Localização de áreas potenciais para pegmatitos litiníferos em Crateús/CE utilizando sensoriamento remoto multiespectral a partir de imagens landsat 8

Abstract

The energy transition has driven the search for various strategic elements, such as lithium, which plays a central role in technological, economic, and environmental transformations on a global scale. In the Brazilian context, the identification of occurrences of this metal is associated with pegmatites, which have aroused the interest of researchers and companies in the mineral sector. Therefore, this work aims to study potential areas for the occurrence of lithium-bearing pegmatites in the municipality of Crateús-CE, through the application of multispectral remote sensing techniques, in addition to contributing to the advancement of knowledge about lithium mineralizations in a region where scientific investigation is in its initial phase. The methodology of this research was structured based on the application of Digital Image Processing (DIP) techniques. Initially, remote sensing images were acquired. Then, the data were pre-processed, including atmospheric correction, band reprojection, and the application of the pan-sharpening technique, with the aim of improving the spatial quality of the images. Subsequently, digital image processing steps were applied, including RGB composition, Band Division, and Principal Component Analysis (PCA). Finally, the generated products were analyzed and interpreted, aiming to extract information relevant to the research objectives. In the literature, these techniques have been widely used to enhance spectral features associated with pegmatites and lithium-bearing minerals, allowing the preliminary identification of target areas with potential prospecting potential. In addition, a visit was made to an outcrop in the region, which, according to previous studies, is composed of pegmatitic rocks, making it possible to identify its mineralization. However, the generated products showed significant limitations, such as the low exposure of the pegmatites on the surface, the interference of clouds and vegetation cover, as well as the spatial resolution of the images, which made it difficult to clearly distinguish between the pegmatitic bodies and the host rocks. Despite these difficulties, the technique remains effective depending on the physical characteristics of the site and also on the compositions to be used for image processing.