Geoarchaeology and Landscape Evolution: Geochemical Approaches in the Semi-Arid Environments of Northeastern Brazil

Abstract

Geoarchaeology focuses on the interactions between humans and their physical-natural environment, offering multiple approaches to understanding past contexts. Among these, geochemical analyses stand out for investigating the chemical components of crustal rocks, soil profile alterations, sedimentary deposits, and landscape evolution. This study explores the applications of such approaches in archaeology, particularly in paleoenvironmental reconstructions and landscape formation models. Two archaeological areas were examined: Morro do Chapéu (Bahia) and the Carnaúba River Basin (Rio Grande do Norte/Paraíba), through colluvial and fluvial vertical sections. At Morro do Chapéu, the results enabled the proposition of evolutionary models influenced by climatic, geomorphological, and sedimentological factors, revealing intense chemical alteration, deposition of mature sediments, and pedogenetic stabilization. The elevated relief favored moisture retention, allowing the development of deep mantles in a semi-arid climate, with ferruginous lateritic horizons. In contrast, deposits from the Carnaúba River indicate a semi-arid regime with seasonal high-energy pulses and a braided-channel system, reflecting climatic seasonality and variable transport conditions. Multidisciplinary integration thus provides valuable insights into the evolution of semi-arid landscapes and their connections with human occupations. These results highlight the relevance of geochemical approaches in reconstructing past climatic and environmental dynamics, especially in tropical settings where such processes strongly influenced cultural trajectories.