Exercise: K/Ca plots

The figure on overhead #52 provides an age spectrum plot and another plot on top of the age spectrum, labelled K/Ca on the y-axis. What do you think is exhibited by this plot? How can one determine the K/Ca ratio of a 'temperature step', and what does the variability of this ratio mean?
Tip: Having a second look on overheads #38 and #50 might help to answer this question.

Provide the answer as a PDF.

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