First Wave Seismic Tomography in Ore and Oil Problem-Solving and Studying the Earth's Crust of Siberia

Available surface and industrial subsurface data provide the basis for a general balanced cross-section from the Sahara platform to the Mediterranean Sea in Central Algeria. This section gives an overview of the whole Maghrebian orogen comprising from south to north: the intra-continental Atlas system; the External Tell system, the Flyschs domain and the Kabylides domain of European affinities. Restoration of the southern segment of the section, comprising the Atlas and External Tell systems, yields a minimum value of 40 km (20%) of horizontal shortening. For this part of the section, a four-step kinematic scenario, illustrates the main stages of the deformation history: 1. late Eocene "Atlas" deformation pulse, 2. early Miocene deposition of a thick flexural sequence, 3. middle-late Miocene emplacement of the Tell nappes and 4. late Miocene to present out-of-sequence thrusting. On this basis, a conceptual geodynamic model is proposed for the Maghrebian orogen. After the Atlas event, which just preceded the roll-back of the Tethyan slab, the model emphasises the role of subduction responsible for: flexuration of the subducting plate (slab pull effect); development of both accretionary prism and back-arc basin and late uplift linked to slab break-off.