ABSTRACT

In recent years, world-wide studies by numerous specialists on planktonic Foraminifera and calcareous nannoplankton have been extended into the type European sections. It is now possible to establish zonations and correlations that appear to be synchronous over long distances, validating, for the first time, the use of European stratigraphic terminology in areas remote from the type localities. The recognition of planktonic microfossils for these purposes is a milestone in Tertiary biostratigraphy, particularly for those who have long found the Lyellian percentage method inadequate as a precise means of determining the age of a Cenozoic formation. The identification of these fossils in the subject areas is also a "breakthrough" because of the significance of many of the sites as type-localities for mollusks, and because of the question of the exact position of these formations in the geologic time scale.

Planktonic Foraminifera and the calcareous nannofossil genera, Discoaster, Catinaster, and Sphenolithus are identified from the subject areas, and the species indicate stratigraphic relationships that are at variance with ages traditionally ascribed to some of the formations of northwestern Florida, the Yorktown and Waccamaw sections on the coastal plains of the eastern United States, the Moin Formation of Costa Rica, and the Encanto and Agueguexquite Formations of Mexico. Comparative ranges of these ubiquitious microfossils pose a Burdigalian age for the Chipola Formation, a late Langhian age for the Encanto and Yellow River Formations, a Tortonian to Messinian age for the Red Bay Formation, and an early middle Pliocene age, at some localities, for the Jackson Bluff, Yorktown, and Agueguexquite Formations. From several sites, material assigned to the Waccamaw Formation is correlated with the Moin Formation, for which an early Pleistocene age is indicated.

Editor's Note: Unfortunately the printer received this paper too late for the text to be included. The illustrations are included.

End_Page 445------------------------

MAP 1. LOCATION OF NEOGENE FORMATIONS INVESTIGATED FOR THIS REPORT NUMBERS REFER TO TULANE LOCALITIES

MAP 2. CHOCTAWHATCHEE AND CHIPOLA LOCALITIES OF NORTHERN FLORIDA FROM WHICH PLANKTONIC MICROFOSSILS HAVE BEEN IDENTIFIED

End_Page 446------------------------

FIGURE 1. CORRELATION OF SOME FORMATIONS OF THE CHOCTAWHATCHEE STAGE BY PLANKTONIC MICROFOSSILS

FIGURE 2. CORRELATION OF SOME NEOGENE FORMATIONS BY MEANS OF PLANKTONIC MICROFOSSILS NOTE: "FAUNIZONE" IS USED THROUGHOUT THIS REPORT IN THE SENSE OF PURI AND VERNON (1964)

End_Page 447------------------------

FIGURE. See caption on page 449

End_Page 448------------------------

FIGURE 3. RANGE AND CHECK CHART

End_of_Record - Last_Page 449-------