The discovery and development of metal as a tool medium is a topic of global interest. A fundamental research goal involves establishing the timing of human experimentation with naturally occurring copper ore, which is commonly associated with sedentary, agrarian-based societies. However, in North America, there is well-documented millennia-scale exploitation of copper as tool media by small, seasonally mobile hunter-gatherer groups in the western Great Lakes. Archaeologists have suggested that Late Paleoindian groups may have begun using copper as a tool medium almost immediately after they entered the Lake Superior basin. However, only a few radiocarbon dates support such early use of copper. Here, we use optimal linear estimation modeling to infer the origin date for copper tool production in North America. Our results show that the invention of copper as a tool media likely occurred shortly after the first pioneering populations encountered copper ore during the Pleistocene-Holocene transition. The origin dates modeled here (ca. 8100 RCYBP) reveal several important features about the behavior of pioneering hunter-gatherer populations. Moreover, our results suggest that this phenomenon represents the earliest known use of metal for utilitarian copper tool production.

金属作为工具介质的发现和发展是全球关注的话题。一个基本的研究目标涉及确定人类对天然铜矿石进行实验的时间，这通常与久坐不动的农业社会有关。然而，在北美，有充分证据表明，五大湖西部的小型季节性流动狩猎-采集群体将铜作为工具介质进行了数千年的开采。考古学家认为，古印度晚期的群体可能在进入苏必利尔湖盆地后几乎立即就开始使用铜作为工具介质。然而，只有少数放射性碳日期支持如此早期使用铜。在这里，我们使用最优线性估计模型来推断北美铜工具生产的起源日期。我们的研究结果表明，铜作为工具介质的发明可能发生在第一批先驱人群在更新世-全新世过渡期间遇到铜矿石后不久。此处模拟的起源日期（约 8100 RCYBP）揭示了有关开拓性狩猎采集人群行为的几个重要特征。此外，我们的研究结果表明，这种现象代表了已知最早的金属在实用铜工具生产中的用途。