This report presents a provincial time scale for the North American continental Tertiary. It proposes a standardized terminology of purely temporal significance based on North American mammal-bearing units, of which the constituents are defined in terms of precisely analyzed faunas and the related stratigraphy. With such a nomenclature, exact information may now be conveyed without facing the continual dilemma between trying to conform to the European standard time scale or using American formation names as time units. The latter has been increasingly the practice in spite of inevitable ambiguities. In addition, it will be possible to discuss problems of relative age relationship and stratigraphic correlation without the distraction of endless controversies over epoch boundaries.
More than 300 significant rock and faunal units are defined, located, and delimited and, if necessary, discussed in the glossary. They have been analyzed in accordance with the most recent data afforded by field research and work on collections by the various specialists.
The correlation chart is in reality a graphic abstract, giving a bird’s-eye view of the North American continental Tertiary as it is known to date. Tentative correlations with the European scale are added. The bibliography is selected for convenience rather than completeness.