Oligocene planktonic foraminifer biostratigraphy of Hole 803D (Ontong Java Plateau) and Hole 628A (Little Bahama Bank), and comparison with the southern high latitudes

Abstract

Ocean Drilling Program Hole 803D (Leg 130) from the western tropical Pacific (Ontong Java Plateau) and Hole 628A (Leg 101) from the western subtropical North Alantic (Little Bahama Bank) contain rich assemblages of planktonic foraminifers. The uppermost Eocene-basal Miocene section of Hole 803D is apparently complete, whereas the Oligocene section of Hole 628A contains three unconformities based on planktonic foraminiferal evidence. Paleomagnetic stratigraphy provides constraints on the last occurrences and first occurences of certain species. In general, taxon ranges, total diversity, and the composition of the planktonic foraminiferal assemblages from Holes 628A and 803D are similar. Differences in the composition of planktonic foraminiferal assemblages between the two sites are interpreted to be primarily the result of enhanced dissolution at Site 803. -from Authors