The Effect of Neotectonic on Haji Arab Fan (Qazvin Plain) by sedimentologic and morphometric data

Alluvial Fans are forms affected by tectonic and climatic conditions. These landforms are very sensitive to tectonic activities and usually show the effect of changes. Haji Arab Fans as a case study located in southern of Qazvin plain. The aim of this research is study effect of tectonic activities on sediment and morphometric characteristics of this fan. To achieve to this object, initially of IRS satellite images (2008), and aerial photos in scales of 1:55000 (1995), 1:20000(1967), 1:40000(2000), are used. In addition, digital topographic maps and geological maps in scale of 1:100000 are used as main tools. Also, through field works, the impact of these activities on the morphometric characteristics of alluvial fan, such as shape, size and location of the deposited sediments, as well as changes in the transverse and longitudinal sections were examined. In addition, the longitudinal and width profiles take for distinguish of the role of tectonic activities in the terraces and sections and was used as a part of the alluvial fans. The result show that the major tectonic activities in the region originate from Eipak and southern Eshtehard faults that located on the upper part of Haji Arab alluvial fan. Finally the main part of morphometric and sedimentology characteristic of fan is effected by tectonic movement of Eipak fault.