Mapeamento Faciológico do Stock Limeira da porção norte da suíte granítica Estrela do Sul na região Alto Paranaíba- MG

Abstract

The Ediacaran magmatism of the Upper Paranaíba region is characterized as the last episode of granitogenesis in the southern portion of the Brasília Mobile Belt. In the tectonic context, this magmatism is related to the collisional event that happened between 642 and 630 Ma, being responsible for the generation of peraluminous intrusive bodies that constitute the Suíte Granítica Estrela do Sul. It is a suite composed of 7 (seven) syn-tectonic granitic bodies mainly hosted in the Araxá group, being the focus of the study the body located north of the municipality of Estrela do Sul, northeast-central sector of the Estrela do Sul sheet - SE.23-Y-A-IV of CODEMIG (2017). The Estrela do Sul Granitic Suite outcrops in the form of "ellipsoid" to "sigmoid" bodies, consisting of lithological types described as granites and alkali-granites, equigranular to porphyritic, fine- to medium-grained, light gray, deformed at the edges, consisting of quartz, orthoclase, microcline, plagioclase as main minerals, muscovite and biotite as secondary minerals; garnet, zircon, tourmaline, monazite and apatite as accessory minerals, showing its peraluminous character. With the evolution of the geological studies in the region, many questions about the faciologic, petrographic, geochemical variations and geodynamic conditions related to the genesis of the magmatism responsible for the generation of the Suíte Granítica Estrela do Sul have been raised, mainly with respect to the understanding of its evolution, origin and type of magmatic lodging. To reach the objectives of this research it was accomplished the faciologic mapping of the central intrusion of the Suíte Granítica Estrela do Sul, described as ameboid body, through systematic geologic mapping, aiming to confirm its spatial geometric disposition for remodeling, to determine its mineralogical composition by macro and microscopic descriptions, textural analysis to understand the petrogenetic context, its relations with the surrounding rocks, as well as associated posterior geologic processes. As a result, an updated geological and facies map of the northeast stock of the Estrela do Sul Intrusive suite was obtained at a scale of 1:25,000.