Abstract: 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.

Key words: Shuidonggou site; Paleolithic; Heat treatment; Stone artifact; Mechanical properties