Variations in Carbon 14 Content in Tree Rings During the Last 30 Years : Application to Wood Dating

1990

3 Abb., 1 Tab.

Unselbständiges Werk

9716

200088578

Robinia pseudoacacia stem annual growth rings from 1958 to 1987 were analyzed for C14 content. The radioactivity of annual rings was found to be strongly correlated with C14 concentration in the atmosphere, which showed a very sharp rise until 1963 due to nuclear weapon tests followed by a regular decrease from then on. Taking into account seasonal variation in both atmospheric C14 concentration and CO2 assimilation slightly improved the relation between C14 in wood and the atmosphere. A predictive curve that gives the year of wood formation as a function of radioactivity with a 5% confidence interval is shown. These results can be used to analyze wood for which traditional analysis is impossible, for example, trees with false rings or missing rings, or wood from stumps or roots.