Abstract:
The primary emphasis of this thesis is the taxonomic evaluation of deep-water benthic foraminifera. The taxonomic position of some important species is updated according to the revised classification of Loeblich and Tappan,1987. Thirty-nine Early Miocene to Pleistocene sediment samples from the Deep Sea Drilling Project, Leg 90, sites 587 to 589, located on the Lord Howe Rise, South West Pacific Ocean were investigated for foraminifera. Planktonic foraminifera were used to erect a biostratigraphic framework into which 5 benthic foraminiferal assemblages were integrated. One hundred and eighty species of deep-water benthic foraminifera were identified. Eighteen isobathyal species indicate mid- to lower bathyal depths throughout the interval. The faunal diversity is high. Assemblage No. 1, Early Miocene, indicates the bottom water mass characteristics of 7 to 8 degrees C, normal salinity and 0.5 to 3ml/L oxygen, in a relatively thermally unstratified ocean. Assemblage No. 2, Middle Miocene, indicates the bottom water mass to have been 2 to 3 degrees C with high oxygen content in a thermally stratified ocean. Assemblage No. 3, Late Miocene, indicates similar water mass characteristies to those of the Middle Miocene assemblage. Assemblage No. 4, Pliocene, indicates a relatively less cold bottom water mass than the Miocene assemblages. Assemblage No. 5, Pleistocene, is divided into two sub-assemblages which indicate interglacial and glacial episodes. The interglacial sub-assemblage indicates bottom water of 4 to 8 degrees C and the glacial sub-assemblage indicates 2 to 3 degrees C bottom water temperature.