地学前缘 ›› 2022, Vol. 29 ›› Issue (4): 179-190.DOI: 10.13745/j.esf.sf.2022.1.7

• 深海沉积与快速气候变化 • 上一篇    下一篇

中全新世以来西南极阿蒙森海沉积物来源和古气候意义

雷子炎1,2(), 葛倩1,2,*(), 陈东1,2, 张泳聪1,2, 韩喜彬1,2, 叶黎明1,2, 边叶萍1,2, 许冬1,2   

  1. 1.自然资源部海底科学重点实验室, 浙江 杭州 310012
    2.自然资源部 第二海洋研究所, 浙江 杭州 310012
  • 收稿日期:2021-09-17 修回日期:2021-11-18 出版日期:2022-07-25 发布日期:2022-07-28
  • 通讯作者: 葛倩
  • 作者简介:雷子炎(1999—),男,硕士研究生,主要从事极地古海洋学研究。E-mail: smhw.lzy@gmail.com
  • 基金资助:
    自然资源部专项“南极重点海域对气候变化的响应和影响()”(IRASCC2020-2022)

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

摘要:

对西南极阿蒙森海A11-02孔沉积物进行粒度和地球化学元素分析,示踪了阿蒙森海沉积物来源,重建了中全新世以来的古气候演化历史。通过对稀土元素北美页岩平均标准化配分曲线以及(La/Yb)N、(Gd/Lu)N、(La/Sm)N等参数的分析和对比,认为A11-02孔沉积物主要来源于玛丽伯德地,而别林斯高晋海也有一定贡献。通过将化学蚀变指数、Na/K、<22.1 μm粒级组分含量以及>63 μm粒级组分含量等相关替代指标与其他古气候记录对比,识别出中全新世以来在阿蒙森海存在4个明显的寒冷阶段(P1-P4)。在时间和空间上,南极地区千年尺度的气候变化具有一致性,主要受日照强度变化和大气环流变化控制。

关键词: 阿蒙森海, 粒度, 地球化学元素, 物源, 古气候

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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