Overlooked shelf sediment reductive sinks of dissolved rhenium and uranium in the modern ocean.

ABSTRACT: Rhenium (Re) and uranium (U) are essential proxies in reconstructing past oceanic oxygenation evolution. However, their removal in continental shelf sediments, hotspots of early diagenesis, were previously treated as quantitatively unimportant sinks in the ocean. Here we examine the sedimentary reductive removal of Re and U and their coupling with organic carbon decomposition, utilizing the ²²⁴Ra/²²⁸Th disequilibria within the East China Sea shelf. We identified positive correlations between their removal fluxes and the rates of sediment oxygen consumption or organic carbon decomposition. These correlations enable an evaluation of global shelf reductive sinks that are comparable to (for Re) or higher than (~4-fold for U) previously established suboxic/anoxic sinks. Th

SUBMITTER: Hong Q 

PROVIDER: S-EPMC11519890 | biostudies-literature | 2024 May

REPOSITORIES: biostudies-literature