Early Evidence (ca. 12,000 BP) for Iron Oxide Mining on the Pacific Coast of South America

Iron oxides have been used extensively in the Americas from the Paleoindian period up to the ethnographic present. But, because archaeological mining sites are extremely rare in this continent, we still know very little about how indigenous groups exploited and processed these minerals. Here we report finds from the San Ramón 15 site, located on the arid coast of northern Chile, where our research revealed a prehistoric mine with associated tailings and mining debris that was exploited by hunter-gatherer-fisher groups. The mine was first exploited during the Pleistocene-Holocene transition (ca. 12,000–10,500 calibrated years before present [cal yr BP]) and then again during the Late Archaic (ca. 4300 cal yr BP), representing the earliest known mining activity in the Americas. This discovery has important implications, including (1) the record of undisputed mining activity in the continent is extended by several millennia, showing the first insights into Early Archaic mining techniques and technologies; (2) the earliest inhabitants of the Pacific Coast of South America had a well-developed mining knowledge, that is, they were hunter-gatherer-fisher-miner communities; and (3) mobility patterns of early nomadic maritime adaptations in northern Chile were influenced by repeated access to iron oxide pigments used mainly for symbolic purposes.