SIG integrado a aerogeofísica no reconhecimento e delimitação de limites litológicos e estruturas - NW do Escudo Sul-riograndense, RS

Abstract

In the northwest region of the Sul-Rio-Grandense Shield, in the São Gabriel Terrane, there are peculiar rocks of a basic ultrabasic character that arouse interest for investigations, either because of their complex structure and arrangement or because of their mineral prospective potential. Among these lithologies, the so-called Cambaí Complex stands out, which consists of a polydeformed supracrustal association composed of komatiitic cumulates, komatiitic basalts, serpentinites, basalts, and tholeiitic gabbros. Controversies about its formation and articulation among researchers suggest more detailed investigations regarding the spatial (geometry) and structural disposition of these lithotypes. Therefore, aiming at these more concise investigations, data from satellite images of the Sentinel - 2 mission, airborne magnetometry geophysicists, and the application of the enhancement technique through shaded maps were interpreted. The methodology applied in this work had as main steps the production of the database, analysis, and interpretation, carrying out the processing of satellite images and aerogeophysical data, production of thematic maps dealing with the exposure of information, and integration through comparison between the anomalous areas delimited on geophysical maps and geological information and the relationship between the traced lineaments and structures in the literature. Thus, it was obtained an expressive addition of the region's lineaments, correlation with geological contacts, proposition, and revision of the geophysical litho limits. It was noted that the integration with magnetometric anomaly enhancement techniques, subjected to shading techniques, both satellite and aeromagnetic images with the application of vertical exaggeration called Z factor, provided significant means of detection and delineation of rocky bodies and of the structural framework. It is found that among the shaded RTP-ISA magnetometric filter, together with the sentinel images - 2 with 20 m shaded resolution, are appropriate for qualitatively delineating and tracing structures and that the RTP-GHT filter together with the DEM proved to be more suitable for the review of lithological boundaries. And finally, that the integration of different data sets is an important tool for detecting a structural trend in a region is an excellent subsidy for future and similar works of a regional nature.