Why Are Clovis Fluted Points More Resilient than Non‐Fluted Lanceolate Points? A Quantitative Assessment of Breakage Patterns Between Experimental Models

Abstract

For decades, archaeologists have wondered whether the Clovis Palaeoindian (c.11 600-10 800 radiocarbon years BP) practice of 'fluting', a flake removal technique that creates a distinctive shallow channel extending from the base of the projectile point towards the tip, bestowed a functional advantage over non-fluted projectile points. Using analytical modelling and static engineering experiments, Thomas et al. (2017) found that points that more effectively redistribute stress and relocate damage can absorb significantly more energy, last longer and remain intact relative to points that do not experience these phenomena. In general, stress redistribution and damage relocation is significantly more likely to occur in fluted points, as opposed to non-fluted points, suggesting that fluting acts as a 'shock absorber'. Here, we present a comparative quantitative assessment of breakage patterns between Thomas et al.'s (2017) experimental points that shows those experiencing stress redistribution and damage relocation were also able to significantly better resist breakage, and to incur noncatastrophic breaks, than points that less effectively redistribute stress and relocate damage. This more beneficial breakage pattern explains the material advantages provided by stress redistribution and damage relocation, and hence the potential motivation for fluting. This does not preclude the possibility that the process of fluting was accorded significance beyond its possible utilitarian value. Additional tests will be necessary to further resolve the 'shockabsorbing' capabilities of fluting.

Using 3D Models to Understand the Changing Role of Fluting in Paleoindian Point Technology from Clovis to Dalton

“…Clovis populations, the innovators of fluting, in the Southern Plains and throughout the South were mobile hunter-gatherers who relied on high-quality stone sources that outcropped at spatially dispersed locations across the landscape. Fluting—and its potential advantage of channeling impact forces to improve Clovis point resilience through shock absorption (Story et al 2019; Thomas et al 2017)—would have prolonged a Clovis point's use life. Their descendants, Folsom hunter-gatherers, were even more residentially mobile and regularly occupied areas of the Plains where high-quality stone sources were limited to absent.…”

“…Snyder (2017) shows that partially fluted Clovis points are more durable than fully fluted Folsom and unfluted Midland points, although more work is needed to determine the role of other factors such as point size and shape differences. Others show that flute design offered shock-absorbing properties that channeled impact forces and improved Clovis point resilience (Story et al 2019; Thomas et al 2017). Hypotheses for fluting in Folsom often highlight the utilitarian role of the prominent flutes that extend nearly up to the tip.…”

Lithic Technological Organization and Hafting in Early Villages

“…The choice to haft seems straightforward when it is required for the tool to function, although stone tools are not always necessary for effective projectile technology (e.g., Waguespack et al 2009). The type of haft can also affect the tool's functional efficiency, as Story and colleagues (2019) suggest for fluted and unfluted projectile points. Second, hafted tools are often more efficient than unhafted tools when used for the same activity.…”

Setting the Stage: The Late Pleistocene Colonization of North America

“…Similarly, it was proposed that fluting enhanced hafting a point into a split shaft [45]. Experimentation suggests, however, that the thinner base that results from fluting acts as a "shock absorber" that increases point robustness and the ability to withstand physical stress through stress redistribution and damage relocation [46,47]. Microwear analysis shows that at least some Clovis points were used to tip spears that were thrust and/or thrown [48].…”

“…Often, the intensification of a function is all that is required for a structure to be able to take on a new function. The crucial factor in the acquisition of most evolutionary novelties is a shift in behavior [146], coupled with, especially in the case of humans, "attentive observation and practical, daily application" [46], (p. 2). Perhaps incipient basal thinning, undertaken to reduce the longitudinal thickness of a biface-what Bradley [110] refers to technological fluting-underwent a significant series of changes in structural function, equivalent to Schiffer's [142] "stimulated variation."…”