Shu, Q.; Du, Y.; Chen, Z.; Zhang, A., and Ye, H., 2024. Factors influencing carbon burial in Holocene sediments of the coastal zone of Subei Basin (eastern China). Journal of Coastal Research, 40(2), 268–277. Charlotte (North Carolina), ISSN 0749-0208.

Coastal zone sediments are effective recorders of carbon burial changes in coastal areas under different sedimentary environments. Based on analysis of age, grain size, total carbon (TC), total organic carbon (TOC), total inorganic carbon (TIC), in situ density, and other sediment indicators in the Gangxi (GX) profile of Jianhu County in the Subei Basin, eastern China, the burial fluxes of various carbon components were calculated, and potential factors influencing the carbon content and carbon burial fluxes were examined. The study results showed that the changes in carbon content in the GX profile were closely related to the depositional environment, and the TOC content was higher in the deep freshwater depositional environment. The TIC content was higher in tidal flats and shallow-sea depositional environments. The carbon burial fluxes in the GX profile sediments were affected by factors such as deposition rate and in situ density. The deposition rate was significantly positively correlated with the TC, TOC, and TIC burial fluxes (0.760, 0.59, and 0.86, respectively). The in situ density was significantly negatively correlated with the TC and TOC burial fluxes (–0.62, and –0.71, respectively); however, the negative correlation with TIC was not significant (–0.11). Regional comparisons show that the TOC contents and burial fluxes recorded in the GX profile sediments were lower than those in the modern coastal tidal flat sediments, coastal wetlands, and lakes in eastern China, possibly due to the long burial time of the sediments in the GX profile. During the burial process, part of the organic carbon was mineralized and decomposed through the action of microorganisms. The burial fluxes of organic carbon in the coastal sediments were relatively high, and they represent an effective carbon sequestration sink.