The Early Triassic Tanamert Member (T3) is a relatively thin band of volcaniclastic conglomerate, likely emplaced by braided rivers.

The Middle Triassic Aglegal Member (T4) is a thick sequence of muddy and silty cyclical deposits interspersed with wide sandstone lenses.

It would have been deposited within a semi-arid playa, mudflat, and ephemeral lake system cut by meandering streams or sheet floods.

The late Carnian (or possibly early Norian)[2] Irohalene Member (T5) comprises bioturbated mudstone complemented by an increasing abundance of sandstone beds.

[1] The Timezgadiouine Formation is quite fossiliferous; footprints and other trace fossils are found throughout the entire strata,[5][6][7][8] while skeletal material is common in the Irohalene Member.

[9][10][2] Several animals are distinctive, such as the large herbivorous archosauromorph Azendohsaurus laaroussii,[11][12][13] and massive three-toed footprints (Eubrontes sp.)

The Argana Basin is a northeast-to-southwest oriented valley extending for about 85 km (53 miles) in the western part of the High Atlas.

This unconformity may be a result of tectonic instability and erosion related to crustal thinning or post-orogenic collapse of the Variscan mountains.

This was partially driven by the assumption that the entire Timezgadiouine Formation was Late Triassic in age, equivalent to rift basins in eastern North America and elsewhere in Morocco.

Laminated sediments are eventually broken up by mudcracks, giving way to a thick section of massive and warped paleosols with randomly dispersed calcareous nodules.

Subsequent drying exposed and fractured the lakebeds, and the area transitioned into a system of semi-arid mudflats and playas which were occasionally supplied with water carrying fine sediments.

Brackish water, seeping through the soil, deposited analcime and calcite, minerals which helped to preserve granular structures in mudstone.

The mudcracked mudstone at the top of a sequence corresponds to a final drop in the water table, ending a period of sediment processing until humidity increases once more.

The sandstone can be identified as a lithic arenite, with a high amount of feldspar, mud pellets, and reprocessed rock alongside quartz grains.

This was justified by the supposed presence of proposed Otischalkian index fossils such as Paleorhinus, Angistorhinus, Longosuchus, Placerias, and Metoposaurus.

Several proposed Otischalkian index fossils (namely Parasuchus and Angistorhinus) are paraphyletic or have a long temporal range extending into the early Norian in other regions.