BREAKAGE PATTERNS
Numerous studies have been undertaken in an attempt to separate
intentional from accidental snaps or breakage (for example, Bergman et al 1987, Kobayashi
1985, Owen 1982, Roche
& Tixier, 1982). Although distinct features are associated
with intentional breakage patterns, such features can also occur
from natural agents such as trampling and soil movement.
intentional break
"A method of producing a transverse fracture to sever flakes
or blades. Pressure or percussion force is applied from the ventral
toward the dorsal side" (Crabtree
1982., 53).
Normally undertaken to reduce the size, or remove unwanted sections,
of an artifact (such as the bulbar end or the distal end). This
is surprisingly difficult to accomplish directly by hand with
any degree of accuracy (Owen 1982,
78-79).
Either a hard hammer or soft hammer can be used. This leaves characteristic
features of a normal detachment, such as a bulb, lines of force,
etc. (Owen 1982,, Roche
and Tixier 1982).
indexmanufacturing snaps
Manufacturing snaps can occur in many different ways. Some examples
of these are:
-snaps from buckling of the artifact during detachment from the
core (Cotterell & Kammiga
1987, 700)
-breaks that occur during attempts to truncate the artifact, called
languette fractures (Lenoir 1975;
Roche & Tixier, 1982,
71)
-damage that occurs when inappropriate amounts of force are applied
to an artifact. An example of this is transverse snaps which occur
during the application of retouch, particularly from pressure
flaking (Roche & Tixier, 1982,
69). Manufacturing snaps are often caused by inadequate core preparation
or the application of inappropriate amounts of force, however,
faults in the raw material can also be the culprit.