Application of Riesz Transform to the aeromagnetic data of the central In Ouzzal terrane and adjacent zone, southern Algeria

The main objective of this work is to interpret aeromagnetic data of the central In Ouzzal terrane and adjacent zone, southern Algeria using the Riesz Transform (RT) method. In this paper, we developed the RT method using the concepts of monogenic functions with Cauchy Riemann conditions. The result, obtained by calculation, led us to the new expression of the Riesz Analytic Signal Amplitude (RASA) and Riesz Local Phase (RLP), respectively. Tests on a synthetic magnetic model showed that the RASA and RLP had a better performance in delineating the geological contacts that were not seen in the original data. The advantage of this RT method is that it is less sensitive to noise. By applying the Euler deconvolution method using the RASA to the aeromagnetic data of the study area, we obtained the West Ouzzalian Fault (WOF), which is below the Paleozoic cover and has a depth of 0.8 km. At a distance of 30 km from the WOF, we find the East Ouzzalian Fault (EOF) with a depth of about 5 km. According to the RLP, the dip of the WOF, the EOF and the Adrar Fault are vertical. The fault systems located inside of the central In Ouzzal terrane are, generally, inclined towards the west.