Ferramentas multidisciplinares aplicadas à cartografia geológica: o exemplo da Folha Sobral – CE (SA-24-Y-D-IV)

Abstract

The northwestern region of Ceará includes land belonging to areas Médio Coreaú and Central Ceará of Borborema Province. Studies in this region, which fits Sobral Sheet (SA. YD-24-IV) scale of 1:100,000, sought to contribute to the advancement of geological knowledge of the region and this was done initially to systematize data and pre-existing geological information from an extensive body of work carried out by IG / UFPA, since the 1980s. Digital images (Landsat-5/TM and SRTM) also had been used. About the image in digital format (Landsat) were applied techniques for enhancement, filtering, processing by principal components and IHS transformation, which helped supplement the results of visual interpretation. The airborne data Project Rio Acaraú 1974 were processed using the software Montaj Oasis, and was basically in the interpolation of data (125m), micro generation and the themes processed. For magnetic data, were generated images of the anomalous magnetic field, derived from the horizontal (dx and dy) and vertical (dz), amplitude of the horizontal gradient analytic signal amplitude and slope of the analytical signal. Data airborne gama-ray spectrometry was possible to generate images of the channels of K, U, Th and CT images and ternary (RGB and CMY). The interpretation of the products of remote sensing and airborne geophysics, geological mapping associated with the scale of 1:100,000 Sheet Sobral allowed characterization of the pattern of Lito-structural region. Based on the objectives in this research and the methodology for its implementation were produced a geological map enriched with the contribution of geometric elements revealed by integrated analysis of all products considered, as well as other thematic maps. The work demonstrates the importance of using images from remote sensing and airborne integrated data digitally as important tools for geological mapping, making the maps produced richer and more reliable also providing information that may be available for fast since all products resulting from this work are in digital format.