ABSTRACT
Not all of Mesopotamia is alluvium, however. The alluvium proper is contained in the state of Iraq, and appropriately-for the term al Iraq means ‘the shore’ or ‘the cliff’ in Arabic-extends from the head of the Gulf to (and beyond) Samarra on the Tigris and Hit on the Euphrates; rivers whose depositional activities have been largely responsible for filling this sunkland between the Arabian and Persian plates. This because only a small proportion of their alluvium reaches the sea, the rest deposited in the deltaic valley to a depth of at least 6mm per annum (Brice 1966:239). The weight of material causes continual sinking of the fill, so that at Nasiriyah, over 160km from the Gulf, the surface of the Euphrates is only some 2.4m above sea level (Brice 1966:242), indicating the dangers inherent (waterlogging, salination) in irrigation agriculture.
