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About
The hydrothermal portion of the laboratory includes four horizontal hydrothermal (water-pressurized) furnaces and three vertical furnaces that can reach temperatures of up to 950°C and pressures of up to 300 MPa. Individual pressure vessels can be isolated from the main pressure line permitting rapid exploration of Pressure-Temperature space (e.g. simultaneous examination of multiple P-T conditions). The experimental system is pressurized with water and is ideal for studying andesites, dacites, rhyolites, and other silicic magmas. Pressure vessels in the horizontal furnaces can be quenched in <30 s whereas the vessels in the vertical furnaces can be quenched in ~1 s. The hydrothermal apparatuses are capable of computer-controlled pressure and temperature ramps.
The laboratory is also equipped with a rapid-quench gas-pressurized (Ar-CH4) cold seal rig. We employ Hafnium-Molybdenum-Carbide (HMC) pressure vessels to achieve the higher temperatures (up to ~1300°C) relevant to basaltic compositions in the mid to upper crust (250 MPa). Sample capsules are suspended while under gas pressure with electromagnets in the hot spot of the furnace. The HMC vessel is bathed in argon gas and sheathed in Inconel to prevent oxidation of the pressure vessel. Quenching drops the capsules to a water-cooled jacket to achieve quench rates in excess of 150 degrees/second.
Applications
- The HMC cold-seal apparatus is ideal for studying basalt phase equilibria with volatile compounds (water, CO2, sulfur species) present
- The hydrothermal system is ideal for studying phase equilibria, and dynamic crystallization/dissolution/bubble growth in evolved volcanic compositions, such as rhyolites.