Diagram 5A: Extended RASC ranges for Cenozoic Foraminifera in Gradstein's (1985) database for the Labrador Shelf and Grand Banks. Letters for taxon 59 on the right represent (A) estimated RASC distance, (B) mean deviation from fitted line of correlation, and (C) highest occurrence of species (i.e., maximum stratigraphically upward deviation from line of correlation). B is shown only when it differs from A. Good markers such as taxon 50 (Subbotina patagonica) have approximately coinciding positions for A, B and C.
Diagram 5B: Comparison of range charts obtained by five different methods applied to Palmer's (1955) database. Modified RASC and normal RASC results were added to ranges previously plotted by Edwards (1982). First and last occurrences were ranked for each method and these ranks were used to display the ranges. The modified RASC, Shaw (1964) and Edwards (1978) results are similar. The Hay (1972) and RASC ranges were based on average first and last occurrences. These generally are shorter than the other (conservative) ranges (from Agterberg, 1990).
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