Caracterização petrográfica da intrusão São Félix - 04, no município de Monte Carmelo (MG)

Abstract

The alkaline igneous rocks of the South American platform are known for their significant territorial distribution, as well as their petrographic heterogeneity and diversity in age of emplacement. Although they are commonly identified in intraplate regions, such rocks can be associated with convergent environments, a situation exemplified by the Alto Paranaíba Igneous Province, which comprises carbonatite complexes, mafic/ultramafic intrusions and rocks from the Mata da Corda Group. The main objective of this study was to perform the petrographic characterization of the São Felix – 04 intrusion, aiming to understand the main events related to the alkaline magmatism present in the Triângulo Mineiro mesoregion. The theoretical evolution associated with the different lithologies found in the Alto Paranaíba Igneous Province had as its starting point the use of genetic terms, so that, currently, descriptive information precedes subsequent interpretations. Thus, in order to achieve the proposed objectives, the study in question was based on the systematic mapping of the São Félix – 04 body, followed by descriptive analyses of the samples collected in the field, using both optical microscopy and Scanning Electron Microscopy. The results made it possible to classify the studied rocks as olivine leucitite. Microscopic analyzes showed the presence of secondary minerals generated through the alteration of olivine. Additionally, components related to the open magmatic system were found, as indicated by the occurrence of enclaves and olivine xenocrysts, which require more detailed studies for a comprehensive understanding of the textures and structures.