Humans were regularly heat‐treating stone tool raw materials as early as 130 thousand years ago. The late Middle Stone Age (MSA) and Late Stone Age (LSA) of South Africa’s Western Cape region provides some of the earliest and most pervasive archaeological evidence for this behaviour. While archaeologists are beginning to understand the flaking implications of raw material heat treatment, its potential functional benefits remain unanswered. Using silcrete from the Western Cape region, we investigate the impact of heat treatment on stone tool cutting performance. We quantify the sharpness of silcrete in its natural, unheated form, before comparing it with silcrete heated in three different conditions. Results show that heat‐treated silcrete can be significantly sharper than unheated alternatives, with cutting forces halving and energy requirements reducing by approximately two thirds. Our data suggest that silcrete may have been heat treated during the South African MSA and LSA to increase the sharpness and performance of stone cutting edges. This early example of material engineering has implications for understanding Stone Age populations’ technological capabilities, inventiveness, and raw material choices. We predict that heat treatment behaviours in other prehistoric and ethnographic contexts may also be linked to edge sharpness increases and functional performance concerns.

中文翻译：

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热处理显着增加了silcrete石工具的锋利度

早在13万年前，人类就定期对石器原材料进行热处理。南非西开普地区的中石器时代晚期 (MSA) 和石器时代晚期 (LSA) 为这种行为提供了一些最早和最普遍的考古证据。虽然考古学家开始了解原材料热处理的剥落影响，但其潜在的功能优势仍未得到解答。我们使用西开普地区的硅质混凝土，研究热处理对石材工具切削性能的影响。在将其与在三种不同条件下加热的 silcrete 进行比较之前，我们量化了天然、未加热形式的 silcrete 的锐度。结果表明，经过热处理的硅质混凝土比未加热的替代品明显更锋利，切削力减半，能源需求减少约三分之二。我们的数据表明，在南非 MSA 和 LSA 期间，silcrete 可能已经过热处理，以提高石材切割刃的锋利度和性能。这个材料工程的早期例子对理解石器时代人口的技术能力、创造力和原材料选择具有重要意义。我们预测，其他史前和民族志环境中的热处理行为也可能与边缘锐度增加和功能性能问题有关。这个材料工程的早期例子对理解石器时代人口的技术能力、创造力和原材料选择具有重要意义。我们预测，其他史前和民族志环境中的热处理行为也可能与边缘锐度增加和功能性能问题有关。这个材料工程的早期例子对理解石器时代人口的技术能力、创造力和原材料选择具有重要意义。我们预测，其他史前和民族志环境中的热处理行为也可能与边缘锐度增加和功能性能问题有关。