Search

Lithic raw material properties are often invoked to explain the presence, absence, form, or ontogeny of Paleolithic stone tools. Here, we explore whether the frequency of the Middle Paleolithic Nubian core form and core‐reduction systems co‐varies with toolstone quality in two neighboring regions in Oman: the southern region of Nejd, Dhofar, and the south‐central region of Duqm, Al Wusta. Specifically, we predicted that if raw material differences were influencing the distribution of Nubian cores, the chert would be of higher quality in the southern region, where Nubian cores were frequent, and of lower quality in the south‐central region, where they were scarce. We tested this prediction by collecting 124 chert samples from 22 outcrops and then quantitatively assessed two geochemical variables that are widely thought to influence knapping: impurity amount and silica content. We also examined the mineralogical composition, and the crystallite size and lattice strain for quartz (crystalline α‐SiO2) of representative chert samples. Our results suggest that the cherts in the two regions are similar, which is not consistent with the hypothesis that lithic raw material quality contributed to Nubian core spatial distribution in Oman. We discuss potential alternative hypotheses to explain Nubian core geographic patterning, and provisionally suggest that the scarcity of Nubian cores in south‐central Oman may be due to a concomitant scarcity of toolmakers, given a lack of water availability. [ABSTRACT FROM AUTHOR]

Researchers use a variety of target materials, and sometimes combinations of materials, in their archaeological experiments to examine thrust‐spear or projectile penetration, impact angle, durability, and other issues involving prehistoric hunting weaponry. This variety of target materials is beneficial to archaeological science in several ways, but it may also hinder the comparison of results because many of these target materials do not necessarily share similar physical properties. Here, we assess the penetration properties of four different target materials—store‐bought meat, clay, and two types of gelatin—via static penetration tests of a modern broadhead‐tipped arrow and a stone‐tipped projectile attached to an Instron Universal Materials Tester. Our analyses of load‐deflection curves, peak load, and work energy demonstrate how the four target materials are similar in some ways but different in others, which suggests that researchers may strategically employ one or several depending on the question asked or hypothesis tested. [ABSTRACT FROM AUTHOR]

Stone‐tipped weaponry was important for the survival of past peoples, and many functional and non‐functional factors likely influenced their design. Two functional factors that past peoples likely considered in the design of their stone tips are durability (whether or not a stone tip breaks) and robusticity (how much damage is incurred upon breakage). Many factors have been shown experimentally to influence stone tip influence durability and robusticity, including stone raw material. Here, we further explore the relationship between stone raw material and stone tip durability and robusticity via controlled experiments comparing chert and obsidian. We first demonstrate with semi‐static fracture strength analyses that obsidian stone tips require less force to break than do chert stone tips. We then show with dynamic ballistics impact testing that obsidian stone tips are less durable and robust than chert stone tips. Our results are entirely consistent with previous experimental comparisons of chert versus obsidian stone tips, and support the hypothesis that past peoples, when presented with multiple raw materials, likely weighed their costs and benefits in the process of selection. [ABSTRACT FROM AUTHOR]

Stone that fractured conchoidally was an important resource for prehistoric hunter‐gatherers. In recent years, archaeologists have come to realize that rather than defining stone "quality" simply and implicitly as "high" or "low," a stone's quality can be best defined in several different explicit and often quantitative ways involving production, function, or social benefits. Here, we examine the stone quality—defined as "fracture predictability"—of Upper Mercer chert when it is locally versus nonlocally acquired by prehistoric people in Ohio, USA. By quantitatively assessing silicon dioxide (SiO2) content and loss on ignition, we compared stone tools from a site at the Upper Mercer outcrop (n = 42) to those found at archaeological sites over 100 km north of it (n = 126). Our results showed that the former on average were of significantly higher quality than the latter. We conclude with a consideration of factors that could cause this difference in quality, suggesting that the lower quality of Upper Mercer chert in northern Ohio might be explained by northern people's decreased familiarity with it during the Archaic period and by their decreased access to it during the Woodland and Late Precontact periods. [ABSTRACT FROM AUTHOR]

Backing is a procedure for retouching a stone tool edge to an angle of or near 90°. Archaeologists have recorded backed lithic specimens in the Pleistocene and Holocene around the world. One prominent hypothesis for the occurrence of backing is that it increases a stone tool's adhesion relative to what it would have otherwise been with unmodified, sharp edges. We conducted a highly controlled semi‐static tensile test in which we assessed lithic specimens that possessed both a backed and a non‐backed edge, opposing each other. We hafted each specimen's backed and non‐backed edges to wood, and the bi‐hafted stone implement was then pulled apart using an Universal Instron Materials Tester, allowing for a direct ‘head‐to‐head’ comparison of the two edge types’ adhesive properties. Our tensile test results suggested no significant difference between backed and non‐backed edges in terms of adhesion, which does not support the hypothesis that backing increases a lithic specimen's adhesion. [ABSTRACT FROM AUTHOR]