Studying the Morphologic Maturation of Aeolian Sand Grains During Transportation Process of Wind Erosion (Case study: Khartouran Erg)

Wind, in the duration of its erosional process, affec ts considerable changes in a grain's morphology from its removal (detachment) step to sedimentation. in other word, a grain undergoes its gradualevolution during the transit process. in this project, the maturation of aeo lian sand grains had been studied upon as based on texture maturity indicator which includes: sorting, meansize grain, roundness as well as abrasion coefficient parameters. the study area is the transport region of khartouran ergsediments, which founded on the basis of ground index of wind erosion. according to these indicators,the direction of prevailing or strong winds is notably mentioned. in a later step, four transects are selectedin different area in alignment with wind direction. samples of sediment grains are taken at varied distances in anyone of the transects. the samples were taken from the wind ward slope of rebdou landform. the samples were evaluated to using granulometry and morphoscopy techniques. gra in size analysis of was done using dry sieve analysis while morp hoscopy of grains carried out by studying the quartz grains of 150 to 300 μm diameter by using binocular microscope. results indicate a gradualmaturity (evolution) in sediment texture in all transects starting from the upper parts (near sand source)toward the lower parts (in transportation area).also, results indicate that from among the four indicators grain maturity namely: sorting, grain size , roundness and abrasion coefficient the respective factors of either abras ion coefficient index or roundness index in the first value and then sorting and finally grain's mean size index are the ones accounted for validation for determination of maturity.