@article {2628,
	title = {Temporal deconvolution of vascular plant-derived fatty acids exported from terrestrial watersheds},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {244},
	year = {2019},
	month = {Jan-01-2019},
	pages = {502 - 521},
	abstract = {Relatively little is known about the amount of time that lapses between the photosynthetic fixation of carbon by vascular land plants and its incorporation into the marine sedimentary record, yet the dynamics of terrestrial carbon sequestration have important implications for the carbon cycle. Vascular plant carbon may encounter multiple potential intermediate storage pools and transport trajectories, and the age of vascular plant carbon accumulating in marine sediments will reflect these different pre-depositional histories. Here, we examine down-core C-14 profiles of higher plant leaf wax-derived fatty acids isolated from high fidelity sedimentary sequences spanning the so-called "bomb-spike", and encompassing a ca. 60-degree latitudinal gradient from tropical (Cariaco Basin), temperate (Saanich Inlet), and polar (Mackenzie Delta) watersheds to constrain integrated vascular plant carbon storage/transport times ("residence times").

Using a modeling framework, we find that, in addition to a "young" (conditionally defined as < 50 y) carbon pool, an old pool of compounds comprises 49 to 78 \% of the fractional contribution of organic carbon (OC) and exhibits variable ages reflective of the environmental setting. For the Mackenzie Delta sediments, we find a mean age of the old pool of 28 ky (+/- 9.4, standard deviation), indicating extensive pre-aging in permafrost soils, whereas the old pools in Saanich Inlet and Cariaco Basin sediments are younger, 7.9 (+/- 5.0) and 2.4 (+/- 0.50) to 3.2 (+/- 0.54) ky, respectively, indicating less protracted storage in terrestrial reservoirs. The "young" pool showed clear annual contributions for Saanich Inlet and Mackenzie Delta sediments (comprising 24\% and 16\% of this pool, respectively), likely reflecting episodic transport of OC from steep hillside slopes surrounding Saanich Inlet and annual spring flood deposition in the Mackenzie Delta, respectively. Contributions of 5-10 year old OC to the Cariaco Basin show a short delay of OC inflow, potentially related to transport time to the offshore basin. Modeling results also indicate that the Mackenzie Delta has an influx of young but decadal material (20-30 years of age), pointing to the presence of an intermediate reservoir.

Overall, these results show that a significant fraction of vascular plant C undergoes pre-aging in terrestrial reservoirs prior to accumulation in deltaic and marine sediments. The age distribution, reflecting both storage and transport times, likely depends on landscape-specific factors such as local topography, hydrographic characteristics, and mean annual temperature of the catchment, all of which affect the degree of soil buildup and preservation. We show that catchment-specific carbon residence times across landscapes can vary by an order of magnitude, with important implications both for carbon cycle studies and for the interpretation of molecular terrestrial paleoclimate records preserved in sedimentary sequences.},
	keywords = {british-columbia, CARIACO BASIN, compound-specific radiocarbon, MACKENZIE DELTA, marine-sediments, odp leg 169s, saanich inlet, SANTA-MONICA BASIN, SOIL ORGANIC-MATTER, TROPICAL VEGETATION},
	issn = {00167037},
	doi = {10.1016/j.gca.2018.09.034},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0016703718305702https://api.elsevier.com/content/article/PII:S0016703718305702?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0016703718305702?httpAccept=text/plain},
	author = {Vonk, Jorien E. and Drenzek, Nicholas J. and Hughen, Konrad A. and Stanley, Rachel H.R. and McIntyre, Cameron and {\c c}on, Daniel B. and Giosan, Liviu and Southon, John R. and Santos, Guaciara M. and Druffel, Ellen R.M. and Andersson, August A. and {\"o}ld, Martin and Eglinton, Timothy I.}
}
@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.}
}
@article {2438,
	title = {MAGic: A Phanerozoic model for the geochemical cycling of major rock-forming components},
	journal = {American Journal of Science},
	volume = {306},
	year = {2006},
	note = {53},
	month = {Mar},
	pages = {135-190},
