AbstractThis study provides the first survey of Brazilian magnetic susceptibility (MS) data from varying archaeological and geological contexts, including open‐air sites, quartzite, and limestone rockshelters, and Amazonian dark earths. Our MS analyses associated with archaeological findings allow us to propose MS values as proxies of intense anthropogenic burning activities for archaeological sites with (i) systematic use of large hearth lit in the same places; (ii) systematic burns and highly diverse uses; (iii) higher diversity use with few fire activities and knapping playing an essential role; and (iv) incipient human activities and the initial use of the archaeological site. Our data are limited to understanding anthropogenic burning activities and cannot be extended to reveal other archaeological aspects. The results have implications for understanding human occupation in a large area with numerous archaeological sites. This study was the first step in distinguishing archaeological fires from natural fires and provided a new perspective for further research that attempts to identify distinct types of human fires.