Late Neogene of the Gulf of Mexico

Abstract

The calcareous nannofossils have become important shipboard biostratigraphic tools, but the planktonic foraminifers provide the presently accepted stratigraphic framework for Cenozoic oceanic sediments. The ranges of Late Neogene calcareous nannofossils have not previously been well documented in terms of the planktonic foraminiferal zonation scheme. This multiple discipline effort provides that documentation, at least for the Gulf of Mexico region. The planktonic foraminiferal zonation scheme of Lamb and Beard (1972) is reviewed and its calibration with land-based stratotypes for the Late Neogene and Quaternary is discussed. Both the foraminiferal zonation and that of Martini (1971), based on calcareous nannofossils, are applied to the same samples from Late Neogene cores recovered from DSDP Holes 85, 86, 88, 89, 90, 91, 94, and 97, taken in the Gulf of Mexico on Leg 10. Documented also are the overlapping ranges of Globorotalia truncatulinoides and Discoaster brouweri in Calabrian and Emilian equivalents of the Gulf of Mexico-undoubted Early Pleistocene.