古地理学报 ›› 2019, Vol. 21 ›› Issue (5): 855-868. doi: 10.7605/gdlxb.2019.05.058

• 第四纪古地理学及沉积学 • 上一篇    

西太平洋深海沉积物记录的~80ka以来风尘物质输入与东亚冬季风强度*

谢一璇1,2, 杨小强1,2, 张伙带3, 陈琼1,2, 李冠华1,2   

  1. 1 中山大学地球科学与工程学院,广东广州 510275;
    2 广东省地球动力作用与地质灾害重点实验室,广东广州 510275;
    3 中国地质调查局广州海洋地质调查局,广东广州 510075
  • 收稿日期:2018-08-02 修回日期:2018-12-08 出版日期:2019-10-01 发布日期:2019-09-26
  • 通讯作者: 杨小强,男,1972年生,教授,博士,主要从事古地磁与环境磁学和第四纪地质与环境研究。E-mail: eesyxq@mail.sysu.edu.cn。
  • 作者简介:谢一璇,女,1994年生,硕士研究生,主要从事第四纪地质与环境研究。E-mail: xieyx7@mail2.sysu.edu.cn。
  • 基金资助:
    *国家自然科学基金项目(编号: 41672162)、广东省珠江人才计划“环南海地质过程与灾害创新团队”(编号: 2016ZT06N331)联合资助

Eolian input and East Asian winter monsoon records in deep-sea sediment from Western Pacific since ~80ka

Xie Yi-Xuan1,2, Yang Xiao-Qiang1,2, Zhang Huo-Dai3, Chen Qiong1,2, Li Guan-Hua1,2   

  1. 1 School of Earth Sciences and Engineering,Sun Yat-sen University, Guangzhou 510275,China;
    2 Guangdong Provincial Key Lab of Geodynamics and Geohazards,Guangzhou 510275,China;
    3 Guangzhou Marine Geological Survey,China Geological Survey,Guangzhou 510075,China
  • Received:2018-08-02 Revised:2018-12-08 Online:2019-10-01 Published:2019-09-26
  • Contact: Yang Xiao-Qiang,born in 1972,is a doctor and a professor. He is engaged in researches on paleomagnetism and environmental magnetism,and Quaternary geology and environment. E-mail: eesyxq@mail.sysu.edu.cn.
  • About author:Xie Yi-Xuan,born in 1994,is a master candidate. She is engaged in researches on Quaternary geology and environment. E-mail: xieyx7@mail2.sysu.edu.cn.
  • Supported by:
    Co-funded by the National Natural Science Foundation of China(No.41672162)and the Guangdong Province Introduced Innovative R & D Team of Geological Processes and Natural Disasters around the South China Sea(No.2016ZT06N331)

摘要: 大洋沉积物中的风尘记录良好地揭示了风尘源区干旱化过程和季风强度变化。以位于西太平洋采薇海山附近的柱状沉积物(MABC19孔)为研究对象,在基于地磁场相对古强度对比获取年代框架的基础上,从沉积物粒度组分和磁学参数中提取研究区~80ka以来风尘物质的记录。沉积物高矫顽力磁性矿物参数结果指示,研究区风尘输入量自~80ka以来总体呈逐渐增加趋势,在MIS3/MIS2转换阶段风尘输入量增加明显,揭示了风尘源区古气候条件的转变。通过碎屑沉积物粒径—标准偏差方法提取代表风尘输入的敏感组分,其平均粒径记录了东亚冬季风强度在MIS3/MIS2转换阶段显著增大,该记录与黄土地区风尘记录指示的东亚冬季风强度变化在MIS3阶段高度一致,在其余时段存在着差异,初步推测这是由于高空风尘输送机制的海、陆差异所致。

关键词: 风尘沉积, 西太平洋, 东亚冬季风, 海陆对比

Abstract: Eolian records in marine sediments were suggested to reveal the drying process in dust sources area and the variations of the intensity of monsoon. Here we present the eolian records since~80ka deduced from grain size and rock magnetic analysis of a sediments core(Core MABC19)near the Caiwei Seamounts,Western Pacific. The chronostratigraphy of the core was constructed by the relative palaeointensity(RPI)of the earth’s magnetic field. According to the variations of the high coercivity magnetic mineral parameters,the eolian input into the study area increase gradually since~80ka,and reach relatively high level during the MIS3/MIS2 transition,indicating the variations in palaeoclimate and palaeoenvironment conditions in the dust source area. The average grain size of eolian component derived from grain size-standard deviation method is used as an indicator of the intensity of East Asian winter monsoon(EAWM). The average grain size data reveals a significant increase of EAWM during the MIS3/MIS2 transition,which is highly consistent with the variation of EAWM intensity indicated by loess during MIS3 stage. However,differentiation is apparent in the rest periods. The maritime-continental contrast of the dust transportation mechanism at high altitude is likely to contribute to this difference.

Key words: eolian sediments, Western Pacific, East Asian winter monsoon, land-ocean comparison

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