The Mesozoic-Cenozoic Atlas belt (North Africa): An overview

The Atlas domain extends in North Africa (= Maghreb) from the Atlantic (Moroccan Atlas) to Algeria and the Pelagian Sea (Tunisian Atlas), north of the Saharan platform. On top of a Paleozoic basement affected by the Hercynian orogeny in Morocco and, at least, in western Algeria, the Early Mesozoic transgressions deposited a variably, thick sedimentary cover. After a Triassic episode of aborted rifting in the western Maghreb, related to the opening of Central Atlantic, the distribution of the sedimentary facies suggests that an Atlasic trough established during the Late Liassic, trending WSW-ENE, from Morocco to northern Tunisia. This trough was filled then affected by a transpressive deformation during the Mid-Jurassic in Morocco, the Late Eocene in Algeria and at a poorly defined period in northern Tunisia. Thereafter, a Cenozoic shortening event overprinted the previous folds in the Atlas series, particularly along the edges of the chain and uplifted the orogenic belt. The thick-skin vs. thin-skin style of the Cenozoic deformation is not surely determined. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.