The driving force behind tool- stone selection in the African Middle Stone Age

• 成果类型: Article
• 署名作者: Schmidt, Patrick; Pappas, Ioannis; Porraz, Guillaume; Berthold, Christoph; Nickel, Klaus G.
• 署名单位: Eberhard Karls University of Tubingen; Eberhard Karls University of Tubingen; Aix-Marseille Universite; Centre National de la Recherche Scientifique (CNRS); University of Witwatersrand; Eberhard Karls University of Tubingen
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13072
• DOI: 10.1073/pnas.2318560121
• 发表日期: 2024-02-26
• 关键词: diepkloof rock shelter; raw-material quality; howiesons-poort; blombos cave; western cape; heat-treatment; still bay; mechanical-properties; behavioral modernity; lithic procurement

摘要

In the Stone Age, the collection of specific rocks was the first step in tool making. Very little is known about the choices made during tool - stone acquisition. Were choices governed by the knowledge of, and need for, specific properties of stones? Or were the collected raw materials a mere by- product of the way people moved through the landscape? We investigate these questions in the Middle Stone Age (MSA) of southern Africa, analyzing the mechanical properties of tool- stones used at the site Diepkloof Rock Shelter. To understand knapping quality, we measure flaking predictability and introduce a physical model that allows calculating the relative force necessary to produce flakes from different rocks. To evaluate their quality as finished tools, we investigate their resistance during repeated use activities (scraping or cutting) and their strength during projectile impacts. Our findings explain tool - stone selection in two emblematic periods of the MSA, the Still Bay and Howiesons Poort, as being the result of a deep understanding of these mechanical properties. In both cases, people chose those rocks, among many others, that allowed the most advantageous trade - off between anticipated properties of finished tools and the ease of acquiring rocks and producing tools. The implications are an understanding of African MSA toolmakers as engineers who carefully weighed their choices taking into account workability and the quality of the tools they made.