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韩晓钟 《中国海洋湖沼学报》1992,10(3):231-238
The concentrations of major elements and some trace elements were determined at 8 core locations in Taihu Lake. The chemical composition of the cores was related to the sediment particle size-chronology and location of sampling site.Concentrations of Al, Mg, K, Ca and Na, the major mineral species in the sediments, were generally uniform, with only slight fluctuation influenced by water waves and current. Surface enrichment of Cu, Zn, and Ni at some locations was observed to be greater than that of the sediments accumulated 100 years ago. The enrichment of these elements is attributed to anthropogenic input in recent years. Concentration profiles for Mn and Fe are related to the migration of these elements in the pore water. 相似文献
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鄱阳湖现代沉积210Pb测年模式的选择和沉积速率的变化 总被引：4，自引：3，他引：1
由于受到长江和入湖河流双重影响,鄱阳湖沉积可分为南部三角洲前缘、中部开阔湖和北部入江水道三个区域。按各区特点,采用了C.J.C.和C.R.S.不同计算模式,分别得出其沉积速率为0.52、0.16和0.34cm/a。湖区不同沉积地貌单元沉积速率的差异,受物源和水动力条件的影响:水下天然堤、漫滩、堤外洼地及开阔湖沉积速率分别为0.80、0.36、0.13和0.17cm/a。此外,三角洲的迅速伸长,河道分汊或改道,流域水土流失及大型水利工程等天然和人为活动也影响到沉积速率的时空变化。 相似文献
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An 82 cm core was collected from Qinghai Lake in the Qinghai- Xizang Plateau , China and sectioned in intervals of 1 cm for analysis of pigments (i.e. chlorophyll derivatives , carotenoids , myxoxanthophyll .oscillaxanthin) and 210Pb .210Pb dating was used to establish the chronological sequence . The concentrations of myxoxanthophyll and oscillaxanthin from the cyanophytes increase with temperature. There are four peak values at 0-14 cm ( present-1891a), 25cm (1786a), 45cm (1581a) . 60cm (1416a) representing four warm and low water level periods during the past 700 years. This was confirmed by the high concentration of carbonate and 13C in these stages. In these 700 years , there were also 4 periods of cold wet climate and high water level as indicated by the tree ring index and high value of native chlorophyll and high , variable CD/TC ratios . 相似文献
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