TY - JOUR T1 - Temporal constraints on lateral organic matter transport along a coastal mud belt JF - Organic Geochemistry Y1 - 2019 A1 - Bao, Rui A1 - Zhao, Meixun A1 - McNichol, Ann A1 - Galy, Valier A1 - McIntyre, Cameron A1 - Haghipour, Negar A1 - Eglinton, Timothy I. KW - 14C aging KW - Continental shelf seas KW - East China Sea KW - Mud belt KW - organic matter KW - Sediment resuspension AB - 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 “diagenetic aging” of OC. Additionally, sediment translocation can also result in “transport time-associated aging” 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 “aging”. 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. VL - 128 UR - https://www.sciencedirect.com/science/article/pii/S0146638019300075 ER -