@article {2641,
	title = {Petrocarbon evolution: Ramped pyrolysis/oxidation and isotopic studies of contaminated oil sediments from the Deepwater Horizon oil spill in the Gulf of Mexico},
	journal = {PLOS ONE},
	volume = {14},
	year = {2019},
	month = {Apr-02-2021},
	pages = {e0212433},
	abstract = {Hydrocarbons released during the Deepwater Horizon (DWH) oil spill weathered due to exposure to oxygen, light, and microbes. During weathering, the hydrocarbons{\textquoteright} reactivity and lability was altered, but it remained identifiable as "petrocarbon" due to its retention of the distinctive isotope signatures (C-14 and C-13) of petroleum. Relative to the initial estimates of the quantity of oil-residue deposited in Gulf sediments based on 2010-2011 data, the overall coverage and quantity of the fossil carbon on the seafloor has been attenuated. To analyze recovery of oil contaminated deep-sea sediments in the northern Gulf of Mexico we tracked the carbon isotopic composition (C-13 and C-14, radiocarbon) of bulk sedimentary organic carbon through time at 4 sites. Using ramped pyrolysis/oxidation, we determined the thermochemical stability of sediment organic matter at 5 sites, two of these in time series. There were clear differences between crude oil (which decomposed at a lower temperature during ramped oxidation), natural hydrocarbon seep sediment (decomposing at a higher temperature; Delta C-14 = -189 parts per thousand) and our control site (decomposing at a moderate temperature; Delta C-14 = -189 parts per thousand), in both the stability (ability to withstand ramped temperatures in oxic conditions) and carbon isotope signatures. We observed recovery toward our control site bulk Delta C-14 composition at sites further from the wellhead in similar to 4 years, whereas sites in closer proximity had longer recovery times. The thermographs also indicated temporal changes in the composition of contaminated sediment, with shifts towards higher temperature CO2 evolution over time at a site near the wellhead, and loss of higher temperature CO2 peaks at a more distant site.},
	keywords = {C-14 ANALYSES; MARINE SNOW, degradation, fractionation, organic-matter, POLYCYCLIC AROMATIC-HYDROCARBONS; MICROBIAL COMMUNITY RESPONSE, radiocarbon, STABLE CARBON, surface sediments},
	doi = {10.1371/journal.pone.0212433},
	url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0212433},
	author = {Rogers, Kelsey L. and Bosman, Samantha H. and Lardie-Gaylord, Mary and McNichol, Ann and Rosenheim, Brad E. and Montoya, Joseph P. and Chanton, Jeffrey P.},
	editor = {Cooper, Lee W.}
}
@article {2665,
	title = {Selective Preservation of Coccolith Calcite in Ontong-Java Plateau Sediments},
	journal = {Paleoceanography and Paleoclimatology},
	volume = {34},
	year = {2019},
	month = {May-12-2021},
	pages = {2141 - 2157},
	keywords = {BIOMINERALIZATION, caco3 dissolution, CEARA RISE, dissolution kinetics, IN-SITU MEASUREMENTS; DEEP-SEA CARBONATES; PLANKTONIC-FORAMINIFERA; EQUATORIAL PACIFIC, surface sediments, WATER INTERFACE},
	issn = {2572-4517},
	doi = {10.1029/2019PA003731},
	url = {https://apps.webofknowledge.com/InboundService.do?product=WOS\&Func=Frame\&DestFail=http\%3A\%2F\%2Fwww.webofknowledge.com\&SrcApp=search\&SrcAuth=Alerting\&SID=8DpsdyQUduuojUwg61F\&customersID=Alerting\&mode=FullRecord\&IsProductCode=Yes\&AlertId=ab9062f8-b111-4f95-},
	author = {Subhas, Adam V. and McCorkle, Daniel C. and Quizon, Alex and McNichol, Ann P. and Long, Matthew H.}
}
@article {2627,
	title = {Late Pleistocene to Holocene productivity changes in the western equatorial Pacific (Sulu Sea, Philippines) from calcareous nannofossils},
	journal = {Marine Micropaleontology},
	volume = {143},
	year = {2018},
	month = {Jan-09-2018},
	pages = {1 - 11},
	abstract = {We present a new calcareous nannofossil paleoproductivity reconstruction of the southeastern margin of the Sulu Sea to understand how marine productivity varied through time in one of the major fishing grounds of the Philippine archipelago. The study is based on two sediment cores obtained from two different hydrographic locations in the western equatorial Pacific region: an upwelling region off Zamboanga Peninsula (U-GC12) and a non-upwelling area off Panay Island (NU-GC14), covering the past 18,000 years before present (B.P.). Calcareous nannofossil assemblages in the investigated areas were of low diversity and largely dominated by Gephyrocapsa oceanica and Florisphaera profwida, followed by small placolith-bearing taxa, Emiliania hwcleyi, small Gephyrocapsa, and Reticulofenestra minuta. Upwelling episodes off the Zamboanga Peninsula were recorded several times in the past