Quaternary Journal of Iran

Abstract Fractal analysis of earthquakes, lineages and waterways are considered as one of the practical tools to evaluate tectonic activity. With the help of fractal analysis, structural maturity and tectonic dynamics can be evaluated. In this research, using fractal analysis and box counting method and fild studies, the measured fractal dimensions for the designed network of Alborz province were studied and compared. This network consists of 65 square meters with a side length of 12.5 km, for which the fractal dimensions of earthquakes, lines and waterways were calculated separately for all of them. The results of fractal analysis of lineages and network of waterways show high structural activity around Alamut, Mosha, north of Tehran and Taleghan faults located in the northern part and Ipak and Eshtehard faults in the southern part of the study area. In addition, due to the diversity of lithology in the study area, fractal analysis of earthquakes was performed and areas 54, 55, 45 and 46 have high tectonic activity, which these results only in the fractal analysis of earthquakes. Showed. In general, it seems that tectonic activity in Alborz province is strongly affected by the activities of major faults and, of course, the presence of sub-hidden faults (south of Alborz province) in the region, which was found in the analysis of fractal dimensions of earthquakes.

Abstract The main purpose of this research was to identify the faults in Derke area of Tehran. For this purpose, geoelectrical profiles with Wenner-Schlumberger array, ground penetrating radar (GPR), and the diffraction-distance exponential function were used for the fractal measurement of the geoelectrical profile. In the conducted field visits, fractures and faults with different lengths were detected in large areas of rocks in the region. North Tehran fault is the most important and influential fault in the studied area. Among other sub-faults in the region, we can mention Imamzadeh Daoud, Darband and Shirpala faults. The results of geoelectric profile processing show a very strong drop in specific resistance at the distance of 96 meters of the profile due to the existence of a fault zone. The minimum changes of specific electrical resistance under the fractal method shows a linear trend with a relative drop in the fractal dimension. In some areas, an unusual increase in the fractal dimension and the creation of chaotic conditions indicate faulted and fractured areas. Also, the changes related to the sharp drop in the amplitude of electromagnetic waves in the GPR radargram at distances of 90 to 100 meters confirm the existence of a fault zone in the studied area.

Abstract Introduction
 
The left lateral Doruneh Fault System (DFS), is one of the longest, and most prominent, strike-slip faults in Iran, extending from the eastern border of Iran to the central Dasht-e-Kavir with a curved geometry. DFS is the response of the convergence between the Arabian and Eurasian plates in the regional tectonic map. Regarding to scaling relationships this fault with length of >600 km has the potential to produce earthquakes with magnitudes higher than 7.5. M. It performs an important role in the regional tectonics and is certified to be active by its well-preserved geomorphological features all along its trace. However, despite clear Quaternary activity expressed in the geomorphology, has no record of historical and instrumental earthquakes of magnitudes M ≥ 6, which is in contrast to the neighbouring Dasht-e Bayaz region, which has suffered from many earthquakes recorded both instrumentally and historically. Determining whether the Doruneh fault is capable of generating large-magnitude earthquakes similar to the Dasht-e Bayaz is important due to its risk to close cities and towns. In other word, it is necessary to determine the hazard of this fault in the area. One way to conduct the Earthquake Hazard Assessment is to calculate the slip rate. The slip rate of a seismogenic fault is a crucial parameter for establishing the contribution of the fault to the seismic hazard. one method for calculating the slip rate is measuring the displacement by the fault and dividing it by the period during which this displacement has occurred. Clear scarps in alluvial fans and river terraces can be observed both in satelite imagery and in the field along the entire Doruneh fault length. The geomorphology of the fault contains numerous indications of cumulative left-lateral slip over various scales. By dating and finding the age of these offset geologic features, we can determine the average slip rate. We describe one site where Late Quaternary landforms are displaced by the fault. Two generations of alluvial fan are present on the north of Khalilabad village. There are two parallel east-west fault traces on the fan surfaces at this site, with the two traces separated from each other.
 
 
Methods
To determine the slip rate two parameters are required: the displacement and the period that has taken that the displacement occur. Optically Stimulated Luminescence (OSL) is one of the best methods for determining sediment age in arid and semi-arid zones such as Iran. OSL enable evaluation of the time that has elapsed since quartz and feldspar, were last exposed to daylight. During exposure to light the luminescence signal within the grains is optically bleached until the signal is zeroed. Once the grains are buried and sealed from daylight, the luminescence signal being induced by naturally occurring radiation and being accumulates again. The time passed since the last daylight exposure is calculated by dividing the dose accumulated in the sample since its last exposure to light by the dose rate.
The study site in this research is the eastern alluvial fan near Khalilabad, which is located in the west of Kashmar. Google earth was employed to observe and measure the apparent offset of a riser between eastern and the western fan surface, which appears to be relatively straight both upstream and downstream of the fault. The estimate is that Doruneh fault has displaced the eastern alluvial fan by about 40-60 meters. Two sediment samples were collected from this alluvial fan for luminescence dating. Potassium feldspar was then separated from them. To determine the age of potassium feldspar, two parameters of equivalent dose and annual dose are required. SAR method was used to measure the equivalent dose and analyst program was used to analyze the data. The dose rate was calculated using present-day moisture content, radioisotope concentrations and burial depths.
 
Results
The last sedimentation period was determined to be 11000 – 16000 years ago. The slip rate of this part of the fault was estimated to be 2.5-5.5 mm per year by dividing the displacement rate over the displacement period.

Abstract Introduction
Mud volcanos are one of the strangest and most fascinating geomorphologic phenomena in Iran, mostly in the coastal plains of the Oman Sea and in the Caspian Sea. Mudvolcano, sedimentation is one of the most interesting natural phenomena that spread in the Al-Himalayas, the Pacific and Central Asia in the countries of Pakistan, Azerbaijan, Turkmenistan, Georgia, Iran, Italy, Romania, Japan and Anzadeh, Japan, Mexico and Japan. Oef and Feyz Allahov, 2001).In general, the purpose of this study was to evaluate the effect of tectonics on the current morphology of the studied landforms and then to evaluate and validate the use of morphometric indices by evaluating and adapting the morphotectonic evidence of the area for tectonic analysis of the 5 anticlines. This is a study that can ultimately be used in environmental planning. In the present study, it is attempted to study three main indexes in the field of anticline morphometry, considering that 5 main anticlines of the area have been studied. In this study, the morphometric parameters of the basin and the mountain were used in combination, while for the morphometric evaluation of the mountain, specific parameters and for the morphometric evaluation of the basin there are other parameters.The study area is located in the northern coast of the Oman Sea from the eastern part of the Strait of Hormuz to Bandar Gowater in the Hormozgan Provinces of Wissistan and Baluchistan in the geographical range of 25 14 57 to 00 58 east longitude and 38 25 to 00 26 north latitude .
 
2-Materials and methods
The data used in this study were in addition to documentary data, 1: 250000 and 1: 100,000 digital geological maps, DEM30m digital elevation model data, Landsat satellite imagery data, Google earth imagery, and Mudvolcano morphometric data collected during extensive fieldwork. The tectonic activity domain analysis tool has been used to calculate the morphometric indices of the anticline including the three main parameters of the triangular procedures, the wine valleys and the sinusitis of the anticline front. In order to calculate the morphotectonic status of the area, the relevant parameters were first calculated separately in the North and South Duvial, which consist of triangular procedures, canyon valleys, and mountain front sinusitis.
 
3-Results and discussion
Triangular procedures are special shapes that occur on mountain foreheads, fault cliffs, and folding edges Are formed. The occurrence of these phenomena is the result of active tectonics in an area that occurs as uplift and uplift of geological layers and fold formation. If the eruption rate is higher than the water erosion rate, the phenomena are triangular to polymorphic, separated by waterways. The higher the tectonic uplift, the more triangular the procedures will be. In this study, a total of 251 triplicate procedures were identified on 5 antecedents studied, of which 88 were in antecedent 1, 32 measured.
 
4-Conclusion
The results of field impressions described as tectonic forms adjacent to the main faults indicate high tectonic activity in the area, which derives from quaternary movements of the major faults. Also the tectonic dynamics of the region with direct influence on the morphology of the region in satellite images is shown as tilt and cuts along the channels. In general, the results show that tectonic activity is higher in the southern edges of the anticlines. These evidences showed that the highest accumulation of morphotectonic evidence such as displacement of formations, stepping faults and rivers diversion in and around the anticline was observed, suggesting more tectonic activity in the area. In general, the results of the indexes and evidences examined indicate the dominance of the tectonic activity at the regional level and since the accumulation of the studied in this area also indicates the tectonic effect of the area on their occurrence. The study area is affected by compressive forces on the one hand with compressive zone due to subduction of the Oman Oceanic crust below Makran area and on the other hand the area of ​​contact of Makran zone with Zagros zone is rapid sedimentation of Quaternary sediments and trapping of methane gas in layers. The deep clay and fine sediments of trap anticlines caused by the compressive forces of the tectonics have caused mudflows and gases due to this subduction to the studied fault system. So that its faulting process is associated with the birth of new and young Mud volcanoes.

