Active deformation in Alborz range is due to N-S convergence between Arabia and Eurasia. This paper provides geomorphic traces of regional deformation in NW Iran in order to characterize active Faulting on major Faults. Soltanieh and North Zanjan Fault systems are involved in convergence boundary extent between South Caspian Basin and Central Iran. Soltanieh and North Zanjan Faults are major reverse Faults in the study area. Soltanieh Fault has been probably responsible for historical Soltanieh earthquake in 1803. Accurate mapping accompanied by field observations enabled offset determination along active Faults. We presented geomorphic documents indicating left-lateral strike-slip movements in Soltanieh Fault zone. Kinematics is achieved through analyzing inversion results obtained from kinematic measurement sites which are generally scattered along Soltanieh Fault zone. Fault kinematic data inversion results (slip-vector measurement in Fault planes) indicate a dominant NE trending horizontal maximum stress axis (σ 1). Kinematic inversion results infer reverse Faulting mechanism accompanied by strike-slip component.

The Robatkarim Fault is dividable into two segments - NorthWest and SouthEast in view of the general trend of Fault that is North-West and South-East with the length of 91 km. The North-West segment of Fault which is located in Eocene volcanic rocks, extending from south part of Shahriar up to south part of Robatkarim with the length of 26 km. The South-East segment of it is located in upper red formation marl and extending from Robatkarim up to Asadabad mountains and Charmshahr industrial zone in south east with length of 65 Km. In the north - west of segment Fault , considering of Fault plane’s outcrop, normal tectonic measurements such as: strike and dip of plane, slickensides and surveying of joints, etc. In the south - east section, there are no measurable signs of the Fault due to soft type of rocks In this zone the step of Fault emerged in form of uplifting of upper red formation marls with Pliocene-Miocene age with respect to conglomerate formation of Kahrizak with Pleistocene-Pilocene age. Based on this research, Robatkarim Fault is a high angle reverse Fault with left lateral strike - slip component. We proved the left lateral displacement on north-west segment by examination of slickenside on Fault plane. However, in order to be assured of this left displacement, we studied displacement and shift of drainage in south- east segment as well. The left slip displacement of the Fault of Robatkarim was measured between 90-25 m whose locations were marked on the prepared geological map. Considering, the near by of seismogenic Faults such as: South Ray and Garmsar Faults, it is likely that the activation of any of them may cause start off of this Fault. This makes the importance of Robatkarim Fault twice. It is worth mentioning that the absence of large earthquake record on this Fault (excepting one) can be due to non - recognition of the Fault as well as scanty population in the area .Generally, historical earthquakes are not property recorded in central part of Iran because of the scanty population. Furthermore as this Fault is located in central part of seismic area of Iran and as the return period of earthquakes are more longer. we can conclude that the record of one larg earthquake on this Fault is not a good enough reason for non seismicity or inactivity of this Fault. On the contrary, it may indicate the long period of return of this Fault and therefore it can be said that the Robatkarim Fault is amongst potential reactive Faults.

The Kerman’s Structural situation and the Shahdad’s Structural junction, is located in Central Iran, which caused the influence of field stress that results from convergent and collision between the Arabia and Eurasia Plates. Concentration of the Fault and fold structures with the north northwest-south southeast trend indicates stress concentration in this area. The Nayband, Gowk, Lakarkuh and Ravar right lateral strike-slip Faults with the north-south trend as well as Kohbanan, Behabad, Anduhjerd with the northwest -southeast trend convergent had raised expectation about earthquake concentration in this area of the Kerman Province. However, at the latter decades, some parts of Gowk and Kohbanan Faults were increasing their seismic activities. The reason may be related to the special Structural characteristics of the Faults. Forming up the block Faulting with different sizes and forming some junction areas between the Fault structures was the reason for distributing stress and different Structural behavior. For this reasons, at the Shahdad’s Structural junction some parts of Gowk Faults and around Zarand along the Kohbanan Fault, there are concentration of seismic activities. The Mesozoic units and Neogene sedimentary deposits folding as well as anti clock rotation some blocks Faulting are appeared at the Shahdad’s Structural junction area. These seem as reactions of compressional stress affected on the north-south direction in this area.

