Influence of Host Rocks on Hydrothermal Sulfide Mineralization (Case Study of the Irinovskiy Cluster, Mid-Atlantic Ridge)

The article presents the results of a study of the mineral and chemical composition of sulfide mineralization of two hydrothermal fields included in the Irinovskiy ore cluster, located at 13°20′ N of the Mid-Atlantic Ridge. The Irinovskoye-1 hydrothermal field is located on the surface of the dome-shaped tectonic structure of the oceanic core complex (OCC), comprising mainly gabbro–peridotite rocks. The Irinovskoye-2 field is located outside the OCC and is associated with both mafic and ultramafic rocks. Three mineral types of ores have been identified in the Irinovskoye-1 ore field: chalcopyrite, marcasite, and sphalerite; two types in the Irinovskoye-2 field, pyrite–marcasite and chalcopyrite–pyrite. Sulfide ores of the Irinovskoye-1 field are characterized by wide variations of geochemical types: Cu, Cu–Zn, Fe–S, Zn, Zn–Cu, while in the Irinovskoye-2 field, only the Cu–Fe type is manifested. For sulfide ores of the Irinovskoye-1 field, in comparison with the second field, higher Cu, Zn, Au, Se, Te, Pb, Ge and lower Fe, Co, and Ni contents have been noted. Variations in the composition of the sulfide ores of the two fields are associated with differences in the host rocks.