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首页 > 中国极地考察知识库 > 成果信息库 > 已审查 西北冰洋楚科奇海台08P23孔氧同位素3期以来的古海洋与古气候记录

西北冰洋楚科奇海台08P23孔氧同位素3期以来的古海洋与古气候记录

【标题】西北冰洋楚科奇海台08P23孔氧同位素3期以来的古海洋与古气候记录

【Title】PALEOCEANOGRAPHIC AND PLAEOCLIMATIC RECORDS OF CORE 08P23 FROM CHUKCHI PLATEAU, WESTERN ARCTIC OCEAN, SINCE MIS 3

【DOI】10.13679/j.jdyj.2014.1.046

【作者】 章陶亮; 王汝建; 陈志华; 陈建芳; 程振波; 孙烨忱

【Author】 Zhang Taoliang ; Wang Rujian ; Chen Zhihua ; Chen Jianfang ; Cheng Zhenbo ; Sun Yechen

【期刊】极地研究

【Journal】Chinese Journal of Polar Research

【期刊年份】2014

【卷】26

【期】1

【关键词】 西北冰洋; 楚科奇海台; 氧同位素3期; 冰筏碎屑事件; 氧碳同位素; 水团变化

【Keywords】 Chukchi Plateau; western Arctic Ocean; MIS 3; IRD events; oxygen and carbon isotope; water mass changes

【摘要】通过中国第三次北极科学考察在北冰洋楚科奇海台采集的08P23孔样品的多项指标分析以及与其它孔的沉积记录综合对比,初步将08P23孔沉积物分为氧同位素3期(MIS 3)-MIS 1的沉积序列。MIS 3以来,楚科奇海台08P23孔可以识别出5个显著的冰筏碎屑(Ice-Rafted Detritus, IRD)事件,分别出现在MIS 2和MIS 3。其中,MIS 3的IRD事件中碎屑碳酸盐岩主要来自于加拿大北极群岛分布广泛的古生代碳酸盐岩露头,MIS 2的IRD事件中碎屑石英可能来源于欧亚大陆边缘。该孔大部分层位浮游有孔虫左旋厚壁新方球虫Neogloboquadrina pachyderma (sinistral) (Nps)的δ18 O和δ13 C都轻于表层沉积物中的平均值。MIS 3中两个褐色层中偏轻的Nps-δ18 O和-δ13 C值是由冰融水造成;MIS 1和MIS 3灰色层中偏轻的Nps-δ18 O和-δ13 C值指示海冰形成速率的提高,导致轻同位素卤水的生产和下沉。MIS 2的Nps-δ18 O和-δ13 C值变化趋势相反,是因为温度急剧降低导致Nps-δ18 O变重,海水冻结成冰,海气交换明显降低使得Nps-δ13 C偏轻。MIS 1和MIS 3的Nps-δ18 O和-δ13 C受到融冰水或轻同位素卤水影响导致同时偏轻。

【Abstract】 Multi-proxy investigations have been performed on core 08P23 collected from the Chukchi Plateau, Western Arctic Ocean, during the Third Chinese National Arctic Expedition. The core was dated back to Marine Isotope Stage (MIS) 3 by a combination of AMS 14C dating and regional core correlation. A total of 5 prominent Ice-rafted detritus(IRD) events were recognized in MIS 2 and MIS 3. The IRD events in MIS 3 are originated from vast carbonate rock outcrops of the Canadian Arctic Archipelago and clastic quartz in MIS 2 may have a Eurasian origin. Mostδ18 O and -13 C value of Neogloboquadrina pachyderma (sinistral) (Nps) in core 08P23 are lighter than the average values of surface sediments. The light Nps-δ18 O and -δ13 C values in the two brown layers in MIS 1 and MIS 3 were resulted from meltwater events; and those in the gray layers in MIS 3 were caused by the enhanced sea ice formation. The Nps-δ18 O values varied inversely with Nps-δ13 C in MIS 2 indicate that the studied area was covered by thick sea ice or ice sheet with cold temperatures and little meltwater, which prevented the bioproductivity and sea-atmosphere exchange, as well as water mass ventilation. The covaried light values of Nps-δ18 O and -δ13 C in MIS 1 and MIS 3 were resulted from meltwater and/or brine rejection.

【基金/项目】 国家自然科学基金项目(41030859) ; 国家自然科学基金中俄合作与交流项目(41211120173) ; CHIANRE 2013-03-02 ; CHIANRE 2013-04-01 ; 中德合作白令海晚第四纪的古海洋与古气候变化研究

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