@article {2445,
	title = {Radiocarbon-derived sedimentation rates in the Gulf of Mexico},
	journal = {Deep-Sea Research Part Ii-Topical Studies in Oceanography},
	volume = {55},
	year = {2008},
	note = {United States Mineral Management Service [1435-01-99-CT-30991]},
	month = {Dec},
	pages = {2572-2576},
	abstract = {Sedimentation rates were determined for the northern Gulf of Mexico margin sediments at water depths ranging from 770 to 3560m, using radiocarbon determinations of organic matter. Resulting sedimentation rates ranged from 3 to 15 cm/kyr, decreasing with increasing water depth. These rates agree with long-term sedimentation rates estimated previously using stratigraphic methods, and with estimates of sediment delivery rates by the Mississippi River to the northern Gulf of Mexico, but are generally higher by 1-2 orders of magnitude than those estimated by (210)Pb(xs) methods. Near-surface slope sediments from 2737 to water depth in the Mississippi River fan were much older than the rest. They had minimum (14)C ages of 16-27 kyr and delta(13)C values ranging from -24 parts per thousand to -26.59 parts per thousand, indicating a terrestrial origin of organic matter. The sediments from this site were thus likely deposited by episodic mass wasting of slope sediment through the canyon, delineating the previously suggested main pathway of sediment and clay movement to abyssal Gulf sediments. (C) 2008 Published by Elsevier Ltd.},
	keywords = {accumulation, ATCHAFALAYA RIVER, cores, Gulf of Mexico, ice-sheet, Mass, Meltwater, MISSISSIPPI RIVER DELTA, Nepheloid layer transport, Organic carbon burial rates, radiocarbon, Sedimentation rates, TERRIGENOUS ORGANIC-MATTER, wasting},
	isbn = {0967-0645},
	doi = {10.1016/j.dsr2.2008.07.005},
	author = {Santschi, P. H. and Rowe, G. T.}
}
@article {2443,
	title = {Linking lithology and land use to sources of dissolved and particulate organic matter in headwaters of a temperate, passive-margin river system},
	journal = {Geochimica Et Cosmochimica Acta},
	volume = {71},
	year = {2007},
	note = {30},
	month = {Sep},
	pages = {4233-4250},
	abstract = {A number of rivers have been found to transport highly aged organic matter [OM]; however, the sources of this aged material remain a matter of debate. One potential source may be erosion and weathering of headwater lithologies rich in ancient sedimentary OM. In this study, waters, suspended particulates, streambed sediments, rocks and soils from fourteen small headwater watersheds of a mid-size, temperate, passive margin river were sampled and characterized by Delta C-14, delta C-13, and POC/TPN ratios to identify sources of particulate and dissolved OM delivered to the river mainstem. These headwater sites encompass a range in lithology (OM-rich shales, OM-lean carbonate/mudstone facies, and OM-free crystalline rocks) and land use types (forested and agricultural), and allow investigation of the influence of agriculture and bedrock types on stream OM characteristics. Streams draining large areas of both agricultural land use and OM-rich lithology contain particulate OM [POM] that is more C-14-depleted than streams draining forested, shale-free watersheds. However, this is not sufficient to account for the significantly lower Delta C-14-POC measured in the river mainstern. Dissolved OM [DOM] Delta C-14 are in all cases enriched compared to POM from the same stream, but are otherwise highly variable and unrelated to either land use or lithology. POC/TPN ratios were likewise highly variable. POC and DOC delta C-13 signatures were similar across all watersheds. Based on isotope mass balance, C-14-free fossil OM sources contribute 0-12\% of total stream POM. Although these results do not unequivocally separate the influences of land use and lithology, watershed coverage by shale and agriculture are both important controls on stream A Delta C-14-POC. Thus export of aged, particle-associated OM may be a feature of river systems along both passive and active continental margins. (C) 2007 Elsevier Ltd. All rights reserved.},
	keywords = {ATCHAFALAYA RIVER, ATMOSPHERIC O-2, BLACK SHALE, continental-shelf, GULF-OF-MEXICO, marine-sediments, MINERAL, SPACE-TIME CLIMATE, STABLE-ISOTOPES, surface sediments, SURFACES},
	isbn = {0016-7037},
	doi = {10.1016/j.gca.2007.06.056},
	author = {Longworth, B. E. and Petsch, S. T. and Raymond, P. A. and Bauer, J. E.}
}
