摘要
南海拥有较齐全的边缘海地理地貌与生态环境,沉积物中保存的放射虫种类繁多,个体丰富.本文采用数理统计与聚类分析方法,对表层沉积物中放射虫的组合特征进行了较为详细的定量分析,以期获得可靠的放射虫组合与分布的特征.聚类分析结果显示,放射虫组合在南海表层沉积物中的分布大致可区分为5种类型:陆架浅水区型、陆坡珊瑚礁区型、中央海盆区型、南部富营养区型和夏季上升流区型,它们分别对应于特有的海洋环境,并由含有某些优势种类的放射虫群落所组成.进一步分析还表明,南海的北部、中部和南部分别表现为3个不同生态环境的海区:北部海区受陆源影响较为明显;中部海区被中央水团、海底火山活动和夏季上升流活动所控制;南部海区总体上属于典型的珊瑚礁海洋环境,生态与沉积环境明显优越于北部海区.南海表层沉积物中放射虫的组合分布特征较好地响应和反映了所在海区的生态环境与沉积条件,是探讨古海洋环境的重要依据.
The South China Sea (SCS) features relatively complete physiographical units and ecologic environments of marginal sea, where there are a lot of radiolarian species and specimens preserved in the sediments. Methods of quantitative statistics and clustering were used in this paper to analyze the radiolarian assemblages in surface sediments of the SCS so as to obtain their characteristics of compositions and distributions. Result of clustering analysis shows that the radiolarian assem blage in the surface sediments may be mainly divided into five groups, namely, assemblages of shallow shelf, coral slope, central basin, southern rich nutrition and summer upwelling, corresponding to different special marine environments respectively and consisting of certain radiolarian communities of dominant species. It is also indicated that the northern, central and southern SCS take on as three different ecologic costal areas respectively, such as the north affected mostly by terrigenous input, the central area controlled mainly by the central basin waters, submarine volcanic and summer upwelling activities, and the south generally belonging to a typical coral environment where there is a better ecologic and sedimental environment for radiolarian than in the northern SCS. The radiolarian assemblages and distributions in the SCS surface sediments are well responding to and reveal the marine ecologic conditions and sedimental environments, which may be important evidences for paleoceanographic exploration.
出处
《地球科学(中国地质大学学报)》
EI
CAS
CSCD
北大核心
2008年第6期775-782,共8页
Earth Science-Journal of China University of Geosciences
基金
国家自然科学基金课题(Nos.40476024,40631007)
国家“973”项目课题(No.2007CB815905)
国家科技支撑计划课题(No.2006BAB19B03)
关键词
放射虫
组合特征
海洋环境
表层沉积物
南海
Radiolarian
assemblage character marine environment surface sediment South China Sea.