Utilização aerogeofísica para correlação geológica no município de São Sepé-RS

Abstract

In recent years, geophysical methods have been widely used for the purpose of detecting and analyzing discontinuities and geological boundaries, thus serving as a subsidy in the characterization of an area. The gamma spectrometry and magnetometry have great potential in the delimitation of geotectonic structures and the delimitation of lithologies. These methods, when related, produce satisfactory results for the geological and geophysical characterization of large areas, so they are widely used in geological mapping campaigns. The São Sepé region, in the Southwest region of Rio Grande do Sul, composes the São Gabriel Domain in the South of Brazil and is constituted by lithologies with great exploratory interest. In this way, the Mineral Resources Research Company (CPRM), in the project executed in 2010, provided a large amount of geological and geophysical information through the Aerogefísico Project of Rio Grande do Sul (AERO). This study, through the aerial data of magnetometry and gamaspectrometry provided by this project, seeks to characterize and analyze geological and geophysical information to better understand its geological evolution, limiting the lithologies and analyzing the discontinuities. The methodology is based on the interpretation of data on a regional scale correlating with local and regional geology. From this, different geophysical maps were generated that helped to better visualize the geology, as well as the delimitation of the lithology of the area and identification of structures and lineaments. The gamma - spectrometric maps enabled the characterization of the anomalies obtained related to the mineralogy of the rocks, generating a better visualization of the distribution of radiative elements present in the minerals constituent of the rocks and the differentiation of the Granitica São Sepé Suite, where Monzogranito Rincao dos Coqueiros was identified and the Granite São Sepé. The magnetometric maps allowed the identification of main lineaments and their continuities in the studied area. The analysis of the geophysical maps generated provided advance in the geological knowledge of the region, since it allowed the identification of the geological units domains and the geological characterization, presenting contributions for the improvement of information for the studied area.