Sedimentary characteristics of the northern continental slope of the Danube Canyon in the northwest of the Black Sea and its relation with paleoclimate changes
Résumé
This paper is the result of environmental geological survey engineering.[Objective]In the last glacial period, global climate was characterized by rapid, large-scale temperature cycles on a millennial scale. Such climate changes could be recorded in many geological materials such as ice cores, deep-sea sediments, Chinese loess, and cave stalagmites. The Black Sea is located in the transition zone between the North Atlantic and East Asian monsoon regions and has formed representative sedimentary records. This article is aimed at establishing the connections between the regional environmental changes of the Black Sea and the climate changes in the North Atlantic and East Asian monsoon area through the study of the sedimentary sequences of the Black Sea.[Methods]In this study, a 22.0 m core sample taken from Core GAS-CS12 in the northern slope of the Danube Canyon in the northwest of the Black Sea was analyzed for particle size, mineral composition, major elements, organic carbon, total nitrogen, and carbon and nitrogen isotopes.[Results]It was revealed that the core sediments of this section were deposited in the"Neoeuxine"lacustrine stage in the middle and late period of the last glacial period, and can be divided into 5 sedimentary units, corresponding to H4, H3, and H1 climate change events in the North Atlantic, the Last Glacial Maximum (LGM), and Bolling- Allerod climate warming event.[Conclusions]The connections between the sedimentary sequences and regional environmental changes of the Black Sea with the climate changes in the North Atlantic and East Asian monsoon area were established and this paper also confirmed that the millennium-scale climate changes of the last glacial period were highly consistent in the North Atlantic, East Asian monsoon area and their transition zones.
Highlights: Established the connections between the sedimentary sequences and regional environmental changes of the Black Sea; Provided reliable timescales for millennium-scale climate changes in the transition zone between the North Atlantic and East Asian monsoon regions.