Comparison of large and ultra-small Δ14C measurements in core top benthic foraminifera from the Okhotsk Sea
Keigwin, Lloyd D.
Gagnon, Alan R.
MetadataShow full item record
The radiocarbon activity of benthic foraminifera was investigated in surface sediments from a high deposition rate location at a depth of 1000 m in the Okhotsk Sea. Sediments were preserved and stained with Rose Bengal to identify foraminifera that contain cytoplasm. The benthic fauna at this site is dominated by large specimens of Uvigerina peregrina, and bulk samples (~150 individuals) of stained and unstained specimens were dated. The stained sample was about 240 14C yr younger than the unstained, and the presence of bomb 14C is inferred by comparison to water column data in the nearby open North Pacific. Using new methods, multiple measurements were also made on samples of three stained and unstained individuals (as small as 7 µg C). Results are consistent with those from the bulk samples. This suggests that similar ultra-small measurements could be made at other locations to reveal the age distribution of individuals in a sediment sample in order to assess the extent of bioturbation and the presence of bomb 14C contamination.
© The Arizona Board of Regents on behalf of the University of Arizona, 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Radiocarbon 57, no. 1 (2015): 123-128, doi:10.2458/azu_rc.57.18153.
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Ultra-small graphitization reactors for ultra-microscale 14C analysis at the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) Facility Shah Walter, Sunita R.; Gagnon, Alan R.; Roberts, Mark L.; McNichol, Ann P.; Lardie Gaylord, Mary C.; Klein, Elizabeth (University of Arizona Libraries, 2015)In response to the increasing demand for 14C analysis of samples containing less than 25 µg C, ultra-small graphitization reactors with an internal volume of ~0.8 mL were developed at NOSAMS. For samples containing 6 to ...
Blank assessment for ultra-small radiocarbon samples : chemical extraction and separation versus AMS Santos, Guaciara M.; Southon, John R.; Drenzek, Nicholas J.; Ziolkowski, Lori A.; Druffel, Ellen R. M.; Xu, Xiaomei; Zhang, Dachun; Trumbore, Susan E.; Eglinton, Timothy I.; Hughen, Konrad A. (Dept. of Geosciences, University of Arizona, 2010-08)The Keck Carbon Cycle AMS facility at the University of California, Irvine (KCCAMS/UCI) has developed protocols for analyzing radiocarbon in samples as small as ~0.001 mg of carbon (C). Mass-balance background corrections for ...
Connelly, Douglas P.; German, Christopher R.; Asada, Miho; Okino, K.; Egorov, A.; Naganuma, T.; Pimenov, N.; Cherkashev, G.; Tamaki, K. (American Geophysical Union, 2007-08-28)We report first evidence for hydrothermal activity from the southern Knipovich Ridge, an ultra-slow spreading ridge segment in the Norwegian-Greenland Sea. Evidence comes from optical backscatter anomalies collected during ...