My last post explained that we were studying the pottery of the Medieval period as a starting point for this year’s investigation. Here is a collection of photographs showing various elements of the process.
The vast majority of archaeological artifacts come out of the ground badly broken. The beautiful complete or restored museum objects we associate with ancient societies don’t really represent the sorts of materials most archaeologists study because finding complete museum-quality artifacts is rare.
Analyzing pottery relies on careful measurements, great patience, and on experience. What we are doing at our processing station at the Ziyaret Tepe dig house is very low tech. We have balance beam scales, hand-held magnifying glasses, paper forms, and a team of researchers with good eyes and a penchant for details.
Each bag of pottery sherds, which all come from the same well-defined place at the excavation (a “context” in archaeological jargon), is emptied onto a table and sorted first by its fabric. Pottery clay has distinctive colors, textures, and inclusions (fine material added to aid in firing the clay and for decorative purposes) such as sand, chaff, or mica. Since potters in different societies used different clay sources and additives, and had different types of kilns or firing techniques, we are able to distinguish between different pottery traditions and pinpoint the time and place of manufacture for many of the tens of thousands of potsherds we recover each year.
Having sorted the pottery into fabric types, each group of sherds is counted, weighed, and the information recorded on our paper forms for later data entry into our central database. We then divide the sherds by shape (or what we call “form”) which further allows us to discriminate between time periods and different potting practices. We have a master list of forms, built up over a decade of pottery analysis, which illustrates each of our pottery forms, and lists parallels we have found with other sites.
Of course we discover new fabrics, forms, and pottery combinations each season and these are carefully described and added to our descriptions. In this sense one is never “done” with pottery analysis.
What can we do with all this detailed knowledge? Well, when we start to excavate a new area, or a new site in the vicinity, or even when we just find potsherds on the surface of an ancient site 50km away, we are often able to say with some confidence during which periods the site was occupied or when a particular building was used.
As you can see, there is a lot to be learned from even the tiniest shred of evidence!
