Identification of deep magnetized structures in the tectonically active Chlef area (Algeria) from aeromagnetic data analyzed with 2-D and 3-D imaging derived from the wavelet and ridgelet transforms

H. Boukerbout (1) , A. Abtout (1) , Dominique Gibert (2) , B. Henry (3) , B. Bouyahiaoui (1) , M.E.M. Derder (1)

1 CRAAG - Centre de Recherche en Astronomie Astrophysique et Géophysique
2 GR - Géosciences Rennes
3 IPGP - Institut de Physique du Globe de Paris

The Chlef region constitutes a key area to study neotectonics structures and their geodynamical context. Aeromagnetic data analyzed using different processing methods (shaded relief technique, computation of vertical gradient, upward continuation, use of the continuous wavelet transform and ridgelet transform), allow establishing a structural image of emerging and deep structures both onshore and offshore. Magnetic anomalies, over the Mediterranean Sea, the Chlef basin and the Ouarsenis Mounts, are well-correlated with the known geological structures. Long and short wavelength anomalies have been distinguished. The short wavelength anomalies are associated with the volcanic rocks on the coast from Chenoua to El Marsa and with the basement in the Boukadir zone in the sedimentary Chlef basin. The long wavelength anomalies to the South are associated mainly with deep E-W structures, limiting the Chlef basin. To the North, similar structures have been identified in the Mediterranean Sea. The compilation of the identified magnetic features leads to geometrical shape corroborating the structure in blocks of the Chlef basin.

Mots clés: Wavelet transform; Ridgelet transform; 2D - 3D imaging; Deep magnetized structures; Chlef; Aeromagnetic data

Domaines: Géophysique [physics.geo-ph]

H. Boukerbout, A. Abtout, Dominique Gibert, B. Henry, B. Bouyahiaoui, et al.. Identification of deep magnetized structures in the tectonically active Chlef area (Algeria) from aeromagnetic data analyzed with 2-D and 3-D imaging derived from the wavelet and ridgelet transforms. Journal of Applied Geophysics, 2018, 154, pp.167-181. ⟨10.1016/j.jappgeo.2018.04.026⟩. ⟨insu-01785456⟩