In many places, marine phosphorites are accompanied by Fe-Mn crust mineralisations on the seafloor of continental shelves and slopes along the western continental margins of the Atlantic Ocean. They tend to occur in waters of medium depth. Some thick Fe-Mn crusts also contain carbonate fluorapatite, which was incorporated into the crusts during specific periods prior to middle Miocene during main Cenozoic episodes of phosphatization. These deposits are related to strong upwelling along the continental margins and seamounts. Marine phosphorites are known to concentrate rare earth elements and yttrium (REY) during early diagenetic formation. Although there are several references to ferromanganese crusts and their association with phosphorites in the literature, the genetic models for explaining their relationship and metal concentration are still poorly understood.

Seafloor massive sulphides (SMS) are modern equivalents of on-shore (ancient) volcanogenic massive sulphides (VMS) which have constituted important mining targets through history in many regions of Europe. VMS deposits are generally stratiform accumulations of sulphides formed at or just beneath the seafloor as a result of volcano-magmatic activity. The sulphides are precipitated from hot hydrothermal solutions when they come in contact with cold seawater. Deposits of this type that form today are known as seafloor massive sulphides, and the associated sulphurous plumes are called black and white smokers. Data from ancient VMS deposits are essential for the present-day understanding of the formation, structure and composition of SMS deposits. VMS deposits are among the most important deposit types for a number of commodities, including copper (Cu), zinc (Zn), lead (Pb), silver (Ag) and gold (Au). In addition, they may contain economic grades of cobalt (Co), tin (Sn), barium (Ba), sulphur (S), selenium (Se), indium (In), bismuth (Bi), tellurium (Te), gallium (Ga) and germanium (Ge). Several of these minor constituents are considered critical raw materials by the EU. The modern equivalents are found on the ocean floor, along present-day spreading ridges and volcanic centres, and are the target of steadily increasing attention as a possible source for both base, precious and special metals.

Spatial distribution of occurrences of Phosphor in European land and sea and respective genetic types.