Lower Oligocene to Middle Miocene Diatom Biostratigraphy of ODP Site 1140, Kerguelen Plateau

Abstract

Ocean Drilling Program (ODP) Leg 183 Site 1140 provided a lower Oligocene to middle Miocene record of diatom assemblages from the northern Kerguelen Plateau. Samples were examined to improve the resolution of shipboard diatom biostratigraphy. The material is complementary to that recovered during ODP Legs 119 and 120, and the diatom zonation of Harwood and Maruyama could be readily applied. A standard succession of biostratigraphic zones from the middle Miocene and lower Oligocene was delineated, although some zones were unrecognizable because of poor core recovery. The detailed diatom biostratigraphy presented here agrees well with shipboard calcareous nannofossil biostratigraphy. Sediment accumulation rates based on diatom bioevents average 1.26 cm/k.y.

Multivariate complexity analysis of 3D surface form and function of centric diatoms at the Eocene–Oligocene transition

“…The Eocene-Oligocene centric diatom genera are assembled from published accounts in Hajόs (1976), Gombos (1983aGombos ( , 1983bGombos ( , 1987, Gombos and Ciesielski (1983), Fenner (1984a, 1984b, Barron (1985), Baldauf and Barron (1987), Saito et al (1988), Baldauf and Monjanel (1989), Mikkelsen (1990), Fourtanier (1991), Harwood and Maruyama (1992), Barron and Mahood (1993), Barron and Baldauf (1995), Arney et al (2003), Barron et al (2004), Bohaty et al (2011), Oreshkina (2012, and Gladenkov (2012).…”

“…Two additional genera are chosen to be used as Oligocene representatives based on relative abundances even though these taxa may have originated in the Upper Cretaceous (Harwood and Nikolaev, 1995). The genera are: Stellarima Hasle and Sims, the species of which occur frequently (Baldauf and Barron, 1987;Saito et al, 1988), with the genus containing long-ranging taxa (Scherer et al, 2000;Witkowski and Harwood, 2011); Stictodiscus R. K. Greville, where species are common, Stictodiscus kittonianus Greville is a key marker species (Baldauf and Barron, 1987;Barron and Mahood, 1993;Arney et al, 2003), with the genus containing long-ranging taxa (Scherer et al, 2000). Actinoptychus, Arachnoidiscus, and Stictodiscus are benthic, Actinoptychus also has some planktonic species, and all other taxa are planktonic (Baldauf and Barron, 1987).…”

Neogene and Quaternary fossil remains of beaked whales (Cetacea, Odontoceti, Ziphiidae) from deep-sea deposits off Crozet and Kerguelen islands, Southern Ocean

“…The quality of the bone collagen was assessed by the atomic C/N ratio, as well as its C and N content. These numbers should be in specified ranges (DeNiro 1985;Ambrose 1990): the atomic C/N ratio should be c. 2.9-3.6, the carbon content of the collagen (C%) c. 30-45%, and the nitrogen content (N%) c. 11-16%. Values outside this range may indicate diagenetic alteration causing Kerguelen islands area, including the main localities where fossil ziphiid specimens («) described in this work were found via longline fishing, as well as two ODP sites (l).…”