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对冲绳海槽南部255柱状样的66个样品进行底栖有孔虫定量研究。结合浮游与底栖有孔虫稳定同位素分析和AMS~(14)C测年,追溯20ka来深海环境和表层古生产力的变化历史。底栖有孔虫胶结质壳比例和浮游有孔虫碎壳率的变化揭示冰后期的碳酸盐溶解作用比冰期的强。属种分布和Q型因子分析结果显示冲绳海槽区近20ka来存在冰期、冰消期和冰后期3个明显不同的底栖有孔虫组合,其中冰期的Bulimina aculeata组合(特别是优势种Uvigerina peregrina)与高的表层初级生产力和沉积物中富有机质含量有关,冰后期的Uvigerina asperula组合对应于较低的表层初级生产力,而冰消期的Chilostomella oolina组合则可能反映底层水体低氧含量。
A total of 66 columnar samples from 255 southern Okinawa Troughs were used for quantitative study of benthic foraminifera. Based on the stable isotopic analysis of planktonic and benthic foraminifera and the AMS ~ (14) C dating, the evolution of the deep-sea environment and paleoproductivity over the past 20 ka is traced back. The change of the ratio of the benthic foraminiferal cementitious shell and the pelagic foraminiferal fragmentation rate revealed that the carbonate dissolution in the late ice stage was stronger than that in the glacial stage. Species distribution and Q-factor analysis showed that there were three distinctly different benthic foraminiferal assemblages in the Okinawa Trough over the past 20 ka, including the glacial assemblages of Bulimina aculeata (especially the dominant species Uvigerina peregrina) is associated with high primary productivity and organic matter content in sediments. The Uvigerina asperula assemblage in the late glacial stage corresponds to a lower initial productivity of the surface layer, while the Chilostomella oolina assemblage may reflect the low oxygen content in the bottom water.