マグマ性熱水系の地球化学 (1990年度日本地球化学会奨励賞受賞記念) [in Japanese] Geochemistry of magmatic hydrothermal system [in Japanese]
Access this Article
Search this Article
Magmatic hydrothermal solution is formed as a consequence of crystallization of magmas at shallow crust. The ascending magmatic hydrothermal fluid through the crust inevitably experiences large pressure and temperature changes. Pressure-temperature condition of the magmatic hydrothermal system overlaps with the subcritical region of NaCl-H<sub>2</sub>O system, and the phase separation is regarded as a common and important differentiation process of the fluids. Since compressibility and thermal expansibility of hydrothermal fluids are large at high temperature and low pressure condition, large pressure and temperature dependence of equilibrium constants is expected in the P-T regions of the system. Large variations in the appearance of magmatic hydrothermal system are concluded to be due to the phase separation and the reactions with large pressure and temperature dependence under the large pressure and temprature gradients.
Chikyukagaku 25(1), 27-38, 1991
The Geochemical Society of Japan