Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-26T19:23:58.788Z Has data issue: false hasContentIssue false

The Experimental Hydration of Obsidian as a Function of Relative Humidity and Temperature

Published online by Cambridge University Press:  20 January 2017

J. J. Mazer
Affiliation:
Argonne National Laboratory, Argonne, IL 60439-4837
C. M. Stevenson
Affiliation:
Archaeological and Historical Consultants, Inc., P.O. Box 482, Centre Hall, PA 16828
W. L. Ebert
Affiliation:
Argonne National Laboratory, Argonne, IL 60439-4837
J. K. Bates
Affiliation:
Argonne National Laboratory, Argonne, IL 60439-4837

Abstract

The experimental hydration of obsidian for up to 30 days is described at relative humidities (RH) of 60, 90, 95, and 100 percent and at temperatures of 150, 160, and 175°C. Under isothermal conditions, the rate of hydration increased by as much as 25 percent between 60 and 100 percent RH. The RH dependence is nonlinear, with the majority of the rate increase occurring between 90 and 100 percent RH. The effect of RH can be related to the driving force for molecular water diffusion in obsidians as described by the chemical potential difference between water sorbed onto the obsidian surface and intrinsic water in the obsidian. The differences in hydration rates caused by RH differences in experiments approximate the error commonly described for obsidian-hydration dating. These results suggest that obsidian-hydration dating requires a knowledge of the site temperature and relative humidity in order to accurately generate age estimates.

Résumé

Résumé

Se describe la hidratación experimental de obsidiana por hasta 30 días, a humedades relativas (HR) de 60, 90, 95, y 100 por ciento y a temperaturas de 150, 160 y 175°C. En condiciones isotérmicas, el grado de hidratación aumentó hasta un 25 por ciento entre 60 y 100 por ciento de HR. El efecto de la HR puede estar relacionado con la fuerza que impulsa la difusión molecular del agua en obsidianas, descripta por la diferencia en elpotencial químico entre el agua absorbida en la superficie y el agua intrínseca en la obsidiana. La diferencia en los grados de hidratación causada por diferencias en HR durante los experimentos se aproxima al error comunmente descripto para la datación por hiratación de obsidiana. Estos resultados sugieren que la datación por hidratación de obsidiana requiere el conocimiento de la temperatura y humedad relativa del sitio a fin de generar estimaciones de antigüedad exactas.