Abstract 1- Introduction: Geomorphic investigation is a powerful tool for studies of active tectonics in active regions. Active faults and folds commonly have topography that can assist in identifying different geomorphic or structural segments along a structure, and estimating the potentially most active segments. In tectonically active regions, drainage networks and topographic features can be used as a way to quantitatively characterize the interaction between tectonics and surface process providing a basis for modeling landscape evolution. The study area (north and northwest of Damghan) is located in northern Iran and in the eastern part of the Alborz range. The Alborz mountains form a sinuous range over 1,200 km long, separating the high plateau of central Iran from the South Caspian basin, which lies near sea level. The active tectonics of this region appears to accommodate N–S regional shortening by partitioning onto separate thrust and left-lateral strike-slip faults. In this study, neotectonic activity of the north and northwest of Damghan, as a part of the Alborz tectonic-sedimentary unit including Astaneh fault, Damghan fault, North Damghan fault and Attari fault and as the main area destructed during the Qumes earthquake (856 A.D.), has been studied. The 856 A.D. Qumis earthquake (M 7.9) is the most destructive earthquake to have occurred in Iran, killing more than 200,000 people and destroying the cities of Damghan and the old Parthian capital of Shahr-i Qumis (Hecatompylos).
2- Methodology: Morphotectonic indices are useful in evaluating the tectonic activity of regions. Morphotectonic analysis using geomorphic indices has been developed as a basic reconnaissance tool in order to identify areas experiencing rapid tectonic deformation or estimate relative variations of tectonic activity in a specific area. In this research, neotectonic activity evaluation of the region was done mainly based on three important morphotectonic indices: Stream Length-gradient, Mountain-front Sinuosity, and Drainage Density. Using digital topographic data, digital elevation model (DEM), aerial photographs and geological maps, these indices were computed for different parts of the study area.
3- Results and Discussion: The results obtained were shown as digital maps provided using ArcGIS (10.7) software. Maps showing the spatial variation of different studied indices across the area were provided and interpreted in this study. As a result, it is concluded that parts of the northern Damghan area mainly with similar strike to the Damghan fault, North Damghan fault and Astaneh fault show more tectonic activities in comparison to the adjacent areas. In addition, the high correlation between the trend of anomalies and the strikes of faults of the area demonstrates the influence of faulting in forming these geomorphologic features. A comparison between the resulted maps and the general structural map of the area indicates that the approximate trends of abrupt changes in drainage density values, acceptably correlate with the general trends of the major faults and large-scale folds of the area.
4- Conclusions: The results obtained indicate that the analysis of morphometric indices, as well as the quantitative analysis of stream patterns, can be very useful for evaluation of the relative intensity of neotectonic activity of regions especially when the other techniques could not be employed for recognition and assessment of the active structures.

Abstract Introduction:  The study area has various types of geological structures, especially various types of fractures and folds. Evidence indicates that Structures with specific mechanisms in this area have been affected by Compressional - Tensile tensions. Materials and methods: To determine the direction of stress in the fault zone north of Tehran, from various tectonic evidences including fault slip scratches, Conjugated faults and folds in the Eocene rock units of Karaj Formation and Quaternary alluvium was used. For this purpose measured structures Was analyzed using Tectonic FP software and Angelier software was used for paleostress analysis of the area. Results and discussion: According to geologic observations in Karaj formation units and Pleistocene-Holocene deposits of North Tehran fault zone including Slickenside and S-C fabrics, before Pliocene the fault mechanism was right-lateral strike-slip and after that it has changed to oblique-slip some parts the revers component  and in some other parts left-lateral strike-slip component dominates. The tectonic developments of the study area can be presented with a model. According to this model, the area between the two faults north Tehran and Mosha as a triangular block(Mega Duplex) is Turning right, This model is presented in accordance with the tectonic evidence presented below: The tectonic history of central Alborz in the study area is clearly evident and evidence of its compression N-S, NW-SE,NE-SW Has been left out, Seismic data recorded at the Institute of Geophysics of the University of Tehran shows the most seismic activity on the North Tehran Fault slope and its associated with the Mosha fault, By comparing the zoning of the area in terms of aggregation of tectonic structures and seismic data observed at the center of the study area, There is an elliptical basin that shows low tectonic activity. Given that the area is not Lithology significant, This phenomenon can be justified by the rotational model, So that the maximum stress and friction force is applied to the sides of this triangular block and the least to the center of the range, As a result, tectonic activity is minimized in the said area in the center. Axial surface of all folds harvested in Eocene rock units of Karaj Formation In the fault zone north of Tehran in sabu, Darkeh, Hesarak and Kan regions, they have an approximate northeast-southwest. Due to the geometric position of their axial surfaces for the stress of the region in the past, It was northwest-southeast. In the fault zone north of Tehran before Neogene in most areas of northwestern-southeastern stress And the mechanism of faults was straight-slip rectilinear and the time of stress direction change was Neogene. In the Can region, based on the geometric location of the scratches, the landslides were investigated And stretched folds in alluvial sediments of type C, which is the newest sedimentary unit in the region,The direction of tension in the region is northwest-southeast. Therefore, it can be said that in this area, after the Pliocene, the tension has not changed, unlike other parts of the fault zone north of Tehran. And the recent Northeast-Southwest tension has not affected it. This part of the fault is likely to be affected by a smaller local stress.Due to the adaptation of the trend and mechanism of faults harvested in the region with fractures (Riddle) Also, the existence of conjugate faults, the mechanism of strike-slip fault north of Tehran is confirmed. East-west pressure force must Folds with a north-south trend in the region have been created by examining the region, No wrinkles are seen with this trend. This feature can be due to the block rotation in the studied sheet,Between the two driving faults north of Tehran and Mosha with straight-slip components And has formed folds with a northwest-southeast trend.

Abstract Introduction: Seismicity is closely related to active Quaternary faults.This attracts many researchers to investigate the quantitative relationships between them. As a new parameter, FMP is defined to quantify earthquake risk.Iran is one of the most active areas of the world in terms of tectonic activities in the Alps-Himalayan belt. One of the characteristics of this belt includes the presence of thrust faults and associated folds along with the general trend of the belt - northwest - southeast as well as transverse faults with north, northwest - south southeast trend . Folded - Thrust Zagros as a part of the Alpine - Himalayan orogenic belt and one of the youngest and most active continental collision zones on earth, with a length of about 1500 km extending from the Tarsus Mountains in northeast Turkey to Minab fault in the northeast of Hormoz Island in southern Iran.the earthquake risk in Iran, especially in populated cities, is high and the high risk areas are located near Iran's active faults in terms of earthquake events. earthquake is one of the natural disasters and has been a major threat to human being, over the past history. for this reason, man is always seeking a solution to reduce earthquake risk in earthquake-prone areas. The 180-km-long Glabaf fault system and the NNW-SSE overall Trend comprise several fault-stepped fault sections that have steep slopes (60 to 90 degrees) on both the east and west sides. The Gelbaf fault itself is part of a larger fault system, called the Neyband-Golbaf fault. It is a strike-slip fault system and forms the western margin of the Lut desert. In this paper, The Movement Potential Evaluation of the Active Faults of the Golbaf area is investigated based on the relationship between the geometric properties of the fault and the Regional tectonic stress field region. The parameters examined for the active faults and the ratio of the range of possible movement has been obtained. The results of this method show high compatibility with past seismic records, therefore, this theoretical model is based on the relations between the geometrical properties of faults and the Regional tectonic stress field of dominant dominance, to assess the activity of a seismic fault in terms of different criteria have been proposed. In the empirical investigations, there are various estimates for the longitudinal selection of the part of the fault that the movement recovers for each tectonic seismic zone. The problem with these estimates is the lack of sufficient data available for different states tectonic in Iran. There are also various empirical equations for the relationship between seismic fault length and fault length. One drawback of these empirical equations is the failure to pay attention to the mechanism of the faults, Therefore, the relationship created is for the large region, which will cause an error in seismic power calculation. These points have been applied in some equations, and factors such as cumulative fault accumulation, morph faults geometrical , location tectonic region and seismic features of each area should not be overlooked. In this study, the possibility of faults future movement based on the relationship between the maximum axis of tectonic stress and fault geometry and then the estimation of FMP variable for seismic probability in the surrounding of major and active faults in the studied area was evaluated.
Materials and Methods: How to calculate the maximum calculated stress is that it draws calculation to the seams conjugate harvested and Schmidt network, the maximum stress in the region studied was calculated and after the structural impressions at  18 Section, the equations of this model were used. Using the inversion method, the main maximum stress is calculated as the regional stress in each section and is embedded in the equations.
Research findings: In order to properly analyze the study area, The Movement Potential Evaluation of each active fault was calculated in these sections.
Discussion and Conclusion: According to the Movement Potential Evaluation of the Active Faults  values of Golbaf and Shahdad faults, the Golbaf fault is introduced as a young fault in the study area. Regarding the obtained values, it can be analyzed that, in view of the high epicenters of earthquakes occurring in the northwest and southwest of the area, a tension aggregation in a large area in a perpendicular direction to the north-east-south-east trend of not expecting.

