The molar ratios of Mn:Fe in Gulf of Papua
Rigosertib and Sepik River suspended sediment (0.012–0.014 and 0.014, respectively) were slightly lower than average crust (0.017) and much lower than obtained from the linear fit of PMn vs. PFe for equatorial stations in the 200–300 m depth range (0.05, Table 2). The higher ratios in the EUC suggest enrichment due to water column processes and/or multiple sources. For depths within ± 25 m of the equatorial subsurface PFe maximum, the molar PMn
razz Al ratios were even greater, reaching 0.12 (crust is only 0.0033). Interestingly, the equatorial subsurface maximum PMn
razz Fe ratio (0.23) approached the Mn:Fe ratio (0.28–0.3
cool of shallow hydrothermal vent waters near Papua New Guinea (Pitchler et al., 1999) but
nucleosomes vents are only a source to the surface water. PMe in deep-water hydrothermal plumes tend to have much higher ratios (Table 2; Feely et al., 199
cool . We tentatively attribute the Mn enrichment to diagenetic remobilization from margin sediments.
