Techno-cultural singularities in the southwestern region of the Brazilian central plateau in the early Holocene

Abstract

This article aims to contribute to expanding knowledge about the panoply of lithic tools present in Early Holocene archaeological sites located in the Brazilian Central Plateau. These sites have traditionally been interpreted within the context of the Itaparica tradition, whose artifacts called "slugs" or "plano-convex" were used as cultural markers. Technological research over the last twenty years on lithic materials from sites typologically attributed to the Itaparica tradition has allowed a better definition of what came to be called the Itaparica techno-complex. Due to the spectacular nature of the “plano-convex” objects identified in these ancient contexts, other artifacts are usually overlooked in research. Our proposal was, therefore, to look in more detail at the subtle incisive tools that are associated (or not) with “plano-convex” artifactual structures in the collections of two sites from the southwest region of the Central Plateau: the GO-JA-01 site (Diogo Lemes), dated from 12717 - 12143 cal. (Beta-3699), and the site MT-SL-31 (Morro da Janela), dated from 11994 - 11316 cal (Beta-78053). We could see that they are, very often, structured on other technical production principles and associated with specific operational schemes.

We based our research on the Techno-functional Approach. This approach allows us to identify the coherences that are established within a volumetric structure (a specimen) in terms of its structuring subsets -minimally, the transformative edge(s) and the possible prehensive unit(s) - in light of their functional potential. Furthermore, it allows us to think about the technical meaning of artefactual structures by reinserting them into the set of which they are part (a population), providing data on the techno-functional consistency of the collections. In methodological terms, the identification of the operational schemes was carried out based on the diacritical analysis of the negatives present in the artifact, with the production modes being highlighted based on the technical principles of affordance, debitage and shaping.

We were able to group the sharp tools from these collections into five techno-functional categories: unifacial shaped tools from normalized blanks (limaces); unifacial shaped tools on regularized blanks; tools shaped on blanks of cobble; tools with restricted modification; regularized and non-regularized blanks. We were also able to identify in the collections the representative occurrence of unexhausted cores with the presence of small negatives, which led us to infer the production of even smaller blanks which, however, were not detected in the collection. Furthermore, we identified the presence of discoid D-type debitage related to some of the tools. These technological details obtained with the investigation of the aforementioned archaeological sites of the Central Plateau, when considered in the light of spatial, chronological and paleoenvironmental information, allow us to consider the scenarios concerning the population dynamics of that period. The tools categories evidenced in this paper, added to the techno-cultural particularities found in other Central Plateau sites and expands the Itaparica toolbox. They bring about a greater understanding of the Techno-cultural diversity of the technical memories of the human groups that occupied the extensive area of the Central Plateau, enabling further investigations into the connections of technical knowledge between regions.