SYMBIOSIS IN GEOLOGY AND ARCHAEOLOGY: THE IMPACT OF GEOLOGICAL SCIENCES IN 120 YEARS OF CLASSICAL MARBLE PROVENANCE STUDIES

Throughout the past 120 years, the Classical archaeologist has sought to find an accurate method to identify the provenance of marble artifacts. Finding provenance of Classical marble involves sourcing material to the location where it was originally quarried. Accurate provenance can distinguish an artifact from a forgery, help to date the creation of the work, and provide information on ancient economic geology processes. Prior to the late 19^th century, this was a task left to the art historian and archaeologist. Methodology was based solely on visual analysis of artifact marble at the macroscopic level. Issues arose in the case of white or grey marbles, which are nearly impossible to distinguish from one another with the naked eye. Marble, loosely defined as a metamorphic rock with a protolith of limestone or dolomite, is a geologic material and is appropriately analyzed via geochemistry and petrography. With the development of thin-section analysis in the 19^th century, there appeared to be a method for marble to be sourced petrographically when matched with a sample of an original quarry site. This alone was not sufficient in many instances, however. In the late 1960s isotopic analysis and trace element geochemistry were used to typify samples and progress further towards accurate distinctions. Problems with quarry heterogeneity and sample size soon came to light. In addition to this, it was found that the geologic history of each marble quarry site must be understood in order to make proper distinctions. The formation of the Association for the Study of Marble and Other Stones in Antiquity (ASMOSIA) in 1988 has lead to greater communication between the geoscientist and the archaeologist. Even as quantitative analysis of marble continues to improve, it appears that provenance may be more complex than previously thought. There is no single variable that characterizes all marble types uniquely, hence the multi-method approach. In this study the integrated relationship of the geoscientist and the Classical archaeologist from historic to present time is explored, investigated through several case studies. What may have been gained or lost in the transfer from qualitative to quantitative analysis is of greatest importance.