On the sedimentological origin of down-core variations of bulk sedimentary nitrogen isotope ratios
Higginson, M. J.
Eglinton, Timothy I.
Calvert, Stephen E.
MetadataShow full item record
The bulk sedimentary nitrogen isotopic composition of two cores from nearby sites on the northern slope of the South China Sea (Site 17940 and Ocean Drilling Program (ODP) Site 1144) differs by up to >2‰ during the last glacial period. Given their close proximity, both core sites are located in the same biogeographic zone and nutrient regime, and it is thus unlikely that this offset is due to a true gradient in surface ocean conditions. In an attempt to resolve this offset, we have investigated the possible effects of two sedimentological parameters that can affect bulk sedimentary δ15N, namely, the variable contribution of inorganic N to bulk N in the sediment and the grain-size dependence of bulk δ15N. We find that neither effect, singly or in combination, is sufficient to explain the significant δ15N offset between the two down-core records. By elimination the most likely explanation for the observed discrepancy is a different origin of both the organic and inorganic nitrogen at each site. This study adds to the growing body of evidence highlighting the complex nature and origin of the sedimentary components in sediment drifts, such as ODP Site 1144.
Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 20 (2005): PA2009, doi:10.1029/2004PA001081.
Suggested CitationArticle: Kienast, Markus, Higginson, M. J., Mollenhauer, Gesine, Eglinton, Timothy I., Chen, Min-Te, Calvert, Stephen E., "On the sedimentological origin of down-core variations of bulk sedimentary nitrogen isotope ratios", Paleoceanography 20 (2005): PA2009, DOI:10.1029/2004PA001081, https://hdl.handle.net/1912/3435
Showing items related by title, author, creator and subject.
Origin of the deep Bering Sea nitrate deficit : constraints from the nitrogen and oxygen isotopic composition of water column nitrate and benthic nitrate fluxes Lehmann, Moritz F.; Sigman, Daniel M.; McCorkle, Daniel C.; Brunelle, Brigitte G.; Hoffmann, Sharon S.; Kienast, Markus; Cane, Greg; Clement, Jaclyn (American Geophysical Union, 2005-10-12)On the basis of the normalization to phosphate, a significant amount of nitrate is missing from the deep Bering Sea (BS). Benthic denitrification has been suggested previously to be the dominant cause for the BS nitrate ...
Evidence from diatom-bound nitrogen isotopes for subarctic Pacific stratification during the last ice age and a link to North Pacific denitrification changes Brunelle, Brigitte G.; Sigman, Daniel M.; Cook, Mea S.; Keigwin, Lloyd D.; Haug, Gerald H.; Plessen, Birgit; Schettler, Georg; Jaccard, Samuel L. (American Geophysical Union, 2007-03-02)In a piston core from the central Bering Sea, diatom microfossil-bound N isotopes and the concentrations of opal, biogenic barium, calcium carbonate, and organic N are measured over the last glacial/interglacial cycle. ...
Libes, Susan M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1983-01)Isotope studies of nitrogen and carbon were undertaken to investigate the fate of particulate organic matter (POM) during its residence in the water column and after deposition on the seafloor. The processes focused on ...