One of the chief goals of stratigraphy is to correlate the provincial stages used in many countries with the standard chronostratigraphic scale based on European stages. In this study, United States Gulf Coast provincial Paleogene stages in their type area are correlated with the European standard Paleogene stages by use of calcareous nannoplankton. Gulf Coast provincial stage boundaries can be placed in Martini's standard calcareous nannoplankton zonation as follows: Midwayan-Sabinian boundary—mid-NP 5; Sabinian-Claibornian boundary—base NP 12; Claibornian-Jacksonian boundary—mid-NP 17; Jacksonian-Vicksburgian boundary—mid-NP 21; Vicksburgian-Chickasawhayan boundary—base NP 24; upper Chickasawhayan boundary—mid-NP 24.
Gulf Coast stages therefore correlate with the European stages as follows. The Midwayan Stage corresponds to all of the Danian Stage and the lowest part of the Selandian Stage. The Sabinian Stage corresponds to the rest of the Selandian and the lower half of the Ypresian Stage. The Claiboraian Stage includes the upper half of the Ypresian, all of the Lutetian, and approximately the lower two-thirds of the Bartonian. The Jacksonian includes the upper third of the Bartonian, all of the Priabonian, and the lower part of the Rupelian. The Vicksburgian corresponds to all but the lowermost and uppermost fractions of the Rupelian, and the Chickasawhayan, to the upper one-tenth of the Rupelian and the lower one-fifth of the Chattian.