Pfuhl, Helen A.; McCave, I. Nicholas (2004): Integrated age models for the early Oligocene-early Miocene, Sites 1168 and 1170-1172. Texas A&M University, Ocean Drilling Program, College Station, TX, United States, In: Exon, Neville F., Kennett, James P., Malone, Mitchell J., Brinkhuis, Henk, Chaproniere, George C. H., Ennyu, Atsuhito, Fothergill, Patrick, Fuller, Michael D., Grauert, Marianne, Hill, Peter J., Janecek, Thomas R., Kelly, Daniel C., Latimer, Jennifer C., Nees, Stefan, Ninnemann, Ulysses S., Nuernberg, Dirk, Pekar, Stephen F., Pellaton, Caroline C., Pfuhl, Helen A., Robert, Christian M., Roessig, Kristeen L. McGonigal, Roehl, Ursula, Schellenberg, Stephen A., Shevenell, Amelia E., Stickley, Catherine E., Suzuki, Noritoshi, Touchard, Yannick, Wei, Wuchang, White, Timothy S., Proceedings of the Ocean Drilling Program; scientific results; the Tasmanian gateway; Cenozoic climatic and oceanographic development; covering Leg 189 of the cruises of the drilling vessel JOIDES Resolution; Hobart, Tasmania, to Sydney, Australia; Sites 1168-1172; 11 March-6 May 2000, 189, georefid:2005-011455

Abstract:
The aim of this study is to assess the viability of age models based on shipboard and postcruise bio- and magnetostratigraphic datums, as of August 2002, using independently derived control points. The control points are based on matching between-site trends in stable isotope records, carbonate content, and weight percent sand. Site 1170 on the western South Tasman Rise has a good record of magnetic reversals, which suggests a hiatus prior to approximately 30 Ma (early Oligocene) relating to the Marshall Paraconformity, followed by strongly reduced sedimentation in the late Oligocene. Preservation of the Mi-1 event at this site is evidence for continued sedimentation across the Oligocene/Miocene boundary. Correlation of the Mi-1a event to the record at Site 1090 on the Agulhas Ridge confirms the usefulness of the magnetostratigraphic record at this site. However, the timing of the Mi-1 event at Site 1170 appears different from that at Site 1090, but is constrained by four magnetic reversals. At Site 1171 additional control points are consistent with biostratigraphic datums. Site 1172 is marked by the lowest sedimentation rates of all sites. Additional control points before 22 Ma are more consistent with the biostratigraphy than with the magnetostratigraphy. At Site 1168 we suggest that the magnetic reversal record MR1 provides the best match with the biostratigraphy and additional control points, as well as changes in the biogenic and lithogenic composition of the sedimentary record.
Coverage:
West: 144.2400 East: 149.5600 North: -42.3600 South: -48.3000
Relations:
Expedition: 189
Site: 189-1168
Site: 189-1170
Site: 189-1171
Site: 189-1172
Supplemental Information:
Available only on CD-ROM in PDF format and on the Web in PDF or HTML
Data access:
Provider: SEDIS Publication Catalogue
Data set link: http://sedis.iodp.org/pub-catalogue/index.php?id=10.2973/odp.proc.sr.189.108.2003 (c.f. for more detailed metadata)
Data download: application/pdf
This metadata in ISO19139 XML format