@article {2952,
	title = {Terrestrial organic carbon age and reactivity in the Yellow River fueling efficient preservation in marine sediments},
	journal = {Earth and Planetary Science Letters},
	volume = {585},
	year = {2022},
	month = {Jan-05-2022},
	pages = {117515},
	abstract = {The Yellow River is one of the largest suppliers of sediments and organic carbon (OC) to the ocean. Previous studies have revealed that OC transported by the Yellow River largely derives from the erosion of the Chinese Loess Plateau, which is dominated by pre-aged soil carbon and could be efficiently preserved in marine sediments. Here, we used ramped oxidation radiocarbon analysis (RPO-14C) to characterize the age and reactivity distribution of OC in two Yellow River suspended sediment samples and six Bohai Sea and Yellow Sea (BS{\textendash}YS) surface sediments from a transect along the sediment transport pathway. RPO-14C independently characterizes the full spectrum of OC thermal stability and isotope compositions to reveal the source, age and reactivity structure of OC transported by the Yellow River and preserved in Chinese marginal sea sediments. We calculated the activation energy (E) distribution{\textemdash}a proxy for bonding environment and by extension reactivity{\textemdash}which, combined with 14C and stable carbon isotope (δ 13C) compositions, reveals OC origin and stability. Our data suggest that 96\% of OC in Yellow River suspended sediments is biospheric and weathered petrogenic, while unweathered petrogenic OC only accounts for 4\% which is almost an order of magnitude lower than the fossil OC estimates (32\%) based on compound specific 14C analysis. RPO data reveal the prevalence of aged biospheric loess OC in the Yellow River. We use δ 13C, 14C and RPO-derived activation energy data to quantify the contribution of terrestrial OC to surface sediments in the BS{\textendash}YS. The resulting estimates of terrestrial OC proto-burial efficiencies yield an average value of 89 {\textpm} 30\%, revealing overall very high terrestrial OC preservation in the BS{\textendash}YS. Additionally, and somewhat counter intuitively, we find that the preservation of terrestrial OC decreases with increasing E. This pattern may arise from an enhanced preservation of a pre-aged C4 plants derived fraction of the loess-derived OC associated with secondary clays characterized by smaller grain size and higher surface area. Alternatively, the high E component of the Yellow River OC might comprise partially weathered petrogenic carbon, undergoing further mineralization during transport from rivers to marginal sea sediments via marine organic matter priming.},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2022.117515},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X22001510},
	author = {Zhang, Yushuang and Galy, Valier and Yu, Meng and Zhang, Hailong and Zhao, Meixun}
}
@article {2921,
	title = {Climate control on terrestrial biospheric carbon turnover},
	journal = {Proceedings of the National Academy of Sciences},
	volume = {118},
	year = {2021},
	month = {Nov-02-2022},
	pages = {e2011585118},
	abstract = {Terrestrial vegetation and soils hold three times more carbon than the atmosphere. Much debate concerns how anthropogenic activity will perturb these surface reservoirs, potentially exacerbating ongoing changes to the climate system. Uncertainties specifically persist in extrapolating point-source observations to ecosystem-scale budgets and fluxes, which require consideration of vertical and lateral processes on multiple temporal and spatial scales. To explore controls on organic carbon (OC) turnover at the river basin scale, we present radiocarbon (C-14) ages on two groups of molecular tracers of plant-derived carbon-leaf-wax lipids and lignin phenols-from a globally distributed suite of rivers. We find significant negative relationships between the C-14 age of these biomarkers and mean annual temperature and precipitation. Moreover, riverine biospheric-carbon ages scale proportionally with basin-wide soil carbon turnover times and soil C-14 ages, implicating OC cycling within soils as a primary control on exported biomarker ages and revealing a broad distribution of soil OC reactivities. The ubiquitous occurrence of a long-lived soil OC pool suggests soil OC is globally vulnerable to perturbations by future temperature and precipitation increase. Scaling of riverine biospheric-carbon ages with soil OC turnover shows the former can constrain the sensitivity of carbon dynamics to environmental controls on broad spatial scales. Extracting this information from fluvially dominated sedimentary sequences may inform past variations in soil OC turnover in response to anthropogenic and/or climate perturbations. In turn, monitoring riverine OC composition may help detect future climate-change-induced perturbations of soil OC turnover and stocks.},
