Quaternary sediments were recovered at all five sites drilled during Ocean Drilling Program (ODP) Leg 189 in the Tasmanian Gateway. Two of these sites lie north of the present-day Subtropical Front (STF), and three sites lie south of the STF. Quaternary sediments recovered at Sites 1168, 1170, 1171, and 1172 were studied in detail to determine the calcareous nannofossil biostratigraphy and construct an age model for these sediments. The Pliocene/Pleistocene boundary was identified by the last occurrence (LO) of Discoaster brouweri at Site 1172 and approximated by the LO of Calcidiscus macintyrei at the other sites because of a lack of discoasterids. A hiatus encompassing the entire Helicosphaera sellii Zone was tentatively identified at Sites 1168 and 1172 by the coincident LOs of C. macintyrei and H. sellii. Similar hiatuses have been noted at ODP Site 1127 on the Great Australian Bight, Deep Sea Drilling Project Site 282 off the Tasman subcontinent, and ODP Site 1165 in Prydz Bay, Antarctica.
1Stant, S.A., Lara, J., McGonigal, K.L., and Ladner, B.C., 2004. Quaternary nannofossil biostratigraphy from Ocean Drilling Program Leg 189, Tasmanian Gateway. In Exon, N.F., Kennett, J.P., and Malone, M.J. (Eds.), Proc. ODP, Sci. Results, 189 [Online]. Available from World Wide Web:<http://www-odp.tamu.edu/publications/189_SR/109/109.htm>. [Cited YYYY-MM-DD]
2Department of Geological Sciences, 108 Carraway Building, Florida State University, Tallahassee FL 32306-4100, USA. Correspondence author:roessig@gly.fsu.edu
Initial receipt: 17 December 2002
Acceptance: 23 December 2003
Web publication:
22 April 2004
Ms 189SR-109