浙江温州、镇海和福建九龙江沉积微型硅藻的初步研究

利用透射电镜研究了温州早、中全新世剖面,九龙江地区晚全新世中期剖面和镇海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14属20种(包括变种).Cyclotellacaspia是九龙江地区晚全新世中期剖面中的优势种;温州中全新世剖面的优势种为Cyclotellastriata;温州早全新世剖面和镇海晚全新世剖面中Thalassionemanitzschioides是优势种.微型硅藻在几个剖面中所占的比例变化较大,以在九龙江地区晚全新世中期剖面所占的比例最高,可达77.4%,表明微型硅藻在沉积硅藻中占有重要的地位.

Preliminary Studies on Nanodiatoms in Sedimental Samples of Wenzhou City and Zhenhai City in Zhejiang Province and Jiulong River in Fujian Province

The species composition and density of nanodiatoms in sedimental sections were studied by TEM for the sedimental samples from different sedimental sections in Early and Middle Holocene in Wenzhou city in Zhejiang province?in later Holocene in estuary of Jiulong River in Fujian province and in Zhenhai city in Zhejiang province. In total, 20 diatom species (including varieties) belonging to 14 genera of Bacillariophyta were described and the ecological distribution of each species was described together with TEM photographs. The dominant species was Cyclotella caspia in later Holocene in estuary of Jiulong River in Fujian province, Cyclotella striata in Middle Holocene in Wenzhou city, and Thalassionema nitzschioides in early Holocene in Wenzhou city and in later Holocene in Zhenhai city. The contribution of nanodiatoms to total diatom assemblages in sedimental sections varied highly, and which was up to 77.4 % in later Holocene in estuary of Jiulong River in Fujian province, indicating the importance of nanodiatoms in diatom assemblages in sediment.