Radiocarbon of quaternary along shore and bottom deposits of the Lena and the Laptev Sea sediments

Radiocarbon ages of organic matter within the soils and Quaternary deposits of the Lena catchment area, bottom deposits of the Lena river and bottom deposits of the Laptev Sea were measured. The organic matter of the Laptev Sea bottom sediments is completely derived from Quaternary deposits of the catchment area and has an average radiocarbon age of 7,000 yr. From the radiocarbon distribution in the cores mean sedimentation rates and their distribution along a profile at 130 °E north of the Lena delta were derived. The position of the modern and the ancient (10,000 yr B.P.) depocenters of the Lena — the delta margin — has been established. The sites of depocenters are determined by the intensity of flocculation process of the suspended particles at the sea/river interface, the current velocity and the bottom topography. The position of the depocenters vary with time in relation with sea level changes in the Holocene and the Late Quaternary. Magnetic susceptibility measurements enabled development of a magneto-chronological scale for the interval from 0 to 16,000 yr. The scale needs refinement, as it is compiled on the basis of data from only 6 bottom sediment cores.