Mapeamento e peetrografia do granito São Geraldo e do granito dos coelhos associados ao complexo Monte Carmelo , Patrocínio - Mg

Abstract

The Monte Carmelo Complex is a prominent geological manifestation located in the Tocantins Structural Province, specifically delimited in the internal zone of the southern sector of the Brasília Fold Belt. This complex, recognized for its extent and geological relevance, is intrusive, extending geographically between the municipalities of Monte Carmelo, Abadia dos Dourados and Coromandel. From a lithological point of view, the Monte Carmelo Complex presents a diversity of lithotypes predominantly composed of tonalites, granodiorites, monzogranites and syenogranites. These geological materials exhibit a varied range of shades, ranging from whitish gray to yellowish, and are essentially made up of minerals such as quartz, orthoclase, plagioclase, biotite, titanite, apatite, epidote and sericite. It is important to highlight the presence of xenoliths in the enclosure and a significant amount of pegmatite veins, which intrude the igneous body. Additionally, the granite body displays an alternation between metaluminous (Type – I) and peraluminous (Type – S) signatures, evidencing a syn-collisional context. Such features developed predominantly in shear zones with a preferential direction to the NW. Thus, from the mapping and petrography of the bodies named as São Geraldo and dos Coelhos, through textural, structural and mineralogical relationships, six distinct Facies were defined for these bodies, which made it possible to understand the genesis of these rocks. It is possible to trace an older age and little differentiated evolution for the Dos Coelhos body, while in the São Geraldo body the rocks are more evolved, and have undergone greater differentiation, consequently being younger. Furthermore, the lack of aluminous minerals suggests that these rocks were formed from deeper regions and did not experience involvement with sedimentary/metasedimentary rocks, classifying them as Type - I granites.