Seawater chemistry carbon isotopes

Spero H. J., Bijma J., Lea D. W., and Bemis B. (1997) Effect of seawater carbonate chemistry on planktonic foraminiferal carbon and oxygen isotope values. Nature 390, 497-500. 

Much of what is currently understood about the Cenozoic history, of deep-sea temperature, carbon chemistry, and global ice volume, has been gleaned from the stable isotope ratios of benthic foraminifera. Benthic foraminifera extract carbonate and other ions from seawater to construct their tests. In many species, this is achieved near carbon and oxygen isotopic equilibrium. Kinetic fractionation effects tend to be small and constant (Grossman, 1984, 1987). As a result, shell fi C and strongly covary with the isotopic... 

Zeebe, R. E., Wolf-Gladrow, D. A. Jansen, H. 1999. On the time required to establish chemical and isotopic equilibrium in the carbon dioxide system in seawater. Marine Chemistry, 65, 135-153. 

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