How Do Trees Record Time?
ES2905  Dating Trees

  !   Compare the timeline you recorded to the one shown here. If necessary, go back to Step 8 and realign the patterns to see how this master chronology was constructed.

Now you will use the master chronology to date two samples of wood from ancient cliff dwellings. Skeleton plots for each sample have been prepared. The left edge of each plot represents when the tree started growing. The right edge of each plot represents when it was cut.

  !   Click and drag the skeleton plot for sample A to match it against the master chronology. After you answer question 10 below, click Continue and determine the date of sample B.



10. What year was tree sample A cut?

11. What year did tree sample B begin growing?

Consider another situation: What if you found a sample of wood and constructed a skeleton plot for it, but it did not match any patterns on the master chronology? What could you infer about the wood? How might you go about finding its age?


 Step:   1   2   3   4   5   6   7   8   9   10