CONTRIBUTION OF AIRBORNEGEOPHYSICALIMAGING TO THE MAPPING OF BIRIMIAN FORMATIONS IN THE KALAMONMINING PERMIT, BOUNA, NORTHEASTERN CÔTE D'IVOIRE

The Kalamon area, located within the Bouna mining district in northeastern Cote d Ivoire, forms part of the Paleoproterozoic domain of the Man Shield (West African Craton). In this sector, the presence of a subcontinuous and particularly thick lateritic cover (30 to 90 m) represents a major obstacle to direct geological mapping. This study combines high resolution airborne geophysical data processing (aeromagnetics and gamma ray spectrometry) with detailed petrographic examination of core drill samples to map and characterize the dolerite dyke swarms traversing the Kalamon mining permit. Filtered analysis of the total magnetic field (reduction to the pole, analytic signal, and first vertical derivative) reveals narrow, highly magnetic linear anomalies with preferential N-S to NNE-SSW and NW-SE trends. Microscopic examination demonstrates that these basic intrusions exhibit a typical ophitic to subophitic texture, dominated by interlocking plagioclase laths (labradorite to bytownite) and augite, accompanied by a significant proportion of iron titanium oxides (titaniferous magnetite and ilmenite), which account for the high aeromagnetic response. Low-grade deuteric alterations are marked by partial uralitization of pyroxenes and sericitization of plagioclases. This integrated geophysical and petrographic approach proves highly effective in reconstructing subvolcanic magmatic conduits and refining the regional geodynamic framework.