Experimental Study of Unequilibrated Silica Transfer from Liquid Water to the Vapor Phase
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Experiments were carried out in hermetically sealed platinum capsules, with water saturated with silica with respect to quartz at 300°C in the lower parts of the electric furnaces, where the temperature slightly increases upward at 0.15°C/cm. Our earlier studies (Alekseyev and Medvedeva, 2017) have shown that these exactly experimental parameters are favorable for silica transfer from the liquid to vapor phase. The statistically processed experimental results show that the molal silica concentration in the liquid phase (m) exponentially decreases with time. This dependence and the fact that the newly produced opal occurs on the capsule walls above the meniscus are consistent with the distillation model. The scatter of the experimental m values turned out to be caused not by differences in the temperature gradient in different wells of the electric furnaces but by the natural roughness of the inner walls of the capsules, which differed from one capsule to another and could even change with time in any given capsule. In the capsules with roughness artificially made on their walls, m decreased much more rapidly, and not only in the bottom but also in the upper parts of the electric furnaces, where temperature decreased upward (–0.08°C/cm). This may suggest that the discovered phenomenon is spread in nature more widely than surmised previously, because this phenomenon does not strongly depend on the direction of the temperature gradient, and voids in natural rocks usually have rough walls.
Keywordsquartz water temperature gradient equilibrium disturbance distillation roughness opal quartz veins
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- A. W. Adamson and A. P. Gast, Physical Chemistry of Surfaces. 6th ed., (John Wiley & Sons, New York, 1997).Google Scholar
- V. A. Alekseyev, V. M. Balashov, and G. P. Zaraisky, “Kinetics and modeling of fluid–rock interactions,” Petrology 5, 37–44 (1997).Google Scholar
- J. D. Dana, E. S. Dana, and C. Frondel, The System of Mineralogy. V. 3. Silica Minerals. (John Wiley and Sons, New York, 1962).Google Scholar
- P. M. Dove, “Kinetic and thermodynamic controls on silica reactivity in weathering environments,” Rev. Mineral. 31, 235–290 (1995).Google Scholar
- L. R. Drees, L. P. Wilding, N. E. Smeck, and A. L. Senkayi, “Silica in soils: Quartz and disordered silica polymorphs,” in Minerals in Soil Environments, Ed. by J. B. Dixon and S. B. Weed, (Soil Sci. Soc. Am., Madison, 1989), pp. 913–974.Google Scholar
- O. W. Flörke, H. Graetsch, B. Martin, K. Röller, and R. Wirth, “Nomenclature of micro– and non–crystalline silica minerals, based on structure and microstructure,” Neues Jahrbuch Miner. Abh. 163, 19–42 (1991).Google Scholar
- R. M. Gel’man, and I. Z. Starobina, Photometric Methods of Determination of Rock–Forming Elements in Ores, Rocks, and Minerals (Min. Geologii RSFSR, Leningrad, 1970) [in Russian].Google Scholar
- K. M. Hay and M. I. Dragila, “Physics of fluid spreading on rough surfaces.,” Int. J. Numerical Analysis 5, 85–92 (2008).Google Scholar
- S. Kitahara, “The solubility of quartz in water at high temperatures and high pressures,” Rev. Phys. Chem. Jpn. 30, 109–114 (1960).Google Scholar
- E. Merino and Y. Wang, “Self–organization in rocks: occurrences, observations, modeling, testing––with emphasis on agate genesis,” in Non–Equilibrium Processes and Dissipative Structures in Geoscience V. 11, Ed. by H.–J. Krug and J. H. Kruhl, Yearbook “Self–Organization” (Duncker & Humblot, Berlin, 2001), pp. 13–45.Google Scholar
- G. P. Zaraiskii, “The conditions of the nonequilibrium silicification of rocks and quartz vein formation during acidic metasomatism,” Geol. Ore Deposits 41, (4), 262–275 (1999).Google Scholar