Integrating geological and airborne geophysical data to review the cartography of Rio Itanguá Batholith Araçuaí Orogen Brazil

Abstract (English)

Rio Itanguá Batholith (RIB) is a plutonic body located in the Northern border of Guanhães block, one of the various basement blocks reworked within the Araçuaí orogen, Eastern Brazil. Although its existence is known since the beginning of the 20th century, its tectonic history remains poorly understood. The RIB was mapped at 1:100,000 scale in the 1990s, before geophysical and satellite data became available. This work aims to re-evaluate the cartography of the RIB, as an initial step towards understanding its genesis and evolution. In order to do so, field and petrographic data, together with airborne gamma-ray spectrometry and magnetometry data, were integrated, resulting in a geologic map that shows different features from the previous maps produced in the area, such as the batholith division into two different petrographic and geophysical units; the presence of a mafic dike intruding the batholith rocks and the reduction in size of the batholith area. The magnetometric and gamma-spectrometric data proved to be important tools for geological mapping, and the substantial data obtained in the analysis of this tiny area points to the importance of re-evaluating older geological maps, taking geophysical data into account.