Abstract Introduction
Paleoclimatics studies can respond the many uncertainties about past climate change; an issue that is being studied seriously in the world but less attention has been paid in Iran. The Late Quaternary can be considered as Holocene. Holocene, which spans over 11,000 years ago; In general, it is considered as a period with relatively warm and stable climatic conditions. However, recent studies have shown that the Holocene climate is relatively unstable and characterized by several short-term climate fluctuations. The present study attempts to investigate the events of the late quaternary climate change in Iran. Hence, by studying various internal and external sources, first major climatic changes were identified at the late quaternary, and then these changes were detected in Iran. Then, based on the results of a case study, the results of the studies were tested.
This research seeks to answer the following questions:
- Is it possible to detect the major events of the Holocene climate change in Iran?
- Is there a difference between the time of occurrence of major Holocene climate changes in Iran and other parts of the world?
- How has moisture changes been in cold and hot periods?
 
Method and Materials
This research consists of two sections. In the first, a review has been conducted. In this section, first, using studies in relation to the late Quaternary climate change in the world, major climatic changes were identified in the Late Quaternary. Then, by studying and reviewing existing theories and resources, including books and articles, it has been attempted to determine the overall framework for climate change in Iran at the Late Quaternary. In the second part, the results of a case study were used to confirm the review studies. This case study includes a core length of 8.5 m, taken from the Parishan lake floor. In this section, two proxies were used to carry out analyzes and identify climate changes of late Quaternary, which include the use of palynology and magnetism susceptibility methods. The magnetism susceptibility technique was used to determine the warm-cold periods and the reconstruction of paleo-vegetation was used to determine wet-dry periods. To calculate the AP/NAP index, samples were taken in 10 cm interval from the sedimentary cores and pollens extracted and identified by the method of Moore et al., 1991 (with slightly change). Samples were also used to measure the magnetism susceptibility by use the Bartington Susceptibility Meter with a 1 cm interval.
 
Results The studies on climate change in this period show a number of significant fluctuations, including four cold events: The Younger Dryas, The 8.2 ka cooling event, The Cold period of Migration time and The Little Ica Age (LIA), and 4 warm events: The climatic optimum, The Roman warm period, The Medieval Warm Period (MWP) and The Modern warming period. In the Parishan Lake, 6 major cold and warm periods in Holocene can be identified, for the four of them, it can be found that there is an approximate correspondence with the temperature changes occurring on the planet, but these courses have been delayed.
Discussion
The results indicate a reverse relationship between the moisture index and the magnetism susceptibility; in fact, during warm periods humidity has increased, and humidity has decreased during cold periods. The rate of moisture index has also decreased with increasing cold intensity; in the Younger Dryas and The 8.2 ka cooling events have lowest temperatures in the region and the lowest moisture index has been recorded in these two periods. The highest moisture content was recorded in The Climatic Optimum.
 
Conclusion
The results of this study showed that there is a good correlation between cold and warm periods in other parts of the world with Iran, although between these periods in Iran and North Europe and the United States there is a time lag of approximately 200 to 300 years. Also, the existence of cold-dry and warm-wet periods was confirmed in the past of Iran. In the studied region, at the Younger Dryas and The 8.2 ka cooling events, with the lowest temperatures in the area, the amount of tree species has reached almost zero, which indicates the dryness of the area during cold periods. In all warm periods, the moisture index of AP/NAP was higher than the cold periods. It can be concluded that warm periods were generally more humid than cold periods.

Abstract -Introduction
The Main Recent Fault (MRF) is a seismic structure on the northwestern boundary of the Zagros belt and southern border of the Sanandaj-Sirjan belt. This fault as a major strike-slip fault consists of several segments in the Zagros collision zone. The seismic activity of the southwestern segments is greater than the northwestern segments. Several earthquake events have occurred along the MRF zone in the past decade, as the largest was the 1909 Silakhor earthquake with 7.4 magnitude. Several structural studies have been done along the MRF from the southwest segment (Dorud fault) to northwestern segments (Marivan and Piranshahr segments), because of the seismicity importance of this fault zone. However, there is no any structural and morphotectonics studies along this fault in the Sarvabad region. Therefore, in this research, the relative tectonic activity of the MRF in the Sarvabad region has been investigated based on field studies and measurements of the morphometric indicators.
 
2-Materials and methods
In this study, six morphometric indicators were measured in the basins of the study area, to assessment of the tectonic activity related to the MRF fault zone in the Sarvabad region. These indicators include: stream length-gradient index (SL), asymmetry factor index (Af), basin shape index (Bs), hypersometric integral index (Hi), valley height-width index (Vf) and topographic symmetry factor index (T). These indicators have been extracted using digital elevation model (DEM) and geological maps of the study area. Then, for a detailed study of the relative active tectonic using analytical hierarchy process (AHP), we first considered weight of each index based on its importance, and finally, weighted average of indicators has been analyzed for data standardization using fuzzy logic.
 
3-Results and discussion
In the northwest basins of the study area and along the MRF zone, SL index indicates high values, according to the SL map and related graphs. According to the Hi index diagrams, the basins of the study area are classified in three categories. Category 1 (young topographic and convex curve shape), category 2 (sigmoid curve shape and mature basin) and category 2 (concave curved shape) and nine measured basins are classified in the first category. Three categories for the Af index are considered in the study area. The basins of the central part of the study area indicate the highest asymmetry, because of the strike-slip activity of the MRF. Almost half of the basins of the study area are classified in class 1 and 2, according to Bs index classification map. The values of the Vf index is decreased in the basins along the active strike-slip fault in the study area. The T index in the most basins of the study area shows 1 and 2 classes, indicating an asymmetric region in the central part and along the active strike-slip fault systems. In this study, we used a weighting system for morphotectonic indices to calculate the exact relative tectonic activity. morphotectonic indicators affected by tectonic structures have the most weights and indices controlled by topography and mineralogy are less weights. The weight of each indices is multiplied in the measured map of each basin, after weighing the indices in the studied area. Then the finalized weight maps are shown separately for the indices. All values of the weighted map have been converted into the same range from zero to one using the fuzzy method, in order to standardize the values of the indices. Then, six index maps was combined using a simple additive weighting (SAW) model. Then the final map and, in fact, the output of the SAW model, are classified into 3 classes of relative tectonic activity from high to low. Based on this model, the Southeastern and West parts of the region show a higher relative tectonic activity related to the Northwestrn parts.
 
4- Conclusion
Based on final map obtained from the SAW model Basins with high relative tectonic activity is located in the Southeastern and West parts and in northwest-southeast line trend along the MRF zone. Field evidence indicate that the recent tectonic activities in the study area are visible as V-shaped valleys, linear fault valleys, and fault planes. In the northern part of the MRF zone in the Sarvabad region, the strike-slip movement of the fault indicates an extensional component. This extensional component is visible as normal faults and the formation of veins. In the southwestern part of the study area, the strike-slip fault movements indicates compressive component, as reverse faults and flower structures.

Abstract Abstract
 
the study area of this study is located in central iran and part of the Urmia-Dokhtar volcanic belt.  It is the oldest rock in the region, depending on the median eocen. there are several earthquakes in this area caused numerous earthquakes. in general, an earthquake risk analysis study consists of several steps that will be addressed in this chapter. Two basic parts are important here. first, the recognition of tectonic Source that includes the recognition of seismic Source and knowledge of their main characteristics.  these features can include length, distance, dip and dip direction, Siesmic potential, active faults, quaternary deposits. The second part deals with the seismic activity of the region. in this part, we identify and analyze the seismic status of the region as we identify prehistoric earthquakes (benefiting from the historical data of seismology). Such investigations resulted in the identification of valuable information, such as the  Siesmic rate of Gutenberg- Richter coefficients, and  seismic pattern. finally, the combination of these two parts in the form of a comprehensive model is modeled as the seismic model and can be considered as input data
Research Method.
 
