Quantitative Stratigraphy, Splining and Geologic Time Scales - Geomathematics: Theoretical Foundations, Applications and Future Developments - page 317

Fig. 9.6 Hay's ( 1972 ) example. One last occurrence and nine “first” occurrences of Eocene
nannofossils selected by Hay ( 1972 ) from the Sullivan Eocene database. Explanation of symbols:
ʴ ¼ LO, Coccolithus gammation ; Φ¼ LO Coccolithus cribellum ; ʘ¼ LO, Coccolithus solitus ;

V ¼ LO, Discoaster cruciformis ;

< ¼

LO, Discoaster distinctus ; ʠ¼ LO, discoaster germanicus ;

U ¼ LO, discoaster minimus ;W ¼ HI, Discoaster tribrachiatus ; ʔ¼ LO, Discolithus distinctus ;

□ ¼

LO, Rhabdosphaera scabrosa . See Fig. 8.3 for locations of the nine sections (A-I). Some LOs
are for nannofossils also found in Paleocene (Sullivan 1964 , Table 3). The columns on the right
represent subjective ordering of the events and Hay's original optimum sequence (Source:
Agterberg 1990 , Fig. 4.2)

Table 9.7 Two possible RASC sequence (SEQ) files for Hay example

Source: Agterberg ( 1990 , Table 4.3)
Minus signs (or hyphens) denote coeval events ( cf . Fig. 9.2 ). The last entry is followed by 999 to
indicate end of sequence. Left side: SEQ file for stratigraphically downward direction; right side:
SEQ file for stratigraphically upward direction