Significant contribution of seamounts to the oceanic rare earth elements budget

The rare earth elements (REEs) are a crucial resource and frequently used as proxies for reconstructing paleomarine environmental conditions. However, many details concerning the marine REE cycling, including relationship between benthic diffusion of REEs and seamounts, remain unclear. Here we present REE and trace elements data of porewater and seawater from the seamounts area and abyssal plain, respectively. Our results evidence that dissolved porewater REE, Mn and Al in sediments near seamount are much higher than those at abyssal plain, which lead to a substantial benthic source of REE to ocean at regions with seamounts. The REE enrichment processes in porewater at uneven seafloor are mainly based on re-suspension associated with the strong currents and/ or partial dissolution of detrital from seamounts. We suspect this process to occur in other world regions with seamounts and infer that these sediments can account for a significant contributor to the oceanic REE budget.