The expansion of dead zones was arguably an efficient kill mechanism during several of the most devastating animal crises in Earth history, including during the Cambrian6,7. When anoxia impinges on the seafloor, it changes the behavior of redox sensitive elements and leads to trace metal ...
Molybdenum (Mo) and uranium (U) isotopes in ancient sediments have become powerful redox-sensitive proxies that can track global marine anoxia including the proportion of sediment buried in anoxic versus oxic settings in the oceans. Both systems build on the same two fundamental attributes: 1) ...
2004). In our previous studies, we identified evidence for anoxia and for water-mass denitrification and sulfate reduction on the relatively deep slope/basin along the continental margin, prior to the extinction (Fig. 1c; Isozaki et al. 2008; Saitoh et al. 2013a, 2013b, 2014a). Here, ...