【摘要】 利用透射电镜研究了九龙江口现代潮间带表层沉积物、九龙江地区中全新世剖面和东屿中-晚全新世剖面的微型硅藻(细胞大小为2～20μm)的组成和丰度.共计硅藻12属26种(包括变种).对每个种的生态分布作了描述,并提供了相应的壳面电镜照片.Thalassionemanitzschioides是九龙江口现代潮间带表层沉积物中的优势种;九龙江中全新世地层的优势种为Naviculaclimacospheniae,Thalassionemanitzschioides;东屿中-晚全新世地层中,Cyclotellastriata,Thalassionemanitzschioides是优势种.微型硅藻在各个样品中所占比例都相对较高,最高可达86.7%,表明微型硅藻在沉积硅藻中占有重要的地位.更多还原

【Abstract】 The species composition and cell density of nanodiatoms(cell size smaller than 20 μm) were investigated with TEM for the sedimental samples from different sedimental sections at modern intertidal zones and Middle Holocene in the Jiulong River, and in Dongyu Island in late Middle Holocene and Late Holocene. In total, 26 diatom species (including varieties) belonging to 12 genus of Bacillariophyta were found. The ecological distribution of each species was described together with TEM photographs. The dominant species at the modern intertidal zones in the estuary of Jiulong River is Thalassionema nitzschioides, and that in Middle Holocene is Navicula climacospheniae and Thalassionema nitzschioides; in Dongyu Island in late Middle Holocene and Late Holocene the dominant species is Cyclotella striata and Thalassionema nitzschioides. The percentage contribution of nanodiatoms to total diatom assemblages in sedimental sections is relatively high which can be up to 86.7%, showing the importance of nanodiatoms in diatom assemblages in sediments.更多还原