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| 摇蚊亚化石记录的苏干湖近千年来盐度变化研究 | |
| 引用本文： | 陈建徽,陈发虎,张恩楼,周爱锋.摇蚊亚化石记录的苏干湖近千年来盐度变化研究[J].第四纪研究,2008,28(2):338-344. |
| 作者姓名： | 陈建徽 陈发虎 张恩楼 周爱锋 |
| 作者单位： | 1. 兰州大学西部环境教育部重点实验室中德干旱环境联合研究中心,兰州,730000 2. 中国科学院南京地理与湖泊研究所,南京,210008 |
| 基金项目： | 教育部高等学校博士学科点专项科研基金 , 国家自然科学基金知识创新研究群体项目 |
| 摘 要： | 利用摇蚊亚化石重建湖泊古盐度进而分析区域干湿变化已成为国际上古气候重建研究的热点之一。本文利用苏干湖SG03I孔的摇蚊亚化石组合变化分析了湖泊水体近千年来的盐度波动过程,沉积序列可划分为3个摇蚊组合带,通过高咸水属种Orthocladius/Cricotopus和Psectrocladius barbimanus,以及低咸水属种Psectrocladius sordidellus和Procladius的相对丰度变化实现盐度重建。结果表明,990～1450A.D.期间高咸水种处于绝对优势,湖泊盐度较高;1450～1850A.D.期间低咸水种显著增加,指示了小冰期期间较高的入湖水量与蒸发量之比;1850～2002A.D.期间低咸水种丰度回落,湖泊水体盐度逐渐增加至现代水平。SG03I孔岩芯摇蚊指标与其他代用指标的结果有很好的对应关系,摇蚊亚化石组合变化揭示的苏干湖区小冰期相对湿润的气候状况在干旱区其他记录中也有反映,证实了摇蚊亚化石分析在西北干旱区古环境研究中的有效性。 |
| 关 键 词： | 苏干湖 摇蚊亚化石 盐度 小冰期 |
| 文章编号： | 1001-7410(2008)02-338-07 |
| 收稿时间： | 2007-07-19 |
| 修稿时间： | 2007年7月19日 |
A PRELIMINARY STUDY ON CHIRONOMID-BASED SALINITY RECONSTRUCTION FOR SUGAN LAKE IN THE LAST MILLENNIUM |
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| Chen Jianhui,Chen Fahu,Zhang Enlou,Zhou Aifeng.A PRELIMINARY STUDY ON CHIRONOMID-BASED SALINITY RECONSTRUCTION FOR SUGAN LAKE IN THE LAST MILLENNIUM[J].Quaternary Sciences,2008,28(2):338-344. | |
| Authors: | Chen Jianhui Chen Fahu Zhang Enlou Zhou Aifeng |
| Institution: | 1. Center for Arid Environment and Paleoclimate Research, Key Laboratory of West China's Environmental System(Ministry of Education), College of Earth and Environment Sciences, Lanzhou University, Lanzhou 730000; 2. Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 |
| Abstract: | Subfossil Chironomidae are recently introduced but useful palaeosalinity indicators and thus are considered as potential indicators of evaporation/precipitation balance in arid and semi-arid regions.In this study,assemblages of chironomid subfossils from the Sugan Lake,Northwest China,were analyzed to reconstruct the salinity fluctuation from 990A.D.onwards.A total of four chironomid taxa was found,of which two（Orthocladius/Cricotopus,Psectrocladius barbimanus）are high-salinity adapted taxa and the others（Psectrocladius sordidellus,Procladius）are low-salinity adapted.Three assemblage zones on the basis of changes in the chironomid biostratigraphy are identified by constrained cluster analysis and three corresponding climatic episodes are inferred as follows: From 990～1450A.D.,the high-salinity taxa predominated the succession,indicating high salinity in the lake water.During 1450～1850A.D.,there was a significant increase up to 46.27% in the low-salinity taxa percentage,which reveals a much higher inflow/evaporation ratio during the Little Ice Age.The abundance of high-salinity taxa became dominant again from 1850A.D.onward,suggesting that the water salinity of the Sugan Lake increased to modern level gradually and thus a regional aridification prevailed during this period.Generally the chironomid-inferred salinity fluctuations are in good agreement with other proxy records such as oxygen isotope of carbonate,valve type and valve thickness from the same sediment core.And the relatively humid Little Ice Age climate indicated by our chironomid data was reflected by other climate reconstructions in the arid NW China in previous studies.Therefore,our study strongly proves that chironomid analysis is a feasible and efficient tool which can throw new light on palaeoenvironmental research in arid China. |
| Keywords: | Sugan Lake subfossil Chironomidae salinity Little Ice Age |
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