Geology of the Central High Atlas diapiric province (Rich-Imilchil): a cartographic synthesis

We present a geological map of the Central High Atlas of Morocco (excluding the mountain fronts), illustrating a structure consisting of narrow ridges of lower Jurassic carbonates, occasionally cored by Triassic Keuper rocks and basalt, or by mid-late Jurassic alkaline intrusions. The ridges are separated by broad synforms filled with upper Lias–Dogger strata. The ridges are interpreted as salt walls formed by salt tectonics during the Jurassic rifting, whereas the intervening synforms, which often show growth strata, halokinetic unconformities and rapid facies variations, are interpreted as salt-withdrawal minibasins. These structures were later affected by shortening during the Late Cretaceous to Cenozoic Atlas orogeny, which often resulted in diapir welding and layer steepening in megaflaps and minibasins. However, not all the mapped ridges were demonstrably produced during the Jurassic halokinesis; some were probably generated as neoformed thrusts and folds during the orogeny.