Diagram 3A: Types of zones commonly used for biostratigraphic correlation (simplified from Hedberg, ed., 1976).
Diagram 3B: RASC zonations are based on average stratigraphic events. The average interval zone between the exists of taxa A and B begins before the highest occurrence of B in section 3, and ends before the highest occurrence of A in section 2.
Diagram 3C: First and last occurrences of 8 taxa plotted along relative distance scale (left side), and same information represented by means of a dendrogram (from Agterberg, 1990).
Back to homepage | Next Poster | Previous Poster