Geomorphology of Meso-Yardang Formation and Evolution in Fahraj Plain, SE Iran: The Role of Stream Incision, Sandblasting, and Nebkha Transformation

Ahmad abbasnejad

The purpose of this study is to investigate on meso - yardags of Fahraj Plain in SE Iran. The playa on which the yardangs have taken shape has been divided into northern and southern parts as a result of incision by Nesa ephemeral stream . Detailed field investigations were performed and samples were taken to determine the texture, mineralogy and chemical characteristics of mudrocks comprising the yardangs. In addition, morphometric measurements on 51 yardangd were carried out and analyzed. The study demonstrated that stream incision has played a major role in creation of these yardangs. And some or all of them are the product of Nebkha transformation considered as an important agent. Sandblasting has played a crucial role in creation and evolution of these landforms and undercutting at nosal and lateral parts of yardangs by sandblasting is destroying them via mass wasting process. Yardang formation has progressed up windward (retrogressively) in the northern playa and down windward (progressively) in the southern playa.