Earth Science Frontiers ›› 2009, Vol. 16 ›› Issue (6): 33-47.

• Article • Previous Articles     Next Articles

Variation in carbon and sulphur isotopes and environments during the critical geological transitions.

 HONG Jian-Guo, CHEN Dai-Zhao, YAN De-Tian   

  1. 1Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
    2Key Laboratory of Education Ministry for Biogeology and Environment Geology, China University of Geosciences(Wuhan), Wuhan 430074, China
  • Received:2009-08-01 Revised:2009-11-08 Online:2009-12-16 Published:2009-12-10

PDF (PC)

1984

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 photosynthesis and equilibrium between oceanic dissolved inorganic carbon and atmospheric CO2 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.

Key words: Key words: carbon and sulphur cycles; isotope fractionation; photosynthesis; bacterial sulphate reduction; the mass extinction