Sabkhat regions of Iraq

Most of the desert region of Iraq lies below 200 m on the lower plains, rising westwards to a maximum elevation of about 900 m (Jabal Anaiza), near the border to Saudi Arabia and Jordan. Geologically this region consists of undisturbed limestone with some shale of Cretaceous (135 MYBP), Eocene (60 MYBP), Miocene (25 MYBP) and Pliocene (11 MYBP) origin. This is a part of the Arabian Shield, which forms the western part of the Arabian Peninsula. The oldest (Cretaceous) part of this shield in Iraq is at the southwest corner (Rutba District) surrounded by Eocene limestone and marls. The only extensive zone of sand dunes in Iraq stretching over 270 km lies from south of Najaf in the south to west of Basra in the southeast, forming a belt of dunes 15 to 20 km wide.

The desert soils of Iraq are calcareous, usually gypsiferous, often with a cover of recent unsorted material as a result of wind erosion, and contain a low organic content (generally below 0.5%) (Guest, 1966). The soils are often covered with a thin layer of gravel, or with a gypsum or limestone crust. The subsoil starts at a depth of a few centimetres, and has high lime content. The desert soils (gypsum and limestone) occupy the greater part of the desert plateau region of Iraq (the Jazira, the Western Desert, and the Southern Desert). Many saline marshy depressions may be found in these deserts, especially near Karbala (central Iraq) around the two large salt lakes, Bahr al Milh and Lake Abu Dibbis.