@article { ISI:000389875700005,
	title = {RAPID C-14 ANALYSIS OF DISSOLVED ORGANIC CARBON IN NON-SALINE WATERS},
	journal = {RADIOCARBON},
	volume = {58},
	number = {{3}},
	year = {2016},
	month = {SEP},
	pages = {505-515},
	type = {Article},
	abstract = {The radiocarbon content of dissolved organic carbon (DOC) in rivers, lakes, and other non-saline waters can provide valuable information on carbon cycling dynamics in the environment. DOC is typically prepared for C-14 analysis by accelerator mass spectrometry (AMS) either by ultraviolet (UV) oxidation or by freeze-drying and sealed tube combustion. We present here a new method for the rapid analysis of C-14 of DOC using wet chemical oxidation (WCO) and automated headspace sampling of CO2. The approach is an adaption of recently developed methods using aqueous persulfate oxidant to determine the delta C-13 of DOC in non-saline water samples and the C-14 content of volatile organic acids. One advantage of the current method over UV oxidation is higher throughput: 22 samples and 10 processing standards can be prepared in one day and analyzed in a second day, allowing a full suite of C-14 processing standards and blanks to be run in conjunction with samples. A second advantage is that there is less potential for cross-contamination between samples.},
	keywords = {carbon-cycling, dissolved organic carbon, method development, wet chemical oxidation},
	issn = {0033-8222},
	doi = {10.1017/RDC.2016.17},
	author = {Lang, Susan Q. and McIntyre, Cameron P. and Bernasconi, Stefano M. and Fruh-Green, Gretchen L. and Voss, Britta M. and Eglinton, Timothy I. and Wacker, Lukas}
}
@article {2549,
	title = {Radiocarbon and 230Th data reveal rapid redistribution and temporal changes in sediment focussing at a North Atlantic drift},
	journal = {Earth and Planetary Science Letters},
	volume = {301},
	year = {2011},
	month = {Jan-01-2011},
	pages = {373 - 381},
	abstract = {In locations of rapid sediment accumulation receiving substantial amounts of laterally transported material the timescales of transport and accurate quantification of the transported material are at the focus of intense research. Here we present radiocarbon data obtained on co-occurring planktic foraminifera, marine haptophyte biomarkers (alkenones) and total organic carbon (TOC) coupled with excess Thorium-230 (230Thxs) measurements on four sediment cores retrieved in 1649{\textendash}2879m water depth from two such high accumulation drift deposits in the Northeast Atlantic, Bj{\"o}rn and Gardar Drifts. While 230Thxs inventories imply strong sediment focussing, no age offsets are observed between planktic foraminifera and alkenones, suggesting that redistribution of sediments is rapid and occurs soon after formation of marine organic matter, or that transported material contains negligible amounts of alkenones. An isotopic mass balance calculation based on radiocarbon concentrations of co-occurring sediment components leads us to estimate that transported sediment components contain up to 12\% of fossil organic matter that is free of or very poor in alkenones, but nevertheless appears to consist of a mixture of fresh and eroded fossil material. Considering all available constraints to characterize transported material, our results show that although focussing factors calculated from bulk sediment 230Thxs inventories may allow useful approximations of bulk redeposition, they do not provide a unique estimate of the amount of each laterally transported sediment component. Furthermore, our findings provide evidence that the occurrence of lateral sediment redistribution alone does not always hinder the use of multiple proxies but that individual sediment fractions are affected to variable extents by sediment focussing. 

