Geomorphologic Evidences of the Influence of Glacier Sediments in Lake Formation Case Study: the Formation of Gahar Lake, in Iran

ABSTRACT: The existence of the glacier forms represents the function of the glaciers in development and evolution of the earth surface. Gahar Lake in Iran is one part of the old and cold climate heritage still existing in today warm and half-dry climate of Iran. This lake is located in the southern slope of Oshtorankuh in a fault valley having the area of about 88 hectares; its height is 2355m, its maximum depth 28 m, and its circumference 5245m. Previous researches claim that the formation of this lake was due to the landslide. This is the question of this research; what is the effect of the process of glacier sediments in formation of this lake? This research has been done by using field study, the study of mass deformation of shapes, and by using ETM sensor images, aerial photos, topography and geological maps. The results show that moraines Sholila and Ghiff Glacier valleys have caused the formation of the Gahar Lake. They have done this by moving and locating against the flowing of the Gahar River. The spectral reflection of the blocking sediments of the lake corresponds to the sample sediments of moraine present in the center of Sholila and Ghif circuses. Therefore, the lake has been formed due to the movement and situating of the glacier sediments. So it is considered as the heritage of cold climate of Iran, and tectonic and sliding origin of its formation proves invalid.