Plunging occurs when the fracture plane turns abruptly towards the centre of the piece and takes away part of the core. The two main characteristics are a very concave ventral surface, and a thickening at the distal end. (Tixier 1974, 19). This occurs when the angle of detachment is too acute on the platform and the face of the core is too convex (Cotterell and Kammiga 1987, 701). (Also see Roche and Tixier 1982, 72-73). This is the exact opposite of hinged flake.






plunged negative removal

The negative detachment from a plunged removal leaves a highly characteristic scar. When this occurs on a blade core it is often detected by the full removal of the opposite platform. This is a knapping error, which, to quote Tixier 1974, 19, anyone who tries flaking experiments will discover sooner or later to their cost.