The technology of Stone Age colonization: an empirical,regional-scale examination of Clovis unifacial stone tool reduction,allometry, and edge angle from the North American Lower Great Lakes region

There is now broad consensus that the appearance of Clovis in Northeastern North America (Great Lakes, New England) represents a colonization pulse into recently deglaciated landscapes. Due to the increased resource uncertainty that comes with colonizing unfamiliar landscapes, it was hypothesized that the majority tool component of Clovis assemblages, unifacial stone tools, should have been knapped on tool blanks possessing the design properties of longevity and functional flexibility to facilitate exploration mobility and guard against the absence of toolstone sources in the new landscape. These properties are optimized by large, flat flakes, possessing large surface area relative to flake thickness. Since discarded and, at times, exhausted unifacial stone tools do not preserve the original dimensions of the blank upon which they were created – necessary items for a true test of blank morphology selection – this study presents a set of predictions for inferring whether Clovis unifacial stone tool blanks were selected for the properties of longevity and functional flexibility based on evidence that Clovis people actually capitalized on those properties. Due to the nature of Clovis unifacial stone tools, tool size was of necessity used as a proxy for tool reduction, on the grounds that smaller tools are more likely to have been resharpened than larger tools, at least in the case of unifacial flake tools. The results showed that less resharpened tools possessed flatter, less spherical shapes than the more resharpened tools, which possessed more globular, spherical shapes, suggesting Clovis foragers exploited the retouch potential afforded by the larger, flatter blanks. Edge angles showed no relationship with tool reduction, suggesting that Clovis foragers exploited the functional flexibility afforded by flatter blanks by adjusting the edge angle to be either higher or lower as needed. These results are consistent with the notion that human colonizers, who did not know the abundance or location of stone outcrops prior to settling an unfamiliar territory, not only “geared up” before leaving a stone source, but geared up as efficiently as possible by carefully selecting the blanks they chose to carry. Broader implications for such careful unifacial stone tool blank selection are discussed.