A Structure Model for the Uzon-Geyser Hydrothermal System in Kamchatka

Abstract

A structure model for the Uzon Geyser hydrothermal system in the Eastern volcanic belt of Kamchatka is described relative to hydrothermal activity. The system is controlled by the volcano tectonic pre Pleistocene dome, in the center of which a series of eruptions occurred and subsidence calderas formed. Depths were calculated for near surface subsidiary magma chambers of acid composition beneath the calderas and for the deep magma chamber located in the zone of low density of the regional NNE oriented deep fault. The western portion of the structure, the Uzon caldera, is an almost closed hydrogeological structure and the eastern portion is opened by a NNW oriented tension rupture (spreading), the intense activity which is Holocene predetermines the functioning of the thermally anomalous zone of the Geyser Valley. The hydrothermal system is assigned to the epochs of acid magma chamber emplacement when the upsurge of tectonic movements and formation of "compression - tension" structures occurred. The Uzon Geyser hydrothermal system, in terms of chemical composition of its water and enthalpy has analogs in the other volcanic areas (New Zealand, California, etc) which are intensely drilled for geothermal energetic purposes. Their exploration will develop an understanding of the mechanism of formation and structural characteristics of paleohydrothermal systems.