A Synthesis of the Dibble et al. Controlled Experiments into the Mechanics of Lithic Production

Abstract

Archaeologists have explored a wide range of topics regarding archaeological stone tools and their connection to past human lifeways through experimentation. Controlled experimentation systematically quantifies the empirical relationships among different flaking variables under a controlled and reproducible setting. This approach offers a platform to generate and test hypotheses about the technological decisions of past knappers from the perspective of basic flaking mechanics. Over the past decade, Harold Dibble and colleagues conducted a set of controlled flaking experiments to better understand flake variability using mechanical flaking apparatuses and standardized cores. Results of their studies underscore the dominant impact of exterior platform angle and platform depth on flake size and shape and have led to the synthesis of a flake formation model, namely the EPA-PD model. However, the results also illustrate the complexity of the flake formation process through the influence of other parameters such as core surface morphology and force application. Here we review the work of Dibble and colleagues on controlled flaking experiments by summarizing their findings to date. Our goal is to synthesize what was learned about flake variability from these controlled experiments to better understand the flake formation process. With this paper, we are including all of the data produced by these prior experiments and an explanation of the data in the Supplementary Information.

An overview of standardizable raw materials for controlled knapping experiments

“…Controlled experimentation is an important tool for developing our understanding of the prehistoric knapping phenomenon, from the mechanics of fracture to the cognitive processes residing within the knapper (Johnson 1978;Li et al 2022;Lombao et al 2017;Moore & Preston 2015;T. Morgan et al 2015;Pargeter et al 2019;Putt et al 2014;Schick & Toth 1993;Snyder et al 2022;Toth 1985;.…”

“…Experimental replication of stone tools has generally been performed in order to better understand how those tools would have likely been produced in the prehistoric past (e.g., Johnson 1978;Toth 1985;Schick & Toth 1993;. Such experimental replication of prehistoric artifacts has been used to understand processes like the mechanics of conchoidal fracture (reviewed in Li et al 2022), the reduction sequences of specific artifact types (e.g., Moore & Perston 2015;Toth 1985), and the cognitive mechanisms that guide the production of stone tools and the acquisition of the toolmaking skill (e.g., Lombao et al 2017; T. Morgan et al 2015;Pargeter et al 2019;Putt et al 2014;Snyder et al 2022). Modern experimental archaeology has placed an increasingly strong emphasis on controlled experiments for the study of the physical as well as cultural and biological processes inherent to knapping behavior (cf.…”

“…One particularly useful means of experimental control is the standardization of raw material types and blank forms (including blank size). Researchers have previously created and utilized standardized blanks (in some instances, preforms 1 ) in replication experiments (e.g., Li et al 2022;Khreisheh et al 2013;Sheets & Muto 1972;Speer 2018). Standardized blanks can be made from naturally-occurring or synthetic materials -so long as they can fracture conchoidally -and are somehow shaped to follow a specific design concept.…”

“…In the archaeological record, there has been extensive use of obsidian and other naturallyoccurring volcanic glasses as a preferred knapping material of modern humans and pre-modern hominins in various locales around the world, including exploitation in the Acheulean at Melka Kunture, Ethiopia (Mussi et al 2022) and the Lower and Middle Paleolithic of the Armenian Highlands (Adler et al 2014;Frahm et al 2020). Due to its model properties of conchoidal fracture, glass has been an important and reliable material for controlled experiments in archaeology (Li et al 2022). Using soda-lime glass, experimenters have previously been able to control for extraneous variables in order to study what determines the characteristics of flakes.…”

“…Glass is especially suited for controlled experiments due to the reproducibility of the same sized and shaped glass blanks, an advantage not shared with all materials (Dogandžić et al 2020;Li et al 2022).…”