Lagoa do Camargo 1, a Paleoindian archaeological site located in southeast Brazil dated between 10.5 and 8.3 ka, was studied using a variety of analyses: artifact and charcoal frequencies, soil morphology and micromorphology, magnetic analysis, optically stimulated luminescence, and radiocarbon dating. Our results show that the sandy tropical Oxisol present at the site was accumulated by episodic erosion and accumulation of materials along the slope, by means of diffuse runoff (sheet wash), and that bioturbation, albeit present, played a minor role in the soil formation. From a geoarchaeological point of view, the site poses an important problem, which is the presence of a deeply buried archaeological site almost at the top of a plateau. Our conclusions are relevant for understanding the genesis of sandy Oxisols that cover a large portion of southeast Brazil, where charcoal fragments are abundant, and whose genesis is considered by some authors to be strongly related to pedoturbation.