Magnetic Structure of Agadem Petroleum Block (Termit Basin, Eastern Niger): Analysis and Interpretation of Aeromagnetic Data

The Agadem block is an area of major oil interest located in the large sedimentary basin of Termit, in the south-east of the Republic of Niger. Since the 1950s, this basin has known geological and geophysical research activities. However, despite the extensive research carried out, we believe that a geophysical contribution in terms of magnetic properties and their repercussions on the structure of the Agadem block allowing the improvement of existing knowledge is essential. The present study aims to study the structural characteristics of the Agadem block associated with magnetic anomalies. For this, after data shaping, several filtering techniques were applied to the aeromagnetic data to identify and map deep geological structures. The reduction to the pole map shows large negative wavelength anomalies in the southeast half of the block and short positive wavelength anomalies in the northwest part embedded in a large positive anomaly occupying the lower northern half of the block. The maps of the total horizontal derivative and tilt angle show lineaments globally distributed along the NW-SE direction in accordance with the structural style of the study area. The resulting map highlights numerous lineaments that may be associated with faults hidden by the sedimentary cover. The calculation of the Euler deconvolution allowed us to locate and estimate the depths of magnetic sources at variable depths of up to 4000 m. The compilation of the results obtained allowed us to locate zones of high and low intensities which correspond respectively to horsts and grabens as major structures of the Agadem block.