Type
Reports
Copyright
Copyright © The Society for American Archaeology 1991

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

References Cited

Abrajano, T. A., Bates, J. K., and Mazer, J. J. 1989 Aqueous Corrosion of Natural and Nuclear Waste Glasses : II. Mechanisms of Vapor Hydration of Nuclear Waste Glasses. Journal of Non-Crystalline Solids 108 : 269288.Google Scholar
Ambrose, W. R. 1976 Intrinsic Hydration Rate Dating of Obsidian. In Advances in Obsidian Glass Studies, edited by Taylor, R. E., pp. 81105. Noyes, Park Ridge, New Jersey.Google Scholar
Ambrose, W. R. 1980 Monitoring Long Term Temperature and Humidity. Institute for the Conservation of Cultural Material Bulletin 6 : 3642.Google Scholar
Ambrose, W. R. 1984 Soil Temperature Monitoring at Lake Mungo. Australian Archaeology 19 : 6474.Google Scholar
Bartholomew, R. F., Tick, P. A., and Stoodey, S. D. 1980 Water/Glass Reactions at Elevated Temperatures and Pressures. Journal of Non-Crystalline Solids 38-39 : 637.Google Scholar
Bates, J. K., Abrajano, T. A., Jr., Ebert, W. L., Mazer, J. J., and Gerding, T. J. 1988 Experimental Hydration Studies of Natural and Synthetic Glasses. In Materials Issues in Art and Archaeology, edited by Sayre, E., Vandiver, P., Druzik, J., and Stevenson, C.. Materials Research Society Symposium Proceedings 123 : 237.Google Scholar
Cleland, J. 1990 Induced Hydration at Coso : Part III. Paper presented at the 24th Annual Meeting of the Society for California Archaeology, Foster City, California.Google Scholar
Doremus, R. H. 1964 Exchange and Diffusion of Ions in Glass. Journal of Physical Chemistry 68 : 2212.Google Scholar
Ebert, W. L., and Bates, J. K. 1990 The Reaction of Synthetic Nuclear Waste Glass in Steam and Hydrothermal Solutions. In Scientific Basis for Nuclear Waste Management, edited by Oversby, V. and Brown, P.. Materials Research Society Symposium Proceedings 173 : 339.Google Scholar
Ebert, W. L., Hoburg, R. F., and Bates, J. K. 1991 The Sorption of Water on Obsidian and a Nuclear Waste Glass. Physics and Chemistry of Glasses, in press.Google Scholar
Ericson, J. 1988 Obsidian Hydration Rate Development. In Materials Issues in Art and Archaeology, edited by Sayre, E., Vandiver, P., Druzik, J., and Stevenson, C.. Materials Research Society Symposium Proceedings 125 : 345354.Google Scholar
Friedman, I., and Long, W. D. 1976 Hydration Rate of Obsidian. Science 191 : 347352.Google Scholar
Friedman, I., and Smith, R. L. 1960 A New Dating Method Using Obsidian, Part 1 : The Development of the Method. American Antiquity 25 : 476522.Google Scholar
Friedman, I., Smith, R. L., and Long, W. D. 1966 Hydration of Natural Glass and the Formation of Perlite. Geological Society of America Bulletin 77 : 323328.Google Scholar
Friedman, I., Trembour, F., Smith, F., and Smith, G. 1990 Obsidian Hydration Dating as Affected by Relative Humidity? Ms. on file, U. S. Geological Survey, Denver, Colorado.Google Scholar
Hagymassy, J., Brunauer, S., and Mikhail, R. Sh. 1969 Pore Structure Analysis by Water Vapor Absorption. I. t-curves for Water Vapor. Journal of Colloid Interface Science 29 : 485.Google Scholar
Jeffery, P. G., and Hutchinson, D. 1981 Chemical Methods of Rock Analysis. 3rd ed. Pergamon Press, New York.Google Scholar
Leach, B. F., and Hamel, G. E. 1984 The Influence of Archaeological Soil Temperatures and Obsidian Dating in New Zealand. New Zealand Journal of Science 27 : 399408.Google Scholar
Lee, R. R., Leich, D. A., and Tombrello, T. A. 1974 Obsidian Hydration Profile Measurements Using a Nuclear Reaction Technique. Nature 250 : 4447.CrossRefGoogle Scholar
Michels, J. W., Tsong, I. S. T., and Smith, G. A. 1983 Experimentally Derived Hydration Rates in Obsidian Dating. Archaeometry 25 : 107117.Google Scholar
Stevenson, C, and Friedman, I. 1990 Soil Temperature and Relative Humidity Determinations on Easter Island : Implications for Obsidian Hydration Dating. Ms. on file, Diffusion Labs, Spring Mills, Pennsylvania.Google Scholar
Stevenson, C. M., Carpenter, J., and Scheetz, B. E. 1989 Obsidian Dating : Recent Advances in the Experimental Determination and Application of Hydration Rates. Archaeometry 31 : 193206.Google Scholar
Stevenson, C. M., Dinsmore, D., and Scheetz, B. E. 1989 An Inter-Laboratory Comparison of Hydration Rim Measurements. International Association for Obsidian Studies Newsletter 1 : 714. Chico, California.Google Scholar
Stevenson, C. M., Freeborn, W., and Scheetz, B. E. 1987 Obsidian Hydration Dating : An Improved Optical Technique for Measuring the Width of the Hydration Rim. Archaeometry 29 : 120123.Google Scholar
Tomozawa, M., Ito, S., and Molinelli, J. 1984 Hygroscopicity of Glasses with High Water Content. Journal of Non-Crystalline Solids 64 : 269278.Google Scholar
Tomozawa, H., and Tomozawa, M. 1989 Diffusion of Water in Borosilicate Glass. Journal of Non-Crystalline Solids 109 : 311317.Google Scholar
Trembour, F., Smith, F., and Friedman, I. 1988 Diffusion Cells for Integrating Temperature and Relative Humidity Over Long Periods of Time. In Materials Issues in Art and Archaeology, edited Sayre, E., Vandiver, P., Druzik, J., and Stevenson, C.. Materials Research Society Symposium Proceedings 123 : 245251.Google Scholar
Yoko, T., Huang, Z-J., Kamiya, K., and Sakka, S. 1983 Hydration of Silicate Glasses by Water Vapor at High Temperatures. In International Congress on Glass 13 : 650655. Hamburg.Google Scholar