1 EVOLUTION OF MAGMATIC FLUIDS IN ACTIVE VOLCANIC HYDROTHERMAL SYSTEMS: A THERMODYNAMIC MODEL (EBEKO

• Main Authors: Northern Kuriles, Paramushir Island, Bessonova Elizaveta Pavlovna
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Key words; physical-chemical model; volcano-hydrothermal system; magmatic fluid; Kamchatka
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.518.2325; http://geo.web.ru/conf/khitariada/1-2003/informbul-1_2003/magm-20e.pdf

Evolution of fluids in igneous and hydrothermal activity is a key point in understanding magmatic processes. Overview papers on melt inclusions and quench glasses [1, 2] contain a collection of 5000 reliable analyses of volatiles. A large database has been obtained on high-temperature (>700°C) hydrothermal systems [3] in which gas composition approaches the composition of fluids in magmatic sources. All these data can be synthesized in a physical-chemical model. Methods We applied the program "Petrofluid " to estimate the fluid flow and the vertical distribution of temperature and pressure in rocks above the magmatic chamber [4] based on standard and specific parameters. The standard parameters included initial melt temperature, solidus, specific heat, thermal conductivity, density of melt and fluid, and nonuniform effective porosity and permeability of the wall rock; contents of volatiles in the melt and lithology of rocks above the source were used as additional specific parameters. The temperature and pressure computed with "Petrofluid", as well as the compositions of rocks, fluid, and meteoric water, were used in the thermodynamic model implemented as a software package «SELECTOR-WIN», in the flow reactor version [5]. The compositions were taken from our field data (several active volcanoes on Kamchatka) and from literature. The modelling