Metallurgical traditions under Inka rule: A technological study of metals and technical ceramics from the Aconcagua Valley, Central Chile
Authors:
Plaza et al
Abstract:
The spread of the Inka state in the Aconcagua Valley (Central Chile) is thought to have been culturally mediated, avoiding military coercion, and thus leading to different forms of cultural acceptance, resistance or hybridisation. However, there has been no previous attempt to investigate the extent to which these interactions are reflected in the use of metals and metallurgical technologies. Here we present analytical work on metallic artefacts and technical ceramics from Cerro La Cruz and Los Nogales, two Valley sites with evidence dated to the Late Period (ca. AD 1400-1540). The analyses included SEM-EDS, optical microscopy, petrography, XRD and FTIR. The results suggest that the sites represent different technological traditions. At Cerro La Cruz, the style of the metal objects and the lack of tin bronzes reflect continuity with an ancient metallurgical tradition with bases in the Diaguita Culture, rather than a wholesale adoption of an Inka metallurgical tradition. In Los Nogales, the presence of tin bronze and the use of perforated crucibles and other technical ceramics lined with bone ash is consistent with a tradition closely related to the Inka expansion and north-western Argentina, perhaps reflecting a stronger receptivity towards the new technologies. This disparity supports the idea that the Inka domination in the Valley was not forceful, and suggests a closer relationship between the state and some local groups, not previously identified.
Humans began contributing to environmental lead pollution as early as 8,000 years ago, according to a University of Pittsburgh research report.
The Pitt research team detected the oldest-discovered remains of human-derived lead pollution in the world in the northernmost region of Michigan, suggesting metal pollution from mining and other human activities appeared far earlier in North America than in Europe, Asia, and South America. Their findings are highlighted on the cover of the latest issue of Environmental Science & Technology.
"Humanity's environmental legacy spans thousands of years, back to times traditionally associated with hunter-gatherers. Our records indicate that the influence of early Native Americans on the environment can be detected using lake sediments," said David Pompeani, lead author of the research paper and a PhD candidate in Pitt's Department of Geology and Planetary Science. "These findings have important implications for interpreting both the archeological record and environmental history of the upper Great Lakes."
The University of Pittsburgh research team—which included, from Pitt's Department of Geology and Planetary Science, Mark Abbott, associate professor of paleoclimatology, and Daniel Bain, assistant professor of catchment science, along with Pitt alumnus Byron A. Steinman (A&S '11G)—examined Michigan's Keweenaw Peninsula because it is the largest source of pure native copper in North America. Early surveys of the region in the 1800s identified prehistoric human mining activity in the form of such tools as hammerstones, ladders, and pit mines.
The team from the Department of Geology and Planetary Science investigated the timing, location, and magnitude of ancient copper mining pollution. Sediments were collected in June 2010 from three lakes located near ancient mine pits. They analyzed the concentration of lead, titanium, magnesium, iron, and organic matter in the collected sediment cores—finding distinct decade- to century-scale increases in lead pollution preserved from thousands of years ago.
"These data suggest that measurable levels of lead were emitted by preagricultural societies mining copper on Keweenaw Peninsula starting as early as 8,000 years ago," said Pompeani. "Collectively, these records have confirmed, for the first time, that prehistoric pollution from the Michigan Copper Districts can be detected in the sediments found in nearby lakes."
By contrast, reconstructions of metal pollution from other parts of the world, such as Asia, Europe, and South America, only provide evidence for lead pollution during the last 3,000 years, said Pompeani.
