Japan Geoscience Union Meeting 2015

Presentation information


Symbol S (Solid Earth Sciences) » S-MP Mineralogy & Petrology

[S-MP44] Dynamics of melt, ductile and brittle rock mass and energy system

Mon. May 25, 2015 6:15 PM - 7:30 PM Convention Hall (2F)

Convener:*Noriyoshi Tsuchiya(Graduate School of Environmental Studies, Tohoku University), Hiroshi Asanuma(AIST)

6:15 PM - 7:30 PM

[SMP44-P04] Natural Analogue of Supercritical Geothermal Reservoir

*Noriyoshi TSUCHIYA1, Ryoichi YAMADA1, Masaoki UNO1 (1.Graduate School of Environmental Studies, Tohoku University)

Keywords:Supercritical fluid, Geothermal reservoir, Granite-Porphyry system

To understand the geological properties of a supercritical geothermal reservoir, we investigated a granite?porphyry system as
a natural analog. Quartz veins, hydrothermal breccia veins, and glassy veins are present in Neogene granitoids, Tohoku Japan.
The glassy veins formed at 500-550 C under lithostatic pressures, and then pressures dropped drastically. The solubility of
silica also dropped, and the quartz veins formed under hydrostatic pressures. Connections between the lithostatic and hydrostatic
pressure regimes were key to the formation of the hydrothermal breccia veins, and the granite?porphyry system provides useful
information for understanding supercritical geothermal reservoirs.