Mapping of Lithium-Bearing Pegmatites Using Aeromagnetic Data and Field Outcrop Descriptions in the Bougouni Area, Southern Mali

Within the West African Craton, the Baoulé-Mossi domain is known for its potential in mineral resource among which, lithium now occupies an important place. Tied to pegmatite facies, the lithium is beared by spodumene (LiAlSi2O6) mineral. In southern Mali, pegmatites are located in the Bougouni Pegmatite Province (BPP) and are generally hosted within magmatic (e.g., granodiorites, monzogranites etc.) or metamorphic formations. This province is classified as one of the most important Lithium-bearing in Africa. However, the poor knowledge on their repartition and the thickness of soil cover constitutes a handicap to their characterization. It is why available aeromagnetic data have been used to identify the probable areas for pegmatite intrusive which are followed on the ground. This study requires understanding pegmatites distribution and their spatial relationships with the host rocks in the Bougouni area. For this, aeromagnetic data interpretation has been integrated with field geological descriptions. This study has allowed to understand that pegmatites dykes of Bougouni are low or even non-existent magnetic signature. It was also established that these pegmatite dykes are contained in metasedimentary and granitoid rocks which have moderate to high magnetic response.