The study area is located in the east of Yazd and is part of Yazd block (western block of central Iran). There are two major fault systems, Anar and Kharanagh with lengths of 100 and 62 km and numerous minor faults represents an important tectonic phenomenon in the region. The aim of this study is to investigate neotectonics in this area by using geomorphic indicators. To achieve this goal, have been used of seven geomorphic indicators: Hypsometric integral (HI), Drainage basin asymmetry factor (AF), Stream length-gradient index (SL), Mountain Front sinuosity (Smf) and the ratio of valley floor width to depth Valley (Vf), River sinuosity index (S), Basin shape factor (Bs). Based on Active tectonics indices (Iat), the study area is divided in Four terms of tectonic activity rates, category 1 (very high tectonic activity, 7. 4% of the region), category 2 (up 74%), category 3 (average 11%) and category 4 (less 7. 4%). Morphotectonical and morphological evidences indicate that the rate of tectonic activity in this region is moderate to high. According these evidences, the northern part of Kharanagh fault and southwestern part of Anar fault are more active than other parts.

Kuhbanan fault is located between Tabas and Yazd blocks in the south west margin of central Iran microplate, extending from North west of Kerman to East of Bafgh, with 300 km length and NW-SE strike. The fault is one of the most seismic structural trend in the region. The latest seismic activity of the fault occurred on the first of April, 2002 with Ms=4,3 over the north-east Dehzo-segment of the fault. Kuhbanan  earthquake fault consists of several segments. Movement in the southeast and central segments has been dextral strike-slip with a large reverse component during Plio-Quaternary.Study of alluvial fan deposits in Zarand, Toghroljerd and Bahabad plains indicates that deposition, development and morphology of the alluvial fans have been affected by the tectonic activity of Kuhbanan fault segment and morphology of the alluvial fans have been affected by the tectonic activity of Kuhbanan fault segment which are located in the mountain front of Kerman-Kuhbanan and west Bahabad mountain ranges. Several coalesced alluvial fans exist which are adjacent to Tikdar-Gorcho, Khanok, Rigabad-Daho, Apang-Sarbagh, Gisk, Dartangal, Dehzo and NW Dehzo fault segments in the eastern margin of Zarand plain. The youngest part of the fans is formed in the fanhead area and apex of fans does not progress to the mountain front. Active and inactive areas are formed at the surface of fans some of them are deeply dissected. Longitudinal profile of the fans is usually segmented and some show a decreasing slope.  Vertical profile of the fans is wedge shape, with maximum thickness adjacent to the fault segments and some fans are lense shape. Internal structure of the fans is mostly buried, but imbricated and inset fan also occur Main channel is in the margin or edge of the fans. Fan deposits are poorly sorted, coarsening upward. Apparent neotectonic fractures occurred in Khanok, Sarbagh, Dehzo and NW Dehzo semi-consolidated fan deposits. Several coalesced alluvial fans also exist adjacent to Toghroljard, Abassabad, Dargaz-Godgaz, SE Gavar, Fakhrabad, Khoshabad, Hossinabad and Kuh-e-Sorkh fault segments in the eats margin of Toghroljard plain and in the west margin of the Bagabad plain. Apex of the fans does not progress to the mountain front. Active and inactive areas are formed at the surface of dissected fans. Main channel is in the margin or edge of the fans. Apparent neotectonic fractures occurred in Fakhrabad, Khoshabad and Hossinabad fan deposits. Based on the surface morphology, vertical variation and internal structure of the alluvial fans, it is concluded that 1) neotectonic activity of fault segments have caused continuous elevating of mountain front or sinking of piedmont, and right lateral displacement of mountains relative to plain at late Quaternary. 2) The highest tectonic activity have occurred over Khanok, Righabad, Gisk, Dartangal, Apang-Darbagh, NW Dehzo and Fakhrabad segments during and after deposition of alluvial fans.    

Sabalan Mountain is one of main morphtectonic units of Iran. This unit has extensive area, therefore in this research only southern slopes of Sabalan have been selected. Study area is located between 37o 56´ to 38o 14´ N and 47o 36´ to 48o 00´ E. Selected area from hydrograph is formed of four basins, including Pislarchay, Aghmion, Biokchay and Aghlaghanchay. There are several faults in this area as geomorphic evidences. Main effects of these include linear valley, offset stream, escarpment, shutter ridges, displacement of alluvial fan and hot spring.Southern slopes of Sabalan Mountain are active in terms of tectonic processes. For investigation of neotectonic characteristic we used several geomorphic indexes such as mountain front sinuosity (Smf), ratio of valley-floor with to valley height (VF), drainage basin shape ratio (BS), asymmetry factor (AF), topographic symmetry factor (T) and latitude ratio. This index was calculated in four basins in separation. According to Smf and VF results, two basins have active conditions and two others are semi active. BS index for all basins presents active tectonic. The results of AF and T confirm the above conclusion. In the end we used Latitade (Lat) ratio. According to this index, three basins are in active condition.