 
Methodology
 
in this study, advanced EZ - Frisk software has been used for analyses. since in such studies it is necessary to apply at least a suitable  Atteniuation relation. regard to features and geological conditions,  tectonics and Siesmotectonic of this area  in Iran,  have finally used four new generations to calculate the seismic velocity parameters of the region by considering equal weight for each relationship. the probabilistic approach for determining the Siesmic parameters of this study is the probabilistic approach of risk analysis. in the PSHA method, using probabilistic models from Siesmic Source (point, line, path, or region), the maximum amount of seismicity values of the  pick Ground Acceleration is calculated while using probabilistic models from  Siesmic Sourse (point, line, path, or region).
 
 
 
Analyses
 Important faults of this area are Alborz, Kushke-e-Nosrat, Indes, qom – Zefreh, and Ipak. the Ipak fault over 100 km, along with east - west, is the most active element of  Siesmotectonic in this range. The earthquake event of 1962 with magnitude 7.2 has occurred as the largest instrument event in the region, relating to the activity of the Ipak fault. Alborz fault, 2 km distance, is the closest Siesmotectonic element to the  Saveh city. this fault has overturned the from south east on quaternary deposit. according to the explanations that have been studied in the study section, the PSHA diagram for the Saveh city is calculated based on Fig. 3. therefore, the 0.22 acceleration for Saveh city is evident in the period of 475 years. The most probable magnitude during the 475  year period is 5 / 5 and at a distance of approximately 21 km. the results clearly show that although Alborz fault is located near the middle of the Saveh city, it is not the main factor in the production of earthquakes for this city and produces only 8.5 percent of total risk. Instead of the Kushk-e-Nosrat and Indes, respectively, at 18 and 21 km, respectively, have 90 % of the risk for the  Saveh city.
 
 
 
Conclusion
 
 
It was thought that the acceleration was the result of Alborz Fault that is almost from the middle of the Saveh city . therefore, the risk separation calculation was performed to determine the validity of this issue. but it was found that the main factor in the earthquake production was not for the city. After magnitude-distance deaggregation analysis, it is clear that the Indes fault with 21 km distance from Saveh city create the 45.12% of hazard within its activity. In fact the controlling earthquake at 475 year return period is associated with Indes fault.

Abstract Introduction:
Quaternary basalts are one of the last signs of magmatism in Iran, some of which are related to deep fractures and active faults in the Quaternary. Quaternary basalts of Tabas are very important due to their high expansion and location in eastern Iran, and are located 140 km south east of Tabas city and according to the proposed divisions are part of the Lut zone. The aim of this study was to investigate the petrogenesis of these basalts and determine the tectonomagmatic environment of the region, in which the role of the great Nayband fault should be considered. The great Nayband fault is one of the deep and large fractures in Iran's general building, which is about 500 kilometers long and extends to the Bam city. The operation of this fault is straight and displaces Quaternary sediments up to 20 meters.
 
Materials and methods:
More than 180 thin sections were prepared and their petrographic studies were carried out. Then 30 samples were selected and analyzed by X-ray fluorescence (XRF) method for 32 main and minor elements. Four samples from the basalts of the study area were selected and at the University of Carleton, Canada, radiogenic isotopic analysis was performed for Sr-Nd isotopes, then the lithological and tectonomagmatic diagrams were drawn.
 
Results and discussion:
Most of the basalts are black in color and a little red in the dark brown color, indicating their oxidation. The samples are aphanithic and no minerals can be detected. Microscopically, the texture of these rocks are porphyry with microlithic and sometimes microgranular and some samples also have a porphyric texture with a glass microlithic mesostar. phenocrysts are olivine, clinopyroxene augite and plagioclase with a labradorite compound. . Some samples do not have phenocryst. Phenocrysts  vary from about 5 to 20 percent. Magmatic series of these rocks are often alkaline and some of them are sub alkaline. The young basaltic rocks of the Tabas region are derived from an alkaline magma, and this magma is contaminated by crust material on its ascent with different intensities, and where this contamination has been intensified, magma has found the characteristics of sub alkaline. In the tectonic environment, the basalts of the region are within the continental plate. Moho depth along the Nayband fault has the lowest value in Iran's plateau. The decrease in pressure along the fault, especially in areas with new sub-divisions, causes the formation and rise of magma, probably repeated injections of new and hot melt materials have been done in the magmatic chamber. The magma began to differentiate and crystallize in the magmatic chamber and then climb upward along the faults and minor fractures of the Nayband great and has been impregnated with silica stones along its path and its chemical composition has changed a bit ,after passing through the crust, magma erupted on the surface of the earth and became cold and crystallized. The tectonic studies of the area indicate the presence of the Nayband fault during the quaternary period, there are several springs along the Nayband fault, some of which are hot springs, and the most important is the hot spring of Dige Rostam, which itself indicates the depth of this fault.
The Nayband fault zone is a straight-right fault whose displacement is estimated to be 50 to 100 kilometers. Signs of activity of Nayband fault during Quaternary، presence of spa springs along the fault zone, dikes of volcanic materials in alluvial deposits, Presence of fault precipitations in alluvial deposits, Channel deviation along fault stretch, The earthquake of 1979, Tabas, which occurred due to the activity of one of the branches of this fault.
At the same time as the tension is applied to the northeastern direction, Nayband fault  begins to move with the right movement. The continuation of this movement in the fault leads to the branching of the flap in the lateral sections of this fault to be split into the Parvade block, the branches and move dislocation slip on the fault Nayband to amend. The movement of the Tabas block to the west or southwest has created an expansion zone in the south-east of the Tabas plain and the quaternary basaltic eruption.
 
Conclusion:
The south-east bases of Tabas to Quaternary, located in the Lut zone, were part of the eastern volcanism of Iran, which erupted in the vicinity of the large and active fault of Nayband . According to geochemical studies, these basalts are part of the alkaline sodic series, some of which show sub alkaline properties. The origin of the primary magma from the fertile layer of the upper mantle, which was followed by the process of separation and normal crystallization, with the presence of phenocrysts  of the various indicating the severity of separation of magma before the eruption, which was accompanied by repeatedly hot and fresh injections into the magmatic chamber. Basaltic magma has been impregnated with siliceous rocks during the ascent to the surface of the earth and erupted, and its chemical composition has changed slightly, resulting in sub alkaline properties. Regarding field studies and tectonomagmatic diagrams, Tabas basalts are part of the continental basalts that erupted due to the activity and of the major fault of Nayband  and its lateral branches in the early quaternary, indicating the activation of this fault and branches during Quaternary.

