Ore Mineralization in Pleistocene Sediments of Long Strait (East Siberian Sea)

A mineralogical–geochemical study of Late Pleistocene bottom sediments of the LV 77-10 core collected in the central part of Long Strait was carried out. Two horizons of sediments enriched in Au, Pd, and Ag, varying in the chemical composition have been established. Using scanning electron microscopy and X-ray microanalysis, a wide spectrum of ore minerals was found, including the most common pyrite–marcasite, as well as arsenopyrite, chalcopyrite, chalcocite, native Au, Ag, and Pb, acanthite, and complex phases of Fe–Ni–Cr and Ag–Cu–Pb–Zn. It is concluded that ore particles were transported together with wood fragments and some of them were formed as a result of chemical reactions in delta facies deposits in coastal marine environments.