Stone Tool Analysis: Step termination
If the force applied to the stone is insufficient, the crack can stop entirely. Since the indentor is moving away from the core face, pulling the platform away with it, the proximal end of the stalled flake will bend and then break transversely, detaching from the core and creating an abrupt shelf called a ‘step’ termination.
The bend-snap usually occurs a short distance up from the end of the stalled crack, and the distal end of the flake is left attached to the core. The crack defining the distal end can often be seen continuing into the core. Importantly, the transverse bend fracture that breaks off the flake is morphologically identical to the transverse bend fractures that can occur when fully-formed flakes break, either during detachment or afterwards. For this reason, it is not possible to reliably identify step terminations on flakes without conjoining them back to their scars. It is possibly, however, to identify step terminations on cores, and most cores have them.
As with hinge terminations, flakes struck too close to a step-terminated scar will also end in step terminations. Because step terminations can disrupt the smooth surface of the core, they are generally considered a stoneworking mistake. However, experienced flintknappers have techniques for removing step scars from the faces of cores, such as by removing additional flakes that eliminate the steps by travelling under them. Another technique is to strike a punch resting on the step termination—or to replace the broken-off proximal end of the flake and strike it again—in the hope that the embedded crack will initiate again and exit the core.
In Australia, step-terminated flake scars were the deliberate result of maintaining the mass of horsehoof cores; the series of step terminations were then eliminated by striking a flake that propagated under them. Quina ‘scalar’ retouch, associated with Neanderthals in Europe, was a strategy of scraper resharpening that involved striking off flakes that ended in step or hinge terminations.