First anthrachological studies at the eastern Pampa-Patagonia transition (Argentina). Hunter-gatherers management of wood material and Initial Late Holocene vegetal communities inferred from the Zoko Andi 1 archaeological site

Abstract

In the lower basin of the Colorado River (Buenos Aires province, Argentina) the Zoko Andi 1 archaeological site was occupied by hunter-gatherer groups during the Late Holocene (ca. 1500–400 14C years BP). The site is the only one in the entire study area that has an important presence of charcoals in a stratigraphic context, particularly related to the Lower Component, dated at ca. 1500–1300 14C years BP (1430–1296 cal years BP). This contribution presents the first anthracological results for the study area, which contribute to the understanding of the use of woody resources by hunter-gatherers and to the knowledge about the past vegetal communities and climate in the eastern Pampa-Patagonia transition. The charcoals were assigned to Prosopis caldenia, Prosopis sp., Senna sp. (Fabaceae), Jodina rhombifolia (Santalaceae), Condalia sp. (Rhamnaceae) and Larrea sp. (Zygophyllaceae). The archaeological charcoals show the existence of an ecotone between the Monte and Espinal Provinces during the Initial Late Holocene, which indicates the xerophytic open forests with a predominance of Prosopis caldenia and xeric shrub-dominated by Larrea ssp. The vegetation developed under an arid to semi-arid climate. This is consistent with other proxies (geomorphology, sedimentology, phytoliths, and microvertebrates) suggesting a similar environment for this area. Prosopis and Condalia have high caloric power and long fuel duration. These burning xerophytic forest resources were probably used by hunter-gatherers for cooking, heating, and lighting.