Geology of Morocco

In the Cenozoic, a microcontinent covered in sedimentary rocks from the Triassic and Cretaceous collided with northern Morocco, forming the Rif region.

[1] The Adoudounian Series overlies the Ouarzazate and marks the start of the Cambrian, formed in parallel with the rapid expansion of multicellular life.

The Amouslek Formation, within the Adounian Series is made up of shale and limestone and is laden with trilobite and archaeocyathid fossils, from an Early Cambrian shallow marine environment.

Silurian strata is common in the central Anti-Atlas, represented by sandstones, shales and dark mudstones that sometimes contain carbonate nodules.

Devonian mudstones with limestone beds unconformably overly the Late Silurian in the western Anti-Atlas, with brachiopod, conodont and tentaculite fossils, while basalts are found in the east.

Southern Morocco was flooded by a massive shallow marine shelf, building up significant carbonates, mixed with continental sediments pouring in from inland areas now in the Sahara.

Large alluvial fans began to fill the down-dropped grabens with fluvial sandstones, mudstones and conglomerates, intercalated with evaporite sequences of dolomite, halite and gypsum.

A large scale marine transgression in the Cretaceous, timed with subsidence in the region led to the maximum extent of seas in Morocco.

[4] The Rif microcontinent shifted westward and collided with the African Plate in the Oligocene and the Miocene, generated the complex Rift overthrust.

Seismic studies have found that Carnian sandstones, mudstones and conglomerates from the Triassic, lie unconformably atop the microcontinent's crystalline basement rock in north Morocco.

Low permeability clay and silt divided these deposits into multilayer aquifers and they typically range between five and 150 meters deep, with recharge from rainwater and Atlas Mountains runoff.

Paleozoic, Mesozoic and Cenozoic sandstone aquifers in the northern plains and around Tadla, Saïsis and Tensift range between 10 and 200 meters thick.

The country is a major exporter of phosphates and remains well positioned for peak phosphorus shortages through its occupation of Western Sahara, which holds much of the world's supply.