	keywords = {Carbon cycle, carbon turnover times, fluvial carbon, plant biomarkers, radiocarbon},
	issn = {0027-8424},
	doi = {10.1073/pnas.2011585118},
	url = {https://www.researchgate.net/publication/349357864_Climate_control_on_terrestrial_biospheric_carbon_turnover},
	author = {Eglinton, Timothy I. and Galy, Valier V. and Hemingway, Jordon D. and Feng, Xiaojuan and Bao, Hongyan and Blattmann, Thomas M. and Dickens, Angela F. and Gies, Hannah and Giosan, Liviu and Haghipour, Negar and Hou, Pengfei and Lupker, Maarten and McIntyre, Cameron P. and Montlu{\c c}on, Daniel B. and Peucker-Ehrenbrink, Bernhard and Ponton, Camilo and Schefu{\ss}, Enno and Schwab, Melissa S. and Voss, Britta M. and Wacker, Lukas and Wu, Ying and Zhao, Meixun}
}
@article {2661,
	title = {On the Origin of Aged Sedimentary Organic Matter Along a River-Shelf-Deep Ocean Transect},
	journal = {Journal of Geophysical Research: Biogeosciences},
	volume = {124},
	year = {2019},
	month = {Jun-08-2021},
	pages = {2582 - 2594},
	abstract = {To assess the influences of carbon sources and transport processes on the C-14 age of organic matter (OM) in continental margin sediments, we examined a suite of samples collected along a river-shelf-deep ocean transect in the East China Sea (ECS). Ramped pyrolysis-oxidiation was conducted on suspended particulate matter in the Yangtze River and on surface sediments from the ECS shelf and northern Okinawa Trough. C-14 ages were determined on OM decomposition products within different temperature windows. These measurements suggest that extensive amounts of pre-old (i.e., millennial age) organic carbon (OC) are subject to degradation within and beyond the Yangtze River Delta, and this process is accompanied by an exchange of terrestrial and marine OM. These results, combined with fatty acid concentration data, suggest that both the nature and extent of OM preservation/degradation as well as the modes of transport influence the C-14 ages of sedimentary OM. Additionally, we find that the age of (thermally) refractory OC increases during across-shelf transport and that the age offset between the lowest and highest temperature OC decomposition fractions also increases along the shelf-to-trough transect. Amplified interfraction spread or C-14 heterogeneity is the greatest in the Okinawa Trough. Aged sedimentary OM across the transect may be a consequence of several reasons including fossil OC input, selective degradation of younger OC, hydrodynamic sorting processes, and aging during lateral transport. Consequently, each of them should be considered in assessing the C-14 results of sedimentary OM and its implications for the carbon cycle and interpretation of sedimentary records.},
	keywords = {Carbon cycle, hydrodynamic processes, organic carbon, radiocarbon, sediments},
	issn = {2169-8953},
	doi = {10.1029/2019JG005107},
	url = { https://doi.org/10.1029/2019JG005107},
	author = {Bao, Rui and Zhao, Meixun and McNichol, Ann and Wu, Ying and Guo, Xinyu and Haghipour, Negar and Eglinton, Timothy I.}
}
@article {2642,
	title = {Temporal constraints on lateral organic matter transport along a coastal mud belt},
	journal = {Organic Geochemistry},
	volume = {128},
	year = {2019},
	month = {Jan-02-2019},
	pages = {86 - 93},
	abstract = {Constraints on timescales of lateral transport of sedimentary organic carbon (OC) over continental shelves and associated influences on the distribution and abundance of OC remain sparse. Preferential degradation of labile, young OC during lateral transport results in apparent {\textquotedblleft}diagenetic aging{\textquotedblright} of OC. Additionally, sediment translocation can also result in {\textquotedblleft}transport time-associated aging{\textquotedblright} of associated organic matter (OM) as a function of the lateral transport time (LTT). Here, we use a coupled thermal decomposition and radiocarbon (14C) approach to constrain timescales of lateral transport and concomitant loss of OC associated with different grain size fractions of sediments collected from two locations \~{}275 km apart along a dispersal pathway on the inner shelf of the East China Sea. The 14C age contrasts between corresponding thermal fractions are used to distinguish these two components of sedimentary OM {\textquotedblleft}aging{\textquotedblright}. To minimize interferences from hydrodynamic sorting and diagenetic aging of OC accompanying lateral transport, we assess 14C age differences of decomposition products from the most thermally-refractory OC components associated with specific grain size fractions between locations. We show that LTTs vary among different grain size fractions, and examine relationships between LTTs and sedimentary OC loss in order to assess the decomposition of OC as a consequence of lateral transport. We suggest that the decomposition of OC associated with protracted lateral transport exerts a strong influence on OC burial efficiency, with broad implications for carbon cycling over continental shelves.},
