A study of experimental archaeology on the influences of lithologic characters of stone materials into manufacturing stone implements.

本研究探讨了岩性对石器制作的影响因素。为了解决这一问题，我进行了石器制作实验，并与考古遗址出土的石器进行了比较。特别是以史前时期广泛流传于西日本的赞岐石为主要分析对象，在实验中，我使用了赞岐石和黑曜石、石英岩、图表作为样品。首先，在从原材料中分离出大尺寸薄片的阶段，所有岩石之间通过实验产生的薄片没有明显差异。而对于sanukite，片状剥落的方向被调整为具有流态结构。在使用分开的原料的实验中，黑曜石芯显示很容易连续地从芯中分离出细长的薄片。相反，赞岐石核很容易连续地从核中分离出宽的薄片。这是因为通过软锤容易控制打击力。岩石破碎明显地受到sanukite的流动结构的影响。在用芯坯制作石尖的实验中，用赞岐石制作石尖，图表与黑曜石制作的石尖没有相互区别。这些原因是因为冲击角度小，平台平坦。这种特性与一般的看法不同，赞岐石材料表明它并不不利于制造石尖。

In this study, I examined factors that lithologic characters influence to productions of stone implements. I performed experiments of stone implements making and compared it with stone artifacts excavated from archeological site due to resolution of this problem that I assumed. Particularly, a sanukite which circulated widely in western Japan in prehistoric age was a main analysis object.On the experiment, I used sanukite and obsidian, quartzite, chart as samples. At first, in the stage for detached large-sized flakes from raw materials, there were no clear differences in the flakes produced by the experiment between all rocks. However, as for sanukite, a direction of flaking was taken regulation to have fluxion structure. On the experiment used the divided raw material, obsidian cores showed that it was easy to detach elongate flakes from the core in succession. By contraries, sanukite cores are easy to detach wide flakes from the core in succession. This reason is because it is easy to control a percussion power by a soft hammer. Stone knapping are evidently influenced by the fluxion structure of sanukite. In the experiment of making stone points from core blanks, the stone points were manufactured by sanukite and chart were not different from obsidian points mutually. These reasons are because percussion angles are small and platforms are flat. Such a characteristic is different from a common view, and sanukite materials show that it was not disadvantageous for manufacturing of stone points.