Geochemistry of Holocene–Late Pleistocene Floodplain Sediments in the Berezovka River Valley, Near-Yenisey Siberia

Despite their great importance, floodplain sediments and floodplain soils are poorly studied in the valleys of small rivers in the Krasnoyarsk forest-steppe territory. We present the first detailed study of the geochemical composition of floodplain sediments in the valley of the Berezovka River, and the continuous accumulation that occurred at the end of the Late Pleistocene and throughout the Holocene (from 20833 ± 519 cal yr BP). This is of great fundamental importance and is the basis for further studies on the influence of anthropogenic activities on the natural environment in the Krasnoyarsk agglomeration. Alluvial dark-humus hydrometamorphosed soil was developed on the surface. Macromorphological studies and investigation of the humus content have revealed a well-developed process of humus formation and humus accumulation, namely, a gley process. The measured contents of some elements (U, Pr, Rb, V, Bi, Cd, As, Th, Ga, Co, and Sm) exceeded the respective Clarke values for the Earth’s crust. The distribution of most elements and their accumulation in the Middle-Late Holocene (from to 5477–4985 to 1241–803 cal yr BP) in the middle of the sediment profile is explained by the high content of mud and clay minerals. Based on the coefficients of radial migration, we established that most of the studied elements were introduced into the sediments during high water levels and floods. The features of sedimentation depend on the hydrological regime of the Yenisey River. The values ​​of palaeomarkers indicate a change in climatic conditions in the Late Pleistocene and Holocene from dry and cold to more humid and warm, and from arid and cold (in the Early Holocene) to modern climatic conditions, respectively