Contribuição de dados aeromagneticos para o estudo do complexo granítico Caçapava do Sul

Abstract

The present work uses the aeromagnetic data of the Sul-Riograndense Shield Project of 2010 from CPRM, as a geophysical study of the Caçapava do Sul Granite Complex. The study covers an area approximately 3400km², largely covering the municipality of Caçapava do Sul-RS, With the objective of identifying the magnetic lineaments and the depth of the magnetic anomalies from the grid of the Anomalous Magnetic Field of the area. The processing of the aeromagnetic data received enhancement filter routines: Directional Derivatives, Analytical Signal Amplitude, Reduction to the and Upward Continuation to 50 km. The obtained results show that the magnetic lineaments are associated with structural lineaments with direction NE and NW. The NW magnetic lineaments are related to the boundaries between the Camaquã Basin (CB) and Santa Bárbara Formation (SBF) with crystalline basement, represented by the Passo Feio Metamorphic Complex (PFMC) and the Southern Caçapava Granite Complex (SCGC). The latter are located between the two sedimentary basins, which are marked by low values of magnetic intensity, representing a height of the raised basement that served as the source area for the basins. The average depth of the magnetic anomalies is around 6 km deep, determined from the power spectrum of the Continuation Filter to the Top of the Reduction to the Pole for 50km. The results also highlight the boundaries of the Caçapava do Sul and São Sepé Granites with the adjacent lithologies and basalts of the Hilário Formation, which occur in both PFMC and SBF.