The Role of Platform Angle and Core Size in Hard-Hammer Percussion Flaking

ABSTRACT

Steel balls were dropped on to massive equilateral and right-angle glass prisms in order to investigate the effects of varying platform angle and prism size on the shape and size of hard-hammer percussion flakes. Ball diamėter, drop height, and impact angle were held Constant. For a given platform angle [measured between striking platform and exterior surface of prism or flake], a decrease in the size of the prism is accompanied by a decrease in terminal flake length, terminal flake width, and terminal platform thickness, and by an increase in the minimum ball diameter required to remove a flake. For prisms of comparable size, a decrease in platform angle is accompanied by a decrease in terminal flake length and in the average values of the length/width, length/platform thickness and width/platform thickness ratios. A decrease in platform angle is also accompanied by a marked increase in the width of the zone along the edge of the prism within which flakes can be produced. Thus, the larger the platform angle, the greater the accuracy required to remove a flake. Further investigations are needed in order to determine to what extent the relationships and trends observed in the present study are applicable to the more complex core geometries generally encountered by archaeologists.