Conducting studies aimed at geological knowledge is extremely important to know which are the main mineral deposits and their quantity in the subsoil. Such information provides for the rationing of the extraction of certain ores, so that it does not compromise its reserves for the future.
The Brazilian surface is basically constituted by three geological structures: crystalline shields, sedimentary basins and volcanic terrains.
• Crystalline Shields: are areas whose surface was constituted in the Pre-Cambrian, this geological structure covers approximately 36% of the Brazilian territory. In the regions that were formed in the Archean eon (which occupies about 32% of the country) there are several types of rocks, especially granite. In terrains formed in the Proterozoic eon, metamorphic rocks are found, where minerals such as iron and manganese are formed.
• Sedimentary basins: most recent geological structure, which covers at least 58% of the country. In regions where the terrain was formed in the Paleozoic era there are coal deposits. On land formed in the Mesozoic era there are oil deposits. In areas of the Cenozoic era there is an intense sedimentation process that corresponds to the plains.
• Volcanic terrains: this type of structure occupies only 8% of the national territory, this is because it is a rarer formation. Such terrains were subjected to volcanic spills, the lavas gave rise to rocks such as basalt and diabase, the first is responsible for the formation of the most fertile soils in Brazil, the “earth purple”.
By Eduardo de Freitas
Graduated in Geography
Source: Brazil School - https://brasilescola.uol.com.br/brasil/estrutura-geologia-brasil.htm