This chert microblade core from France dates to the Mesolithic period. It was likely made between ca. 7000-11,500 BP.
The core in this model was likely reduced by a mixture of hard-hammer and soft-hammer direct percussion. The core is ‘unidirectional’—all of the microblades were removed in the same direction—with a relatively acute platform edge at one end. The core was made on a minimally-modified section of a chert nodule.
In archaeological terminology, a ‘blade’ is a flake struck down parallel ridges on a core face, and measures at least twice as long as it is wide. The edges of the blade are approximately parallel. The core face is maintained by prior removals, and blades are struck off in series. If they are struck from one platform, the removals are ‘unidirectional’, and if they are struck from two opposed platforms, they are ‘bidirectional’. Blades were struck by direct percussion (using a hard or soft hammer) or indirect percussion using a punch; or they were pressed off using a pressure technique. This involved placing the end of the indentor onto the platform edge and applying a load—either by hand or using a lever—until the crack initiated. The placement of the indentor and the amount of applied force can be precisely controlled, resulting in extraordinary control of the size and shape of the resulting pressure blades. A common approach was to set up the core so that most of the blades had a trapezoidal cross section; these are called ‘prismatic’ blades.