碳、硫在表层储库和地质储库以不同的形式相互转换,在这个过程中都伴随着一定的同位素分馏.碳同位素的分馏主要受到光合作用以及海水溶解无机碳与大气CO_2交换的控制,而硫同位素的分馏则主要受控于硫酸盐细菌还原作用.表层储库碳、硫同位素的组成通过地质作用被很好地保存在地质储库中,因此通过对地质储库中碳、硫同位素的分析和研究,可以很好地了解地球各圈层相互作用的规律,重塑地质历史特别是重大关键转折时期的演化过程.同时文中借助一些碳、硫同位素应用实例,进一步加深理解影响碳、硫同位素组成和变化的原因,以提高对不同时期全球环境变化的认知程度.%Stable isotopes of carbon and sulphur are fractionated during cycling between surface reservoirs and geological reservoirs. The main processes that control the isotopic composition of various reservoirs are photosynthesis and equilibrium between oceanic dissolved inorganic carbon and atmospheric CO_2 for carbon, and bacterial sulphate reduction for sulphur. C-S cycling from surface reservoirs and stored in geological reservoirs provides a geological record of ancient isotopic compositions. These isotopic signals can be used to improve and refine our understanding of historical changes in global geochemical cycles through geological time, especially for some key transitional periods. A number of case studies with detailed applications of these principles have been discussed to illustrate the causes and effects of ancient global environmental change.
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