Abstract Summary:
Introduction:
The 200 km long Gailatu-Siah Cheshmeh-Khoy (GSK) fault, with the same trend as the North Tabriz, Chaldiran, Nakhichevan and Pambak-Sevan-Syunik faults, is regarded as a part of the strike-slip fault system in the middle of Arabian and Eurasian collision zone, which extends from 42˚ E to 48˚ E with the Tutak and North-Tabriz faults in the west and east, respectively. This system includes a series of right-lateral strike-slip faults between the southern front of the Lesser Caucasus in the northeast and Bitlis-Zagros suture zone in the southwest. Tchalenko (1977), Apart and Iz (1977) and Baraka and Kadinsky-Cade (1988) was studied different segments of GSK fault and Berberian (1997) and Karakhanian et al. (1998, 2002 & 2004) describe them as a unified active strike-slip fault. Different sections of GSK fault was named by previous authors as the Northwestern Fault System (Tchalenko, 1977) and Balikgölü fault (Baraka and Kadinsky-Cade, 1988), as well as, considering this fault as the western continuation of the North-Tabriz and Chaldiran faults by some authors has been called, North Tabriz-Gailatu fault system (Krakhanian et al., 1998) Balikghel-North-Tabriz fault (Karakhanian et al., 2002), Guilato–Siahcheshmeh–Khoy– Tabriz (Solaymani Azad et al., 2015) and Chaldiran-Khoy fault (Berberian, 1977).
Seismicity:
 During historical times, some destructive earthquakes especially on the northwestern parts of GSK fault have been occurred. The disastrous M=7.4 earthquake of 1840 A. D., reported as a strongest historical earthquake along GSK fault, destroyed the region along the NW part of this fault and more than 1000 people were killed in the towns of Maku, Dogubayazit, Avajigh (Kelissa-kandi) and many villages around NW part GSK fault (Ambraseys and Melville, 1982). About 72 km surface rupture along this and eruption of Ararat volcano is presumably was related to this event (Ambraseys and Melville, 1982; Karakhanian et al., 2002). After 3 years, an earthquake in 1843 A. D. devastate khoy city and killed between 500 and 1000 people (Berberian. 1977). Maku, Avajikh, Siahcheshmeh and its surrounding area, in 1968 A.D. damaged by Bedavli earthquake, considered to be related to activity of GSK fault (Berberian. 1977). Earthquakes of 363 A.D., 1319 A.D. (Qara Kelisa earthquake), 1808 A.D., 1834 A.D (Pambukh earthquake), 1900 A.D. and 1970 A.D. (khoy and Badalan earthquakes) are the other moderate historical and instrumental earthquakes of GSK fault (Ambraseys and Melville, 1982; Berberian. 1977).  Outlines of this fault is very obvious and display a series of well-developed and preserved morphologic evidence indicating recent activity of the fault, same as, fault scarps and horizontal deflection in the Quaternary features, pull-apart basins, hot water springs and uplifted terrace deposits. The available literature, fault plane solutions, offsets of various geomorphological, man-made features and basaltic lavas indicate the right-lateral strike-slip nature of the GSK fault. Debate on the eastern and the northwestern terminations of the Chaldiran and North-Tabriz faults, respectively, have been raised in the few recent decades.  In this paper, we investigated linkage of the North-Tabriz and Chaldiran faults, to the southeast and northwest of GSK fault, respectively.
Methods and discussion:
 This paper also provides critical data for the Quaternary slip rate and kinematic behavior of the GSK fault. One of the remarkable structural features is the Siah Cheshmeh pull-apart basin at a right step-over of the GSK fault. Two remarkable offsets along the strike of GSK fault define its horizontal slip rate. To determine long-term slip rates, Copley and Jackson (2006) studied two morphological features that have been displaced along the GSK fault up to 13-km, SPAB and Agchay river. By using these displacements, they estimated an average horizontal slip rate of 2-4 mmyr-1 since late Miocene along GSK fault. Along the SK,  Quaternary basaltic lavas, known as Maku basalts, form a few ridges that are elongated parallel to the strike of the fault and displaced by ~ 725±50. Using the about 400 kyr published age of these basalts (Pb206/U238 and Ar40/Ar39 dating methods, Allen et al., 2011; Lechmann et al., 2018), a mean slip rate is 1/65 ± 0.1 mmyr-1. On the SK segment, we excavated a trench to determine the fault geometry and its rake, and assessment of offsets which conditioned by the fault activity. In the trench, faults are shallow dipping with thrusting components that resemble foreberg structures in pressure ridges along strike-slip faults. Radiocarbon dating of the youngest deposits in the stream wall which displaced by 42±4 m, yield 6764±283 calBC, indicate the horizontal slip rate of 4.6±0.3 mmyr-1. Also, ourOur field observations have not identified any step along the SK segment, where more than four releasing and restraining bends have been reported by some authors along the GS segment. The existence of multiple bends along the GS segment relative to SK fault indicates lower geological offset of GS fault relative to SK fault, in accordance with theoretical consideration of Wesnousky (1988) for strike-slip faults. Based on this theory, the number of steps per unit length along the trace of strike-slip fault zones is a decreasing function of cumulative geological offset. In addition, published geodetic results show that the largest displacements occur along the North-Tabriz and Chaldiran faults, in the northwestern Iran and Eastern Turkey.
Conclusion:
 Our results indicate that, SK segment of the GSK  fault, due to its greater activity relative to its GS segment, can be considered as the western and eastern continuation of north Tabriz and Chaldiran faults, with a high slip rate.

Abstract The most of previous study about tectonic activities concern to the seismic evidences. But, we observe destroyed region due to tectonic activity without seismic evidences. Therefor for the accurate evaluation of tectonic activity, recently the morphotectonic assessments with other studies are used. Hence, in this research, we try to indicate the areas with the high relative tectonic activity based on assessment of the morphotectonic indices in the southern edge of central Alborz and analysis of these indices according to the tectonic and climate conditions. These areas can be the regions with high potential hazard in future. In this study, first we prepare the Digital elevation model based on the several topography maps in GIS. Then, the morphometric indices are calculated and evaluated. Since the priority value of these indices is different in the evaluation of relative tectonic activity in the area, we use analytical hierarchy method (AHP). Based on these data, the study area divided to several regions with different tectonic activity classes. The most of the subbasins according to the North Tehran fault (specially the central segment of the fault) in the southern edge of the central Alborz indicate the high and very high the tectonic activity. The evidences demonstrate tectonic activity classes 1 and 2 relate to the area between Amamzadeh Davood fault and North Tehran fault. The eastern Taleghan fault zone and the western segment of the Mosha fault in the Northwest of the area correspond with high class of relative tectonic activity. Also, in this research, the results, the final map and morphotectonic assessment indicate the subbasins according to the Ipack fault, Eshtehard fault and Limited regions of the North Ghazvin fault are compatible with high and relatively high classes.

Abstract The Zagros range extends for 1500 km from southeastern Turkey to Hormuz Strait and Persian Gulf. This active fold and thrust belt is composed of deformed sediments of the Arabian margin and has grown since Early-Middle Eocene in response to convergence and ongoing collision between Arabia and Eurasia plates. Crustal shortening in the Zagros is expressed by active folding and thrusting associated with a widely distributed shallow seismicity (depth < 20 km). The Dorud fault with general trend of NW-SE has known as one of the most important seismic in segments of Zagros Main Recent fault, near the Arjng area.In this study we use morphotectonic evidences to show that seismic behavior of this fault in the past has a clustering model in some time intervals. Geomorphic indicators are used as a tool to identify recent structures and movements. However, prior study of the region and the presence of high magnitude earthquakes that destroyed 100% of the villages with a 1 meter vertical displacement of the area indicate high tectonic activity. For this purpose at the first near-field morphotectonical analysis performed using Real Time Kinematics (RTK) GPS survey, digital elevation model and digital topographic map with high accuracy of surface ruptures of past earthquake prepared. To calculate the amount of displacement on the fault plane after applying the software steps on the DEM in Surfer software, perpendicular to the strike of the fault. These two lines extend the tangent to break the fault. The distance between the two points that cut two tangent lines indicates the amount of vertical displacement on the earth's surface. Digital elevation model and digital topographic map with high accuracy from the level of ruptures created from these findings were used to determine the quaternary fault of Dorud. Also, the geophysical studies of this part of the Dorud Fault after the preliminary studies of geology and the investigation of the probable extension of the fault using a special bipolar resistivity method (bipolar- bipolar) with a profile of 10 meters in 10 meters of two profiles were used. After the final processing and modeling the resilience data in Res2dinv software, the cesium magnetometric scanning was carried out on 4, 160-meter profiles.  According the results calculated for 3 stations amounts displacement respectively: The horizontal cumulative displacement on the fault surface is 21.59, 10.05, and 13.94, the vertical displacement of the vertical side on the fault surface is calculated 58.6, 57.5 and 13.47 and the net cumulative displacement is measured 22.88, 11.49 and 40/19. In order to investigate the fault mechanisms, the rake angles were calculated of the fault respectively as 17, 29 and 44 degrees. According to the results, the fault has a dip- slip component. Geoelectric impressions using a bipolar and bipolar arrangement on 2 the highest for the apparent resistivity of 101.7 and the least value 7.2 mm. Geo-electric resistivity measurements with CRP arrangement with the characteristics of OA = 50m and MN = 20m included two profiles with 70 points and a total of 145 points. In order to determine the lateral changes of the ground resistance, CRP resistivity measurements with OA = 50m and MN = 20m profiles on 0 profiles containing 33 points and profiles 80 including 37 points were performed, the highest value for the specific strength of 135 the least value is 13 ohm-meter. Investigation was done by magnetization on four profiles of 0, 40, 80 and 100 consecutive (Continue) with linear 0.64m. Geophysical studies on faults Dorud, the resistivity data acquisition with dipole-dipole array and 10 and 10 meter electrode spacing. After final data processing and inversion of resistivity data in Res2dinv software, cesium magnetometery survey on 4 profiles 160 metric. After the completion of field operations and data question clearer interpretation of the subsurface structures, especially faults and discontinuities in the study area were obtained. The Dorud fault in this site is characterized by three fault lines, which is to say that the F'4 fault, according to morphotectonic studies, has been made as the main Drood fault and the rest as faults parallel to it.There are three possible fault symbols F'3, F'4 and F'5 in the region showed that there can be prepared a series of fault according to the geological map of the studied area is confirmed. The main fault as the fault F'4 Dorud and other faults are parallel to it. All branches of the fault are partly in parallel with stepped-up right and left Stairs in some places just to releasing bend small landslides were observed in the region and in the region just too restraining bend with compression strike- slip duplex.

