EVALUATION OF ENHANCEMENT TECHNIQUES OF MAGNETIC ANOMALIES APPLIED TO STRUCTURAL INTERPRETATION OF THE ITAITUBA REGION, STATE OF PARÁ – BRAZIL

Abstract

The purpose of this article is to describe the work carried out for evaluating enhancement techniques of magnetic anomalies applying the reduction-to-the-pole method and its implications for structural interpretation of a region located in low magnetic latitude. With this objective, the answer given by several data enhancement methods with and without reduction-to-the-pole was analyzed. These methods were applied to synthetic prisms located at low magnetic latitudes similar to the area of analysis and the resulting anomalies were compared to those calculated at the magnetic pole. The synthetic data has been generated from a program that calculates the anomalies from prisms with arbitrary dimensions, susceptibilities and depths. The enhancement methods were also applied to magnetic data of rocks from the Amazon Basin and the Amazonian Craton, in the Itaituba region, Par´a state, northern Brazil. The reduction-to-the-pole algorithm applied to synthetic data during this work improved the performance of the enhancement methods, once, after its application, the maximum amplitude of the transformed anomalies were positioned over the edges of the sources, facilitating magnetic-structural interpretation. Good correlation among magnetic lineaments – particularly those inferred by the recently proposed tilt derivative of the total horizontal gradient method – and the already interpreted geologic structures back up the reduction to the pole indicating it may be applied even when data is collected in low magnetic latitudes.