The results of lithic experiments performed on glass cores are applicable to other raw materials

Abstract

About 10 years ago, a new experimental design, based on a mechanical flaking apparatus, allowed complete control over several independent variables essential to flintknapping. This experimental setting permitted the investigation of more fundamental aspects of stone technology, including the effect of particular platform attributes, core surface morphology, and the application of force on flake size and shape. These experiments used cores made of glass that were molded to exact configurations. Here we set out to investigate whether results obtained from experiments on glass cores can be extended to other materials, in this case varieties of basalt, flint, and obsidian that were cut to the exact core configurations. We focused on the relationships between the independent variables of exterior platform angle and platform depth and dependent variables of overall size (weight or mass), volume, and linear dimensions. It was found that in almost every comparison, all four materials show similar relationships in nature and degree. What differs instead is the amount of force needed to detach a flake. In other words, given the same core morphology and platform attributes the resulting flakes will be the same, but harder materials require more force to remove the flake. These results were additionally verified on Middle Paleolithic archeological materials made mostly on Late Cretaceous flints. Our results demonstrate that experiments using glass cores are valid and can be generalized and extended to other materials.

The Role of Different Raw Materials in Lithic Technology and Settlement Patterns During the Middle Stone Age of Southern Africa

“…"Flint thinking" (Knutsson, 1998(Knutsson, , 2014 in Europe is one manifestation of this paradigm, which in other regions might be replaced by an "obsidian mindset" or "silcrete reasoning." This study has focused on raw materials that strongly deviate in their properties from glass on which the classic models of fracture mechanics and resulting knapping traces are based (Cotterell & Kamminga, 1979, 1987Cotterell et al, 1985)-raw materials such as fine-grained flint, obsidian, or basalt (e.g., Dogandžić et al, 2020). This study has some methodical implications and lessons for future lithic analyses.…”

“…The sites and assemblages that have received such attention include Hoedjiespunt 1 (Will et al, 2013), Varsche Rivier 003 (Steele et al, 2016), Layer 8 at Die Kelders (Thackeray, 2000), the Late MSA J-I at Elands Bay Cave (Porraz et al, 2016), and PBA/PBB at Klipdrift (Douze et al, 2018). In addition to quartzite and quartz, the raw materials used during the MSA in southern Africa include sandstone and calcrete which feature flaking properties that deviate from classic conchoidal fracturing as in flint, the latter breaking similar to glass models (e.g., Dogandžić et al, 2020). In this article, these raw materials are collectively referred to as having lower-knapping suitability instead of the more value-laden term "low-quality" that has been used to denote them.…”

Controlled experiments in lithic technology and function

“…One of the most discussed topics in this issue is the use of controlled experimental replication to identify and interpret the impact of raw material variation on past human technological decision-making. These papers explore the manipulation of the raw material (Mackay et al 2018), lithic tool production and design (Dogandžić et al 2020;Pargeter et al 2018), tool efficiency and durability (Abrunhosa et al 2019 and Pereira et al submitted), and tool use (Pfleging et al 2018).…”

“…The impact of rock mechanical properties is also explored by Dogandžić et al (2020). Here, the researchers follow previous investigations on fundamental aspects of lithic production, including the association between core and tool morphological attributes and knapping force.…”

A versatile mechanized setup for controlled experiments in archeology

“…Several controlled mechanical experiments have been performed in the last years for different purposes: knapping (e.g. Dibble and Pelcin 1995;Dibble and Rezek 2009;Dibble and Whittaker 1981;Dogandžić et al 2020;Mraz et al 2019), formation of use-wear (e.g. Astruc, Vargiolu, and Zahouani 2003;Martisius et al 2018;Pfleging, Iovita, and Buchli 2019;Vargiolu, Zahouani, and Anderson 2003), projectile technology (e.g.…”