极地研究

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白令海盆17 Ka以来的古海洋与古气候记录

王磊1 王汝建1 陈志华2 陈建芳3 程振波2 孙烨忱1   

  1. 1同济大学海洋地质国家重点实验室,上海,20092; 2国家海洋局第一海洋研究所,青岛,266061; 3国家海洋局第二海洋研究所,杭州,310012
  • 出版日期:2014-03-30 发布日期:2014-03-30

PALEOCEANOGRAPHIC AND PALEOCLIMATIC RECORDS IN THE BERING BASIN OVER THE LAST 17 KA BP

Wang Lei1, Wang Rujian1, Chen Zhihua2, Chen Jianfang3, Cheng Zhenbo2, Sun Yechen1   

  1.  
    1Laboratory of Marine Geology, Tongji University, Shanghai, 200092, China;
    2First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, China;
    3Second Institute of Oceanography, State Oceanic Administration, Hangzhou, 310012, China
  • Online:2014-03-30 Published:2014-03-30

摘要: 通过白令海盆08BR02钻孔(57°0.06′ N,174°29.97′ E,水深3805 m)的AMS14C测年数据、颜色反射率b*与NGRIP(North Greenland Ice Core Project)氧同位素曲线及白令海4个钻孔颜色反射率b*记录作对比,建立该孔的地层年代框架,顶、底部沉积物年龄分别为4.2ka和17.0ka。该孔自17 ka以来,IRD (Ice-rafted detritus:冰筏碎屑)、粒度的砂组分以及敏感组分中的33-63 μm组分百分含量在全球性冷事件H1 (Heinrich event 1)、B/A (Bølling/Allerød)中期和YD (Younger Dryas)期间明显增加。IRD和有孔虫丰度在H1、B/A和YD期间同步增加,可能反映海冰融化为表层水提供营养物质,促使表层钙质生产力勃发并将有机质进一步输送至海底,为底栖生物提供营养物质。

关键词: 白令海盆, 末次冰消期, 冰筏碎屑, 海冰扩张, 有孔虫

Abstract: Terrigenous-biogenic fraction investigations have been performed on core 08BR02 collected from the Bering Basin, North Pacific Ocean, during the Third Chinese National Arctic Expedition. Depth-age model of this core is based upon age control points of AMS14C dating on organic carbon and platonic foraminifers, and correlation of the color b* in this core with NGRIP δ18O curve and color b* of four sediment cores in the North Pacific and Bering Sea. Sea ice extension history in the Bering basin over the last 17 ka is reconstructed by ice-rafted detritus (IRD), sand component and sensitive component (sized in 33-63 μm), which were carried by sea ice and iceberg, and increased during the H1, mid-B/A and YD periods. The IRD and foraminifera abundance in core 08BR02 increased simultaneously during the H1, mid-B/A and YD periods, which indicate the melt water enhanced surface water nutrient and then promoted planktonic foraminifera bloom, surface organic material deposited on the sea bottom provided nutrient for benthic foraminifers.

Key words: Bering Basin, last deglaciation, IRD(ice-rafted detritus), sea ice extension, foraminifera