Eolian sediments are comprised of two groups of loess and eolian sands. They, in distances close to origin, are exposed as sand dunes and then become apparent in the form of loess. Loess sediments are usually yellow but grizzly and contain silt size materials. Iran loesses, have mostly been located in its northeast regions. The purpose of this research is to investigate their morphoscopical properties and also, to determine the continuity among the layers of studied sections in which the sedimentation conditions have probably been different. These sections, are located in two types of climates of the Ghapan region (semiarid and humid) in southern Gorgan. The different stages of this research consist of field operations, chemical tests, brief identification of loess components in sand part (greater than 53 microns) and a morphoscopical study of Quartz grains. Investigation concerning the components of loesses in Ghapan region indicates that gypsy-clayey aggregates and the primary minerals are abundant, whereas in the southern Gorgan regions, secondary calcareous-clayey aggregates are the dominant. Morphoscopy research concerning quartz mineral indicates that a high percentage of the samples (greater than 70 percent) fall in angular to semi angular class which indicates that these sediments have not been moved a far distance from their source regions. From the view point of surface texture, quartz grains are mainly (about 75 percent) aureole and partially (about 25 percent) blur. The form of their aureole (in a high part of the sediments) indicates that they have originated from ancient river beds and have not been transported so far a distance from their origins. Their blurring is generally caused by color blending by Sesquioxides and secondary calcareous effect. That indicates a relatively long time of sediment accumulation as well as the effect of varied climatic conditions, along with salts leaching from the upper horizons and their being deposited in lower horizons.
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