Sanfilippo, Annika; Fourtanier, Elisabeth (2004): Oligocene radiolarians, diatoms, and ebridians from the Great Australian Bight (ODP Leg 182, Site 1128). Texas A&M University, Ocean Drilling Program, College Station, TX, United States, In: Hine, Albert C., Feary, David A., Malone, Mitchell J., Andres, Miriam, Betzler, Christian, Brooks, Gregg R., Brunner, Charlotte A., Fuller, Michael, Molina Garza, Roberto S., Holbourn, Ann E., Huuse, Mads, Isern, Alexandra R., James, Noel P., Ladner, Bryan C., Li, Qianyu, Machiyama, Hideaki, Mallinson, David J., Matsuda, Hiroki, Mitterer, Richard M., Robin, Cecile, Russell, Joellen L., Shafik, Samir, Simo, J. A., Smart, Peter L., Spence, Guy H., Surlyk, Finn C., Swart, Peter K., Wortmann, Ulrich G., Proceedings of the Ocean Drilling Program; scientific results; Great Australian Bight; Cenozoic cool-water carbonates; covering Leg 182 of the cruises of the drilling vessel JOIDES Resolution; Wellington, New Zealand, to Fremantle, Australia; Sites 1126-1134, 8 October-7 December 1998, 182, georefid:2005-041662

Abstract:
Eocene and Oligocene radiolarians were recovered from Site 1128 on the slope of the upper continental rise during Ocean Drilling Program (ODP) Leg 182 in the Australian Bight. The early Oligocene radiolarians cored at Site 1128 vary considerably in abundance and preservation. Many intervals are barren or contain only rare fragments of radiolarians. Early Oligocene assemblages are dominated by sponge spicules and diatoms, similar to faunas of modern cold temperate shelf waters, and age diagnostic radiolarians useful for stratigraphic determination are rare. The interval is characterized by abundant actinommids and a dominance of robust artostrobiids representing the genus Siphocampe. In contrast, tropical taxa are present sporadically in rare abundance in the Eocene sediments. The radiolarian assemblages from the Eocene-Oligocene sequence at Site 1128 lack zonal marker species reported from regions further south or north, and thus, age estimates cannot be made using previously published zonations. However, the presence of diverse and well-preserved radiolarians in these assemblages indicates that it should be possible to establish a zonation for this intermediate latitude sub-Antarctic region as more comparable material becomes available. The ebridian Ammodochium ampulla Deflandre is present at Site 1128. A. ampulla was originally described from the upper Eocene diatomite of Oamaru, New Zealand, and was previously recorded in assemblages from the sub-Antarctic southwest Pacific, Deep Sea Drilling Project Sites 277, 281, and 283. Diatoms were either absent or rare and poorly preserved in the samples examined between Cores 182-1128C-9H and 21X. Zonal markers for both the low-latitude and the high southern latitude diatom zonations for the Oligocene are absent, and precise correlation of this interval is impossible. The diatom assemblage in Sample 182-1128C-8H-4, 130-132 cm, contains a combination of oceanic and neritic diatoms, and the presence of Rocella vigilans and Coscinodiscus rhombicus suggests a late Oligocene or earliest Miocene age. Between Cores 182-1128C-22X and 26X, the diatom assemblages contain a combination of neritic and oceanic taxa, including the species Cestodiscus reticulatus and Cestodiscus convexus, which are indicative of an early Oligocene age.
Coverage:
West: 127.3527 East: 127.3527 North: -34.2328 South: -34.2328
Relations:
Expedition: 182
Site: 182-1128
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.182.004.2003 (c.f. for more detailed metadata)
Data download: application/pdf
This metadata in ISO19139 XML format