Integrated uppermost Campanian–Maastrichtian calcareous nannofossil and foraminiferal biostratigraphic zonation of the northwestern margin of Australia

Abstract

Abstract. During the latest Campanian–Maastrichtian the northwestern Australian margin was situated between the cool-water Austral Province to the south and the warm-water Tethyan Province to the north. The transitional nature of calcareous microfossil assemblages on the margin makes application of Tethyan biostratigraphic zonation schemes awkward, as many marker-species are missing or have different ranges. This study presents an integrated uppermost Campanian–Maastrichtian calcareous microfossil zonation based on two Ocean Drilling Program (ODP) holes on the Exmouth Plateau and eight petroleum exploration wells from the Vulcan Sub-basin. The zonation is refined and revised from the previously unpublished KCN (nannofossils), KPF (planktonic foraminifera), KBF (benthonic foraminifera) and KCCM (composite nannofossil and planktonic foraminifera) zonations, which are commonly used for petroleum exploration wells drilled on the northwestern margin. Revision of the zonations has highlighted a major Upper Campanian to lower Upper Maastrichtian disconformity on the Exmouth Plateau, which went largely unnoticed in previous examinations of the ODP material, but had been recorded previously elsewhere on the northwestern margin. The duration of the disconformity in the Vulcan Sub-basin is unclear, since intervals of the succession may be condensed in this area.

Carbonate pelagites in the post-Gondwana succession (Cretaceous – Neogene) of East Timor

“…Eighty-nine samples are described in Appendix 1* and the age-important planktonic foraminifera found in these are listed in Appendix 2*. Age determinations (Appendix 1*) are based on planktonic foraminiferal zones and datum levels outlined by Caron (1985), BouDagher-Fadel et al (1997), Petrizzo (2000), Howe et al (2003) and Campbell et al (2004) for the Cretaceous; Tourmakine and Luterbacher (1985) and Berggren and Pearson (2005: P zonation for Paleocene, E zonation for Eocene) for the Paleogene; and Blow (1969: N zonation), Kennett and Srinivasan (1983: revised N zonation) and Berggren et al (1995a, b) for the Neogene. The T-Letter Stages, based on larger benthic foraminifera, follow Adams (1970Adams ( , 1984.…”

Correlation of Turonian continental margin and deep-sea sequences in the subtropical Indian Ocean sediments by integrated planktonic foraminiferal and calcareous nannofossil biostratigraphy

“…During the Turonian, Ocean Drilling Program (ODP) Hole 762C (Exmouth Plateau, southeast Indian Ocean) was located near 50°S (von Rad et al 1992, Lawver et al 1992, Hay et al 1999) on the northwestern Australian margin in a transitional setting between the Tethyan and Austral bioprovinces ( Fig. 2; Howe et al 2003). Previous biostratigraphic studies of Cretaceous planktonic foraminifera at Hole 762C highlighted a strong Tethyan affinity of the Albian to early Campanian assemblages with some exceptions due to the absence and/or diachronous appearance of some Late Cretaceous subtropical biostratigraphic markers.…”