Abstract   The investigation and analysis of the morphotectonics of catchment area can be helpful in identification of the area’s active morphotectonics and it can also provide us with some significant and valuable information regarding the district's tectonic features and its tectonic activities. Rivers are of such indicators that show extreme reactions to tectonic activities and therefore, the results of investigating their changes and alterations can be a suitable guide for analyzing and determining the amount of tectonic activities of the study area.
     As a river is shaped under active tectonic circumstances, some morphologic alterations would take place in such structures as channels and longitudinal profiles in reaction to tectonic alterations. Investigating the rivers' drainage system is so important especially in thrust systems since these structures show extreme reaction to vertical tectonics and folds. The river’s bedrocks undergo eroding on the ground and their vertical profile alterations are of the most important geomorphological components regarding the development of mountains views. In situations when the river is not capable of removing the gradient anomalies, Knick points would be made; and if it creates a vast area, it would be called Knick zone which would be found in the shape of a waterfall in flow-paths with flow.
    The study area is located in Southern Alborz to Varamin plain and Qom's salt lake. The controlling factors of the area's tectonics include lithology, climate cycle, and structural factors (fold and fault). The northern part of the area (the Southern hill of Alborz) is completely folded and faulty and has made a totally active area tectonically. The highest part of study area is Damavand summit and its height is 5610 meters above sea level. The south area has some hills and mountains; however, they are totally scattered and plains (Varamin plain and the surrounding areas) have occupied most of the space of the area. This area has created a very tectonically active area since it is located in Alborz foothill, and there are so important faults such as Mosha's thrust fault, the thrust fault of north of Tehran, Taleghan fault, Emamzade Davood fault, and in southern areas, garmsar, eivanaki, hesarbon, and gharbilak faults are located. 
    The northern half of the area, which is affected by orogenic activities of Alborz, has shown totally a higher amount of activities comparing to the other parts of the area.  In this article, the active tectonics of the south of central Alborz in catchment areas of Jajrood, Eivanaki, and Hablerood have been measured in ARC GIS 10.1 environment using  river indexes including Hierarchical anomaly (Ha), Bifurcation index (Bi), Hypsometric integral and curve (Hy), Basin shape (Bs), Basin relative relief (Bh), and Drainage density index (ρ). To this end, the study area has been divided into 18 basins and most of the basins related to the northern and north-eastern areas which are located in the uplift zone have recorded high tectonic activities in most of the measured data. Moreover, the basins have been divided into five levels according to the rate of their tectonic activities; level 1 indicates the highest rate of activities and level 5 indicates the lowest.
    After measuring all the indexes, the active tectonic index (lat) was measured for all the study area in order to come up with an overall conclusion. This index also, confirmed other data and observations as expected. A number of 6 catchments out of 18, all of which related to the northern and north eastern areas, revealed the highest rate of tectonic activities, and their activity index was 1. A number of 11 catchments revealed medium activity, and they were mostly related to the central and southern areas of the study area; and only 1 catchment revealed the lowest tectonic activity which was related to the most southern study area. Totally, according to the data collected from the three catchment areas which were investigated in this study, the highest rate of tectonic activity is recorded in Hablerood catchment area and the lowest rate is recorded in Eivanaki (Galooshoot) catchment area, and Jajrood catchment area has revealed a medium rate of tectonic activities. The results showed that in catchments affected by the main faults of the area  such as Mosha, Emamzade Davood and Porkan faults in the northern area and Hesarbon, Eivanaki and Garmsar faults in the central and southern area, high tectonic activities were recorded which were also confirmed by field observations.

Abstract Improvement of our understanding in the environmental and geomorphological changes’ effects on marshes andisolated waters is a critical step to address issues related to continental marshes and their responses to thesechanges. Also, sedimentological studies are proper tools to interpret the evolution of sedimentary environment(Ward et al,1998). Additionally, to assess the ecological impact of contamination to the environment, it is vitally important tounderstand the full extent and the level of pollution into the background in the area.Regarding its capabilities in providing goods, marshes environments are classified as the most precious ecosystemson earth(Moreno,2015). Considering the effects of climate changes and human interferences, today the future ofthese important landforms and ecosystems seems to be at risk and it may cause possibly irreparabletransformations(Murray et al,2011). Also characterizing of the composition and the sedimentology of surfacesediments is vital not only from geochemical point of view, but also from an environmental perspective. Thusvariations in mineral compositions, trace elements and lithogenic components should be considered as valuabletools to find out the possible sediment sources and physico-chemicalprocess affecting the geological records) Bernardez,2012).Nowadays, Eynak marsh is strictly isolated from any riverine and oceanic sediment input. Anthropogenic effects (as an instance intense construction operation, sewage input to marsh and etc.) likely contribute to changing the circumstances and its natural habitat. Despite the importance of this area, there is no worthy investigation devoted to the study of, geophysical, mineralogical and sedimentological signature of Eynak marsh. This investigation could be more momentous if we spot contamination of sewage entrance from the urban areas and also underground linking to GoharRood River. It is noteworthy that, GoharRood by itself is a fully contaminated river transporting sewage from upstream.
Materials and methods
Eynak Marsh is located in west of the Rasht city, North of the Guilanprovince.Eynak naming comes from Persian translation of word Glasses, because of similarity between glasses and aerial photos of EynakMarsh.Eynak Marsh is located on Gohar Rood river near by at the urban area with dimensions of more than two thousand meters in length and more than 150 meters in width.
To study the sedimentary environment of the Eynak Marsh, 44surface sediment samples were collected using of a sediment sampling device (Van Ween Grab). Afterward, on the lab, samples were dried at 70˚ and dried bulk sediment was sieved to separate various fractionsusing wet sieving (based on standard test ASTM for determining average grain size). Grain size analysis of the 44 surficial sediment samples performed by Analysette 19 wet sieving instrument. Therefore, samples grouped into mud, sand and gravel fraction according to Udden and Wentworth. A detailed description of grain size <63 μm fractions executed by Laser Particle Seizer (model analysette 22).Collected samples analyzed for granolometery and it calculated same statistical parameters such as mean, sorting, skewness, and  kurtosis. Moreover, X-Ray diffractions in 44 sediment samples in the area have been performed using an automaticpowder EQUINOX 3000 X-ray diffractometer.Geophysical studies done using of Geoelectric and ground penetration radar techniques to determine depth and material of surrounding sediments and checking for sub-surface discontinuities existence and connection of this marsh with Gohar Rood River.
Results and discussion
mineralogicaland physical characteristics of the sediments in Eynak marsh can be influenced by rock assemblages inupstream such as basaltic-andesitic lava, dark grey limestone, slate and Arkozic sandstone which has been subjectedinto weathering, eroded and transported to downstream. In fact, due to terrestrial sources of sediments inEynak marsh, it is characterized by similar mineralogical and physical features.According to grading studies, 13 sedimentary types existed in surface sediments including: Gravelly Mud,Muddy Gravel, Gravelly Sand, Muddy Sandy Gravel, Gravelly Muddy Sand, Muddy Sand with a Little Gravel,Sandy Mud with a Little Gravel, Mud with a Little Gravel, Silty Sand, Muddy Sand, Sandy silt, Silt, Sandy Mud.Various statistical parameters of Eynak marsh sediments computed. Mean grain size: Different values obtained for textural statistical parameters varying from minimum 1.5 to maximum6.6, i.e. thusit falls between coarse sand and medium silt. Sorting: In the study area sedimentsranges in 3 sorts: poorly sorted,very poorly sorted, and moderately sorted. The closer to GoharRood, the sorting number increases and sedimentspoorly sorted. Skewness: In the present study skewness values ranges −0.43 to 0.68 with an average−0.02 representsfive sorts: strongly fine skewed, fine skewed, near symmetrical, coarse skewed, strongly coarseskewed.Kurtosis: Many curves designated to minute Kurtosis and it varies from platykurtic to mesokurtic. Also thevalues are among 0.5 to 2 with an average of 0.99. Scatter plot with mean, standard deviation and skewness can be used successfully for the distinction of the sedimentaryenvironments, always using a large number of samples for each sedimentary body sampled(Martins,1997).The scatter diagram proved that the distribution of grains belongs to fluvial and riverinesediments.
Conclusion
The results of granolometery shows thirteen dispositional types in the region and major component mineral were quartz, calcite,feldspar, and mica and minor mineral were pyroxene, evaporates along with some heavy minerals.bad sorting in Eynak Marsh shows that the source of sediments near the basin pass through a short transportation route. Skewness generally seen as near symmetrical shows the abundance of coarse grains in an energetic environment, where as kurtosis is generally seen as platykurtic and mesokurtic. The essence is revealed that between the Eynak Marsh and the Gohar Rood River exists a high resistive anomaly due to Rasht fault on the sidelines of  Marsh and change the kind of sediments in this area. Therefore, sedimentary statistical parameters and geophysical studies show that the Eynak Marsh Tributary of Gohar Rood Riverwere cut-off By  Rashtfault and it has shaped in current form.

