Manganese metalliferous sediments of the Deryugin Basin (Sea of Okhotsk): Chemical composition and geological setting

This paper reports the results of an investigation of the chemical composition and distribution of manganese-rich metalliferous sediments in the Deryugin Basin. They compose an upper sedimentary layer up to 30 cm thick within a strip up to 40 km wide and 180 km long in the central part of the basin along the East Deryugin suture zone bounding the Deryugin sedimentary basin to the east. The sediments are enriched relative to the regional background composition in Mn (by a factor of 35); Au; Ni; Zn; Co (by a factor of 3–5); and, locally, in Mo, V, Ba, Cu, Pb, and Hg. It was supposed that their formation was controlled by several processes: precipitation of Mn and some other trace elements from hydrothermal plumes of seawater that occasionally form above submarine hot vents in the northern part of the basin, precipitation from anoxic bottom waters at the eastern boundary of the Deryugin sedimentary basin, and early diagenetic migration of Mn into the surface sediments.