Termination type
In
lithic reduction,
termination type is a characteristic indicating the manner in which the distal end of a
lithic flake detached from a
core. Common types include:
- Snap/bending fractures, which occur when the material breaks because its elasticity has been exceeded;
- Step fractures, which terminate in abrupt right-angle breaks;
- Hinge fractures, which result because of the application of a force insufficient to detach the flake at the intended point but sufficient to be redirected through the material ahead of the flake. Such a flake is characterized by a rounded or blunt distal end;
- An overshot or outrepasse fracture, which occurs when the flake dips and removes a section of the opposite margin of the artifact
- Perverse fractures, "twisting" breaks caused when force is redirected through the material in a helical fashion;
- Feather or monotomic fractures, which produce flakes with distal edges that only a few molecules thick. These flakes are extremely sharp, indicating a flawless detachment. These are the intended results of some lithic reduction techniques, and are very desirable for opportunistic tool use that does not require retouching or sharpening.