Complex sentence: The Aoufous formation was firstly reported by Dubar (1948) as part of the "Sillon Preafricain", who described it from a lithological point of view: mainly clay-sandstones and green marls with gypsum.
Split into simpler sentences: The Aoufous Formation was first reported by Dubar (1948) as part of the "Sillon Preafricain". Dubar described it from a lithological point of view as consisting mainly of clay-sandstones and green marls with gypsum.