Hydrothermal Deposits: Evidence for Pliocene-Quaternary Volcanism in the Central Part of the Sea of Okhotsk

摘要

Low-temperature hydrothermal deposits with Fe-Mn mineralization are reported from many areas of the World Ocean. They are confined to spreading zones, zones of intense rifting, and underwater volcanoes located both in the oceans and back-arc basins f 1-7 and others]. Paragenesis of ferromanganese crusts with ferruginous smectites-nontronites is one of the most important criteria for recognizing the hydrothermal origin of these sediments. Such a mineral association is also established in the Sea of Okhotsk in several underwater volcanoes of the Kuril island arc [7-9] and in the northeastern part of the Kuril deep basin [10]. In addition, ferromanganese deposits were also found in other areas of the Sea of Okhotsk beyond known areas of young (Quaternary) island-arc volcanism manifestations [9, 11, 12]. Dissimilar to typical hydrothermal deposits, they do not associate with ferruginous smectites-nontronites and judging from some features are of a hydrogene nature [12].