	keywords = {14C aging, Continental shelf seas, East China Sea, Mud belt, organic matter, Sediment resuspension},
	issn = {01466380},
	doi = {10.1016/j.orggeochem.2019.01.007},
	url = {https://www.sciencedirect.com/science/article/pii/S0146638019300075},
	author = {Bao, Rui and Zhao, Meixun and McNichol, Ann and Galy, Valier and McIntyre, Cameron and Haghipour, Negar and Eglinton, Timothy I.}
}
@article {2692,
	title = {Organic Carbon Aging During Across-Shelf Transport},
	journal = {Geophysical Research Letters},
	volume = {45},
	year = {2018},
	month = {Apr-08-2020},
	pages = {8425 - 8434},
	abstract = {Compound-specific radiocarbon analysis (CSRA) was performed on different grain-size fractions of surficial sediments to examine and compare lateral transport times (LTTs) of organic carbon. 14C aging of long-chain leaf wax fatty acids along two dispersal pathways of fluvially-derived material on adjacent continental margins implies LTTs over distances of ~30 to 500 km that range from hundreds to thousands of years. The magnitude of aging differs among grain size fractions. Our finding suggests that LTTs vary both temporally and spatially as a function of the specific properties of different continental shelf settings. Observations suggest that 14C aging is widespread during lateral transport over continental shelves, with hydrodynamic particle sorting inducing age variations among organic components residing in different grain sizes. Consideration of these phenomena is of importance for understanding carbon cycle processes and interpretation on sedimentary records on continental margins.},
	issn = {0094-8276},
	doi = {10.1029/2018GL078904},
	url = {https://core.ac.uk/download/pdf/222887698.pdf},
	author = {Bao, Rui and Uchida, Masao and Zhao, Meixun and Haghipour, Negar and Montlucon, Daniel and McNichol, Ann and Wacker, Lukas and Hayes, John M. and Eglinton, Timothy I.}
}
@article {2766,
	title = {Sources and radiocarbon ages of aerosol organic carbon along the east coast of China and implications for atmospheric fossil carbon contributions to China marginal seas},
	journal = {Science of The Total Environment},
	volume = {619-620},
	year = {2018},
	month = {Jan-04-2018},
	pages = {957 - 965},
	abstract = {Aerosol deposition is an important mechanism for the delivery of terrestrial organic carbon (OC) to marginal seas, but OC age characteristics of aerosols are not well constrained and their contributions to sediment OC burial have not been quantified. Total suspended particle samples were collected along the east coast of China at Changdao (CD), Qingdao (QD) and Huaniao Island (HNI), and were analyzed for total organic carbon (TOC) isotopes (13C and 14C) in order to bridge this information gap. TOC δ13C and Δ14C values ranged from - 23.6 to - 30.5{\textperthousand}, and - 153 to - 687{\textperthousand}, respectively, with the latter corresponding to 14C ages ranging from 1280 to 9260 yr. Estimated contributions of fossil carbon to TOC based on 14C mass balance approach ranged from 26 to 73\%, with strong seasonal variations in fossil carbon observed at CD. Fossil carbon at CD showed the highest proportion (73\%) in winter, reflecting anthropogenic emissions and the lowest proportion (26\%) in summer, caused by biomass contribution (annual ave., 52\% {\textpm} 17\%). In contrast, the fossil carbon at both QD (57{\textendash}64\%) and HNI (57{\textendash}67\%) dominated throughout the year, reflecting local anthropogenic influences and long-range transport. Mass balance estimates indicate that atmospheric deposition and riverine export accounted for 31\% and 69\% of fossil carbon inputs to the China marginal seas (CMS) respectively, with fossil carbon burial efficiencies approaching 100\% in the CMS. On a global scale, an atmospheric fossil carbon deposition flux of 17.2 Tg C yr- 1 was estimated, equivalent to 40\% of the estimated fluvial flux to the ocean, and potentially accounting for 24{\textendash}41\% of fossil OC burial in marine sediments. Therefore, the atmospheric deposition constitutes an important source of fossil carbon to marine sediments, and could play a key role in regional and global scale OC budgets and biogeochemical cycles.},
	keywords = {AEROSOLS, China marginal seas, Fossil carbon, Radiocarbon (14C) tracer, Total organic carbon},
	issn = {00489697},
	doi = {10.1016/j.scitotenv.2017.11.201},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S004896971733259X},
	author = {Yu, Meng and Guo, Zhigang and Wang, Xuchen and Eglinton, Timothy Ian and Yuan, Zineng and Xing, Lei and Zhang, Hailong and Zhao, Meixun}
}