	abstract = {A dynamical model (MAGic) is presented that describes the elemental cycling of sedimentary materials involving sodium, potassium, calcium, magnesium, chloride, carbon, oxygen, iron, sulfur and phosphorous through much of the Phanerozoic. The model incorporates the basic reactions controlling atmospheric carbon dioxide and oxygen concentrations, continental and seafloor weathering of silicate and carbonate rocks, net ecosystem productivity, basalt-seawater exchange reactions, precipitation and diagenesis of chemical sediments and authigenic silicates, oxidation-reduction reactions involving carbon, sulfur, and iron, and subduction-decarbonation reactions. Although MAGic contains feedback and forcing functions adapted from the GEOCARB models (Berner, 1991, 1994; Berner and Kothavala, 2001), these functions are incorporated in a reservoir-reaction scheme that is considerably more detailed. Coupled reservoirs include shallow and deep cratonic silicate and carbonate rocks and sediments, seawater, atmosphere, oceanic sediments and basalts, and the shallow mantle. Model results are reasonably consistent with recently published constraints provided by fluid inclusion, isotopic, floral, and mineralogical records. We have used these results to evaluate sensitivity to uncertainties in the history of the earth-ocean-atmosphere system over the past 500 Ma: the advent of pelagic carbonate sedimentation, the importance of burial versus early diagenetic dolomite formation, the importance of reverse weathering, and the relationship of these processes to seafloor spreading rates. Results include a general pattern of dolomite abundance during periods of elevated seafloor spreading and alkalinity production, elevated atmospheric CO2 concentrations for most of the Phanerozoic similar to those predicted by GEOCARB, and covariance of seawater sulfate to calcium ratios with magnesium to calcium ratios. These trends are broadly consistent with proxies for seawater composition and the mass-age data of the rock record itself.},
	keywords = {ATMOSPHERIC CARBON-DIOXIDE, CENOZOIC EVOLUTION, Clay minerals, CO2, DOLOMITE PROBLEM, marine-sediments, REVISED MODEL, SEAWATER CHEMISTRY, SECULAR VARIATION, time},
	isbn = {0002-9599},
	doi = {10.2475/ajs.306.3.135 },
	author = {Arvidson, R. S. and Mackenzie, F. T. and Guidry, M.}
}
@article {1958,
	title = {Sediment Cd and Mo accumulation in the oxygen-minimum zone off western Baja California linked to global climate over the past 52 kyr},
	journal = {Paleoceanography},
	volume = {21},
	year = {2006},
	note = {110idTimes Cited:34
Cited References Count:68
},
	month = {Nov 25},
	abstract = {[ 1] Concentrations of organic carbon (orgC), cadmium (Cd), and molybdenum (Mo) were measured in two sediment cores raised from depths of 430 and 700 m within the oxygen-minimum zone (OMZ) off southern Baja California at a temporal resolution of similar to 0.5 kyr over the past 52 kyr. These records are supplemented with diffuse spectral reflectance (DSR) measurements obtained on board ship soon after collection at a resolution of similar to 0.05 kyr. In the core from 700 m depth, a component extracted from the DSR data and the three geochemical proxies generally vary in concert with each other and over a wide range ( 4 - 22\% orgC; 1 - 40 mg/kg Cd; 5 120 mg/kg Mo). Intervals of increased orgC, Cd, and Mo accumulation generally correspond to warm periods recorded in the oxygen-isotopic composition of Greenland ice, with the exception of the Bolling/Allerod which is only weakly expressed off Baja California. Concentrations of the biogenic proxies are higher in the core from 430 m depth, but erratic sediment accumulation before 15 ka precludes dating of the older intervals that are laminated and contain elevated orgC, Cd, and Mo concentrations. The new data provide further evidence of an intimate teleconnection between global climate and the intensity of the OMZ and/or productivity along the western margin of North America. On the basis of a comparison with Cd and Mo records collected elsewhere in the region, we conclude that productivity may actually have varied off southern Baja California by no more than a factor of 2 over the past 52 kyr.},
	keywords = {continental-margin, enhanced preservation, late pleistocene, marine-sediments, nitrogen isotope, northeast pacific waters, organic-carbon preservation, productivity variations, santa-barbara basin, suboxic sediments},
	isbn = {0883-8305},
	doi = {10.1029/2005PA001239},
	author = {Dean, W. E. and Zheng, Y. and Ortiz, J. D. and van Geen, A.}
}
@article {2020,
