EMODnet Geology WP7 Marine Minerals Cobalt Rich Ferro-manganese Crusts (Area)

Marine ferromanganese crust deposits are potential mineral resources that contain base metals and strategic and critical elements such as cooper (Cu), cobalt (Co), vanadium (V), nickel (Ni), titanium (Ti), platinum group elements (PGEs) or rare earth elements (REEs). Traditionally, marine precipitates are defined as: a) purely hydrogenetic when all constituents are derived from cold seawater, (b) diagenetic, when all constituents are derived from cold sediment pore water; and (c) hydrothermal when precipitation occurs in the vicinity of hydrothermal vent sites from fluids with temperatures higher than ambient bottom waters. Hydrogenetic Fe-Mn crusts occur throughout the global ocean on seamounts, ridges and plateaus, where currents have kept the rocks free of sediment for millions of years. Some ferromanganese (Fe-Mn) crusts exhibit a mixed origin, primarily either hydrothermal-hydrogenetic or hydrogenetic-diagenetic (Hein et al., 2000; 2003; 2013; Muiños et al. 2013; Bau et al., 2014; Marino et al., 2017). 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. 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 (Hein et al., 1993; 2016; González et al., 2016). 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. Research on phosphorites and Fe-Mn deposits have traditionally had two main purposes: 1) their economic importance as potential sources of phosphate for agriculture and metals, rare earth elements plus yttrium (REY), among others, required for high-tech and green-tech applications; and 2) their potential as archives for the study of paleoceanographic events. Phosphorite and ferromanganese crust deposits are frequently associated, and widespread on the seafloor of continental shelves and slopes along the western continental margins of the Atlantic Ocean, also occurring on seamounts, banks and plateaus. They are especially abundant on the volcanic seamounts and ridges from the Macaronesia region (Canary-Madeira-Açores Islands). The proposal is to compile fragmented marine data products and metadata on areas explored and investigated for ferromanganese crusts and phosphorites and make them available through an information platform. The portal will provide access to data and metadata held by each organisation based on standards developed in the Geo-Seas and EMODnet-Geology project and data products compiled at a scale of 1:250,000. This WP will establish the location, extension and formation processes of individual European ferromanganese crusts and phosphorites; how critical metals are concentrated on the mineralisation; where they occur and why they are associated with particular minerals. This is a necessary study, to identify areas with potential CRM deposits as sources of strategic and rare metals within the EU and associated countries waters.