Aims Murghab River is one of the main tributaries of the Zayandeh River. There have been no significant Neotectonic studies conducted in the river’, s basin. However, Shazand, Khansar and Dalan faults cross the basin. This study aimed to investigate the possibility of Neotectonic activities in a part of the Murghab basin near the Shazand fault. Methodology A digital height model with an accuracy of 30 meters was prepared for this area and the geological layers were added afterward. The basin was divided into 18 sub-basins and Hi, Bs, Af, SL, S, Facet%, and V indices were calculated using Arc Map, Arc View and Global Amper software. The relative index of Active tectonics (IAT) was calculated, as well. Field visits were used for the complementary studies. All data were combined in the final analysis. Findings The relative index of active tectonic (IAT) shows that the majority of the sub-basins are active and semi-active. Along fault, some displacements were observed in the Slikenside of the fault. The network of streams in the Murghab Basin shows evidence that some of the streams have rotated 90-degree, which approves Neotectonic activities and lowering of the lake base level and its rupture in the studied area. Conclusion Other nearby studies provide some evidence of the Shazand fault activity in this area. Highly likely tectonic activities in the future might be dangerous for people and facilities in the area and policymakers need to take it into consideration in future planning.

The Sangchal earthquake occurred on July 2, 1957, in the central part of the North Alborz fault zone. The North Alborz fault is an arched shape fault that continues from Lahijan to Gonbad-e Kavos. This fault, along with Khazar, Lalehband, Kandovan and Mosha faults have affected the shortening and rising of the Alborz Mountains. This shortening and uplift are accompanied by large earthquake events that continue today. With knowledge of the geometry of faults and how faults are displaced and the use of computational methods for fault analysis and also, the Focal mechanism, direction of maximum tension governing the part of north Alborz fault has been determined. The two methods show similar acceptable results. In addition, considering the comparison of the findings with the results of geodetic studies of the scope, accuracy of the findings is confirmed. The results of the study show that during the North Alborz Fault, the dominant vector is compressive, and the left-lateral slip is observed. From the central part of the Alborz to the east, the left lateral displacement increases and causes shear mechanism in the eastern parts of the Alborz. This movement has caused compressive earthquakes in the central Alborz and compressive-shear earthquakes in the eastern parts. Therefore, the magnitude of future earthquakes in the eastern part is slightly smaller than the central Alborz earthquakes.

Drainages has been reacting to changes in stream bed to different forms. Case study area has located in Alborz state and in upper of the Mehr Shahr of Karaj. Since basin has located on the bound shake faults and as big and high population cities is in this area, so study of tectonic Activities position is essential in this area. In this paper has tried Neotectonic and its effects on the valleys and rivers direction to survey by using of Af, SL, S, BR, P, T, Smf and Hi parameters. Research method is being analytical – comparison AL. For analysis has used WMS and Arc GIS software’s. For more careful survey of Neotectonic activities in area, case study basin has dispensed to four sub basin, such as Rajayishahr, Kamalshahr, Elahiyeh and Chahardangeh. The research result shown that tectonic has been achieving in different parts of basin, and since western sub basin of area (Chahardangeh sub basin) has weakly activity of tectonic in five geomorphic parameters, so this part of basin has relative equilibrium and to run from stage of erosion puberty.

Introduction: Qom- Zefreh fault system, as the main structure in the area, influences on the geological and tectonical conditions. Study of this active fault has the effects on recognition of tectonical conditions.Aim: In this paper, the young geological features, neotectonic activities and their reprints along Ghom-Zefreh fault system investigated to detect the evidences of qualitative and quantitative rate, type and arrangement of tectonical deformations.Materials and Methods: According to the investigations, this fault system is a dextral fault with a reverse component. Horizontal slip rate in studied part of the Ghom-Zefreh fault system estimated about 2.6 mm/year.Results: According to the morphotectonic indexes (Smf, Vf and SL) and longitudinal profile, lithological changes, and other informations, tectonical activity is calculated for different basins of Baronagh, Jezeh, Ghamsar and Ghohrood. Jezeh has the least tectonical activity. Ghamsar and Ghohrood have the same and the highest activity.Conclusion: Morphotectonic and neotectonic considerations are appropriate tools for evaluating and comparison of tectonical conditions of area qualitativly and quantitatively and the results use practicably.

Faults as important tectonic factors are influnece on geomorphological landforms. The Tabriz fualt with 600 Km length from Zanjan-Soltanieh. to Ararat mountains is most important fault in the north western of Iran, what is recognizable in the satellite images. Derivated data and information of earthquakes indicated probility of event of intensive earthquakes in tabriz and neighbouring areas. Quantitative measurment indicators such as proportion longitudinal profile to reference profile, proportion between the width of vallies to average of the height and sinuosity of montain front ration indicated the active fault. Tabriz fault have horizental and vertical movements. Newest movement is horizontal and strike-slip. According to the last studies of Tabriz fault geomorphological contain horst, graben, overthrust, alluvial fan displaced, river teraces, displaced and cutting streams, scarps, meander, shutter ridges and others are in relation to the tectonic activities. Also formation of Tabriz fualt had indirect effects on magmatism, salty diapers, hot spring, mineral spring, mud volcano and etc.