Compound-specific δ¹³C and Δ¹⁴C values of <i>n</i>-FAs and n-alkanes in sediment samples

In this study, we present compound-specific carbon isotopic compositions (δ13C and Δ14C) of lipid biomarkers (n-FAs; n-alkanes), and combine these new observations with previously published long-chain FA data on surface sediment samples from a transport pathway spanning the Changjiang estuary and mud belt deposits on the adjacent ECS inner shelf. The primary objectives of this study are to (1) further constrain the proportions and ages of specific OCterr pools (pre-aged OC and fossil OC), and (2) assess spatial variations in burial efficiency of these OCterr pools. These new compound-specific 14C data aid in interpretation of bulk OC isotopic signatures and address existing knowledge gaps regarding key processes that modulate OC burial within the ECS, which carry implications regarding future carbon cycle changes in light of anthropogenic perturbation of the land-ocean continuum.