Late Holocene

Pollen analysis, soil micromorphology and radiocarbon dating have been the main scientific tools to unlock palaeoecological information from palaeosols during the past decades. In recent years, the application of optically stimulated luminescence (OSL) dating on polycyclic driftsand profiles and plaggic deposits has been shown to be of great added value to understand the geochronology of the evolution of soils and

The objective of this paper is to evaluate if changes in the social organisation of hunter-gatherer groups from northeastern Patagonia (Argentina) during the Final Late Holocene (ca. 1000-250 years BP) may be understood as a regionalisation process. A portion of this region, the lower course of the Colorado River, is taken as a case study. This arid/semi-arid area is part of an ecotone between the Pampas and northeastern Patagonia situated beside the Atlantic coast. Most of the evidence for occupation is concentrated in the Late Holocene, more precisely from 1000-250 BP. The archaeological record of this period indicates increased human population, along with a greater intensity of site occupation, the first systematic evidence of coastal occupation, reduced mobility and territoriality, diversification and intensification of subsistence practices, changes in the procurement and use of exotic raw materials, more complex funerary practices, and decreased circulation of specific images in portable artefacts. Based on these data, it is proposed that in some sectors of northeastern Patagonia during the Initial Late Holocene (3000-1000 BP) relatively open social networks operated, while for the Final Late Holocene (1000-250 BP) relatively closed social networks took their place within a framework of increasing regionalisation. Factors relating to the latter are likely to have included demographic packing, spatial circumscription, territorial behaviours, and changes in population dynamics that were accompanied by social differentiation and more intense and competitive social interaction networks.