Sedimentological Properties of the Sand Dunes and Valley Sediments in Al-Muthanna, Southern Iraq

Abstract

Sedimentological properties of the dunes and valley terrigenous sediments in Al-Muthanna Governorate, southern Iraq were carried out. Ten samples were collected, where five samples from both sand dunes, and valley sediments. Grain size analysis revealed that sand, silt and clay fractions are the constituents of these sediments. Sand fractions predominant in the dunes and the texture is classified as silty sand, whereas clay fractions dominate in the valley sediments, with sandy clay texture. The mineralogy is determined by X-ray diffraction, which revealed that quartz is the main mineral in both study areas, followed by calcite, feldspars in lesser amount and evaporates (gypsum) in minor component of the light minerals. Petrographically, monocrystalline quartz dominates over polycrystalline quartz in both areas. Rock fragments in the valley sediments are higher than in the sand dunes, which are comprised of carbonate, chert, igneous, metamorphic, evaporate, and mudstone rock fragments. Feldspars are approximately similar in the study areas and comprised mainly alkali feldspar (potash feldspar) and plagioclase. Petrogenically, the sand dunes occupy the quartzose-recycled field, while the valley sediments fall in transitional recycled fields represented recycled orogeny.