Holding your shape: Controlled tip fracture experiments on cast porcelain points

Abstract

The development of projectile technology was a fundamental step in the transition from scavenging to hunting, providing hunters with more reliable access to meat, enabling killing at greater distances and a potential broadening of the human niche. Understanding when and where projectile innovations occurred remains a challenge, as organic components of projectile technology seldom preserve. Consequently, archaeologists have explored tip fractures as a potential means of identifying the speed of projectile impacts and thus the likely weapon systems employed in the past. This paper introduces a novel approach to experimental projectile fractures, employing near-identical vitrified porcelain points to better understand the variables affecting formation, type and length of so-called ‘diagnostic impact fractures’ (DIFs). Using the largest sample of its kind to date (n = 570), we compare DIF type and length for thrusted spear, simple stone tipped projectiles (hand thrown) and complex projectile weapons (spearthrower/dart and bow/arrow) to identify the degree of overlap in the type and size of impact fractures created by each type of weapon. Through statistical comparison of porcelain and flint points, and controlled crossbow and hand delivery methods, we show that porcelain points are an ideal analogue for flint points in controlled ballistic experiments to assist in developing a more robust understanding of the formation of impact fractures and the use of past weapon systems.