Cenozoic deep-sea benthic Foraminifera: turnovers and between-site correlations.

BOLTOVSKOY ESTEBAN; BOLTOVSKOY DEMETRIO

Revue de Micropaléontologie

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Lugar: Paris; Año: 1988 vol. 31 p. 67 - 84

0035-1598

A study of the Cenozoic deep-sea benthic Foraminifera from Deep Sea Drilling Project Sites 208, 289, 305, 357, 360 and 369 shows that Oligocene and post-Oligocene faunas differ little from Recent assemblages, this entire interval being characterized by slow and gradual faunal replacements; the most important faunal turnover recorded in these cores took place below the Eocene-Oligocene boundary. Within the Oligocene-Pliocene interval, most of the overall foraminiferal changes defined are not correlated between sites: faunal similarities are significantly and consistently greater between the stratigraphic units of the same site, than between coeval stratigraphic units of different sites; the makeup and relative proportions of foraminiferal assemblages are much more influenced by geographic location and by ecological factors than by their evolutionary history. Enhanced similarities between Sites 208, 289 and 357 (as compared with Sites 305, 360 and 369) during this same period are most probably due to bathymetric differences between the locales involved. The usefulness of deep-sea benthic Foraminifera for biostratigraphic interpretations is strongly restricted by their spotty occurrence, their long time-ranges, and their markedly local qualitative and quantitative character and variations.