Hydrothermal Experiments

Hydrothermal experiments are widely used in chemistry and geochemistry to investigate solubilities of minerals, organic species, and gases,  kinetics of reactions in gas-solution, solid-solution, and gas-solid-solution type systems, as well as isotope effects of reactions. Likewise, hydrothermal experiments are crucial in consideration the following problems of geochemistry and cosmochemistry: (1) hydrothermal ore formation, (2) hydrothermal alteration of the oceanic crust, (3) synthesis and transformation of organic species in hydrothermal conditions, (4) aqueous processes in comets, asteroids, and icy satellites of outer planets, (5) hydrothermal processes on early Earth and Mars, (6) hydrothermal transformation of presolar organic compounds, (7) habitability of hydrothermal systems, (8) survivability of microorganisms at hydrothermal conditions, and (8) the origin of life. In years to come, some of these problems will be addressed in GEOPIG for experimental study. We are collaborating with Prof. John Holloway in our efforts.

For now, we plan to use two types of hydrothermal technique:  

• One hydrothermal apparatus is based on a titanium pressure vessel that permits sampling and injection of gases and liquids during runs, as well as monitoring of pressure. Sampling of gas and aqueous phases is performed with two sampling valves that are connected to the vessel by capillary tubes, as illustrated in Figure 1. The apparatus is placed into a furnace with an automatic temperature control. In 2002, such an apparatus and a furnace were moved from the Washington University to ASU, and currently the Dr. Zolotov is working on its re-installation in the laboratory space of Prof. John Holloway.

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• Another hydrothermal apparatus consists of outer steel pressure vessel and inner flexible gold cell with a titanium closure (Seyfried W. E. et al. (1987), in Hydrothermal Experimental Techniques, John Wiley and Sons, N. Y., 216-240), as shown in Figure 2. The apparatus allows sampling and injection of fluid during runs. The pressure inside the flexible gold cell is controlled by water pressure in the outer vessel. This apparatus is in process of installation.

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Reagents and reaction products will be investigated in GEOPIG with gas chromatography (two Varian CP-3800 GC with FID and TCD detectors), ion chromatography (two Dionex ICs), Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), and optical microscopy. Other analytical equipment (TOC, GC-MS, X-ray diffraction, electron microprobe, SEM) are available at ASU. 

Ongoing research project:

• Reactivity of CO and related synthesis of organic compounds in hydrothermal solutions.  Some experiments are performed in Woods Hole Oceanographic Institution in corroboration with Dr. Jeffrey Seewald and Dr. Thomas McCollom. Preliminary results are published by Zolotov et al. [2001, 2003]. We plan to reproduced some of those experiments at ASU as a part of the installation procedure. 

Publications:

Zolotov, M. Yu., Seewald, J. S., and McCollom, T. M. (2003) Dissolved Carbon Monoxide in Hydrothermal Fluids on Solar System Bodies: Experimental study of Reactivity and Organic Synthesis. Meteoritics and Planetary Science 38, Suppl. A132.

Zolotov, M. Yu., Seewald, J. S., and McCollom, T. M. (2001) Experimental Investigation of Aqueous Carbon Monoxide Reactivity under Hydrothermal Conditions. Eleventh Annual V. M. Goldschmidt Conference, May 20-24, 2001, Hot Springs, Virginia, abstract 3809.