Donald Jackson’s research while affiliated with University of Santiago, Chile and other places

We explored the site context of a late Holocene shell midden on the coast of Los Vilos in north-central Chile (31°51′ S, South America) to better understand the spatial organization of short-term, small-sized hunter-gatherer campsites. The Dunas de Agua Amarilla (LV 007) site comprises 14 separate surf clam refuse deposits. Extensive stratigraphic excavations of the shell middens and the areas free of residue allowed interpretation of potential activity areas bounded by hearths, the shell middens, and a possible dwelling space. Late Holocene campsites in the area correspond to brief occupational events framed within littoral residential mobility, in which predictable coastal resources became a staple for groups residing and circulating over long periods in the area. Data on shell midden composition and the spatial distribution of site features shed light on the organizational dynamics of dwelling and activity spaces of coastal hunter-gatherers of the South Pacific.

The high Andes of western South America feature extreme ecological conditions that impose important physiological constraints on humans including high-elevation hypoxia and cold stress. This leads to questions regarding how these environments were colonized by the first waves of humans that reached them during the late Pleistocene. Based on previous research, and aided by human behavioral ecology principles, we assess hunter-gatherer behavioral strategies in the Andean highlands during the late Pleistocene and early Holocene. Specifically, we formulate three mobility strategies and their archaeological expectations and test these using technological and subsistence evidence from the six earliest well-dated highland sites in northern Chile. Our results suggest that all of the studied sites were temporarily occupied for hunting, processing animals, and toolkit maintenance. The sites also exhibit shared technological features within a curatorial strategy albeit with different occupation intensities. From this evidence, we infer that the initial occupations of the highlands were logistical and probably facilitated by increased local resource availability during a period of environmental amelioration.

Presentamos los resultados de la investigación arqueológica de un sitio fechado hacia el Holoceno Medio en los Andes del Norte Semiárido de Chile. La escasez de este tipo de evidencias pone de relieve la importancia de dar cuenta cabal del contexto estudiado y los conjuntos ahí recuperados. Las características del sitio como una estación de tareas de tipo avistadero hacen que Techo Negro se integre de forma significativa al conjunto de información regional disponible y permite confrontarla con el actual estado de algunos modelos de ocupación que incluyen la distribución diferencial de sitios y los cambios ambientales a escala de milenios. Palabras claves: uso del espacio, ocupaciones de cordones montañosos, Holoceno Medio, Norte Semiárido de Chile. We present the results of the archaeological research of a site dated to the Mid Holocene in the Andes in a Northern Semiarid region of Chile. The paucity of this type of evidence underscores the importance of fully describing the studied context and the assemblages recovered therein. The characteristics of the site as a logistic hunting stand type station integrate Techo Negro (black roof) significantly to the available regional information and allows confronting it with the current state of some models of occupation that include the differential distribution of sites and environmental changes on a millennial scale.

The variability of radiocarbon marine reservoir age through time and space limits the accuracy of chronologies in marine paleo-environmental archives. We report here new radiocarbon reservoir ages (ΔR) from the central coast of Chile (~ 32°S) for the Holocene period and compare these values to existing reservoir age reconstructions from southern Peru and northern Chile. Late Holocene ΔR values show little variability from central Chile to Peru. Prior to 6000 cal yr BP, however, ΔR values were markedly increased in southern Peru and northern Chile, while similar or slightly lower-than-modern ΔR values were observed in central Chile. This extended dataset suggests that the early Holocene was characterized by a substantial increase in the latitudinal gradient of marine reservoir age between central and northern Chile. This change in the marine reservoir ages indicates that the early Holocene air–sea flux of CO2 could have been up to five times more intense than in the late Holocene in the Peruvian upwelling, while slightly reduced in central Chile. Our results show that oceanic circulation changes in the Humboldt system during the Holocene have substantially modified the air–sea carbon flux in this region.

