This chert redirecting flake is from Germany. The flake was struck down a former platform on the stone core, which is visible on the dorsal surface of the flake.
Stone reduction involves the removal of zones of high mass from the developing core. In some cases this involves striking a flake down a zone of high mass defined by a former platform edge, and the negative scars of flakes struck from that former platform are preserved on the dorsal surface of the redirecting flake. The stoneworker has ‘redirected’ core reduction to a new platform configuration, eliminating the former platform, hence the typological label for this flake type. They often occur fortuitously as a core develops—particularly in reducing multiplatform cores—but they can also result from knapping mistakes such as overshot terminations. ‘Crested blades’ struck in establishing the face of a blade core are a special type of redirecting flake resulting from a carefully-designed sequence of flake removals.
See the annotations for technological details about this stone tool.