},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2010.11.022},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0012821X1000717X},
	author = {Mollenhauer, Gesine and McManus, Jerry F. and Wagner, Thomas and McCave, I. Nick and Eglinton, Timothy I.}
}
@article { ISI:000286640400038,
	title = {Radiocarbon and Th-230 data reveal rapid redistribution and temporal changes in sediment focussing at a North Atlantic drift},
	journal = {EARTH AND PLANETARY SCIENCE LETTERS},
	volume = {301},
	number = {{1-2}},
	year = {2011},
	month = {JAN 3},
	pages = {373-381},
	type = {Article},
	abstract = {In locations of rapid sediment accumulation receiving substantial amounts of laterally transported material the timescales of transport and accurate quantification of the transported material are at the focus of intense research. Here we present radiocarbon data obtained on co-occurring planktic foraminifera, marine haptophyte biomarkers (alkenones) and total organic carbon (TOC) coupled with excess Thorium-230 (Th-230(xs)) measurements on four sediment cores retrieved in 1649-2879 m water depth from two such high accumulation drift deposits in the Northeast Atlantic, Bjorn and Gardar Drifts. While Th-230(xs), inventories imply strong sediment focussing, no age offsets are observed between planktic foraminifera and alkenones, suggesting that redistribution of sediments is rapid and occurs soon after formation of marine organic matter, or that transported material contains negligible amounts of alkenones. An isotopic mass balance calculation based on radiocarbon concentrations of co-occurring sediment components leads us to estimate that transported sediment components contain up to 12\% of fossil organic matter that is free of or very poor in alkenones, but nevertheless appears to consist of a mixture of fresh and eroded fossil material. Considering all available constraints to characterize transported material, our results show that although focussing factors calculated from bulk sediment Th-230(xs) inventories may allow useful approximations of bulk redeposition, they do not provide a unique estimate of the amount of each laterally transported sediment component. Furthermore, our findings provide evidence that the occurrence of lateral sediment redistribution alone does not always hinder the use of multiple proxies but that individual sediment fractions are affected to variable extents by sediment focussing. (C) 2010 Elsevier B.V. All rights reserved.},
	keywords = {alkenones, compound-specific radiocarbon dating, drift sediments, focussing factors, Th-230(xs)},
	issn = {0012-821X},
	doi = {10.1016/j.epsl.2010.11.022},
	author = {Mollenhauer, Gesine and McManus, Jerry F. and Wagner, Thomas and McCave, I. Nick and Eglinton, Timothy I.}
}
@article { ISI:000284192000011,
	title = {The radiocarbon age of organic carbon in marine surface sediments},
	journal = {GEOCHIMICA ET COSMOCHIMICA ACTA},
	volume = {74},
	number = {{23}},
	year = {2010},
	month = {DEC 1},
	pages = {6788-6800},
	type = {Article},
	abstract = {Long-term carbon cycling and climate change are strongly dependent on organic carbon (OC) burial in marine sediments. Radiocarbon ((14)C) has been widely used to constrain the sources, sinks, and processing of sedimentary OC. To elucidate the dominant controls on the radiocarbon content of total organic carbon ((14)C(TOC)) accumulating in surface sediments we construct a box model that predicts (14)C(TOC) in the sediment mixed layer (measured as fraction modern, Fm). Our model defines three distinct OC pools ({{\textquoteright}{\textquoteright}}degradable,{{\textquoteright}{\textquoteright}} {\textquoteleft}{\textquoteleft}semi-labile,{{\textquoteright}{\textquoteright}} and {\textquoteleft}{\textquoteleft}refractory{{\textquoteright}{\textquoteright}}) and assumes that (14)C(TOC) flux to sediments is exclusively derived from surface ocean primary productivity, and hence follows a {\textquoteleft}{\textquoteleft}generic{{\textquoteright}{\textquoteright}} surface ocean dissolved inorganic carbon (DIC) bomb curve. Model predictions are compared to a set of 75 surface sediment samples, which span a wide geographic range and reflect diverse water column and depositional conditions, and for which sedimentation rate and mixed-layer depth are well characterized. Our model overestimates the Fm value for a majority (65\%) of these sites, especially at shallow water depths and for sites characterized by depleted delta(13)C(TOC) values. The model is most sensitive to sedimentation rate and mixed-layer depth. Therefore, slight changes to these parameters can lead to a match between modeled and measured Fm values at many sites. Yet, in some cases, we find that measured Fm values cannot be simulated without large and unrealistic changes to sedimentation rate and mixed-layer depth. These results point to sources of pre-aged OC to surface sediments and implicate soil-derived terrestrial OC, reworked marine OC, and/or anthropogenic carbon as important components of the organic matter present in surface sediments. This approach provides a valuable framework within which to explore controls on sedimentary organic matter composition and carbon burial over a range of spatial and temporal scales. (C) 2010 Elsevier Ltd. All rights reserved.},
