Geologia e mapeamento faciológico do Granito Davinópolis, sudeste do estado de Goiás

Geological and faciological mapping of the Davinópolis Granite, southeast of the state of Goiás

Abstract

The Neoproterozoic acid magmatism present within the metavolcanosedimentary sequences between the cities of Araxá (MG) and Catalão (GO) is represented by dozens of intrusions distributed along an extensive nappe-shaped belt in the southern portion of the Brasília Belt. In this region, the Davinópolis Granite stands out, cropping out in the homonymous municipality, located in the southeastern part of the state of Goiás, within the lithologies of the Araxá Group and the Abadia dos Dourados Complex. The body has an elongated NW–SE orientation, is strongly deformed, and is partially bounded by faults. Its exposed area covers approximately 14 km² and is composed of peraluminous to metaluminous rocks with syeno- to monzogranitic and granodioritic compositions, commonly exhibiting porphyritic and inequigranular textures with fine- to coarse-grained crystals, as well as a well-developed anisotropic structure. Four distinct facies have been identified within the body: (1) muscovite monzogranite; (2) fine-grained syenogranite; (3) monzo-syenogranite with epidote and allanite; and (4) granodiorite with epidote and allanite. These variations are defined by modal differences in microcline, oligoclase, and quartz, along with variable amounts of biotite, garnet, muscovite, allanite, epidote, and titanite. Based on mineralogical criteria, the Davinópolis Granite exhibits features consistent with peraluminous S-type magmatism derived from the crustal melting of metasedimentary rocks. However, the high proportion of alkali feldspar also allows it to be interpreted as an aluminous A-type granite, related to the partial melting of lower-crustal metasedimentary rocks in a late- to post-collisional or extensional continental arc setting.