Abstract This study provides morphology and field survey data on Ghasr-e-Ghand and Kahorkan thrusts, in the central part of eastern Makran accretionary wedge, in southeast Iran. The N-dipping thrusts with E-W strike, which brought Upper Oligocene turbidites onto Lower-Middle Miocene sediments, are one of the most important structure in this area and separate Inner Makran to the north from Outer Makran in the south. A clear facies changes are recorded in hanging wall of Ghasr-e-Ghand thrust, i.e. from shale in the east to sandstone-dominated to the West.
We combined the field data with geomorphic indices and show how lithology changes along Ghasr-e-Ghand Thrust influenced topography and morphology and so reveal not reliable active tectonic areas in view of geomorphic processing.
2_Materials and Methodes
Morphotectonic indices, Stream Length-Gradient (SL), Mountain Front Sinuosity (Smf) and hypsometric integral (Hi), which are sensitive to uplift and topography changes, are used to determine the tectonic activities along Ghasr-e-Ghand and Kahorkan thrusts. 78 adjacent catchment draining are extracted by ArcGIS 10.1 and Arc hydro software in the study area.
Field survey data were used to determine kinematic and recent activities of the thrusts, based on measurements along the thrusts, lithologic observations and stratigraphic relations across the faults.
The results of morphotectonic and field data as well as geological map and Digital Elevation Model (DEM) are combined in ArcGIS software as different layer to determine relationship between the layers and their effect on morphology of the area.
3_Results and Discussion
The morphotectonic analysis consist of low value (<1.10) of mountain-front sinuosity index (Smf) for all part of the Ghasr-e-Ghand and Kahorkan thrust, which points to high activities along the faults. Hypsometric integral index (Hi) shows high tectonic activities in west and eastern part of the Ghasr-e-Ghand and suggest tectonic activities for all over the Kahorkan thrust, while high SL value in most western part of the Ghasr-e-Ghand indicate a high exhumation for this area.
Fault measurements and related slicken lines indicate same kinematic along the Ghasr-e-Ghand and Kahorkan faults, i.e. N-dipping thrust with hanging wall movements toward south. In other hand, the Ghasr-e-Ghand Thrust cut and bended Holocene conglomerate in the eastern segment clearly. This evidence as well as thick Pliocene-Pleistocene conglomerate, which has dips of about 30º in the foot wall of the eastern part of the thrust indicate high recent activities for this segment. The most western part of the thrust in not clear and reveal an inactive fault. The kahorkan thrust did not influenced the quaternary sediments in front, which points to low tectonic activities along the thrust in the study area.
As we shown, the field survey data in contrast with morphotectonic analysis. Detail investigation on field and geological map reveal different lithology along hanging walls of Ghasr-Ghand and Kahorkan thrust. A facies changes occur from weak shale with thin and fine sandstone in the eastern segment to rhythmic sandstone and shale and some time to thick to massive volcanoclastic coarse sandstone in the western segment of Ghasr-e-Ghand. This lithology changes caused an inhomogeneous strength and so different behavior of erosion along the thrusts. The field data show high recent tectonic activities in eastern segment, although this area show very low topography compare to the western part. In other hand, big difference in strength of lithology across the thrust in the western segment, thick sandstone in hanging wall and weak marl in foot wall, caused higher topography and effected the geomorphic indices. E-W mountains in south of the Ghasr-e-Ghand and Kahorkan with almost straight frontal mountain formed by differences of strength in lithology and erosion, i.e. in base weak marl and on top thick and hard sandstone. Filed observation consist of stratigraphy contact between these lithology and for sure absent of faults. For such stratigraphic contact, Smf and width-valley height ratio (Vf) indices were measured in previous work and show a high tectonic activities for this part.
4_Conclusions
Field survey data indicate a recent tectonic activity for the eastern segment of Ghasr-Ghand thrust, which is in contrast with morphotectonic analysis. We believe facies changes in hanging wall of the thrust, caused different lithology with different strength and so different behavior in erosion along the thrust, which caused lower topography in the eastern segment with outcrops of shale in hanging wall to higher topography in the western segment with outcrops of volcanoclastic sandstone. Some E-W mountain, south of Ghasr-e-Ghand and Kahorkan thusts, make a sharp front without present of faults in the northern flank. Different lithologic strength caused to have such a landscape in the southern part of Makran. 

Abstract Behashtabad Damsite is located in High Zagros Zone, at 6-km distance from the south of Ardal Thrust Fault and 7-km from the north of Dopolan Thrust Fault. The outcropped deposits in the studied area locate in Zagros thrust zone. Paleozoic deposits contain red shales and sands belonging to Cambrian. Mesozoic deposits mostly belong to Cretaceous. The lower part contains limestones and dolomite limestones belonging to Fahlian-Dariyan. The middle part includes limestones, bituminous marly limestones, sandy limestones and thin-bedded chert belonging to Kajhdomi. Finally, the upper part contains thick-bedded limestones, abundant with karstic vugs. Thichness of the bed is 900 m and it is related to Sarvak-Ilam Formation. Goorpy Formation includes marly, silt and shaly limestones, marlstones and siltstones. Cenozoic deposits include Jahrom Formation which is made of dolomite limestones and dolomites belonging to Eocene-Oligocene. Chert nodules and shapeless cherts are seen in some beds. Assemary Formation is made of thick-bedded limestones belonging to Oligo-Miocene. Razak Formation, on the other hand, is made of thin-bedded sandy limestones, light green to gray marlstone and conglomerates. Finally, Bakhtiary Formation includes conglomerate outcrops and red sandstone belonging to Polio- Pleistocene. Quaternary deposits mostly include lacustrine sediments and alluvial fans have covered the rocky units in dam site and reservoir. These young deposits spread in a vast area in vicinity plains.
Materials and Methods:
The Dam site is located in Sheikh Mahmoud valley at southern limb of Sangvil Anticline. The study area is located at about 6 Kms south of Ardal fault and 7 Kms north of Dopolan fault with coordinates of 510 39' 10" E and 300 52' 39" N. The anticline axis is in northwestern-southeastern direction with plunge of 16° toward the southeast. This anticline is made of Jahrom-Assemary limestone and Razak marly formations. This zone is a Seismic one in Zagros Zone. Seismo tectonic activities have caused some mega fault in this zone which are mostly reverse thrust ones. The faults at the dam site are mostly secondary thrust faults, which are due to the activity of the main thrust faults. Such faults are seen in the dam site which will definitely threaten the structure. Accordingly, active faults in the dam site area were studied specifically. These local faults are covered by lacustrine deposits. So, these sediments are evidences of last events. Any movement and activity of faults, affect directly these young deposits. Investigating last movement of these faults is possible by studying lacustrine deposits belonging to quaternary period. In terms of Geomorphology, the major Morphology of study area is concluded from high mountains. They are included from limestone, dolomitic limestone and dolomite. Marlstones are located at lower altitudes. Plains and lowlands areas are covered by lake sediments.
Results and Discussion:
Based on field studies, F4 fault is one of the main local faults crossed by F1 fault. Any movement in F4 fault will be transmitted to F1 fault trace. Regarding study on F1 and F4 faults, a trench on lacustrine deposits was drilled perpendicular to F1 fault trace. There was no evidence on replacement of these young deposits. So, it`s concluded deposits ‘age is showing that the latest movement of these faults is occurred before lacustrine deposits composition. In this study, the OLS method was applied to determine the age of quaternary deposits.
Luminescence Dating Techniques are the ones based on the increase of electric charge in crystal minerals (caused by radioactivity). Such method is applied by geologists and archeologists to determine the time of the last exposure of the minerals. The estimated age in this method actually indicates when the older deposits were covered in 1-700 ka timespan. Luminescence dating was proposed by David Huntley in physic department of University in British Columbia in 1985. Basis of this method is the electrons being emitted by alpha, beta and gamma radiations, which is applicable for the deposits containing quartz and feldspar.
Conclusion:
Thermo-luminescence dating of operation method (OSL) on Quaternary deposits located on faults, a good way to approve or disapprove Late Quaternary faulting at the site is by faults in the area.According to the investigations using OSL method, these deposits belong to 190,000 years ago, and no activity evidences have been seen such as cracking, joints, etc on them. Based on seismotectonic principles, regarding the age of Quaternary Deposits, all of faults around the dam site are denied to be active.  

