Regional Structural Positions of High Temperature Hydrothermal Systems of Kamchatka

Abstract

Structural conditions of locations with high-temperature hydrothermal systems in Kamchatka are analyzed herein. It is shown that hydrothermal systems are located within the boundary of Pliocene-Quaternary volcanic belts and confined to areas where these belts are superimposed on deep troughs of the basement. The main structural elements determining the position of high-temperature hydrothermal systems are faults that bound such troughs. These faults are rarely exposed on the surface, they are usually overlapped with a powerful sedimentary -volcanogene cover, but systems of recent (mainly late Pleistocene-Holocene) fractures stretching along the abyssal boundary are formed above them in this cover. Hydrothermal systems are located in places where faults bounding troughs of the basement intersect complicating faults having transversal or intersecting position. Stable and long-existing zones of permeability are formed in these sites. Magma and hydrothermal fluids are constantly rising along them and complex volcanic structures differing in polyorifice volcanicity and presence of extrusive domes of dacite and rhyolite composition are formed on the surface. Thermal manifestations are usually located within and the boundary of such structures and around them. It is shown that lateral displacement of hydrothermal systems relative to these structures is connected with inclination of faults bounding troughs of the basement. Sometimes it is directed to the side of rise of fault planes.