The development and application of geochemical techniques to identify redox conditions in
modern and ancient aquatic environments has intensified over recent years. Iron (Fe)
speciation has emerged as one of the most widely used procedures to distinguish different
redox regimes in both the water column and sediments, and is the main technique used to
identify oxic, ferruginous (anoxic, Fe (II) containing) and euxinic (anoxic, sulfidic) water
column conditions. However, an international sediment reference material has never been …