Processamento de dados geológicos em ambiente SIG para investigação de anomalias geofísicas magnéticas

Abstract

The remote sensing is a tool that made works related to mapping much easier once it made possible to analyze locations without necessarily visiting it. Using this valuable tool, the following work is an analysis of geophysical anomalies in the southern portion of the Paraná Basin more precisely in the basin boundary with the Sul-rio-grandense shield in the Santa Maria region. The data used at this work is from the 2010 Projeto Aerogeofísico Escudo do Rio Grande do Sul (PAERGS), made avaliable by the Companhia de Pesquisa de Recursos Minerais (CPRM) and the bibliography related to the Tiago Rafael Gregory Research Project “Magnetic Lineaments Invertigation on Rio Grande do Sul”. The PAERGS data was processed into magnetic anomaly maps that were submitted to the application of filters in order to generate images more accurate of the actual location of anomalies and highlight in each filter the bodies at the desired depth. Images from the Alos Palsar satellite were processed into hypsometry and slope maps. The prior analysis of maps and work related studies led to the verification of magnetic anomalies only in the NW-SE direction, that could have served as a conduit for the ascent of the Formação Serra Geral (FSG) magmas. The magnetometry, hypsometry, slope and soils maps were compiled in one map (Suitability Map) using the Weighted Linear Combination. The purpose of this map is to point out spots with basalt outcrops and by so prove that the magnetic anomalies of the area are associated with the FGS. By the end of the study the Suitability Map has proven to be trustful to show basalt outcrops. With the field points was possible to prove the existence of a correlation between the magnetic anomalies and the FSG, especially in the Lineamento Magnético Formigueiro (LMF), where it was verified the occurrence of basaltic bodies.