Archaeoanthrosol formation and evolution of the “Santana do Riacho” archaeological shelter: An old burial site in South America

Abstract

AbstractThe “Santana do Riacho” shelter is one of the oldest human occupation sites in Brazil. Dated to the Late Pleistocene, this shelter contains over 40 buried individuals. The shelter is located on the edge of the Espinhaço Range in Mesoproterozoic quartzites. This study aims to investigate the relationship between human activities and in situ soil formation. To this end, chemical, physical, X‐ray fluorescence, X‐ray diffraction using synchrotron light, micromorphology, and scanning electron microscope with energy‐dispersive X‐ray spectroscopy analyses were performed. In situ anthropogenic practices, such as fires and burials, have had the greatest influence on the geochemical parameters. Pedological processes were clearly detected, including (1) the formation of secondary carbonates; (2) the formation of secondary phosphates; (3) the formation of magnetic Fe nodules, and (4) degradation of magnetite into maghemite. The mobility of P, Ca, and C resulted in the enrichment of these elements in layers stratigraphically considered “sterile.” The amounts of available P, K, Ca, total organic carbon, and the pH values can be considered indicators of human occupation. This study provides information on the pedological processes in rockshelters and represents one of the few pedological and geochemical studies on deposits in a tropical rockshelter in quartzite bedrock.