@conference {1278,
	title = {The Effect of Different Acid Treatments on the Radiocarbon Age of Sedimentary Organic Matter},
	booktitle = {EOS, Transactions, American Geophysical Union},
	year = {2001},
	note = {Date revised - 2007-02-01SuppNotes - Session: OS41A 9 The Truth About Paleoceanographic Proxies - What Are They Really Telling Us III Posters.Last updated - 2016-05-27},
	month = {January 2001},
	publisher = {American Geophysical Union, 2000 Florida Ave., N.W. Washington DC 20009 USA, [mailto:service@agu.org]},
	organization = {American Geophysical Union, 2000 Florida Ave., N.W. Washington DC 20009 USA, [mailto:service@agu.org]},
	abstract = {To date the bulk organic carbon in marine sediments it is necessary to first remove any inorganic carbon present by acidification. We tested three different acid treatments to see how the different methods affected the stable and radio-carbon isotopic values of the remaining organic matter. The standard NOSAMS method is to react the sediment with repeated aliquots of1.2N HCl until no visible dissolution reaction is present. The remaining sediment is then rinsed with distilled water. This method leaves a carbonate-free sediment that is easy to combust but suffers from the possible removal of acid-soluble organic matter. We compared this method to two methods that do not require rinsing of the sediments after acid treatment--a vapor phase acidification method using concentrated HCl (Hedges and Stern, 1984) and an in situ acidification with sulfurous acid (Verardo et al., 1990). Scaling these methods up to deal with the amount of sediment required for a radiocarbon date can present challenges that are not evident when dealing with the small quantities required for a percent organic carbon measurement. Vapor phase acidification of high carbonate sediments leaves hygroscopic salts that can impede sample combustion. Sulfurous acid is a weak acid and it is very difficult to determine when all the carbonate has been removed from a sediment sample. We tested sediments from 6 locations in (or near) the Atlantic Ocean that represented riverine, estuarine, and marine environments as well as a range of both organic and inorganic concentrations. We will present the isotopic results for these sediments and evaluate what is the most appropriate method to use. Hedges J.I. and J.H. Stern (1984) Limnol. Oceanogr. 29, 657-663. Verardo D.J., P.N. Froelich and A. McIntyre (1990) Deep-Sea Res. 37, 157-165.},
	keywords = {A, Atlantic, Acidification, Brackish, Brackishwater environment, carbon cycling, Chronostratigraphy, Estuarine sedimentation, organic carbon, organic matter, Palaeoceanography, Radioactivity and radioisotopes, Radiocarbon dating, Sediment chemistry, Stable isotopes},
	url = {https://search.proquest.com/docview/19468089?accountid=29119},
	author = {Batista, F and McNichol, A P and Gerlach, D S}
}
@conference {1279,
	title = {An Ocean-Wide DIC-13 Data Set},
	booktitle = {2000 Ocean Sciences Meeting, San Antonio, TX (USA), 24-28 Jan 2000},
	year = {2000},
	note = {Date revised - 2007-04-01SuppNotes - Abstracts available.Last updated - 2016-12-21},
	month = {January 2000},
	publisher = {American Geophysical Union, 2000 Florida Ave., N.W. Washington, DC 20009 USA},
	organization = {American Geophysical Union, 2000 Florida Ave., N.W. Washington, DC 20009 USA},
	abstract = {High quality DIC-13 measurements were made throughout the world{\textquoteright}s oceans at the University of Washington (UW) and the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) Facility during both the OACES and WOCE programs. We are currently merging these two data sets which represent 25000 individual DIC- 13 measurements from 1260 stations. We will present the inter-laboratory calibration and standardization data. Based on 135 measurements on CO2 gas extracted at UW, the mean offset between the two labs is 0.01 o/oo, similar to the offset observed from an exchange of DIC standards (0.012 o/oo). Stations measured by both laboratories will also be examined for offsets, although one comparison in the Indian Ocean shows no significant differences. We will present our progress towards a global atlas of DIC-13, primarily maps of the merged data sets in the Pacific, Southern, and Indian Oceans. In this poster we will concentrate on regions that have been under-sampled in the past, e.g. the Southern Ocean. Additionally, we will examine the relationship of DIC-13 to PO4 and to DIC-14. A preliminary analysis of DIC-13 and PO4 from three WOCE lines in the Pacific indicates that the expected relationship is observed in the deep waters and that the data from different water masses occupy well-defined regions of the graph. We are examining the potential for using the relationship between DIC-14 and DIC-13 to improve our understanding of the penetration of bomb radiocarbon into the ocean as well as fundamental processes in the deep ocean. The relationship is complex yet the data from shallow to intermediate depths (100 to 1000m) follow two distinct parallel lines that are related to the hemisphere in which},
	keywords = {carbon cycling, Carbon dioxide, Deep water, dissolved inorganic carbon, ISW, Indian Ocean, Marine, Mass Spectrometry, Ocean circulation, Phosphates, PS, Antarctic Ocean, Q2 09146:TSD distribution, water masses and circulation, Stable isotopes, Standardization, Water masses, World Ocean, World Ocean Circulation Experiment (WOCE)},
	url = {https://search.proquest.com/docview/19610793?accountid=29119},
	author = {McNichol, A P and Quay, P D and Stuart, D R and Sonnerup, R E and Key, R M}
}
