Late Campanian and Maastrichtian benthic foraminifers are recorded from 12 samples collected from Leg 183 Hole 1138A in the southern Indian Ocean. In addition, benthic species are identified from the basal Paleocene in the same hole and both planktonic and benthic foraminifers from a dredge site some 220 km to the north. Age estimates are based on planktonic foraminifers and calcareous nannoplankton studies reported elsewhere.
All faunas accumulated on Kerguelen Plateau before its disintegration into Kerguelen Plateau (in the modern sense) and Broken Ridge. Conditions were fully marine in the Austral Faunal Province of Sliter (1977). Depth for the ODP site was mid-bathyal (600-1200 m), and the location was on the plateau surface—a considerable distance from its edge. The fauna is dominated by epifaunal species (75%-85%), indicating a high degree of oxygenation and lack of influence of upwelling. The dredge sample, in contrast, comes from mid-upper slope depths, with higher infaunal component (40%), suggesting lower oxygenation and greater influence of upwelling for a site near the plateau margin.
On the basis of dominance/subdominance characteristics of the benthic foraminiferid fauna, three informal zones are recognized:
Analyses of the foraminifers contained in Eltanin core E54-7 (Quilty, 1973) are included where appropriate. Taxonomic comments are made on several species.