Study of Sedimentological Characteristics in Determining of Sand Dunes Origin in the Western Margin of Urmia Lake

Document Type : Original Article

Authors

1 Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran

2 Associate Professor, Faculty of Natural Resources, University of Tehran

3 Associate Professor. Faculty of Natural Resources, University of Tehran, Karaj, Iran.

4 M.Sc. in Watershed Management, Faculty of Natural Resources, University of Tehran, Karaj, Iran.

Abstract

Identification of the origin of sand dunes and determining their sensitivity are very important for combating wind erosion. The main aim of this research is investigating sediment characteristics and classification of sand dunes created at the western margin of Lake Urmia. At the first, geomorphological unit map was prepared, then 21 and 12 surface samples were selected from detachment wind sediments areas and sand dunes, respectively. The results of morphometry showed that frequencies of particle size are 125-500 micron indicated the short distance transport of particles and close to the site of the deposit. Also, sorting index is poor in detachment wind sediments areas and moderate to good in sand dunes. The index of particle skewness is very fine, fine, symmetrical, coarse, and very coarse and the kurtosis index is classified in categories of Platykurtic, Mesokurtic, Leptokurtic and Very Platykurtic. The results of morphoscopic analysis of quartz beads in 250-micron mesh sieve showed that around 53%, 14.4% and 40% segments of the sediment in sand dune were corona, brilliant carried by water and opaque carried by wind, respectively. Based on Besler classification, sand dunes located in saline and extremely saline classes showed that local winds carrying fine salt particles from the Urmia Lake toward sand dunes.

Keywords