“…In such cases, authigenic Mo is typically ~1‰ lighter than the associated seawater (Arnold et al., ; Barling et al., ; Neubert, Nägler, & Böttcher, ; Poulson Brucker et al., ; Poulson, Siebert, McManus, & Berelson, ; Siebert, McManus, Bice, Poulson, & Berelson, ). In the modern ocean, the isotopic composition of Mo is about +2.3‰ (Barling et al., ; Nägler et al., ; Nakagawa et al., ; Siebert et al., ), which is significantly heavier than the riverine input of +0.7‰ (Archer & Vance, ). This disparity is maintained through dominance by the Mn oxide sink in today's well‐ventilated oceans, exporting large amounts of the lighter 95 Mo.…”