Mapeamento Geológico 1:50.000 da Chapada dos Guimarães (MT) – Área 1

Abstract

The Geological Mapping at a 1:50,000 scale of a 60 km2 area within the Chapada dos Guimarães National Park (MT) aimed to detail the lithostratigraphic units of the Paraná Basin, focusing on their composition, textures, and structures. The study identified, from base to top, a succession of sedimentary environments that includes the Furnas Formation (transitional coastal-fluvial environment, arkosic sandstones), the Ponta Grossa Formation (shallow platform environment, mudstones-siltstones and claystones), the Aquidauana Formation (continental glacial environment, various lithotypes, microscopically classified as wackes), and the Botucatu Formation (eolian/desert environment, quartz-arenites), in addition to alluvial/colluvial deposits. The most significant finding was the unprecedented identification of the Aquidauana Formation in the mapped region, which substantially expands the understanding of the Paraná Basin's local evolution. Petrographic analyses of the older formations (Furnas, Ponta Grossa, and Aquidauana), which were predominantly classified as Wackes, indicate a dominant tectonic provenance of Recycled Orogen. Furthermore, structural analyses revealed that the unit layers remained largely undeformed, displaying low-angle bedding dips (between 1 and 30 degrees), a pattern consistent with the stability of a cratonic sedimentary basin. These results reinforce the regional tectono-sedimentary framework and provide detailed data for the geological and geomorphological knowledge of the Chapada dos Guimarães.