Production and Circulation of Iron Oxides by Hunter-Gatherer-Fisher Societies of the Archaic Period in Northern Chile

Iron oxides have been intensively used by groups of hunter-gatherers in prehistory for at least 300 ka. However, little is known of the methods of mining, processing, and distributing this raw material.
The San Ramón 15 Mine (Taltal, Antofagasta Region) on the arid northern coast of Chile provides outstanding evidence of the extraction of iron oxides by groups of archaic hunter-gatherer-fishers. There is direct evidence of two extraction phases: The first occurred during the Pleistocene-Holocene transition (12,000-10k BP) and the second around 4500-4000 BP. A high amount of percussion instruments and stone hammers were found in situ in the clearings of the operation.

Current research at San Ramón 15 is aimed at understanding the systems of production (technology, extraction techniques, chaîne opératoire, spatial organization), distribution, and consumption (use-function) of the pigments within the coastal hunting-fishing and collection economies. To this end, the research attempts to determine the characteristics of the exploited iron oxides and the subsequent stages of processing and use.

To address these issues, a robust understanding of the lithology of reefs and other surrounding geological formations rich in iron oxides has been essential. Remains of iron oxides were sampled in both the mine and surrounding house sites (middens) to be compared using physicochemical techniques (SEM-EDS, XRD, PIXE) and petrographic characterization. Additionally, a technological study of all stone hammers at the SR-15 mine was conducted, considering variation in dimension, raw materials, active functional ends, and traces of use of the instruments. To support this last goal, the research project has begun the development of an experimental program aimed at determining function and a program of biomechanical studies to recognize osteological indicators of mining activities.

Hernán Salinas Williams received his B.A. in Anthropology with a minor in Archaeology at the Universidad de Chile and holds a B.A. in Psychology from the same university. His interests in the field of archaeology lie in studying pre-Hispanic mining and mining technology. His undergraduate thesis focused precisely on copper mining technologies in the Atacama Desert, and he is currently conducting research on iron oxide mining technologies on the desert coast of northern Chile. His works on mining include ethnographic and experimental studies and he has published and presented his results in diverse forums in America and Europe.

Diego Salazar is an Archaeologist at the Universidad de Chile, where he holds the position of Professor in the Anthropology Department. He has carried out research primarily in northern Chile on topics of interest such as prehistoric economies and, in particular, production systems, using a focus that strives to understand those systems in broader contexts that take into account the environmental, technological, social, political and ideological dimensions of past societies. His principal studies center on systems of mineral production, but more recently he has also delved into the study of systems of metallurgical production. At present, he is complementing his analyses of these two systems by studying agricultural production in the arid highlands of the Atacama Desert. The results of his research have been published in several archaeological journals and specialized books in Chile, Latin America, the United States and Europe.