Figure 6. Concentration variations of (a) 14C [Stuiver et al., 1998], (b) 10Be [Finkel and Nishiizumi, 1997] and (c) 18O [Grootes and Stuiver, 1997] over the time interval of 3300 to 15600 years ago and the selective estimates of the normalized spectral density of the 14C (d), 10Be (e), and 18O (f) concentrations. The numbers denote the time periods used.