Document Type : Original Research Paper

Authors

1 Assistant Professor, Islamic Azad University, Zarand Branch, Zarand, Iran

2 Professor, Islamic Azad University, North Tehran Branch, Tehran, Iran

3 Associate Professor, Islamic Azad University, Sciences & Research Branch, Tehran, Iran

4 Associate Professor, Islamic Azad University, North Tehran Branch; Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran

Abstract

One of the most important tools of recognition for uplifting Movements in an area is study of rivers. The Davaran Mountain Range, which situated between Zarand and Rafsanjan cities, is limited by the Jorjafk fault in the north face. This fault is 160 km long and divided into two northern and southern parts. The north part is in the northern margin of Davaran Mountain Range and 100 km long. The southern part is an intra-mountain fault and 60 km long. In the northern part, thrust faulting of the pre-Neogene rock units over the Neogene-quaternary sediments shows the recent activity movements of this fault, although there is no record of historical and instrumental seismicity of the Jorjafk fault. For investigation of uplifting movements caused by this fault, we studied the morphotectonics of rivers limited to this fault. According to our studies, the sinuosity rates for 21 rivers calculated and gave mean ratio of 1.11. The mean ratio of SL index for 15 major rivers is 165.6. The V index shows less than 1 value for 7 rivers. The long profiles of 7 rivers prepared and all show the concave profiles with the minor dome in their long. The minor dome caused by the lithological variations in floor of the rivers. The greatest concaving belongs to river no 5. Our studies show the moderate uplifting values in central part of the Jorjafk fault, near the Hosen village. The uplifting movements show a reduction from the central to the end point of this fault.

Keywords