Author Description

"In 1982, a series of experiments were conducted to determine something about arrow shaft variability affecting the breakage patterns of projectile points. Thirty identical points were made from fused shale (a local meta-sedimentary SiO2), and then hafted to three different types of arrow-shafts: 1) One-piece solid hardwood (Self arrow with the nock cut into the shaft), b) two piece hardwood “footed arrow”, hardwood spliced or inserted into the pile end as a fore-shaft, for durability and balance, glued in hardwood nock, and c: two-piece hardwood and cane (also a footed arrow). The three groups of arrows, ten of each type, were shot at identical wood plank targets with hand held bow from a distance of 25 feet (8 m). More than 90% of the points broke on impact leaving the broken tip imbedded in the plank. Breaks occurred either at the tip or midsection, sometimes accompanied by basal fractures (broken tangs). Both hinge and languette (tongue like projection) fractures were generated but no burinations or spiral fractures occurred in the thirty trials conducted. Fracture type and location appear to be strongly correlated with hafting form and style of shaft. Compound shafts of wood and cane seem to absorb more shock on impact and therefore fewer points are broken. Also, breaks tend to occur closer to the tip with compound shafts. Points with broken tips are easily re-sharpened and reused, whereas medial breaks usually render the point useless as a projectile point (Knetch 1997, Kelterborn 2001, Titmus and Woods 2006). Broken projectile points from archaeological contexts may be understood more clearly if the cause and mechanisms of use-fracture are better understood."--