Remote sensing techniques to detect areas with potential for lithium exploration in Minas Gerais, Brazil

Detecting Lithium (Li) Mineralizations from Space: Current Research and Future Perspectives

“…In what concerns selective PCA, the two-band subset produced better results in the São João Del Rei pegmatite field while the four-band subset worked better in Araçuaí [66]. Overall, selective PCA presented the most accurate results while band rationing was the least efficient method in Li pegmatite identification [66]. On the other hand, no limitations were found in the use of Sentinel-2 images, unlike that reported in other works [63].…”

“…The methods (RGB combinations, band ratios, and selective PCA) and the algorithms employed (see Appendix A) showed variable performances in the two pegmatite fields. Additionally, Li pegmatite identification was more accurate in the São João Del Rei region than in Araçuaí, having the vegetation coverage in the second area negatively influenced the results according to the authors [66]. It is worth mentioning the ability of RGB combinations to discriminate Li pegmatites from both host rocks and associated tailings and mine dumps, with the exception of the Landsat-5 images [66].…”

“…Additionally, Li pegmatite identification was more accurate in the São João Del Rei region than in Araçuaí, having the vegetation coverage in the second area negatively influenced the results according to the authors [66]. It is worth mentioning the ability of RGB combinations to discriminate Li pegmatites from both host rocks and associated tailings and mine dumps, with the exception of the Landsat-5 images [66]. Additionally, in the São João Del Rei area, the most successful band ratios were the ones proposed based on the reference spectrum of lepidolite (a Li-bearing mica): Landsat-5 3/7, Landsat-8 4/7 and Sentinel-2 4/7 [63].…”

“…In the Araçuaí area, the spodumene based ratios were the most accurate in Li pegmatite identification. In what concerns selective PCA, the two-band subset produced better results in the São João Del Rei pegmatite field while the four-band subset worked better in Araçuaí [66]. Overall, selective PCA presented the most accurate results while band rationing was the least efficient method in Li pegmatite identification [66].…”

“…In follow-up work, Santos et al [66] applied the algorithms proposed by Cardoso-Fernandes et al [63] to evaluate their performance in drawing potential exploration areas in other Li pegmatites occurrences, namely in the pegmatite fields of Araçuaí and São João Del Rei in Brazil. The methods (RGB combinations, band ratios, and selective PCA) and the algorithms employed (see Appendix A) showed variable performances in the two pegmatite fields.…”