Indirect Percussion Flaking
Indirect percussion flaking involved removing flakes using a punch: the punch was placed on the platform and then struck, initiating the flake at the desired location. By adjusting the angle of the punch, the stoneworker could very precisely balance the force of compression down the length of the developing flake (‘downward’ force) and the shearing force which opens up the crack (‘outward’ force).
The punch could be adjusted relative to the contours on the core face and placed at precise distances from the core edge. The tip of a punch could also be positioned in places that would be impossible to reach by direct percussion, such as within a concavity on the core edge. An organic punch flexes when it is struck and more slowly releases the force into the core than in direct percussion.
Punches were mostly made from antler, although horn, bone, or wood may have also been used. Modern flintknappers have successfully used stone punches to shape rectangular-sectioned adze blanks. Indirect percussion arose relatively late in prehistory but was discovered independently in various times and places.
Indirect Percussion Bifacial Thinning and Shaping
Most bifaces in prehistory were probably made by direct percussion; however, historical accounts of flintknappers in Mexico, North America, and South America describe the traditional use of indirect percussion in shaping and thinning bifaces in the 19th and 20th centuries, and the Karuk flintknapper Ted Orcutt continued the tradition into the 1940s.
Early archaeologists working in North America often classified sections of antler with worn ends as ‘drifts’ and interpreted them as punches used in flintknapping, in reference to the historical accounts. The punches for bifacial flaking were shorter and smaller in diameter than the punches used to make blades by European flintknappers.
Indirect Percussion Notching
The archaeological signature of the use of an indirect percussion notching technique is a large flake scar emanating from a platform deep within the ears defined by the notch. The indirect percussion technique delivered far more force to the platform than could be achieved by the pressure flaking, resulting in larger flakes which removed more mass, and this allowed deep notches to be made into relatively thick blanks.
Punch-notching was widespread for notching bifacial tools in the eastern and midwestern part of North America, particularly during the Early Archaic period. Indirect percussion notching was used to manufacture eccentrics in Mesoamerica and may have been developed independently on Rapa Nui (Easter Island) to manufacture stems on mata’a points and knives.
Indirect Percussion Blade-making
The indirect percussion technique facilitated the efficient production of long, thin, and exceptionally sharp tools from high-quality raw materials. Some of these blades were up to 40 cm long, although most were less than 10 cm long. Blade-making punches from Early Holocene sites in Denmark were about 10-15 cm long, slightly curved, and made of antler tines from red deer (Cervus elaphus).
Indirect Percussion Quadrifacial Shaping
Creating the rectangular section by flaking decreased the amount of time necessary to grind the axe or adze into shape. Producing a rectangular section by direct percussion flaking is difficult because the flakes tend to overstrike the opposite edge, eliminating the sharp corner. However, the use of a punch allowed the flintknapper to increase the shearing force relative to the compression force by angling the punch outwards, thereby preventing overstruck terminations.
Indirect Percussion Stitching
In Denmark, stitching was used to create a decorative seam on the centre of the handles on Type IV flint daggers. In Java and Sumatra, Indonesia, stitching was used to create a straight ridge down the centre of Type 7 stone gouges; the seam was ground away during the final stages of gouge manufacture.
To make the stitching, the punch was first placed at end of the flat surface and a small flake was detached, creating a scar. The next flake was removed by placing the punch on the side of the negative bulb of force on the first flake scar. This created a new negative bulb of force and the process was repeated, alternating (or ‘stitching’) back-and-forth between platforms, until the seam reached the desired length. The seam has the appearance of a slightly raised bifacial edge.
The early stages of seam production in Denmark was accomplished by indirect percussion but was refined using a pressure-flaking technique. Stitching in Indonesia was likely accomplished by indirect percussion rather than pressure.
