Affiliation:
1. Division for Geology, Tomsk Polytechnic University, 634050 Tomsk, Russia
2. V.I. Il’ichev Pacific Oceanological Institute, Far Eastern Branch, Russian Academy of Sciences, 690041 Vladivostok, Russia
3. Laboratory of the Arctic Land Shelf Interaction, Tomsk State University, 634050 Tomsk, Russia
Abstract
The study of rare earth elements (REEs) in marine sediments is a powerful geochemical tool for determining depositional processes and sediment provenance, as well as for understanding paleoenvironmental changes. In this context, we present REE, some major and trace elements, grain size, and mineralogy data on surface and core sediments, which were collected in different areas of the eastern Laptev Sea Shelf (LSS; Arctic Ocean). The primary objective of this paper was to assess the principal controlling factors influencing REE concentration and their vertical to lateral distribution. The total REE content (ΣREE) ranged from 139 ppm to 239 ppm within the studied sediment samples, predominantly consisting of silt. The normalized REE distribution patterns, based on North American Shale Composite (NASC) standard, exhibited an enrichment in light REE (LREE) when compared to heavy REE (HREE), which is similar to that in Lena River suspended particulate matter. The primary sources of REEs in the eastern LSS were both the suspended particulate matter from the Lena River and sediments originating from the coastal ice complex. The spatial distribution of REEs was primarily contingent upon the distance from sediment sources and prevailing hydrological conditions and was generally characterized by a decrease in REE concentration seaward. There was a moderate positive correlation between ΣREE and mean grain size in the studied surface sediment. However, this relationship was specific only for surface samples and was not found in the sediment cores, indicating that sediment grain size does not play a significant role in the REE vertical distribution. The strong positive correlation between ΣREE and Al, K, Ti, V, Cr, Zr, Hf, and Th suggests that REEs are hosted by not only heavy but also clay minerals. The vertical fluctuations of LREE/HREE, Eu/Eu*, (La/Lu)N can point at variable dominance of one or another REE source for during sediment accumulation.
Funder
Russian Science Foundation
Reference73 articles.
1. Dobrovolsky, A.D., and Zalogin, B.S. (1982). Morya SSSR, Moscow State University.
2. Accelerated Decline of Summer Arctic Sea Ice during 1850–2017 and the Amplified Arctic Warming during the Recent Decades;Cai;Environ. Res. Lett.,2021
3. Sedimentary Response of Arctic Coastal Wetlands to Sea Level Rise;Ward;Geomorphology,2020
4. Are, F.E. (1999). Land-Ocean Systems in the Siberian Arctic: Dynamics and History, Springer.
5. Chronology of the Holocene Transgression at the North Siberian Margin;Bauch;Glob. Planet. Chang.,2001