Quantitative Stratigraphy, Splining and Geologic Time Scales - Geomathematics: Theoretical Foundations, Applications and Future Developments - page 316

Table 9.5 RASC dictionary
(DIC file) for Hay example
Source: Agterberg ( 1990 , Table 4.1)
LO and HI represent lowest and
highest occurrences of nannofossils,
respectively
Table 9.6 Nannofossil name file (preliminary DIC file) for Sullivan database as originally
coded by Davaud and Guex ( 1978 ) and used by Agterberg et al. ( 1985 )
Source: Agterberg ( 1990 , Table 4.2)
RASC DIC file of Table 9.5 was obtained automatically from this file
for the Media Agua Creek section that contains nine of the ten stratigraphic events
used for example. Guex ( 1987 ) used graph theory to construct “unitary associa-
tions”, which have essentially the same properties as Oppel zones in biostratigra-
phy. Emphasis in this approach is on coexistences of taxa. Adjoining samples are
combined into levels representing “maximal horizons” ( cf . Guex 1987 , p. 20) as
illustrated for the Media Agua Creek example in the bottom row of Table 9.8 .
The two columns on the right of Fig. 9.6 represent a subjective ranking and
Hay's original optimum sequence, respectively. This optimum sequence has the
property that every event in it is observed more frequently above all events below it
than it is observed below these other events. Every frequency for superpositional
relationship of a pair of events can be tested for statistical significance by means of