Figure 16. Variation in maximum grain size and thickness for the Toba, Campanian, and Santorini marine tephra fall layers (from Fisher and Schmincke, 1984). Vertical dashed line corresponds to the minimum distance from the Central American Tertiary volcanic province to Leg 165 Sites 998, 999, and 1000. Horizontal lines with arrows show the mean of the maximum feldspar crystal sizes in the Miocene tephra layers from Sites 998, 999, and 1000.