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doi:10.2204/iodp.proc.318.201.2014

Data report: elemental, isotopic, and Rock-Eval compositions of bulk sediments from Hole U1357A in the Adélie Basin, Antarctica1

Gee Soo Kong2 and Robert B. Dunbar3

Abstract

We examined the elemental (total nitrogen, total organic carbon, and C/N), isotopic (δ13Corg and δ15Norg), and Rock-Eval pyrolysis (S2, S3, hydrogen index, oxygen index, and Tmax) compositions of bulk marine sediments from Hole U1357A in the Adélie Basin, Antarctica, to assess the organic geochemical characteristics and vertical variations in the late Holocene diatomaceous-dominated sediments. Pyrolysis parameters indicate that most of the organic materials are immature and in the Type II stage, indicative of a marine source. In contrast, the results from a conventional cross-plot of δ13Corg vs. total organic carbon/total nitrogen indicate organic materials that originated as freshwater organic carbon, not marine organic carbon. Given that 13C-depleted phytoplankton are dominant in diatomaceous ooze–rich sediments of the Adélie Basin, the apparent dominance of freshwater organic matter is likely attributable to the extremely low δ13Corg (‰) values in the bulk sediments.

1 Kong, G.S., and Dunbar, R.B., 2014. Data report: elemental, isotopic, and Rock-Eval compositions of bulk sediments from Hole U1357A in the Adélie Basin, Antarctica. In Escutia, C., Brinkhuis, H., Klaus, A., and the Expedition 318 Scientists, Proc. IODP, 318: Tokyo (Integrated Ocean Drilling Program Management International, Inc.). doi:10.2204/iodp.proc.318.201.2014

2 Petroleum and Marine Research Division, Korea Institute of Geoscience and Mineral Resources, 92 Gwahang-no, Yuseong-gu, Daejeon 305-350, Korea. kong@kigam.re.kr

3 Department of Geological and Environmental Sciences, Stanford University, Stanford CA 94305-2115, USA.

Initial receipt: 28 February 2013
Acceptance: 24 July 2014
Publication: 14 October 2014
MS 318-201