Dehshir Fault is located in the southern part of Shirkuh Mountains, with a relatively parallel trend with Zagros Main Fault. This Fault is an important zone for the occurrence of the Coloured Melange. To the west and southwest areas of this Fault Gavkhouni, Abarkuh and Sirjan depressions (Nabavi, 1355). With the length of some 350 km, it starts with a NW-SE trend from Nain and ends near Sirjan (Berberian, 1367).A significant characteristic of Dehshir-Baft Fault is related to its neotectonic activities. Examples of such processes have been discussed in this paper. Around the main Fault zone, even along the secondary local Faults within this zone, dry channels displacement occurred which could be related to mostly right-lateral strike slip movement of these Faults. On the other hand, Mesozoic sediments and Ceneozoic intrusive features have gone through a metasomthism phase (or phases) by hydrothermal processes. The hydrothermal activities probably occurred during early Quaternary which was due to reactivating of the Fault during post-Passadenian orogenic movements. Throughout the Fault zone, younger alluvial fans overtopped the older ones which is also the evidence of neotectonic activity of the Fault. Such morphologic features indicate the recent activity of Dehshir Fault. Travertine springs and domes also appeared within the Fault zone, which mainly concentrated around the Fault-based joint systems. The joint systems follow the main course of the Fault. Another evidence of tectonic movements along the Fault zone is indicated by a sharp mountain front along the Fault. In some places the Fault line cut through travertine layers which has led to the occurrence of escarpments and steep slope, while near to the playa areas causes distinct different elevations.Geomorphological and geological evidence suggest the last activity of this Fault had a right-slip nature with an orthogonal constituent. Dehshir Fault, from a seismologic point of view, could have immobile characteristics with no evidence of large-scale earthquake in its territory (Berberian, 1967). However, it could be the source of potential risk in the future, so needs more survey and study to establIsh a firm suggestion for the probable activity of the Fault.

Generally the most important factor in the Structural evolution of Alborz is thrust and reverse Faulting that often has an east-west trend, parallel to the mountain chain. Mosha Fault, one of the main Faults, in this study covers the area between longitudes 51o, 30´ to 51o, 45´ including central-western part of Mosha Fault. The stress evolution on the available Faults in northeast of Tehran city was studied by means of inversion of 120 striated Fault planes and related striations. Finally, two different movement systems were identified. One of them generated dextral reverse Faulting and the other one which is younger created sinistral reverse Faulting. The dextral system, known to resulted from the movement of the Arabian plate toward the north, is determined to be Miocene and probably older. The sinistral system originates from Structural transition of Alborz Mountain (progressive deformation in Alborz). Obtained result shows that the movement vector on the thrust Mosha is the consequence of the combination of sinistral and reverse Faulting. The ages of stress changes were determined by using the cross cutting relations of individual Fault planes and differentiation of event.

Anbaran inlier is located at the NW of Namin city. In the inlier Pre-Paleozoic roks surrounded by young Eosen and Cretaceouse rocks. To interpret the inlier deformation and its evolution model, geometry as well as kinematic characteristic its major structurs analysed for the first time. For the Faults kinematic, indicator, such as slickenside, Fault associated folds and S-C structure were used. The results of analysis show that the major structurs of inlier are the Anbaran and RF1 Fault at its Norht and South margins. The high angle Anbaran and RF1 Faults cause thrusting of the Pre-Paleozoic Biandor and Soltanieh formation in the core of inlier over the Eocen volcanic units and Cretaceouce limeston respectively. This resulted in development of a pop-up structure that form the present morphology of the region. The Fault high angele dip, and deposition of Cretaceous sediments on its hanging wall provide evidence for the Fault inversion. therefor the RF1 Fault is considered as the inverted anbaran Fault backthrust.

