Figure F35. Ash frequency for Sites 1237-1242 was calculated as first derivative of the cumulative number of ash horizons plotted vs. age. Red lines = volcanic ash frequency, green bars = thickness of each ash layer.

Figure F35. Ash frequency for Sites 1237-1242 was calculated as first derivative of the cumulative number of ash horizons plotted vs. age. Red lines = volcanic ash frequency, green bars = thickness of each ash layer.