Paleo-redox context of the Mid-Devonian Appalachian Basin and its relevance to biocrises

The Devonian Period witnessed the expansion of vascular land plants and an atmospheric oxygenation event associated with enhanced organic mass burial. The deposition of organic-rich shales (e.g. black shales of the Marcellus subgroup) and several biotic crises in the marine realm have been linked to Devonian ocean anoxia. However, it is not clear how redox conditions evolved in different parts of the water column in such a context of dynamic...