The Neolithic sites of Aşıklı Höyük and Musular and the Chalcolithic site of Güvercinkayası in central Cappadocia yield substantial numbers of bone artifacts shaped by scraping, whittling, and grooving with edged instruments. The production of these tools was based on the exploitation of the obsidian sources of Göllü Dağ and Nenezi Dağ. Flint was introduced to the sites through exchange and appears in low quantities. The purpose of collaborative research within the framework of the ANR-08-BLANC-0318-CSD9 project included consideration of the following questions:
- What are the wear patterns produced on the bone by obsidian tools?
- Can these patterns be distinguished from those produced by flint tools?
The method employed to explore these questions includes experimentation and optical observation and measurement of surface topography with a confocal microscope at the Laboratoire de Tribologie et Dynamique des Systèmes-École centrale de Lyon. Based on archaeological evidence, hare and sheep bones were chosen for the experiments. The most significant wear variations are observed on the artifacts worked by scraping and grooving.
Image 4 shows the scraped outer surface of a hare humerus shaft. In this experiment, unretouched blades of Göllü Dağ obsidian and a brown flint (mudstone) from southeastern Anatolia were employed to scrape 50 humeri of hare. A number of factors that can influence the development of the wear marks were controlled. These factors include the angle of the stone edge; the direction of the movement; the duration of the work; the state of the bone prior to scraping; and the age of the animal. The topography and roughness of the bone’s natural surface were also recorded in order to evaluate its modifications during the shaping. Measurements were always taken on the same area of the humerus. A separate set of experiments deals with the mechanical properties of the bone subject to loads.
During the experiments, we observed that the flint was wearing the bone down faster than the obsidian. Five minutes of scraping of the thin compact bone of the humerus shaft was the minimum amount of time tested for comparison of shaped surfaces. Images 5 and 6 show respectively obsidian and flint-scraped surfaces observed under a metallographic microscope. Image 7 shows surface profiles. The publication of the test results is in preparation.