text: Under euxinic conditions, some trace elements such as Mo, U, V, Cd, Cu, Tl, Ni, Sb, and Zn, become insoluble. This means that euxinic sediments would contain more of the solid form of these elements than the background seawater. For example, Molybdenum and other trace metals become insoluble in anoxic and sulfidic conditions, so over time the seawater becomes depleted of trace metals under conditions of persistent euxinia, and preserved sediments are relatively enriched with molybdenum and other trace elements.