Finials on stone flakes

Abstract

When a conchoidal flake is detached from a stone the fracture can either terminate at a small angle to the stone's surface, creating a feather flake, or turn to end at rightangles, creating a hinge or step flake. If a crack turns towards the surface of the stone its path is unstable, and the crack often turns once again, to propagate parallel to the surface of the stone and form a retroflexion or an inflexion on the end of the flake. The retroflexion on the end of a hinge termination has long been recognized, but the inflexion, and its combination with a retroflexion to form a pseudo-bifurcation, has not. Recognition of these finials is important in use-wear analysis for the accurate identification of the various flake scar types and the determination of stone tool function.