Deciphering the origin of sedimentary material in the Arctic can contribute to a deeper understanding of modern transport and sedimentation processes. Here, the application of rare earth elements (REEs) is particularly promising, as they can serve as indicators of sources as well as chemical and physical conditions and processes. This study aimed to determine the distribution of REE sources in the bottom sediments and the forms of their occurrence on the East Siberian Arctic Shelf. The concentrations and distributions of the REEs and major and trace metals, grain size, and mineral composition of 72 surficial sediment samples and two sediment cores that were collected from the Laptev and East Siberian seas were studied. Increasing REE content, the predominance of light REE, and close correlation with Zr, Nb, Y, Sc, and Ti were revealed in the Laptev and western East Siberian sea sediments in the zone of influence of the Lena River runoff. The source of the REEs was the eroded Yedoma complex along the coast. The REE content in the sub-colloidal fraction of the sediments was comparable to the REE concentration of the bulk bottom sediments and varied in the East Siberian Sea from 104–220 mg kg-1, with the maximum content around the submarine valley of the Indigirka River, in the Laptev Sea, ranging from 124–197 mg kg-1. The findings could be used to study ice dynamics and to conduct lithostratigraphic and paleoceanographical reconstructions of the Central Arctic.
2023. V. 254, Art. no. 104907

Using inductively coupled plasma mass spectrometry (ICP-MS), the distribution of rare-earth elements (REE) at the surface and Holocene sediments of the Chukchi and East Siberian Seas was studied in two cores of up to 8.5 ka in age. The total REE concentration of the surface sediments of the Chukchi Sea varied from 62 mg kg−1 to 169 mg kg−1. The NASC-normalized REE patterns were relatively similar to each other and are characterized by a slight enrichment in the middle lanthanides. The total REE concentrations in surface sediments from the East Siberian Sea ranged from 123 mg kg−1 to 200 mg kg−1. The normalized patterns showed a strong predominance of light REE, in particular, La and Ce. The main concentrators of REE are the sand and silt fractions of the sediment. The East Siberian Sea is characterized by REE association with elements contained in heavy stable clastic minerals (Zr, Nb, Hf, Th, and Ti). REE in this region are derived from the erosion of the mainland coast and the New Siberian Islands ice complex, as well as from river discharge, primarily from the Lena River, the basin of which comprises ancient crystalline shield and magmatic rocks enriched in light REE. The sediments in the eastern and southern Chukchi Sea have low REE contents, indicating that the terrigenous flux supplying the Chukchi Sea is through the Bering Strait.
2019. V. 20. P. 148-159