Abstract:
During the past 10 years, about 150 scientists in 25 countries have collaborated under the auspices of the International Geological Correlation Programme Project No. 148: Evaluation and Development of Quantitative Stratigraphical Correlation Techniques. This paper reviews mathematical methods of stratigraphical correlation, mainly in biostratigraphy but also in chronostratigraphy and lithostratigraphy. Sequencing methods treat the relative order of stratigraphic events such as the highest occurrences of fossil taxa as observed in many sections. Intervals between successive events in an ordered sequence can be estimated and the results expressed in linear time if a subgroup of the stratigraphical events can be dated. Recently such methods have been used to develop a new deep-water benthic foraminiferal zonation for the Cenozoic strata of the Central and Viking Grabens, North Sea. Several regional hiatuses of 2 to 5 m.y. in duration, can be recognized and matched to changes in sea level. The same methods have been used for automated isochron contouring with error bars in depth or time units in Cenozoic and Cretaceous basins, off eastern Canada. Such information may be used for automated basin history analysis.