as shown by an increase in the abundance of high productivity indicator species (G. oceanica, small Gephyrocapsa, E. hwcleyi) and of bulk sediment CaCO3 (\%), and a concomitant decline in the total organic carbon (TOC; \%). The high abundance of low surface water productivity species F. profunda and Umbellosphaera irregularis indicates a stratified water column with a deeper nutricline, probably caused by the reduced upwelling intensity. This condition was corroborated by the decrease in CaCO3 (\%) and an increase in TOC (\%). We propose that the modern day high productivity conditions off Zamboanga Peninsula started at 2500 years B.P., whereas the low productivity off Panay Island was recorded from 4000 years B.P., and persists to the present day. Evidence of the Younger Dryas (YD) event was recorded from 11,100 to 10,400 years B.P. in UGC12, synchronous to the YD event reported from other areas in the Northern Hemisphere, and in accordance with the timing in the Sulu Sea as reported from previous studies in this region. This event in the Sulu Sea is characterized by a decrease in total nannofossil abundance and estimated primary productivity, together with an increase in CaCO3 (\%) and a decrease in TOC (\%). We interpreted that dilution caused by the increase in precipitation experienced in the Southeast Asian region during the YD event could have led to the decline of the total calcareous nannofossils whereas the recorded increase in CaCO3 (\%) is attributed to the high abundance of planktonic foraminifera during this interval.},
	keywords = {arabian sea, EAST-ASIAN MONSOON, GLOBAL YOUNGER-DRYAS, indian-ocean, last deglaciation, OCEANIC PRIMARY PRODUCTION, south china sea, surface sediments, UPWELLING SYSTEM, YR BP},
	issn = {03778398},
	doi = {10.1016/j.marmicro.2018.07.001},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0377839816301219https://api.elsevier.com/content/article/PII:S0377839816301219?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0377839816301219?httpAccept=text/plain},
	author = {Tangunan, Deborah N. and Peleo-Alampay, Alyssa M.}
}
@article {1899,
	title = {Diagenetic and sedimentological controls on the composition of organic matter preserved in California Borderland Basin sediments},
	journal = {Limnology and Oceanography},
	volume = {52},
	year = {2007},
	note = {149kgTimes Cited:43
Cited References Count:67
},
	month = {Mar},
	pages = {558-576},
	abstract = {Compound-specific radiocarbon (C-14) contents, stable carbon isotopes, and abundances of phytoplankton and vascular plant derived lipid biomarkers (alkenones and fatty acids) were obtained from Santa Barbara Basin and Santa Monica Basin sediments, along with radiocarbon contents of planktic foraminifera and total organic carbon. We investigated core-top and prebomb sediment intervals at sites from the flanks and depocenters of the basins deposited under contrasting bottom water oxygen concentrations. Bulk organic matter generally has the lowest radiocarbon levels of all sediment constituents measured, whereas planktic foraminifera tend to be the most radiocarbon enriched. Alkenones are systematically depleted in radiocarbon with respect to foraminifera. Short-chain (C-14, C-16, C-18) fatty acids decrease rapidly in absolute abundance and relative to longer-chain (> C-24) homologues from core-top to prebomb samples. The loss of short-chain fatty acids with depth is associated with C-13 depletion of short-chain fatty acids, indicating preferential preservation of terrestrially derived fatty acids. Short-chain fatty acids tend to be more C-14-enriched relative to alkenones in core-top sediments, whereas longer-chain homologues are generally the most radiocarbon depleted of the lipids studied here. Less refractory compounds (e.g., short-chain fatty acids) are thus enriched in radiocarbon with respect to more recalcitrant biomarkers (alkenones, long-chain fatty acids). The lower C-14 content of more refractory compounds reflects a larger proportion of laterally supplied, preaged material. Greater preservation of labile organic compounds observed at the depocenters than in flank sediments results in the presence of "younger" biomarkers, underlining the important influence of selective degradation of labile compounds on their radiocarbon ages.},
	keywords = {c-14 measurements, compound-specific radiocarbon, continental-margin, fatty-acids, marine-sediments, monica basin, oxic degradation, oxygen exposure time, santa-barbara basin, surface sediments},
	isbn = {0024-3590},
	doi = {10.4319/lo.2007.52.2.0558},
	author = {Mollenhauer, G. and Eglinton, T. I.}
}
@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.}
}
