| 引用本文: | 余俊清,王小燕,李军,安芷生.湖泊沉积有机碳同位素与环境变化的研究进展.湖泊科学,2001,13(1):72-78. DOI:10.18307/20010111 |
| YU Junqing,WANG Xiaoy an,LI Jun,AN Zhisheng.Paleoenvironmental Interpretations on Organic Carbon Isotopic Records from Lake Sediments:A Critique. J. Lake Sci.2001,13(1):72-78. DOI:10.18307/20010111 |
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| 摘要: |
| 湖泊沉积有机质稳定碳同位素(δ13Corg)在区域气候与环境变化方面的应用研究近年来发展迅速,成果令人瞩目.保存在各类湖泊岩芯中的δ13Corg记录揭示了晚更新世以来大气CO2浓度的变化、湖泊水位波动、湖区生态与植被的变迁以及气温变化等重要环境信息.由于造成δ13Corg值变化的影响因素较多,确定个湖与环境变化有关的主导因素时常有赖于其它证据的帮助,诸如地球化学、古湖沼学、孢粉学、分子同位素地层学等等.前人通过研究来自不同类型湖泊、具不同曲线形态特征的δ13Corg记录,提出了多种环境解释模型.本文对此作了归纳和评述.鉴别和澄清湖泊沉积有机质的源物质以及有机物源随环境变化而发生过的变动,是研究δ13Corg记录环境意义至关重要的基础性工作.由于有机质含量、碳氮比值、氢指数、生物残留物鉴别等常能提供有关湖泊有机质来源、产率、成岩作用等方面的有用信息,这方面的研究结果应该尽可能一并提供,以利于恰当地应用现有的环境解释模型,或者建立个湖新模型.单体生物标志化合物鉴别通常也能为区分湖积有机质中陆生、水生、细菌生等不同碳的来源提供有用信息.特定化合物同位素分析技术近年来成功地应用于建立单体生物标志化合物碳同位素地层学,为湖积有机碳同位素在生态环境演变? |
| 关键词: 湖泊沉积 有机质 碳同位素 环境解释模型 冰后期气候变化 |
| DOI：10.18307/20010111 |
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| 基金项目:中国科学院重大项目(KZ951-A1-402);国家自然科学基金项目(49971074)联合资助 |
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| Paleoenvironmental Interpretations on Organic Carbon Isotopic Records from Lake Sediments:A Critique |
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YU Junqing1,2, WANG Xiaoy an1, LI Jun1, AN Zhisheng2
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1.Institute for Salt Lake Studies, Chinese Academy o f Sciences, Xi'an 710043, P. R. China;2.State Key Laboratory of Loess and Quater nary Geology, Xi'an 710054, P. R. China
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| Abstract: |
| Organic carbon isotopic records from lake sediment s are valuable pro xies used to indicate g lacial-interglacial change in atmospheric pCO2, major changes in catchment vegetation, lake level fluctuations, and variations in regional temperature.While factors af fecting variations in organic carbon isotope (δ13Corg)are numerous, predominant control(s)on the shif t of δ13Corg value w ere of ten found out with the aid of evidence from o ther investigations on the lake sediment s such as paleolimnological, geochemical, sedimentological and palynological studies, as well as molecularisotopic stratig raphy.Environmental explanation models (EEMs), proposed by investig ators in the previous researches for those long-term isotopic records showing different curve patterns, are reviewed. Recognition and clarification of source materials of organic matter (OM)buried in lake sediments and of possible changes in organic source materials in the past are fundamental aspects and important for the environmental interpretations of δ13Corg records.OM contents, organic carbon to nitrogen (C/N)rat ios, hy drogen index (HI), petrog raphic examination of organic remains in lake sediments of ten provide useful information on organic productivity, origin, maturation, and diagenesis.Hence, they should be presented, if available, alongside w ith δ13Corg record.In this way, EEMs can then be properly applied, otherwise new EEMs may well be provided.In addition, identification of individual biomarkers of ten provides indication of specific terrestriall, aquatic, and bacterial sources of organic mat ter in lake sediments.New carbon iso topic signals ref lecting Glacial/interglacial environmental change may well be indicated by molecular-isotopic stratigraphy.Long-term δ13Corg records from many interested lakes in China aw ait us to investigate, depending largely on bottom sediment cores from those lake centers become available.These records have g reat potential for the researches of the past global changes. |
| Key words: Lake sediments o rganic matter carbon stable isotope environmental explanation models post-glacial climatic change |
