Sedimentological and geomorphological study of sand dunes in the Western Desert of Iraq

Abstract

Details are given of sedimentological and morphological studies of the sand dune belts in the south and south-western parts of the Western Desert of Iraq. The Najaf and Nasiriya sand dunes are of the barchan type but in Samawa there are fixed dome-like dunes with some smaller elongated dunes. Samples were collected from the three sand dune areas: 40 from Najaf, 60 from Samawa and 60 from Nasiriya. Mechanical analyses showed that sand grain-size distributions are unimodal in Najaf and Nasiriya dune sands, and bimodal in Samawa dune sands. Morphometric analyses of dune sand particles in all cases indicate immaturity and short distance transport. Heavy minerals, clay and quartz grain surface features indicate local sources. The Najaf dunes are derived from the Euphrates, Fars and Dibdibba formations, and recent sediment from the Euphrates river. The Samawa dunes are derived from the Lower and Upper Fars formations, and from recent sendiment of the Euphrates. The Nasiriya dunes are derived from weathering of the Dibdibba formation and recent sediment from the Euphrates.