Identificação e caracterização dos pegmatitos litiníferos na região do Seridó, entre os Estados da Paraíba e do Rio Grande do Norte

Abstract

The Borborema Pegmatitic Province (PPB), located in the Seridó region, has historically known occurrences of industrial minerals, gems, and rare elements (Li, Ta- Nb, Be and Sn) associated with pegmatites. However, the true economic potential of PPB is unknown, due to the lack of studies from a prospective point of view. The recent increase in world demand for lithium, associated with the manufacture of batteries for electric vehicles, has regained attention for mineral prospecting in pegmatites. In this context, the main purpose of this work is to identify and characterize the lithiniferous pegmatites of the PPB, in the Seridó region, between the states of Paraíba and Rio Grande do Norte, with a view to contributing to the geological knowledge of the area and promoting future prospective works in the area. region. For that, data from remote multi-source sensors were used to identify areas of economic interest, followed by field checking of these areas with potential occurrences of lithium minerals associated with pegmatites (eg spodumene, lepidolite and amblygonite). The remote analysis methods used were remote sensing and aerogeophysics, the first being the digital processing of satellite images (Landsat-8 and Sentinel-2), with the elaboration of color compositions (RGB), band ratios and analysis. component (PCA). For the aerogeophysical data, the analysis of magnetic data was performed, through thematic maps of analytical signal amplitude and vertical derivative, as well as gamma spectrometric data, through thematic maps of ternary composition, concentrations of eK, eTh e eU. The field stage was based on checking and describing the pegmatitic bodies present in the study area, identified in the remote sensing data, as well as on collecting samples of potential lithium-bearing minerals for mineral characterization. The effectiveness can be proven by the identification of previously mapped pegmatitic bodies, in addition to mineralogical analysis, such as X-Ray Diffraction (XRD) that confirmed the minerals of spodumene, lepidolite and amblygonite. The integration of the data obtained so far provided a more complete understanding of the geology of the study area, considering the geological aspects that may influence the occurrence of lithium-bearing pegmatites, as well as validating the approach used to recognize the potential for exploration of the element in the pegmatites of the region. However, the methodology has limitations that prevented obtaining more satisfactory results and greater efficiency, such as the spatial resolution of the sensors of each satellite, which prevents the identification of small bodies, in addition to the spectral signature of the analyzed minerals, which can be affected by the geological context or impurities present in the pegmatites, which prevented the mapping of other possible litiniferous targets.