Resumen de The late Miocene to Quaternary ostracoda of leg 94, deep sea drilling project

Robin C. Whatley, Graham Coles

• A study of the Ostracoda of all 6 sites of Leg 94 has revealed a higher diversity for the Neogene and Quaternary than previously recorded from DSDP studies in the Atlantic. The 172 samples yielded 88 species (discounting the genera Krithe and Parakrithe not considered in detail in this study) belonging to 43 genera. This diversity is, however, much lower than that recorded by one of the authors, Whatley, 1983) from DSDP sites embracing a similar interval in the S.W. Pacific.

  The highest diversity and incidence for most sites occurs in the mid Pliocene (NN 15, 16). Late Miocene diversity is relatively low; that of the Quaternary is similar to the Pliocene. A subsequent paper, devoted solely to Krithe and Parakrithe from the same sample confirms these trends. Range charts for each site and for Leg 94 overall, exhibit a clear distinction between the Late Miocene, Pliocene and Quaternary components of the fauna.

  Global palaeoceanographic events in the Late Miocene, mid Pliocene and early Quaternary are clearly depicted in a graph of origination and extinction of non-Krithe and Parakrithe species in Leg 94.

  Energy levels at Site 609 seem to have been abnormally high, surprisingly low at Site 610 on the Feni Drift and high on the Gardar Drift (Site 611) only in the Late Pliocene.

  Twenty-two new species and one new genus are described from deep sea sediments in the Atlantic. Many of the species are shown, for the first time, to be pan-abyssal in their distribution.