(Estimating glacial ages) The following oxygen-18 data were obtained from soil samples tak...

(Estimating glacial ages) The following oxygen-18 data were obtained from soil samples taken at different depths in Ontario, Canada. Assuming that all the 18O was laid down during the last glacial age and that the transport of 18O to the surface takes place by molecular diffusion, estimate the number of years since the last glacial age from the following data. Independent measurements give the diffusivity of 18O in soil as 2.64 × 10-10 m2/s.

Figure 3 Glaciers.