A term first proposed by D. V. Ager (1973) for the recognition, study, and correlation of the effects of significant physical events (e.g. marine transgressions, volcanic eruptions, geomagnetic polarity reversals, climatic changes), or biological events (e.g. extinctions), on the stratigraphic record of whole continents, or even of the entire globe. It is argued that by correlating these effects, as they are evidenced in the sedimentary record, it will be possible to define truly synchronous horizons, thus leading to greater resolution and a more accurate chronostratigraphic scale. More recently A. Seilacher (1984) has suggested the term ‘event stratinomy’ for the study of events at the level of individual beds.