidence confirming the presence of three complexes of artifacts belonging to different periods. A preliminary chronological framework of stone industries has been proposed based on malacofaunal analysis and paleomagnetic studies. For establishing the exact age, absolute dating of all geological horizons of the site was carried out using the OSL method, yielding thirteen dates which make it possible to determine the age of cultural horizons at the site. The collection of artifacts from the first complex is distinguished by Levallois splitting technique and typical Middle Paleolithic toolkit; the artifacts were located in the paleosoil horizon (layer 1b). Chronologically, this horizon belongs to the Riess-Wurm (Eem, Mikulin) interglacial in the interval of 125,000-110,000 BP (MIS 5e). Artifacts of another complex discovered in layer 3 (pebble-gravel deposits) belong to the Final Acheulean. Their age corresponds to the chronological range of 250,000-220,000 BP (MIS 7). The collection of stone objects from layer 5 (sea pebbles and sands) belongs to the Late Acheulean and testifies to the earliest appearance of ancient humans in that territory in 370,000-330,000 BP (MIS 11-10).

In 2021, the Lower Volga Paleolithic research team of the IAET SB RAS, participating in the Interdisciplinary Lower Volga Expedition organized by the IIMK RAS, the study of the Sukhaya Mechetka Middle Paleolithic site located in the northern outskirts ofVolgograd City was continued. The research was aimed at studying the chronostratigraphic position of the cultural layer and reconstructing the paleoclimate during the Neanderthal habitation period. In 2021, an additional geological section was established to the west of the buffer zone of the excavation area to study the stratigraphy of the right-side slope of the Sukhaya Mechetka gully. In 2021 the upper part of SM 14-18 (SМ East) stratigraphic sequence has been completely excavated (26 m thick). The new SM West stratigraphic sequence was established in 155 m westwards. Preliminary correlation of the layers and paleosol horizons in these two profiles was carried out. Samples for palynological, micromorphological, physicochemical and phytholithic analyses with the purpose to correlate the two sequences have been collected. Sediments were sampled for OSL dating. Studies of the buried paleosol are extremely important for understanding the dynamics of the climatic changes during the cultural layer accumulation at Sukhaya Mechetka. Pedogenetic levels that have been revealed in 2021 are comparable to the buried paleosol identified at the site earlier in depths, continuity and features of pedogenesis. Texturally graded buried paleosol described here for the first time for the SM West sequence expand our understanding of the soil spatial inhomogeneity, and, consequently, conditions of human habitation. Results of the ongoing field investigation will allow determining the cultural-chronological position of Sukhaya Mechetka in the context of the Eastern and Central European Middle Paleolithic complexes for the first time.