热处理对水洞沟遗址石器原料力学性能的影响

宁夏水洞沟遗址的发现首次证实了旧石器时代东亚古人类的热处理行为。本文通过压缩实验和XRD(X射线衍射)检测,对宁夏水洞沟遗址区采集的白云岩石料热处理前后的力学性能进行了定量研究。结果表明,经过450℃热处理的白云岩石料材质更加均匀,硅质含量减小、钙质含量增加,抗压强度下降31%,最大应变提高27%,在应力-应变曲线上出现了明显的锯齿状波动现象。这些变化降低了打击石料所需的力度,使石料易于产生多次开裂,不容易发生一次性灾变破坏,为古人类调整打击点、打击方向和力度创造了机会,从而降低了打制难度,提高了石器的制作质量和效率。

Influence of Heat Treatment on the Mechanical Properties of Raw Stones Collected from the Shuidonggou Site

The Shuidonggou site in Ningxia Province shows for the first time confirmed existence of heat treatment in the East Asian Paleolithic. In this paper, quantitative study about the mechanical properties was conducted on dolomitic stones from the Shuidonggou site through compression tests and XRD (x-ray diffraction). The results showed that after the stones were heated at 450oC, raw materials became more homogeneous with a decrease of SiO2 and an increase of calcium content. Correspondingly, a 31% decrease of the average value of compression strength was observed, along with a 27% increase of the average value of maximum strain. Zigzag phenomena occurred in stress-strain curves through intermittent cracking of the stone. These transformations led to less knapping force and more opportunities to adjust knapping directions, and consequently reduced knapping difficulties. Through heat treatment, the quality and production efficiency of stone improves.