Benthic and planktonic foraminifera in ODP Hole 123-766A (Table 1-4)

The distribution of 79 foraminiferal species is recorded among 23 samples taken from Cores 123-776A-16R through 123-766A-25R. The benthic species belong to the Ammodiscidae, Ammosphaeroidinidae, Spiroplectamminidae, Verneuilinidae, Tritaxiidae, Globotextulariidae, Eggerellidae, Ichthyolariidae, Nodosariidae, Vaginulinidae, Polymorphinidae, Glandulinidae, Bolivinidae, Turrilinidae, Fursenkoinidae, Pleurostomellidae, Patellinidae, Bagginidae, Quadrimorphinidae, Globorotalitidae, Osangulariidae, and Gavelinellidae families. The planktonic species belong to the Globigerinelloididae, Planomalinidae, Schackoinidae, Hedbergellidae, and Rotaliporidae families.On the basis of foraminiferal biostratigraphy, the interval from Sections 123-766A-16R-3 through 123-766A-17R-3 has been placed confidently in the uppermost Albian (equivalent of the Rotalipora appenninica Zone of Caron, 1985). Below this, correlations are tentative because of the absence of commonly used zonal index species. The interval from lower Core 123-766A-17R to upper Core 123-766A-18R has been placed in the upper Albian; that from lower Core 123-766A-18R to Core 123-766A-21R has been included in the lower to middle Albian; and Cores 123-766A-24R and 123-766A-25R have been correlated with the upper Aptian.The fauna is compared to that known from Aptian-Albian deposits in the Australian epeiric basins and at other sites along the western margin of the continent. These deposits were positioned at middle to high paleolatitudes in the Southern Hemisphere. The benthic assemblages from Site 766 belong to the Marssonella Association (of Haig, 1979) and are similar to those recorded elsewhere along the continental margin, but differ from those of the Ammobaculites Association (of Haig, 1979) within the epeiric basins. In overall aspect, the Australian fauna contains few genera not recorded elsewhere, but lacks many families present in Tethyan (low-latitude) faunas. Comparison of late Albian planktonic foraminifers known from along the continental margin indicates that assemblages from Site 766 are similar to those from the Papuan Basin at approximately the same paleolatitude, but are more diverse than those of the Naturaliste Plateau (approximately 10° of paleolatitude south of Site 766), where Rotalipora and Planomalina are absent. This suggests that a significant gradient in surface water temperature existed on the late Albian continental margin between Site 766 and the Naturaliste Plateau.