论文部分内容阅读
盘星藻化石在我国第四纪湖相地层中频繁出现,但其在第四纪古环境研究中的指示意义存在较大的争议.一些研究认为盘星藻大量的出现代表了湖泊变浅,一些研究则认为盘星藻主要集中在湖泊水深较大的区域.本文对位于云南中部的星云湖现代水样和湖床表层沉积物样品中盘星藻的分布状态进行调查研究,结果显示湖面水体中盘星藻浓度在水平方向上随水深基本没有变化,在垂直方向上盘星藻在湖水底部浓度最大,推测可能与盘星藻重力沉降及波浪扰动底泥产生的再沉积作用有关;湖床表层沉积物中盘星藻含量与水深无明显关系.初步认为,在一些较大湖泊的沉积物中,盘星藻的分布与水深的关系可能是沉积过程造成的,较大湖泊中风浪的作用使得盘星藻趋中沉积非常明显;而湖水中是否有大量盘星藻生长可能与河流输入、水体营养化状态、水温、p H、盐度等水环境状态有关.不同区域、不同类型的湖泊可能机制并不一样,没有统一的规律.因此,在第四纪古环境研究中将盘星藻含量作为水深的指标需结合其他指标综合分析.星云湖过去3000年化石盘星藻含量的变化与沉积物粒度和磁化率指示的区域人类活动强度变化趋势一致,且更敏感地响应了人类活动导致的湖泊水体富营养化过程.
In the Quaternary period lacustrine strata of China, the frequent occurrence of Fossillus albino fossils, however, there is much controversy about the significance of the indicator in Quaternary paleoenvironment research.According to some researches, Some studies suggest that the genus Chlamydomonas is mainly concentrated in the lake where the water depth is relatively large.This paper investigates the distribution of Platymonas algae in the modern water samples of the Xingyun Lake in central Yunnan and the sediment samples from the lake beds, In the vertical direction, the concentration of Radix Platycodon was the highest at the bottom of the lake, suggesting that the concentration of Radix Platycasteris may be related to the gravity sedimentation and the sedimentation of the wave-disturbed sediment. There was no significant relationship between the content of Panax notoginseng and the water depth in the surface sediments. It is preliminarily believed that the relationship between the distribution of Panax notoginseng and water depth may be caused by the deposition process in the sediments of some large lakes, Making the deposition of Plastids algae is very obvious; and whether there is a large number of Lake Platycladus growth may be river input, water body eutrophication state, water temperature, p H, salinity and other water ring Different states and different types of lakes may have different mechanisms and no unified laws.Therefore, the index of water depth of Platymonas alba in the study of Quaternary paleoenvironment should be combined with the comprehensive analysis of other indicators.Xingyun Lake The change of the content of algae in the past 3000 years coincided with the trend of human activity intensity in the region indicated by the grain size and susceptibility of sediment and more sensitively responded to the eutrophication process of lakes caused by human activities.