| 稳定碳同位素在第四纪古环境研究中的应用 |
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| 引用本文： | 王国安.稳定碳同位素在第四纪古环境研究中的应用[J].第四纪研究,2003,23(5):471-484. |
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| 作者姓名： | 王国安 |
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| 作者单位： | 北京大学环境学院,北京,100871 |
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| 基金项目： | 国家自然科学基金项目 (批准号 :40 2 73 0 0 6和 40 0 72 0 5 9) |
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| 摘 要： | 文章对陆相沉积物、湖沼相沉积物以及脊椎动物牙齿中的δ13C研究作了系统的综述,特别对存在的问题提出了一些看法,认为黄土-古土壤序列中有机质δ13C与碳酸盐δ13C变化趋势相反的原因是CO2与碳酸盐交换平衡时的分馏系数在古土壤堆积时和黄土发育时不一致造成的;陆相沉积物的有机质δ13C较碳酸盐δ13C能更加直接地反映沉积时地表植被状况,陆相沉积物的碳酸盐δ13C在古生态中的应用还有待于对它的形成机制和形成过程进行进一步的研究;我国黄土高原末次冰期的气候不利于C4的生长.文章强调古环境、古生态研究应该从现代过程入手,了解现代植物δ13C与气候参数的关系以及现代C4植物的分布规律.同时还认为分子化石的稳定同位素研究这一新研究手段将会给第四纪研究带来更新的活力.
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| 关 键 词： | 稳定碳同位素 古环境研究 |
| 收稿时间： | 2003-05-22 |
| 修稿时间： | 2003年5月22日 |
APPLICATION OF STABLE CARBON ISOTOPE FOR PALEOENVIRONMENTAL RESEARCH |
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| Institution: | College of Environmental Sciences, Peking University, Beijing 100871 |
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| Abstract: | Paleobiogeo chemistry has been breaking a new path for paleoenvironmental research. Carbon is one of basic elements in organism, and stable carbon isotope has been widely applied in paleoenvironmental research. This paper summarizes accomplishment of application for paleoenvironmental reconstruction from stable carbon isotope in terrestrial sediments, lacustrine sediments, tree rings and vertebrate tooth enamel, and puts forward some new ideas: 1) Because of the difference between environmental condition under which loess deposits and that under which paleosol forms, the fractionation factor of CO 2 calcite in loess is different from that in paleosol; We thinks that it is the different fractionation factor that makes carbon isotopic composition of organic matter to show an opposite varying trend to that of coexisting carbonate in sequence of loess paleosol; 2) Organic matter in terrestrial sediments is a direct product of decomposition of vegetation, so, carbon isotopic composition of organic matter more directly effects change of vegetation than that of carbonate does. In order to availably apply carbon isotope of carbonate for paleoenvironmental research, the mechanism of carbon isotope in carbonate should be further studied; 3) C 4 plants in the Loess Plateau in China would have been at a greater disadvantage over C 3 plants under the climate of the last glacial, and this disadvantage is mainly attributed to enough large decreasing of temperature in the last glacial. This paper emphasizes that the relationship between carbon isotope of standing plants and climate, and between distribution of standing C 4 plants and climate should be further studied in order to apply carbon isotope for paleoenvironmental research. Stable carbon isotope of molecular--a new means will even push paleoenvironmental research. |
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| Keywords: | stable carbon isotope paleoenvironmental research |
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