1388 / 2019-08-10 06:21:49

Riverine sediment as a significant source to global marine Nd budge: Nd isotope estimate the lithogenic release flux to marine waters

6、海洋地球科学 > 专题5：从流域到深海：沉积物的产生，搬运和埋藏

Neodymium (Nd) isotope compositions (εNd) and Y/Ho ratio in seawater samples collected in the third largest river estuary (Changjiang River) along a salinity gradient were analyzed to deal with the Nd budget in the oceans. The Y/Ho ratio exhibits an increasing trend from the Changjiang river (Y/Ho=57) to the ECS (Y/Ho=98), and the εNd remain constant at -12.0±0.3 (s.d., n=2) in the low-salinity area (<0.5). In the Changjiang estuary fresh-salt water mixing area (S<20.6) approximately 2.9±1.1% of NdSPM is released to the dissolved Nd pool from lithogenic sediments. Our results estimated that 650±370 t of Nd is transported through China's marginal seas to the northwest Pacific Ocean, this is approximately equal to the global dissolved river-Nd load. The findings of this study are highly significant for a better understanding of estuarine Nd cycle and marine Nd balance.