	title = {Compound-specific radiocarbon dating of the varved Holocene sedimentary record of Saanich Inlet, Canada},
	journal = {Paleoceanography},
	volume = {19},
	year = {2004},
	note = {819piTimes Cited:18
Cited References Count:69
},
	month = {May 1},
	abstract = {[1] The radiocarbon contents of various biomarkers extracted from the varve-counted sediments of Saanich Inlet, Canada, were determined to assess their applicability for dating purposes. Calibrated ages obtained from the marine planktonic archaeal biomarker crenarchaeol compared favorably with varve-count ages. The same conclusion could be drawn for a more general archaeal biomarker (GDGT-0), although this biomarker proved to be less reliable due to its less-specific origin. The results also lend support to earlier indications that marine crenarchaeota use dissolved inorganic carbon (DIC) as their carbon source. The average reservoir age offset DeltaR of 430 years, determined using the crenarchaeol radiocarbon ages, varied by +/-110 years. This may be caused by natural variations in ocean-atmosphere mixing or upwelling at the NE Pacific coast but variability may also be due to an inconsistency in the marine calibration curve when used at sites with high reservoir ages.},
	keywords = {british-columbia, compound-specific radiocarbon dating, crenarchaeol, ionization mass-spectrometry, marine-sediments, mediterranean sea, membrane-lipids, ne pacific, odp leg 169s, organic-matter, pacific-ocean, rapid isolation, Reservoir age, reservoir ages, saanich inlet},
	isbn = {0883-8305},
	doi = {10.1029/2003PA000927},
	url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2\&amp;SrcAuth=Alerting\&amp;SrcApp=Alerting\&amp;DestApp=WOS\&amp;DestLinkType=FullRecord;UT=WOS:000221326700001},
	author = {Smittenberg, R. H. and Hopmans, E. C. and Schouten, S. and Hayes, J. M. and Eglinton, T. I. and Damste, J. S. S.}
}
@article {2086,
	title = {Accumulation of biogenic and lithogenic material in the Pacific sector of the Southern Ocean during the past 40,000 years},
	journal = {Deep-Sea Research Part Ii-Topical Studies in Oceanography},
	volume = {50},
	year = {2003},
	note = {662agTimes Cited:82
Cited References Count:86
},
	month = {2003},
	pages = {799-832},
	abstract = {The (230)Th-normalization technique was applied to surface sediments and down-core records from the Pacific sector of the Southern Ocean between 120degreesW and 170degreesW in order to reconstruct vertical rain rates, corrected for lateral redistribution of sediment. Preserved rain rates of opal, organic carbon and biogenic Ba all indicate that biological productivity south of the Antarctic Polar Front (APF) was much lower than today during the Last Glacial Maximum (LGM), probably in response to increased ice cover. However, by analogy with modern opal fluxes south of the ACC, we show that year-round ice cover is not a prerequisite for very low rates of opal accumulation. Available records from north of the APF indicate little to no change in opal export, in contrast to records from the Indian and Atlantic sectors, which show enhanced opal export north of the APF during the LGM. Glacial records from north of 66degreesS in the Pacific all show lithogenic fluxes that were greater than today, but significantly lower than lithogenic fluxes in the glacial Atlantic and Indian sectors. Together, these new records from the Pacific sector show that during the LGM the three basins of the Southern Ocean were significantly more differentiated than today. The observed inter-basin distribution of lithogenic fluxes and opal burial, and the presumed geographical distribution of increased dust input to the Southern Ocean during the LGM, are consistent with an Atlantic-Indian-Pacific gradient in the degree of iron-stimulated diatom productivity within the zone lying between the APF and the Subantarctic Front. Previous studies, which focused primarily on the Atlantic sector, may have overestimated the glacial increase in the strength of the biological pump in the Southern Ocean. (C) 2002 Elsevier Science Ltd. All rights reserved.},
	keywords = {antarctic circumpolar current, atmospheric co2, biological productivity, Deep-sea, interglacial changes, Last glacial maximum, marine-sediments, organic-carbon, pa-231/th-230 ratio, terrigenous sediment},
	isbn = {0967-0645},
	author = {Chase, Z. and Anderson, R. F. and Fleisher, M. Q. and Kubik, P. W.}
}
@article {2073,
	title = {Radiocarbon dating of individual fatty acids as a tool for refining Antarctic margin sediment chronologies},
