4 - Weathering of Inorganic Materials: Dating and Other Applications

Abstract

This chapter describes weathering to mean any alteration that occurs to the surface of a material as a consequence of chemical interactions with its atmospheric, aquatic, or soil environment. The resulting surface is often referred to as patina. The international emphasis on the safe disposal of nuclear waste materials has provided the funds and interest required to develop a scientific understanding of weathering. Future problems of chemical waste disposal and acid rain promise to maintain the momentum in this important area of research. The understanding of weathering has been significantly enhanced by the availability of routine surface-analytical equipment capable of submicrometer spatial resolution. New instrumentation can provide assistance in the interpretation of materials from archaeological sites, including how they are transformed through time. One must also keep in mind that the interpretation of data obtained from these techniques relies heavily on the understanding obtained from a variety of archaeological analyses. Previous knowledge on the part of the archaeologist about prehistoric contexts is important in the ability to interpret intelligently the data that result from the application of instrumental techniques. The collaboration of archaeologists, materials scientists, and surface scientists has provided the necessary cross-fertilization to produce a fundamental understanding of the weathering problem. Archaeologists, although interested in weathering for different reasons, have helped to confirm the findings of the materials scientists.