Calcareous Nannofossils from the Southern Southwest Pacific, Deep Sea Drilling Project, Leg 29

Abstract

Calcareous nannofossils were obta ined from all sites drilled in the southern southwest Pacific on Leg 29 (Figure I). They occur in mid Paleocene to late Pleistocene sediments and show highly variable states of preservation. Diversity is generally low, as might be expected from the high southern latitudes of the sites drilled. Consequently the biostratigraphic resolution is much lower than that in subtropical and tropical areas, especially the mid Oligocene to early Pliocene part of the column. Great similarity was found between the high southern and high northern latitude assemblages of the same age, although a number of species seem to occur only in the north whereas only very few seem to be restricted to the south. Observations on the fine structure of coccoliths and nannoliths, and comparison with their northern high latitude equivalents, showed a surprisingly high degree of morphological agreement. Three new species, Ericsonia tasma niae, Hettcopontosphoerot subantarcnca, and Ifornibrookina australis are described.