南海北部表层沉积硅藻及其与环境关系探讨

DIATOM ASSEMBLAGES FROM SURFACE SEDIMENTS IN THE NORTERN SOUTH CHINA SEA AND THEIR RELATION WITH THE ENVIRONMENTS

本文在指出了南海常见硅藻种类地理分布的基础上,将南海北部表层沉积硅藻划分为五个组合和二个亚 组合,并将其与所在分布区的海洋水文、地质地貌等条件相对照,着重研究了硅藻组合与沉积环境之间的关系。

Diatoms from the bathybic sediments in the northern part of Scuth China Sea are dominated by tropical and subtropical abyssal species with a lew epeiric and littoral ones, and in the continental shelf by littoral species. Belonging to assemblage types which separately reflect four environmental factors,five diatom assemblages and two subassemblages can be distinguished in the northern part cf South China Sea based on the ratio changes of dil-ferent kinds of species and their relation with environmental factors as temperature, salinity, depth and currents etc.Ⅰ. Thalassionema nitzschioids-Thalassiosira-Rhizosolenia bergonii-Cosci-nodiscus nodulifer assemblageⅡ. Coscinodiscus nodulifer-Rhizosolenia bergonii-Thalassionema nitzsch-ioides-Diploneis assemblageⅢ. Cyclotella-Thalassionema nitzschioides-Coscinodiscus nodulifer-Melo-sira sulcata assemblageⅢa. Cyclotella-Coscinodiscus nodulifer-Campylodiscus brightwellii subas-semblage Ⅲb. Cyclotella-Thalassionema nitzschioides-Melosira sulcata subassemblageⅣ. Cyclotella-Plagiogramma-Melosira sulcata-Coscinodiscus assemblageⅤ. Melosira sulcata-Cycloltella assemblage