中文摘要：

本文对北部湾中部海域水深2.4m到61m、共计184个站位表层沉积物中的有孔虫进行研究。结果显示浮游有孔虫丰度非常低,种类也较稀少,仅在南侧水深较大的少数站位有发现,且含量不超过5%;而底栖有孔虫则较丰富,多数样品中以含有螺旋式与平旋式的玻璃质壳类型为主,暖水或大型底栖有孔虫分子常见。和其它海区相较而言,该海域底栖有孔虫中胶结壳类含量偏高,可能与沉积物底质颗粒较粗及海水盐度较低有关。该研究详细报道了底栖有孔虫主要属种在北部湾的分布特征。与海洋环境对比显示,水深和沉积物底质类型是影响这些属种平面分布的主要因素,而湾外温暖水团则是控制暖水种分子分布的另一重要因素。

英文摘要：

This study reports the distribution of foraminifera from 184 samples of sea surface sediments in the Tonkin Gulf,northern South China Sea.Planktonic foraminifera are seldom found and only occur in the southern part,near the outlet of the gulf.Benthic foraminifera have a high abundance in all samples and are mainly the planospiral and trochospiral hyaline tests.The arenaceous tests have a relatively higher content in the the Tonkin Gulf,possibly resulted from the coarser sediments and less saline water.The warm water and larger benthic foraminiferal species were often seen.The distributions of main benthic foraminiferal species were detailedly analyzed and compared with the water depth and the coarse fraction of sediments.This study shows that the water depth and sediment type greatly controll the benthic foraminiferal distribution in the Tonkin Gulf.In addtion,the foraminiferal characteristics also imply a warm water influence from the open area of the northern South China Sea.