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Petrographic, chemical, technological and distributional analyses of obsidian artifacts are a main focus of research in Fuego-Patagonia (Argentina and Chile, Southernmost South America). Despite the increasing interest in rocks exploited by Patagonian hunter-gatherers, few studies explored the large-scale distribution pattern of different types of obsidian. This paper compiles geographical data from stratified archaeological sites which record two main obsidian types over the past 10,000 years: black obsidian from Pampa del Asador (exploited by terrestrial hunter-gatherers from the Patagonia mainland) and green obsidian from the Otway Sound (exploited by maritime populations from the Fuegian Archipelago). The spatial distribution of sites with black and green obsidians is evaluated separately using spatial statistics. Results from spatial analyses statistically prove the differential nature of the spatial pattern between both sets of sites over time. It is suggested that the difference in the initial chronology of the human colonization, recognition of obsidian sources and long-distance transport of exotic raw materials between the mainland and insular spaces largely explains these results. Differences in human mobility and social interactions between terrestrial and maritime hunter-gatherers would account for further spatial variability between both sets of sites. [ABSTRACT FROM AUTHOR]

• Six obsidian sources increased their use in the Late Holocene in north Patagonia. • The closer source to Diamante Valley, is the least used. • The best quality source, Las Cargas, was the most used across the Late Holocene. • Obsidian helped to minimize risk in the occupation of high elevation locations. • Obsidian exchange routes may find a pattern in least cost path analysis results. • Exchange of obsidian followed routes through High elevations villages to sources. In this paper we explore obsidian conveyance in the Diamante Valley, in northwestern Patagonia, Argentina. Obsidian is the third most-common toolstone used in the Diamante Valley after basalts and local cryptocrystallines. Obsidian artifacts are predominantly projectile points and bifaces, with few cores and early-stage reduction debris. To explain these patterns, we conducted XRF sourcing and technological analysis of 177 obsidian artifacts collected there. We also conducted a GIS-based least cost path analysis to assess the costs of conveying obsidian from sources to sites in the Diamante watershed. We found that hunter-gatherers used Las Cargas as the principal obsidian source, followed by Maule 1 and 2, El Peceño, and Coche Quemado. The nearest source, Laguna del Diamante, was the least used. These data, combined with an analysis of the ways cores, formed tools, and debitage types were conveyed and ultimately deposited at sites in the Diamante watershed, suggest a late Holocene pattern of highland-oriented indirect access, implying highland village sites likely served as nodes in a regional and extraregional exchange network focused not only on obsidian but also on other goods, information, and social obligations. [ABSTRACT FROM AUTHOR]