Endmember Extraction for LCT Pegmatite Detection in Brazil – A New Approach for Greenfield Prospection using Hyperspectral Data

This study addresses the challenge of subpixel occurrence in identifying Lithium Cesium Tantalum (LCT) pegmatites, crucial sources of lithium for electric batteries. Previous spectral unmixing methods have been applied in brownfield sites with pre-existing large mines, facilitating pegmatite endmember acquisition. However, this work focuses on a method for greenfield exploration, presenting a knowledge transfer approach to transfer pre-extracted pegmatite endmembers to new areas using a spectral unmixing based method. Two study areas in Minas Gerais, Brazil, were chosen: Area 1 (A1) as a brownfield site for deriving a pegmatite endmember, and Area 2 (A2) simulates a greenfield area to test the efficacy of the pre-extracted endmember. The Mixture Tuned Matched Filtering (MTMF) classification method was employed, showcasing potential value in scenarios where no pegmatite occurrences are known.