| IODP Proceedings Volume contents Search | |||
|
|||
| Expedition reports Research results Supplementary material Drilling maps Expedition bibliography | |||
|
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, Antarctica1Gee Soo Kong2 and Robert B. Dunbar3AbstractWe 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. |
||
Figures