Scanning Electron Microscopy

In 2005, Project ArAGATS launched a research initiative centered upon the examination of ceramics using Scanning Electron Microscopy (SEM). This research is being carried out at Argonne National Laboratorys Electron Microscopy Center, under the auspices of the University of Chicago, Department of Anthropologys Making of Ancient Eurasia project. The aim of this experimental initiative is to determine the ceramic production technologies employed by communities of the Tsaghkahovit plain from the Early Bronze Age to the second half of the first millennium BC. This research is motivated by a conviction that the practices entailed in ceramic production can inform social dynamics, and that material culture assemblages do not simply reflect, but also produce communities, societies, and cultures.

Ceramics

The potential for SEM to assist in the study of archaeological ceramics has been known for some time. Many studies to date have focused on the possibilities offered by SEM energy dispersive X-ray (EDX) microanalysis, which can provide information on chemical composition of clay matrices, and as a result, can inform questions surrounding fabric preparation and the movement of ceramics and different scales. Other studies have used SEM secondary electron detector and EDX to examine ceramic surface treatments through the analysis of slip composition and microscope imaging of the slip/body interface. SEM has also been employed in the study of ceramic firing technology through the investigation of vitrification structures and variations in chemical and mineralogical composition at different firing temperatures.

There are fewer precedents, however, for the use of SEM in the investigation of ceramic structure. Can SEM be used to discern differential production strategies that result in identical external surfaces? Can examination of ceramic microfabrics using SEM discern vessels thrown on a fast wheel from coil built vessels smoothed by some rotational force? At stake in this question are not only mechanics and technological choice but degrees of standardization and specialization within communities. The hypothesis of this research is that ceramic microfabrics, and particularly the orientation of pores, clay domains, and grain inclusions across and along the horizontal and vertical planes of a vessel wall can indicate different production technologies.

Our preliminary research entails the analysis of an experimental assemblage produced in Armenia in 2006 under controlled production and firing conditions. If parameters can be defined to distinguish production strategies, we will then turn our attention to archaeological ceramics, with an initial focus on sherds from the mid-first millennium BC settlement at Tsaghkahovit.

Metals

A crucible and stone mold for casting gold jewelry were recovered from a Late Bronze Age ceremonial complex within the Gegharot fortress (Operation T2E). We will analyze these by placing the entire objects in a large-chamber scanning electron microscope, with an energy-dispersive spectrometry microanalyzer (SEM-EDS). We will use SEM-EDS to examine the refractory properties of the crucible, and whether or not either object was utilized. If not, it may indicate that tools for metalworking were cached in the complex in an effort to control circulation and means of producing these objects.