| Summary: | 通过对中国第1~4次北极考察在西北冰洋采集的表层沉积物中底栖有孔虫丰度及其优势种分布特征与环境因素关系的综合研究发现,楚科奇海区低的底栖有孔虫丰度主要受较高的陆源物质输入的稀释作用影响;楚科奇海台和阿尔法脊较高的底栖有孔虫丰度主要受到暖而咸的大西洋中层水的影响;受碳酸钙溶解作用影响的门捷列夫深海平原和加拿大海盆底栖有孔虫丰度较低,并且水深3 597M的站位出现了似瓷质壳的PyrgO WIllIAMSOnI和QuInQuElOCulInA OrIEnTAlIS,说明该区的CCd深度大于3 600M。根据底栖有孔虫7个优势属种的百分含量分布特征可以划分出5个区域组合:南楚科奇海陆架-白令海峡组合以优势种ElPHIdIuM EXCAVATuM和buCCEllA frIgIdA为特征,可能反映受白令海陆架水影响的浅水环境;阿拉斯加沿岸-波弗特海组合以优势种flOrIluS SCAPHuS和ElPHIdIuM AlbIuMbIlICATuM为特征,可能反映受季节性海冰融化,低盐的阿拉斯加沿岸流以及河流淡水输入的低盐环境;大西洋中层水组合以优势种CASSIdulInA lAEVIgATA为特征,可能反映高温高盐的大西洋中层水影响的环境;北极深层水组合以优势种CIbICIdES WuEllErSTOrfI为特征,可能反映水深大于1 500M低温高盐的北极深层水环境;门捷列夫深海平原组合以优势种OrIdOrSAlIS uMbOnATuS为特征,可能反映低营养的底层水环境。 Benthic foraminiferal assemblages in 139 western Arctic surface sediment samples recovered during the CHINAREⅠ~Ⅳcruises were studied.The relative abundances of each species were calculated and according to the spatial distribution pattern of dominant species,benthic foraminiferal assemblages were divided to determine the relationship between the assemblage and environmental parameters.Our results show that the spatial distribution pattern of low benthic foraminiferal abundance in the Chukchi shelf area is controlled by high terrigenous matter input.In Chukchi Plateau and Alpha ridge,high benthic foraminiferal abundance is influenced by the warm and saline intermediate Atlantic water.In the Mendeleev Abyssal Plain and Canadian Basin,low benthic foraminiferal abundance is influenced by calcium carbonate dissolution and the appearance of porcelain-like species Pyrgo williamsoni and Quinqueloculina orientalis at 3 597 msites indicates the carbonate compensate depth(CCD)is greater than3 600m.Five assemblages related to spatial environmental factors can be determined by 7 dominant species:Southern Chukchi shelf-Bering Strait assemblage is dominantly characterized by Elphidium excavatumand Buccella frigida,representing the influence of shallow Bering Sea Shelf Water;Alaska Coast-Beaufort Sea assemblage is dominantly characterized by Florilus scaphus-Elphidium albiumbilicatum,indicating the low salinity environment due to seasonal sea ice melting and/or Alaska Coastal Current or riverine input;Atlantic Intermediate Water assemblage is dominated by Cassidulina laevigata,representing warm saline Atlantic Intermediate Water;Arctic Deep Water assemblage is dominated by Cibicides wuellerstorfi,reflecting the low temperature and high salinity environment greater than 1 500m;Mendeleev Abyssal Plain assemblage is dominated by Oridorsalis umbonatus,showing the oligotrophic bottom water environment. 国家自然科学基金重点项目(41030859); 南北极环境综合考察与评估专项——2012年度北极海域海洋地质考察(CHINARE2012-03-02); 中国地质调查局项目(水[2012]01-011-05)
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