[SCG58-P07] Evolution and The Total Budget of Fluid in Granitic Magma through Magmatism and Volcanism in The Subduction Zone, NE Japan
Keywords:water budget, fluid evolution, melt inclusion, fluid inclusion
Samples were taken from caldera fill sediment and porphyry copper deposits in NE Japan region. The P-T condition and fluid composition are measured from the melt inclusion in quartz from the caldera fill sediments and fluid inclusions in the granite intrusion and the veinlets. The sample is divided into several types, namely volcanic rock samples from caldera fill sediment, granite from porphyry copper deposits, and the veinlets contained in the granite body including quartz vein, glassy vein, and hydrothermal breccia vein. In volcanic rock samples, quartz crystals were picked, encased in resin and polished for major element and water content analysis. In granite samples and veinlets, the rock thin sections were made for fluid inclusion microthermometry analysis and fluid diffusion analysis using apatite mineral.
Water budget in the upper crust is estimated from caldera fill sediments to be 2.3–7.6 t /yr/m. Water budget in the deeper part of the crust can then be determined from porphyry copper deposits.