【摘要】 为探讨冲绳海槽表层沉积物中钙质超微化石的分布规律及其影响因素 ,对海槽北部槽坡区 ( 2 9°5 8.33′— 31°31 .2 3′N ,1 2 7°39.5 5′— 1 2 8°5 9.61′E) 34个表层样品进行了分析和研究。共发现 35种钙质超微化石 ,其中优势种为Gephyrocapsaoceanica、Emilianiahuxleyi和Florisphaeraprofun da ;G .oceanica、E .huxleyi等的百分含量变化和特征属种U .tenuis的出现 ,表明该区钙质超微化石组合面貌与东海外陆架相似 ,和东海及南海都属于北太平洋中央水团组合。G .oceanica的含量与海水营养盐存在一定的关系 ,但两者之间并不存在明显的正相关性 ;暖水分子U .irregularis、U .sibogae和O .fragilis的较高含量和冷水分子G .caribbeanica和Calcidiscusleptoporus的较低含量 ,进一步反映该区钙质超微化石的分布受到黑潮及对马暖流的影响 ,其中温度、盐度和表层海水结构性质 ,如海水透明度等因素可能为主要控制因素。更多还原

【Abstract】 Calcaerous nannofossils analysis has been carried out for 34 surface sediment samples taken from the northern Okinawa T1rough to investigate distribution patterns of nannofossils and related environmental characteristics. A total of 35 taxa were identified with dominant species G. oceanica, E. huxleyi and F. profunda. The relative abundance of G. oceanica, E. huxleyi and other subordinate species along with the presentation of U. tenuis show the nannofossil assemblage of this area is similar to that of the outer shelf of the East China Sea. So this area belongs to the central zone of the North Pacific in biogeographic zonations of nannoplankton as the East China Sea and the South China Sea. A relatively higher abundance of G. oceanica does not show positive correlation with high nutrient concentration. Rather abundant Warm water species U. irregularis, U. sibogae and O. fragilis and less abundance of G. caribbeanica and C. leptoporus favoring cold water again reflect the area under the control of warm Kuroshio and its extension.更多还原