重大地质转折期的碳_硫循环与环境演变.pdf

16 6 (();) Vol.16 o.6 2009 11 Earth Science Frontiers (China University of Geosciences(Beijing);Peking University) ov.2009 、 1 1 2 汪建国 , 　陈代钊 , 　严德天 1. , 100029 2.(), 430074 1 1 2 Wang Jianguo , 　Chen Daizhao , 　Yan Detian 1.Instituteof Geology and Geop hysics, Chinese Academy of Sciences, Beij ing 100029, China 2.K ey Laboratory of Education Ministry f or Biogeology and Environment Geology, China niversity of Geosciences(Wuhan ), Wuhan 430074, China WangJianguo, Chen Daizhao, Yan Detian.Variation in carbon and sulphur isotopes and environments during the critical geo- logical transitions.E arth Science Frontiers , 2009, 16(6):033-0 7 Abstract: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 photo- synthesis and equilibrium between oceanic dissolvedinorganic carbon and atmospheric CO for carbon, and bac- 2 terial 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. Key words:carbon and sulphur cycles;isotopefractionation;photosynthesis;bacterial sulphate reduction;the mass extinction 　:碳、硫在表