	journal = {Radiocarbon},
	volume = {45},
	year = {2003},
	note = {735tqTimes Cited:25
Cited References Count:29
},
	month = {2003},
	pages = {17-24},
	abstract = {We have measured the radiocarbon contents of individual, solvent-extractable, short-chain (C-14, C-16, and C-18) fatty acids isolated from Ross Sea surface sediments. The corresponding C-14 ages are equivalent to that of the post-bomb dissolved inorganic carbon (DIC) reservoir. Moreover, molecular C-14 variations in surficial (upper 15 cm) sediments indicate that these compounds may prove useful for reconstructing chronologies of Antarctic margin sediments containing uncertain (and potentially variable) quantities of relict organic carbon. A preliminary molecular C-14 chronology suggests that the accumulation rate of relict organic matter has not changed during the last 500 C-14 yr. The focus of this study is to determine the validity of compound-specific C-14 analysis as a technique for reconstructing chronologies of Antarctic margin sediments.},
	keywords = {carbon, ice-sheet, marine-sediments, north-atlantic, organic-matter, ross-sea, southern-ocean},
	isbn = {0033-8222},
	author = {Ohkouchi, N. and Eglinton, T. I. and Hayes, J. M.}
}
@article {2092,
	title = {Organic carbon deposition on the North Carolina continental slope off Cape Hatteras (USA)},
	journal = {Deep-Sea Research Part Ii-Topical Studies in Oceanography},
	volume = {49},
	year = {2002},
	note = {607kxTimes Cited:31
Cited References Count:77
},
	month = {2002},
	pages = {4687-4709},
	abstract = {The continental slope off Cape Hatteras, NC is a region of high sediment accumulation and organic matter deposition. Sediment accumulation rates range from 3 to 151 cm kyr(-1). Organic carbon deposition rates are 5-13 moles C m(-2) yr(-1), the highest reported for the slope off the eastern US. Burial efficiencies are 3-40\%. The organic matter deposited is marine in origin and a mix of old and young particles. High organic carbon deposition rates support remineralization throughout the upper 2-3 m of sediment. Deep bioirrigation to depths of 60-100 cm within the seabed affects the biogeochemistry of the sediments by extending the zone of sulfate reduction and by steepening DIC porewater gradients through the non-local exchange of porewater. Stable and radiocarbon isotope mixing curves for porewater dissolved inorganic carbon (DIC) indicate that the dominant source of DIC accumulating in the upper 2-3 m of the seabed is of nearly uniform delta(13)C (-21.10parts per thousand) and Delta(14)C (-546parts per thousand.). (C) 2002 Elsevier Science Ltd. All rights reserved.},
	keywords = {anaerobic methane oxidation, early diagenesis, margin, marine-sediments, MATTER, middle-atlantic-bight, sea-floor, shelf, south, waters},
	isbn = {0967-0645},
	author = {Thomas, C. J. and Blair, N. E. and Alperin, M. J. and DeMaster, D. J. and Jahnke, R. A. and Martens, C. S. and Mayer, L.}
}
@article {2387,
	title = {Biogenic Silica in Lake Baikal Sediments - Results from 1990-1992 American Cores},
	journal = {Journal of Great Lakes Research},
	volume = {20},
	year = {1994},
	note = {Px453Times Cited:46
Cited References Count:20
},
	month = {1994},
	pages = {751-760},
	abstract = {The Lake Baikal Paleoclimate Project is a joint Russian-American program established to study the paleoclimate of Central Asia. During three summer field seasons, duplicate Russian and American coves were taken at a number of sites in different sedimentary environments in the lake. Eight cores returned to the U.S. were quantitatively analyzed for biogenic silica using a single-step 5-hour alkaline leach, followed by dissolved silicon analysis by inductively-coupled-plasma atomic-emission spectroscopy. Sediments of Holocene age in these cores have biogenic silica maxima that range from about 15 to 80 percent. An underlying zone in each core with low biogenic-silica concentrations (0 to 5 percent) dates from the last glacial maximum. The transition from the last glaciation to the present interglaciation, recorded by biogenic silica, began about 13,000 years ago. Biogenic silica profiles from these cores appear to be a good measure of past diatom productivity and a useful basis for paleoclimatic interpretations.},
	keywords = {accumulation, Holocene, Lake Baikal, marine-sediments, opal, Paleoclimate, sediments, silica},
	isbn = {0380-1330},
	author = {Carter, S. J. and Colman, S. M.}
}
