Underlying Geological Structure of the Northern Edge of the Mitidja Basin and the Sahel Fold Near Tipasa Town (Algiers, Algeria) Using Magnetotellurics: First Results

Abstract

Magnetotelluric data were collected at seven stations in the northern edge of the Algerian Mitidja basin (around Sidi Rached in Tipasa town,Northern Algeria). MT stations are roughly aligned along a 5-km N-S trending profile, perpendicular to the main geological structures. Dimensionality analysis indicates that the resistivity structure is globally 2D, with small 3D local features. The geoelectric strike of N80°E agrees with the surface geological structures. Data, from 2D inversion, were collected in order to image the underlying deep Mitidja electrical structures and are also in agreement with these surface data. The Mitidja basin and the Sahel fold are still characterized by active tectonics; their present geological knowledge leads to natural risks, particularly seismic hazards. The resistivity model along the profile exhibits a significant deep resistive structure overlying a very conductive body rising up toward the north as related to the inverse fault separating the syncline of Mitidja basin from the Sahel anticline.