Activity evaluation of Zahedan fault by morphotectonic invariant, East of Iran

摘要

The Zahedan fault with ～150 km length and almost north-south trend lies in the eastern margin of the Sistan suture zone. The right- lateral movement of the fault was accepted by the change path of the drainages and the change fans position that at are in our studied area. (E60° 30', E61°, 00 N29° 30', N30° 45'). The fault plan with western dip ～60° is observed in several place of the faults outcrop. By calculation the V ratio for created valise in eastern side of the fault, is computation variable value of uplift in different locales of the fault length. However the uplifting in the east part of the fault is proved entirely, but by using of ten topographic crass sections that was provided with satellite images from north to south of Zahedan fault, irregularly increasing in topographic slop from E to W proved more uplift in west than to east of the fault. Both sides of the fault are uplifting (with different value), so shortening of the area is confirmed. Therefore with considering western dip of the fault and more uplift in the left of it. The reverse component associated with the right-lateral component is necessary. The gradually movement of Zahedan fault is proved by considering the progressive displacement of the fans. The measured displacement value show different movement in the fault and it depend of the lithology, segmentation, fault dip and uplifting ratio. The presence of the several saddles in the eastern side of the fault with is contained of the alluvium is the reason for subdividing the major fault that each saddle is the trace of the minor fault that in the alternative fan is traceable and show the same trend of the major fault.