A Novel Approach to Studies of Prehistoric Exploitation of Stone Tool Materials Using Material Composition, Surface Morphology, Microstructure and Mechanical Properties*

Abstract

For a comprehensive understanding of material exploitation in prehistory, we applied advanced analytical methods to Japanese prehistoric stone tool materials. Compositions, surface morphologies, microstructures and mechanical properties of the primary lithic materials were analysed. As a result of the tests on actual Palaeolithic artefacts, preferential material selection was observed based on composition, structure and other physical properties of the materials. Homogeneous materials composed of a single type of mineral—α‐quartz—were intentionally selected for Palaeolithic tools regardless of the type of rock. These materials unexceptionally present higher hardness and strength. Moreover, materials composed of extremely fine crystal grains of ~0.1 µm in size with highest hardness and strength were selectively used for sharp‐edged blades. These results lead us to the conclusion that quantitative and objective analyses will give us precise information on prehistoric materials, which will enable us to make an analytical approach to the comprehension of prehistoric exploitation of stone materials. This could eventually complement the traditional interpretation of material exploitation based on conventional petrological classifications.

When archaeological context is lacking. Lithology and spatial analysis, new interpretations of the “verracos” Iron Age sculptures in Western Iberian Peninsula

“…To test these hypotheses, we developed a method for identifying the origin of the stone used for carving 'verracos', thus moving beyond our limited knowledge about the original contexts (Yonekura et al, 2008;García Talegón et al, 1999…). The method is based on a combination of three techniques (two mineralogical ones: petrographic analysis and mineralogical analysis through X-ray diffraction; and a chemical analysis: Antonelli et al, 2010;García Giménez et al, 2013;Vigil et al, 2000: Yonekura et al, 2008. We collected small samples of 105 boars and from about 50 potential quarries (easily recognized due to their archaeological remains, their contemporary use or just the proximity to the sculptures), of which 34 gave positive results (Table 1).…”

Petrographical, structural, and mechanical analysis of armorican phtanites: A key raw material for the Mesolithic in Western France

“…Other experimental studies have mainly focused on the effect of the conditions of knapping on the size of products obtained (Dibble & Pelcin, 1995;Dibble & Rezek, 2009) or on the physical properties of raw materials and their use-wear capacities (Lerner et al, 2007). Numerous examples of the evaluation and quantification of the influence of mechanical properties of materials in prehistoric industries are known-notably for the Neolithic axe trade in Great Britain (Bradley et al, 1992), Amazonian Paleoindian axes (Gil Sevillano, 1997), and Japanese Paleolithic sites (Yonekura et al, 2008). In the Japanese study, the structural and compositional features were combined with surface mechanical properties.…”

Characterising the stone artefact raw materials at Liang Bua, Indonesia

“…Studies have shown that stone raw materials with higher indentation hardness tend to be constituted of smaller grains with less porosities and lower surface roughness, potentially allowing flakes to be detached with sharper edges and hence greater cutting abilities (Yonekura, [76]; Yonekura & Suzuki, [78]). Researchers have also used indentation hardness as a proxy for tool edge durability (Sherwood,[65]; Yonekura, [76]; Yonekura et al, [77]), although it should be noted that edge toughness is proportional to not only indentation hardness but also stiffness, such that hard yet stiff (i.e. highly brittle) stones can in fact have low edge toughness (McPherron et al, [42]).…”