ARE THE FRACTIONATION CORRECTIONS CORRECT: ARE THE ISOTOPIC SHIFTS FOR C-14/C-12 RATIOS IN PHYSICAL PROCESSES AND CHEMICAL REACTIONS REALLY TWICE THOSE FOR C-13/C-12?

作者：Southon John^*

来源：Radiocarbon, 2011, 53(4): 691-704.

Conventional radiocarbon calculations correct for isotopic fractionation using an assumed value of 2.0 for the fractionation of C-14 relative to C-13. In other words, isotopic discrimination in physical and chemical processes is assumed to cause relative shifts in C-14/C-12 ratios that are exactly double those of C-13/C-12. This paper analyzes a 1984 experiment that produced a value for the fractionation ratio in photosynthesis of 2.3, which is used to this day by some researchers in the fields of hydrology and speleothem geochemistry. While the value of 2.3 is almost certainly incorrect, theoretical work suggests that the true value may indeed deviate from 2.0, which would have significant implications for C-14 calculations.

• 出版日期2011