Earth Science Frontiers ›› 2022, Vol. 29 ›› Issue (4): 179-190.DOI: 10.13745/j.esf.sf.2022.1.7

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Provenance of sediments in the Amundsen Sea, West Antarctic since the mid-Holocene and paleoclimate reconstruction

LEI Ziyan1,2(), GE Qian1,2,*(), CHEN Dong1,2, ZHANG Yongcong1,2, HAN Xibin1,2, YE Liming1,2, BIAN Yeping1,2, XU Dong1,2   

  1. 1. Key Laboratory of Submarine Geosciences, Ministry of Natural Resources, Hangzhou 310012, China
    2. Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China
  • Received:2021-09-17 Revised:2021-11-18 Online:2022-07-25 Published:2022-07-28
  • Contact: GE Qian

Abstract:

Grain size and geochemical analyses were carried out on sediment core samples from core A11-02 in the Amundsen Sea, West Antarctic to trace the sediment sources and reconstruct the history of paleoclimatic evolution since the mid-Holocene. By analyzing and comparing the North American Shale Composite normalized rare earth element (REE) patterns and indicators such as (La/Yb)N, (Gd/Lu)N and (La/Sm)N, we concluded that the core sediments mainly originate from the Marie Byrd Land, with contributions, to some extent, from the Bellingshausen Sea. By multi-index analysis comparing the Chemical Index of Alteration, Na/K ratio and grain contents for grain sizes less than 22.1 μm or greater than 63 μm with other paleoclimate records, we identified four distinct cooling phases in the Amundsen Sea since the mid-Holocene. We found the millennial-scale climate changes are temporally and spatially consistent across the Antarctic and mainly controlled by changes in insolation and atmospheric circulation.

Key words: Amundsen Sea, grain size, geochemical elements, sediment provenance, paleoclimate

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