@article {3004,
	title = {Implications of Single-Step Graphitization For Reconstructing Late Holocene Relative Sea-Level Using Radiocarbon-Dated Organic Coastal Sediment},
	journal = {Radiocarbon},
	year = {2022},
	month = {08/2022},
	pages = {1 - 20},
	abstract = {Late Holocene relative sea-level reconstructions are commonly generated using proxies preserved in salt-marsh and mangrove sediment. These depositional environments provide abundant material for radiocarbon dating in the form of identifiable macrofossils (salt marshes) and bulk organic sediment (mangroves). We explore if single-step graphitization of these samples in preparation for radiocarbon dating can increase the number and temporal resolution of relative sea-level reconstructions without a corresponding increase in cost. Dating of salt-marsh macrofossils from the northeastern United States and bulk mangrove sediment from the Federated States of Micronesia indicates that single-step graphitization generates radiocarbon ages that are indistinguishable from replicates prepared using traditional graphitization, but with a modest increase in error (mean/maximum of 6.25/15 additional 14C yr for salt-marsh macrofossils). Low 12C currents measured on bulk mangrove sediment following single-step graphitization likely render them unreliable despite their apparent accuracy. Simulated chronologies for six salt-marsh cores indicate that having twice as many radiocarbon dates (since single-step graphitization costs \~{}50\% of traditional graphitization) results in narrower confidence intervals for sample age estimated by age-depth models when the additional error from the single-step method is less than \~{}50 14C yr (\~{}30 14C yr if the chronology also utilizes historical age markers). Since these thresholds are greater than our empirical estimates of the additional error, we conclude that adopting single-step graphitization for radiocarbon measurements on plant macrofossils is likely to increase precision of age-depth models by more than 20/10\% (without/with historical age markers). This improvement can be implemented without additional cost.},
	keywords = {age-depth model, mangrove, Massachusetts, Micronesia, Salt marsh},
	isbn = {0033-8222, 1945-5755},
	doi = {10.1017/RDC.2022.55},
	url = {https://www.cambridge.org/core/journals/radiocarbon/article/implications-of-singlestep-graphitization-for-reconstructing-late-holocene-relative-sealevel-using-radiocarbondated-organic-coastal-sediment/41F75E6A0679F0E659C96F438452D64C},
	author = {Sefton, Juliet P. and Kemp, Andrew C. and Elder, Kathryn L. and Hansman, Roberta L. and Roberts, Mark L.}
}
@article {2104,
	title = {The West Falmouth oil spill after thirty years: the persistence of petroleum hydrocarbons in marsh sediments},
	journal = {Environ Sci Technol},
	volume = {36},
	year = {2002},
	note = {Reddy, Christopher MEglinton, Timothy I
Hounshell, Aubrey
White, Helen K
Xu, Li
Gaines, Richard B
Frysinger, Glenn S
eng
Research Support, Non-U.S. Gov{\textquoteright}t
Research Support, U.S. Gov{\textquoteright}t, Non-P.H.S.
2002/12/19 04:00
Environ Sci Technol. 2002 Nov 15;36(22):4754-60.
},
	month = {Nov 15},
	pages = {4754-60},
	abstract = {The long-term fate of petroleum hydrocarbons in marsh sediments (West Falmouth, MA) contaminated in 1969 by the spill of the barge Florida was investigated. A 36-cm-long sediment core was collected in August 2000, and sediment extracts were analyzed by gas chromatography (GC) and comprehensive two-dimensional gas chromatography (GC x GC). The latter technique is capable of separating 1 order of magnitude more compounds than the former and was used to observe whether any compositional changes in the unresolved complex mixture (UCM) occurred. No evidence of petroleum residues was detected in the top 6 cm (0-6 cm) and the lower 8 cm (28-36 cm) of the core. However, the central sections 16-28 cm) were dominated by a UCM in the boiling range of n-C13-n-C25 alkanes, consistent with a No. 2 fuel oil source. The 12-14- and 14-16-cm sections had the highest concentrations of UCM approximately 8 mg g(-1)). These values are similar to concentrations observed shortly after the spill. Initial GC x GC analysis revealed that only the n-alkanes were completely degraded, and contrary to previous studies, pristane and phytane as well as numerous other branched alkanes are still present in the sediments. These results suggestthatatthis site hydrocarbon contamination will persist indefinitely in the sedimentary record.},
	keywords = {*Accidents, Chromatography, Gas, Environmental Monitoring, Geologic Sediments/*chemistry, Hydrocarbons/*analysis, Massachusetts, Petroleum/*analysis, Ships, Time Factors, Water Pollutants, Chemical/*analysis},
	isbn = {0013-936X (Print)0013-936X (Linking)},
	doi = {10.1021/es020656n},
	url = {https://www.ncbi.nlm.nih.gov/pubmed/12487296},
	author = {Reddy, C. M. and Eglinton, T. I. and Hounshell, A. and White, H. K. and Xu, L. and Gaines, R. B. and Frysinger, G. S.}
}
