Era | Period | Age | Formation | Explanation |
Cenozoic | Quaternary | Holocene-Pleistocene | Recent deposits | Alluvial sediments, valley, depression fill sediments. |
Pleistocene | Habbariyia Gravel | sandy Gravel, Conglomerate | ||
Tertiary | Late Miocene-Pliocene | Zahra Formation | Limestone, calcareous sandstones with hard recrystallized carbonates | |
Lutetian | Dammam Fn. | Fossiliferous limestone and dolomitic limestone alternations with clays chalky and cherty limestone | ||
Danian | Um Erdhuma Fn. | Phosphatic limestone, dolomite, dolomitic limestone, and thin beds of anhydrite. | ||
Mesozoic | Cretaceous | Late Maestrichtian | Tayarat Fn. | Limestone, yellow marl, dolomite, dolomitic limestone, and phosphatic siliceous limestone. |
Late Campanian-Early Maestrichtian | Hartha Formation | Sandy limestone, dolomitic limestone and clayey dolostone interbedded with marly limestone | ||
Turonian-early Campanian | Saadi Formation | Chalky Fossiliferous limestone, marly limestone and organic limestone. | ||
Cenomanian-Turonian | Msad Formation | Coralline limestone, multi colored sandy dolostone, sandy marl and dolomitic limestone. | ||
Cenomanian | Rutba Formation | Sandstones alternating with clayey silty sands, obtained coarse sands, and basal conglomerate. | ||
Jurassic | Bathonian | Muhaywir Fn. | Dolomitic sandstone, fine ferruginous sands, limestone, marly limestone with conglomerate and cherty Clay. |