The studied area is part of East Azarbaijan Province which the important tectonic issue in that area is North Fault of Tabriz. According to the previous investigations the width of this Fault is not constant and equal in that area, second the type of Fault displacement is dextral strike-slip with reverse movement.Tabriz Fault in the category of Alborz Zone, from geological point of view is located in Mako-Tabriz subzone. By investigation at satellite images from the region and following the canal (water print) way can be found that the Fault is dextral strike-slip.As an example the satellite images from Khaje Marjan region and Gouri Gol, canals (water prints) shows dextral displacement in its own way of movement.The trend of Tabriz north Fault is 65 degree west and the dip is 90 degree.According to the facts it seems that the activity of this Fault starts from Devonian period, however it is possible that the age of it becomes older.In this paper it is tried by using Image processing techniques contrast enhancement increases and make the image more useful for processing.The processing techniques which are used in this paper: contrast enhancement, composition of colors (RGB), filtering, principle component analysis, using the DEM images, Band Ratio.Finally in this paper the ETM+ data was used from landsat 7 satellite.

Sedimental-Structural area of Alborz consists of altitudes of northern Iranian plateau, which are ranging from Azarbaijan to Khorasan in a general E-W direction, in the form of a composite anticline.In the western part, structures trend to be NW-SE while in the eastern part they trend to be NE-SW. They both meet each other just in the Central Alborz.The history of the seismicity of Alborz stresses the fact that the Central Alborz area has great potential for seismicity. According to the major Faults, located in the Central Alborz area with a seismic background as well as nearness of the metropolis Tehran to the verge of them, the study of local and regional Faults is of great importance.Last studies demonstrate that Purkan-Vardij Fault is a thrust Fault but new studies shows that this Fault is an old steep Fault partly with a strike-slip component which does not affect the quaternary plain in the area and the strike-slip movement effects appear in the direction of Fault activity. It’s essential to mention that the study of this Fault has not been seriously conducted before, so the mechanism of the Fault and the history of its likely seismicity are not basically clear. Considering data analysis as well as drawing them on the diagrams, Purkan-Vardij Fault illustrates a right lateral movement with a compression component. Also a detailed examination of local joints suggests a dominant N-S stress in the area.

Shotori active Fault zone (in the northern end of Nayband Fault) has a dextral strike-slip mechanism with a revers component. Landsat image studies show that this Fault is uncontinuous and segmented. In this research, based on Fault geometric discontinuity, two segments, were determined on both the northern (with trend of N40w) and southern segments (with trend of N20w). Both of them are reverse with a right lateral slip movement component. The southern segment is the most active segment, based on fractal earthquake and fractal fractures (Ds= 1/60, DN=1/73) and earthquakes (Ds=0/43, DN=0/68) morphotectonic parameters such as river slope indicator (SLs=1703/27, SLN=1526/7), sinuosity river channel (SS=1/24, SN=1/27), the V ratio (Vs=0/7, VN=0/9) and Structural and seismic data. The most frequent recorded earthquakes and the biggest registered earthquake with a magnitude of 7. 4 on the Richter scale have taken place in the southern segment. This indicates a high potential of seismic activity on this segment of the Shotori Fault.

Dasht-e-Arjan is a northeast trending graben located 65 km west of Shiraz. It was formed along active segments of the Korrehbas Fault, perpendicularly to the Shahnesh in and Salamati anticlines. Oriented sampling from bordering Fault planes and striations was carried out to evaluate the relative amounts of paleostress/strain needed to form the graben. Measurements of e-twins and c-axis of calcite properties on XY and XZ planes, using five universal stages in a polarizing optical microscope, showed the presence of type I and II calcites. Because the calcite e-twins and Fault striations register the last deformation phase, measurements of calcite e-twins show the plane strain K=1 in the last graben deformation phase. The inversion method, applied for the analysis of Fault striation data, showed a plane stress ellipse (υ =1), (σ 1=σ 2), and a plane strain ellipse (r0=1). The mean orientation of the sub-vertical maximum principal-stress (σ 1) was N23° . 70° E, and the mean orientation of minimum principal-stress (σ 3) was S58° . 26° E. Based on the analysis of twinned calcite crystals, the mean direction of the determined compression and tension were S55° E ± 9. − 32° and N35° E± 11. − 72° , respectively. Using multiple inversion methods, and based on the investigation of Fault striation data, we can expect two stress phases. The paleostress phase, acting as a tensional regime, caused the formation of SW trending Faults, while the recent phase caused the formation of new fractures within the study area. Based on field and laboratory analyses, it is suggested that a tension tectonic regime is dominant in the studied graben.