Abrasive and impact wear of stone used to manufacture axes in Neolithic Greece

Excavations at the Neolithic settlement at Makriyalos in Northern Greece brought to light a large number of stone axe heads, the majority of which were manufactured from serpentinite and igneous rocks. Detailed study of the manufacturing traces on the archaeological implements identified that both percussive (pecking) and abrasive techniques (sawing and grinding/polishing) were employed for the production of the axes. There is limited evidence, however, of how these processes may have been undertaken. The aim of this work was to build on previous research investigating sawing and polishing methods and the materials that may have been used in these tasks. Modern samples of two types of serpentinite and a dolerite were collected from the environs of the archaeological site. These were tested for strength and porosity. Through archaeological research the materials available to Neolithic people were established and some testing was carried out to establish sliding speeds and loads and percussive impact velocities achievable by a human to feed into the tribological test design. Pin-on-disc wear tests were carried out using quartz, chalcedony and sandstone as the pin material in wet and dry conditions to study sawing and polishing behaviour. Reciprocating tests were carried out using leather and combinations of lubricant (animal fat and water) and abrasive medium (sand) to study effects on polishing. Percussive impact tests were also carried out. The tests indicated that with certain combinations of materials and test conditions, both sawing and polishing could be achieved. A series of stages for the polishing were identified which are in line with observations made by archaeologists. (C) 2011 Elsevier B.V. All rights reserved