Global Event Stratigraphy

Van der Zwan, Kees C.J., Shell Research, Rijswijk, Netherlands

In 1971 Derek Ager observed that many well known lithostratigraphic units (Old Red Sandstone, Chalk, etc) can be found with the same expression in many places around the world. These ‘events’ can be seen as the expression of a complex interaction of many cli­matic, tectonic and other controls, and because of the unique interaction of these process­es at a particular time have a certain time connotation. Since research moved on and focussed on catastrophic events, such as; tectonic, climatic, sea level, volcanic, or other events.

By understanding the controls on catastrophic events, they can often be related to the distribution of particular stratigraphic products, such as reservoirs and seals. By inventoris­ing, evaluating and synthesising these events a global event stratigraphy can be established which may help in the prediction of stratigraphy in areas with no or limited control.

(1) Evaluation of the effects of tectonics on a regional to plate tectonic scale shows thatthe stratigraphy in a areas with similar stratigraphy is highly comparable (2) Similarly the effects of climate on the lithological distribution, particularly of carbonates and clastics is well known. With the improvement of climate circulation models their distribution becomes quite predictable. (3) Finally the research in the nature of catastrophic events has let to improved understanding of the controls governing these events.

Global event stratigraphy combines the effects of Tectonostratigraphy, Climate stratigra­phy and Event stratigraphy and aims to translate this understanding in improved stratigraph­ic prediction.