MAGNETOMETRIC ANOMALIES FROM DIAMANTINA REGION (ESPINHAÇO RANGE, MINAS GERAIS) AND ITS GEOLOGICAL, STRUCTURAL AND TECTONICAL MEANINGS

Abstract

The Diamantina region, Southern Espinhaço Range, is the focus of numerous geological studies, particularly by the diamond-deposits of the Espinhaço Supergroup, the main lithostratigraphic unit that sustains this range. An area still relatively little covered by such studies is geophysics. The aeromagnetometric survey carried out by the CODEMIG state company has allowed the application of new methodologies for the understanding of the tectonic framework of this region, whose basic geology is quite characterized. In order to complement this knowledge in subsurface, modern software was applied, so that with the “Euler Deconvolution” methodology on magnetometric data, it was possible to make representative three-dimensional models for selected anomalies, looking for understand their geologic meanings. Geophysical deconvolution profiles were generated and compared with field data, selected in places where the anomalies (linear and circular) were more evident, with depths of up to 1,500m for the former and 1,900 m for the latter, demonstrating its deep roots. Together with the deconvolution data, thematic maps were generated that allowed a better integration of information, considering the Sopa Brumadinho Formation as the main focus of the anomalies. The magnetometry facilitated the identification of subsurface structures, providing results regarding the formation of the rift generator of the Espinhaço Basin, defining the “master fault” of the rifting. Keywords: Magnetometry, Euler Deconvolution, Diamantina Region, Espinhaço Range.