Local Conceptual Model of the North-Paramushir Hydrothermal System (North Kuril Island)

Abstract

Paramushir Island is one of the largest Islands in the Great Kuril Range. The northern part of the Island is formed by the Vernadsky Ridge, shaped by merged structures of Quaternary volcanoes and has folded-block structure. The volcano Krasheninnikov was formed by young postglacial pyroxene-andesite and andesi-basalt lavas. In the roots of the volcano, for a long time, there was a magmatic melt migration of andesi-basalt composition. A study of hydrothermal manifestations located in the north-eastern slope of the tectonic structure of the Krasheninnikov volcano was carried out as a part of an assessment of the North-Paramushir hydrothermal-magmatic system. The authors constructed a geological profile up to 1115 m depth based on data from well 4-GP, characterized the geochemistry and hydrothermal-metasomatic changes of rocks, and the chemical composition of mineralized thermal waters discharged in Ptichya river. Moreover, the presence of high temperature chloride fluids, located in the roots of the volcano, was identified, the heat flow was evaluated and the fault zones in the area of Krasheninnikov volcano were defined. For consideration is a description of the conceptual model of North-Paramushir hydrothermal system including three main sections: the Krasheninnikov volcano (the upflow zone of hydrothermal fluids), the northeastern slope of the volcano (zone of lateral flow) and the Pacific Ocean (a discharge zone of pressurized and low-temperature hydrothermal carbonate fluid).