A coastal route for the initial peopling of the Americas has been debated for over 30 years. Nevertheless, evidence supporting this coastal dispersal is often elusive, especially bioanthropological data. Here we report archaeological human remains directly dated to ca. 11,200 cal BP from the semiarid north coast of Chile (31 • S), supporting an early settlement along the Pacific Coast. 15 N stable isotope analyses of these remains indicate that the individual relied primarily on marine resources , suggesting coastal dwelling rather than seasonal rounds that included sporadic exploitation of littoral resources. When placed in a regional context, our results suggest that marine resources were important to the subsistence of some groups during the Pleistocene-Holocene transition.

Archaeological sites composed only of surficial lithics are widespread in arid environments. Numerical dating of such sites is challenging, however, and even establishing a relative chronology can be daunting. One potentially helpful method for assigning relative chronologies is to use lithic weathering, on the assumption that the most weathered artifacts are also the oldest. Yet, few studies have systematically assessed how local environmental processes affect weathering of surficial lithics. Using macroscopic analyses, we compared the weathering of surficial lithic assemblages from seven mid-to-late Holocene archaeological sites sampled from four different microenvironments in the Atacama Desert of northern Chile. Changes in polish, texture, shine, and color were used to establish significant differences in weathering between two kinds of locations: interfluves and canyon sites. Lithics from interfluve sites were moderately to highly weathered by wind and possessed a dark coating, whereas canyon lithics were mildly weathered despite greater exposure to moisture, often lacked indications of eolian abrasion, and lacked dark coatings. Our results show that lithic weathering can be used as a proxy for relative age, but only after considering local environmental factors. The power of such chronologies can be improved by combining archaeological, paleoenvironmental, geomorphological, and taphonomic data.

We synthesize lithic evidence from terminal Pleistocene sites in Central Chile (~31-34° S). Quebrada Santa Julia, Valiente, Taguatagua 1 and Taguatagua 2 sites show diverse assemblages, which are not fully understood by a traditional typological approach. This diversity can be better explained due to variations in discard rates, raw material availability, and site function. This approach allows the consideration of early hunter-gatherer occupations as integrated segments of a two-stage evolving use of space/mobility system.

We present bio-indicators of navigation and oceanic hunting practices during the Middle Holocene (ca. 7,000 cal BP) in the arid coast of Taltal, northern Chile. Based on the analyses of ichthyologic remains from the Agua Dulce site we identified large-sized epipelagic fish: swordfish (Xiphias gladius), marlin (Istiophoridae), and two shark species (Notorynchus cepedianus and Galeorhinus galeus), recorded at four occupational moments of the stratigraphic sequence of the Middle Archaic in the arid coast. Similar evidence has been detected at other local contemporary sites (Zapatero, Caleta Bandurrias, Cachinales). This would imply that, since early times, coastal populations had access to new eco-anthropic spaces by means of some sort of vessel, as part of their specialized adaptive system for exploitation of marine resources. Open sea hunting of large epipelagic fish would have developed in the context of increasing social complexity of local hunter-gatherer-fisher populations.

Evidencia estratigráfica de moluscos terrestres (Endodontidae) y dulceacuícolas (Sphaeridae, Amnicolidae y Succineidae) procedente de contextos arqueológicos de la Isla Mocha, sugieren una marcada tendencia a condiciones más húmedas hacia finales del Holoceno Tardío (post-900 A.P.), en coherencia con antecedentes polínicos previamente conocidos. Estos moluscos proporcionan relevante información para discutir el proceso colonizador de micro-moluscos en esta Isla.

We present bio-indicators of navigation and oceanic hunting practices during the Middle Holocene (ca. 7,000 cal BP) in the arid coast of Taltal, northern Chile. Based on the analyses of ichthyologic remains from the Agua Dulce site we identified large-sized epipelagic fish: swordfish (Xiphias gladius), marlin (Istiophoridae), and two shark species (Notorynchus cepedianus and Galeorhinus galeus), recorded at four occupational moments of the stratigraphic sequence of the Middle Archaic in the arid coast. Similar evidence has been detected at other local contemporary sites (Zapatero, Caleta Bandurrias, Cachinales). This would imply that, since early times, coastal populations had access to new eco-anthropic spaces by means of some sort of vessel, as part of their specialized adaptive system for exploitation of marine resources. Open sea hunting of large epipelagic fish would have developed in the context of increasing social complexity of local hunter-gatherer-fisher populations.