	issn = {0016-7037},
	doi = {10.1016/j.gca.2010.09.001},
	author = {Griffith, David R. and Martin, William R. and Eglinton, Timothy I.}
}
@article {2442,
	title = {Relationships between carbon isotopic composition and mode of binding of natural organic matter in selected marine sediments},
	volume = {38},
	year = {2007},
	month = {2007/11//},
	pages = {1824 - 1837},
	abstract = {We have investigated the relationships between radiocarbon (14C) and stable carbon (13C) isotopic composition and the different modes of binding of organic matter (OM) in surficial sediments selected from near-shore and continental margin sites that vary in terms of input and depositional conditions. To improve our understanding of the entire OM pool, isotopic analysis of sedimentary sub-fractions, as opposed to individual compounds, was performed. This was achieved by sequentially treating sediments via solvent extraction to examine unbound compounds, followed by saponification to cleave ester linked moieties. Isotopic analysis was performed on the bulk sediment and resulting residues. The molecular composition of the extracts was examined using gas chromatography/mass spectrometry (GC/MS) and the relative contributions of terrestrial and marine biomarkers were assessed. Radiocarbon abundances (Δ14C) of the bulk sediment reflect a mixture of modern, pre-aged and fossil carbon. Offsets in Δ14C between the bulk sediment and sediment residues demonstrate varying associations of these carbon pools. For the majority of sites, a negative offset between extracted (EX-RES) and saponified (SA-RES) sediment residues results from the removal of relatively 14C-rich material during saponification. Saponification extracts (SAEs) are mainly composed of short chain (n-C12 to n-C24) alkanoic acids with an even/odd dominance, indicating a predominantly marine algal or microbial source. This provides evidence for the protection of labile marine carbon by chemical binding. This study bridges the gap between molecular level and bulk OM analysis of marine sediments.},
	isbn = {0146-6380},
	doi = {10.1016/j.orggeochem.2007.07.008},
	url = {http://www.sciencedirect.com/science/article/pii/S0146638007001751},
	author = {White, Helen K. and Reddy, Christopher M. and Eglinton, Timothy I.}
}
@article {1933,
	title = {Rapid lateral particle transport in the Argentine Basin: Molecular 14C and 230Th evidence},
	journal = {Deep-Sea Research I},
	volume = {53},
	year = {2006},
	note = {id: 543},
	month = {2006},
	pages = {1224-1243},
	author = {Mollenhauer, Gesine and McManus, Jerry F. and Benthien, Albert and Muller, Peter J. and Eglinton, Timothy I.}
}
@conference {1760,
	title = {Radiocarbon ages of marine bimarkers and co-occurring foraminifera: evidence for differential particle transport on continental margins, Poster},
	booktitle = {Eighth International Conference on Palaeoceanography},
	year = {2004},
	note = {id: 549},
	month = {2004},
	address = {Biarritz, France},
	author = {Mollenhauer, Gesine and Eglinton, Timothy I. and Hayes, John M. and Kienast, Markus and Lamy, Frank and Meggers, Helge and Schneider, Ralph R.}
}
@conference {1764,
	title = {Radiocarbon content of alkenones, foraminifera and bulk OC in oxic and anoxic sediments from the California Borderland Basins, Poster},
	booktitle = {Gordon Research Conference Organic Geochemistry},
	year = {2004},
	note = {id: 550},
	month = {2004},
	address = {Holderness School, New Hampshire, USA},
	author = {Mollenhauer, Gesine and Eglinton, Timothy I.}
}
@conference {1761,
	title = {Radiocarbon ages of marine biomarkers and co-occurring foraminifera: evidence for differential particle transport on continental margins},
	booktitle = {AGU Fall Meeting 2003},
	year = {2003},
	note = {id: 1069},
	month = {2003},
	address = {San Francisco, USA},
	author = {Mollenhauer, Gesine and Eglinton, Timothy I. and Hayes, John M. and Keinast, Markus and Lamy, Frank and Meggers, Helge and Schneider, Ralph R.}
}
@conference {1765,
	title = {Radiocarbon dating of alkenones in sediments from the Namibian continental margin},
	booktitle = {European Geophysical Society, XXVII General Assembly},
	year = {2002},
	note = {id: 546},
	month = {2002},
	address = {Nice, France},
	author = {Mollenhauer, Gesine and Eglinton, Timothy I. and Ohkouchi, Nao and Grootes, Pieter M. and Muller, Peter J. and Rullkotter, Jurgen and Schneider, Ralph R.}
}
