Reconstructing a Paleoindigenous Communal Space: Living Under the Trees in the Atacama Desert, 12,800-11,200 Cal Yrs BP

Abstract

For centuries the Atacama Desert in northern Chile, and particularly its hyperarid core (<2,300 masl), has been considered a marginal, uninhabitable place. In the general historic and Chilean imagination, the Atacama is a passage-way between the Andes and the Pacific coast, and a place for the extraction of minerals and salts that provide with c. 12.5% of the country’s GDP (Sernageomin, 2021). However, the Atacama is still inhabited by traditional indigenous communities that strive to continue herding and cultivating in the steep western slope of the Andes, despite the contamination and excessive consumption of water by large mining companies and cities along the coast (Santoro et al., 2018). Not only today, but also in the distant past, the Atacama reveals the presence of life. Due to improved environmental conditions and increased rainfall in the Andes, communities of people managed to make this desert their home between 12,800 and 11,200 years ago. This dissertation is devoted to understanding how these small groups of hunter-gatherers, who were part of the some of the earliest groups to populate South America, were able to access, map, understand and navigate through the core of the desert for over 1,000 years. Specifically, we focus on the relationship established between these groups of people and the trees that were highly adapted to the harsh conditions of the desert. This dissertation uses information from a wide range of sources, including ethnographic records, radiocarbon dating of old trees and archaeological material, soil and sediment analyses and stable isotope analyses of bones, hair, and soils in order to reconstruct and understand the local environments in which these early hunter-gatherers of the Atacama lived. A survey of ethnographic literature indicates that, recent hunter-gatherers in every kind of environment have established profound relationships with the nature around them, treating trees as social beings. Trees are not only important for their economic profitability but also for their shade and temperature regulation capacity, as a source of protection from wind, predators, enemies and spirits, as places for recreation, and because they provide a natural framework upon which several kinds of residences, ephemeral camps, and storage structures are created even without modifying the trees. The results of our surveys, excavations and radiocarbon dating of PaleoIndigenous sites in the Atacama indicate that, in an environment where groves were scarce, circumscribed and vital, hunter-gatherers took care of their trees. Our spatial and chronological record indicates that in at least two residential sites people preferred to live close to tamarugo trees (Strombocarpa tamarugo), which provided shade and shelter. The presence of ancient groves coincided with the placement of hearths. Our data also suggests that in one site, a grove of trees was contemporaneous and spatially coincident with human activities. Diagnostic artifact assemblages suggest the possibly two different human groups (perhaps bands) could have co-existed, congregating around the rich micro-environment provided by this grove for c. 400 years, between 11,600 and 11,200 cal yrs BP. The taxonomic identification of these tree stumps, together with the identification of wood represented as charcoal and tools, indicates that people preferred to use the second most common species (Schinus molle) or sub-fossil wood, and thus to preserve the most common tree species (S. tamarugo) as structural protection for their residential sites. A stable isotope analysis strengthens the hypothesis that at least two different groups of people were co-existing in the area and using a tree grove. The first one, that camped on site QM32, either came from the Puna (3,000 – 3,400 masl) or traveled to this ecological area, bringing with them Vicugna vicugna fiber. These animal remains display a more pronounced C4 plant consumption and higher d15N values. The second group was likely local and inhabited site QM35. These people did not use vicuña hair or any kind of fiber for cordage. In addition, bones and hair coming from QM35 and other sites, such as PR7, contain the remains of probable guanacos (Lama guanicoe) and Caviomorpha rodents, which had a more C3 rich diet and surprisingly, a lower d15N signal. Overall, this dissertation shows us how some hunter-gatherer groups became highly adapted to the hyperarid environment of the Atacama’s core, making this part of the world their permanent home. Some of the scarce biotic resources, specifically S. tamarugo trees, were tended as part of maintaining the value of residential locations. These places may even have become nuclei for the occasional convergence of different groups. Our research also suggests that more than one group of people were using the ecosystem seasonally, and in so doing perhaps establishing social networks linking the coast and highlands, to complement the patchy resources of the western Andean slope.