Yazd block in Central Iran is a district of active deformation within Arabia-Eurasia collision zone. The study area is situated in southwest Yazd and it is surrounded by Dehshir fault in east and Mehriz fault in west. This NW trending fault system comprises numerous evidence for active faulting. Major and minor fault segments were mapped in satellite images in order to recognize fault zones structural and geomorphic characteristics. Epicenter location for five instrumental earthquakes with magnitudes ranging from 4 to 5 are defined in Tang-E-Chenar fault zone and probable causative faults are distinguished. Active NW trending Tezenj fault is introduced in this paper for the first time. Dominant fault mechanism involves right-lateral strike-slip and reverse movements observed all over the region representing recent fault activities. There are several geomorphic data demonstrating dextral strike-slip offsets in rock units, Quaternary alluvial fans and qanats along the faults. There is evidence for right-lateral offset in Triass units for ~840m along Taft fault and for ~2250m in Lower Cretaceous rocks along Mehriz fault. Right-lateral offset of alluvial fans ranges from ~140m to ~500m along Turanposht fault. Geomorphic analyses are together with. field geologic observations and fault geometric and kinematic measurements

Due to the relative displacement of the earth crust micro plates, seismic waves and fault ruptures are formed, which shows different consequences on the ground surface. These effects vary according to fault depth, displacement value, type and sub-surface conditions. Although limited studies have been conducted on fault rupture propagation so far, studies have been accelerated following the occurrence of three earthquakes in Taiwan (Chi-Chi), and Turkey (Duzce and Kocaeli). Because of limited time to study the fault ground rupture after an earthquake, and the huge cost of performing large-scale tests (1 g conditions), it is important to perform studies on centrifugal model of fault rupture phenomena adopting accelerated gravity condition (Ng). In this study, a split box was designed and manufactured to simulate reverse and normal faulting. It was composed of a fixed and movable part designed to simulate footwall and hanging wall, respectively. The Firoozkuh sand No. 161 with a relative density of Dr=70% that is uniformly-graded fine clean sand with a mean grain size (D50) of 0. 3 mm, maximum void ratio (emax) of 0. 943 and a minimum void ratio (emin) of 0. 548 was used in these tests. The tests were performed at the centrifuge facility of the University of Tehran, using Actidyn Systems C67-2 equipment and at a centrifugal acceleration of 60 g. Five initial tests were conducted to improve the boundary conditions of the models. The sidewalls of the model could create undesirable friction that could affect the test results; thus, different solutions were examined for reducing friction. Polyurethane sheets, double polyurethane sheets and silicon oil were used on both sides of the split box to reduce the frictional resistance. These tests were conducted using polyurethane sheets along with silicon oil-covered surfaces, which were determined to be the best solution. The other two experiments were designed to simulate normal and reverse faulting after obtaining desirable and appropriate conditions. The results of simulation showed that the vertical movement of bedrock in reverse faulting dissipated throughout the soil layer, and amplificated throughout the soil thickness in normal faulting that the value of DDR (Dissipated Displacement Ratio) was 91% and ADR (Amplificated Displacement Ratio) was 124%, respectively. The required h/H ratios for complete development of a failure surface were 5. 57% and 1. 85% in reverse and normal faulting, respectively. The failure surface approached the ground surface at a smaller dip angle (50˚ ) than the fault dip angle at bedrock (60˚ ) in reverse faulting and it became increased (84˚ ) in normal faulting. The scarp fault in normal condition is sharper and higher than reverse faulting; therefore, the buildings located in this area suffer damages that are more drastic than reverse faulting. According to the conditions of this study, the width of deformation zone is almost equal in reverse and normal faulting, but its location with respect to bedrock fault tip is different in either types. The width of deformation zone is equal to the soil layer thickness, and its border moved toward hanging wall side almost one third of the soil layer thickness in normal faulting. Increases in the price of urban land and a shortage of land for construction make optimal determination of this zone of special importance. Therefore, for effective usage of land, it is suggested that complementary studies (field investigation or laboratory model testing) be performed.

1-Introduction In this paper fundamental goal is discussed about tectonic activities and survey role of different factors of forming and deformations to understand better about origin of morphotectonic of land forms occurring to reveal geomorphological patterns in the Bakharden-Quchan zone in the context of Arabia-Eurasia collision (Berberian, 1976; Lybris and Manby, 1999; Shabanian, 2009). 2-Methodology This paper uses of satellite images observations from Landsat 7, topographic data (SRTM), GIS and GPS data, geology and topographic maps, field observations of the morphotectonic landforms to clarify the active tectonics in the Bakharden-Quchan zone. 3-Results and discussion In this zone there is an array active right lateral-strike slip fault that they obliquely have cut the range and produced offsets of several Kms in the geological structures. These faults have identifiable ends, where they turn into thrust and link to blind faults mechanism changing of faults to revers have caused shortening by thrusting in their ends bending. Through convergence of Arabia-Eurasia plates have put constantly under neotectonic activities this zone since last phase of Alpine orogeny. Morphotectonic features have revealed by uplifts, deformations, ruptures and incision of late Quaternary traces, displacement of channel this sections, shear and displacement of Quaternary alluvial fan deposits. There faults have rotated anti clockwise around their vertical axes to cause several Kms of NS shortening. They also require of several Kms along strike extension that is taken by the westward component of motion between south Caspian Sea basin, Shahrood Fault system and both Eurasia and central Iran (Hollingsworth, 2006: Bretis and Conrady, 2012). 4-Conclusion The most important results of this paper is the identification of an array of active right lateral-strike slip faults which are almost certainly responsible for major destructive earthquakes in both historical and modern. All of these faults have ended where they turn into thrusts and link to blind faults. Mechanism changing of these faults to reverse of caused to increase stress, shortening by thrusting in their ends bending and their neotectonic activities create different morphotectonic features in Bakharden-Quchan zone particulary along the Qhuchan and Baghan-Garmab faults that there are enough morphotectonic evidences (Tchalenko, 1975; Masson et al., 2007; Shabanian, 2009).