我国某些常见化石硅藻的环境分析

本文详细研究了中国海表层沉积物中的常见化石硅藻,结果表明,这些种的分布范围及数量变化随环境的不同而变化。因此,根据柱状样品中这些种类数量的变化,能够推断古气候变化,恢复古地理环境,再现海平面波动历程,进而划分、对比第四系地层。

ENVIRONMENT ANALYSIS OF THE COMMON FOSSIL DIATOMS FROM THE SEDIMENTS OF THE CHINA SEA

In this paper,surface diatom samples of 131 have been analysed by using HCl and H_2O_3 for the abysmal samples and the samples from the continental shelfs.Distinguished were 191 species,of which 10 common species are in detail discussed on their distributed ranges and the various numbers with changes of environmental factors such as depth,temperature and salinity etc..The results show that the depth has a marked effect on the distribution of benthic species, but plays a less important role in the planktonic species;temperature and salinity exert a tre- mendous influence on both kinds of species. Climatic changes of Quaternary glacial and interglacial periods resulted in many times of transgression and regression in the coast region of China.The research on paleogeography,paleo- climate,sea level fluctuation and division of Quaternary sediments is an important content of the diatom analysis based on changes of the components of the diatoms from the column section. Diatoms from the Quaternary core in the mouth of Minjiang River,Fujian have been studied and 4 diatom assemblages have been distinguished repressenting 4 periods of paleogeographic phases of continent-sea and continental transition-shallow sea-intertide zone, of which the first period may be dated as the late Late Pleistocene and other periods as the early,the middle and the late Holocene respectively. The diatoms from the reworked sediments often have broken valves and dirty surface.Be- cause the ecological environment that diatoms from the reworked sediments require does not tally with that of today,these diatoms should be producer of lower sea level in the late Pleisto- cene.