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How did evaporite deposits form in rift basins between Africa and Laurasia?

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Triassic paleogeography — Triassic Period Distribution of landmasses, mountainous regions, shallow seas, and deep ocean basins during the early Triassic Period. Included in the paleogeographic reconstruction are the locations of the interval's subduction zones.

During the Late Triassic, the supercontinent Pangea began to undergo continental rifting, creating fault-bounded basins (grabens) between Africa and Laurasia. These basins formed in arid or semiarid environments, which were critical for the development of evaporite deposits.12

The formation process occurred as seawater from the Tethys Sea periodically spilled into these newly created troughs. Once isolated within the basins, the water was subjected to intense evaporation—a process where water loss exceeds replenishment from precipitation or inflow. As the volume of the trapped seawater decreased, the concentration of dissolved minerals increased until they reached the point of precipitation, leaving behind thick layers of salts. This cycle of periodic flooding and subsequent evaporation allowed for the accumulation of regionally extensive evaporite sequences, such as those observed in Morocco and off the coast of eastern Canada.134