Abstract Regarding to the importance of the industrial region in engineering project execution, assessment of Geotechnical characteristics is essential to prevent undesired problems. Because of the uprising number of oil and gas industry structures, the Mahshahar Special Industrial Region is very important. So, the Geotechnical investigation in this region is necessary. Executing these investigations guaranties the implementation of any construction projects and prevents any unwanted detrimental events.
The study area is located in Mahshahar Port near in southwest of Iran. This port is one of the important industrial ports of Iran. Mahshahr port is located in area between 49º04´-49º06´E and 30º25´-30º31´N.
Materials and Methods
Based on Sedimentary-structural division of Iran, this area is located in Zagros zone. This zone is limited to Sanandaj-Sirjan zone from the northeast, to the Makran Zone from the southeast, to the highlands of northeastern Iraq and southeast Turkey from the northwest and to Arabian Plate from the south and southwest. Based on geological data, the properties of Zagros zone varies in different areas and this zone is divided to some subzones that Abadan Subzone, in which the study area has located. This subzone is located in the southwestern part of Zagros.
To investigate the Geotechnical characteristics of Quaternary sediments in the study area, eight boreholes data, performed by continuous coring method, with depth 11 to 25m were studied. The seismic downhole test and Standard Penetration Test (SPT) were done in all boreholes. The laboratory tests are included the index tests on soil samples (particle size distribution, Hydrometer, Atterberg test), consolidation, direct shear, uniaxial and triaxial tests. Strata were classified using index tests.
To reveal the stratification of site, the Seismic Downhole test was performed in all boreholes, in which the source was in surface (blow on a plate placed in 2-3m distance from borehole) and the P-wave was measured in geophones installed in different depth of boreholes (1m intervals), so whole depths of borehole were investigated. To measure the S-waves, the blows were stroked in a horizontal direction on timber to generate S-waves. Finally, the relationship between elasticity modulus in downhole and SPT tests and also the relationship between friction angles in triaxial tests with N_SPT values were assessed.
Results and Discussion
The plasticity of soil has investigated using Atterberg test results, performed applying standard ASTM D4318 on all samples. The results show that the Liquid Limit and plasticity index vary between 25-40% and 10-20%, respectively, showing the low to medium plastic characteristic of soil.
The elastic modulus and also the relationship between the elastic modulus on downhole and N_SPT tests were investigated in the study area. Based on the results, the elastic modulus of quaternary sediments of Mahshahar varies between 100-350 Mpa. In general the relative density and the seismic wave velocity of soil strata were increased with depth in this area.
Also, the fitting curve of N_SPT values and elastic modulus in downhole tests show the R²=0.80, in which the N_SPT values were corrected to N₆₀.
Soil classification of the site, regarding the average S-wave velocity of soil up to 30m depth, was performed based on the Iranian Building Code (IBC) 2800. The recorded mean S-wave velocity in all boreholes is less than 375m/Sec so the ground type III (based on IBC 2800) is recommended to be taken into account in the design.
Estimating of friction angle of soils, some researchers like Hunt (1984) have been published some reference tables. In this study, to have a simple equation to estimate the friction angle of quaternary sediments, the results of NSPT and consolidated undrained triaxial test (CU) have been used. The result shows the R²=0.85 for fitting curve. Regarding the results, it can be concluded that because of overestimating of friction angles, the presented tables by Hunt (1984) is not applicable to Mahshahr quaternary sediments. It seems that the main reason comes from remarkable existence Clay soils in the sediments.
Conclusion
In this research, based on data from boreholes, the general characteristics of quaternary sediments were revealed and also the strata were classified based on the Unified System as ML, CL and SM. To determine the elastic modulus of soil, the results of the seismic downhole test were used. Based on these results the elasticity of soil varies from 100 to 350MPa. The relationship between mentioned above elasticity and NSPT was assessed and an equation was determined. In general the relative density and seismic velocity increase with depth in this site. S-wave velocity in Seismic downhole test results were used to determine the site or ground type. This parameter was less than 375 m/Sec in all boreholes. So, the ground type III (IBC2800) is recommended for the whole site. Finally, an equation was concluded for relationship between N_SPT and UC triaxial friction angle which can be more useful than other published relationships (like those by Hatanaka & Uchida) and Hunt’s tables, because these published ones overestimate the friction angle; the main reason of this case is the existence of the great amount of Clay in soil in this site. 

Abstract Introduction: The assessment of major faults to identify the effect of their recent activity on the tectonic evolution of the hydrogeological characteristics of drainage basins is essential. The number of springs as well as the amount of wells discharge often change corresponding to the distribution of fault zones. The 78 km long Sarvestan fault zone is the most typical case according to the distribution of springs. The fault zone, cutting across the fold-thrust belt of Zagros, is dominated by strike-slip (Berberian, 1995), and has deformed some of the previously formed folds. Furthermore, The Sabz-Pushan is an active strike-slip fault zone with length of 220 km, extended along the Zagros fold-thrust belt from northwest of the Shiraz toward the southeast. Since class 1 of Iat, indicative of the most active tectonics, and class 2 of  Iat corresponding to highly active tectonics, occurs mainly in the southwestern part of the study area along the Sabz-Pushan fault zone and also the Sarvestan fault zone, in this research, the relation between these large scale faults which are active in quaternary and the abundance of water resources (spring and well) have been studied.
Materials and methods: In this research, using geological maps, satellite images and field studies, we have analyzed the faults, the springs and the wells of study area through GIS 10.1. The study area, covering an area of 9732 (km^2), is located along a simply folded belt of southeastern Zagros. It is underlain by Phanerozoic sedimentary sequences in elongated, doubly-plunging, box-shaped anticlines, and the synclines are partly buried by younger Quaternary alluvium. The SW–NE oriented contraction that initiated in the Late Cretaceous and strengthened during the Early Miocene due to the collision of the Arabian and Eurasian plates, has led to the development of NW–SE trending, SW-verging folds, and NE-dipping thrusts in the Phanerozoic sedimentary strata covering the Afro-Arabian basement, above a detachment zone of the Infracambrian–Cambrian Hormuz evaporite (Kadinsky-Cade and Barzangi, 1982; Alavi, 1994). In this research, Firstly, all available information for the area of interest was collected and compiled by using geological and topographic maps, satellite images as well as fieldwork. Then, all data were converted to digital format and consequently different layers were created, such as tectonic elements, lithology, slope, elevation and drainage density. The relationship between the number of springs and distance from structural elements is generated by cross operation between springs layer and structural elements layer using buffer and distance operation in the GIS environment. In order to identify the relationship between the amount of slope and the number of springs, the topo-spring layer was crossed with the slope map in the GIS. Springs layer was, also, crossed with 400 m altitude zones of a DEM (digital elevation model) to present the relationship between the elevation levels and the number of springs.
Results and discussion:  The springs at large distance from the main structural elements can be explained by local geologic conditions, including fracturing not mapped at the scale used. The result of topo-spring layer on the the slope map is showing that there is a good correlation between slope class and the frequency of springs located in each class and represent that the number of springs is a function of slope. The output of the existence of springs on different elevation levels clears that the vast majority of springs are in 1400-2200 meter. Springs at high altitude indicate local geologic control. Drainage density has been measured as total stream length per unit area of each basin. The results reveal that high drainage density is correspondent with impermeable sub surface units and mountainous relief, whereas, the low drainage density reveals that the subsurface material are permeable and low relief which results in more infiltration capacity in the basins.
Conclusion: According to the results, there is a tendency for springs to occur at short distances from structural elements. It can be concluded that many of tectonic elements, are conduits of water. However, the water surface is not necessarily on the element itself.  Most of the springs are either faulted ones or identified with major faults through the study area. It has been proved not only by correspondence between the location of springs and the trend of main faults such as Sabz Pushan and Sarvestan, but also by the huge differences in the amount of wells’ discharge. Furthermore, it is concluded that there exists an entwined relationship between the abundance of water resources and structural elements.
 
Introduction: The assessment of major faults to identify the effect of their recent activity on the tectonic evolution of the hydrogeological characteristics of drainage basins is essential. The number of springs as well as the amount of wells discharge often change corresponding to the distribution of fault zones. The 78 km long Sarvestan fault zone is the most typical case according to the distribution of springs. The fault zone, cutting across the fold-thrust belt of Zagros, is dominated by strike-slip (Berberian, 1995), and has deformed some of the previously formed folds. Furthermore, The Sabz-Pushan is an active strike-slip fault zone with length of 220 km, extended along the Zagros fold-thrust belt from northwest of the Shiraz toward the southeast. Since class 1 of Iat, indicative of the most active tectonics, and class 2 of  Iat corresponding to highly active tectonics, occurs mainly in the southwestern part of the study area along the Sabz-Pushan fault zone and also the Sarvestan fault zone, in this research, the relation between these large scale faults which are active in quaternary and the abundance of water resources (spring and well) have been studied.
Materials and methods: In this research, using geological maps, satellite images and field studies, we have analyzed the faults, the springs and the wells of study area through GIS 10.1. The study area, covering an area of 9732 (km^2), is located along a simply folded belt of southeastern Zagros. It is underlain by Phanerozoic sedimentary sequences in elongated, doubly-plunging, box-shaped anticlines, and the synclines are partly buried by younger Quaternary alluvium. The SW–NE oriented contraction that initiated in the Late Cretaceous and strengthened during the Early Miocene due to the collision of the Arabian and Eurasian plates, has led to the development of NW–SE trending, SW-verging folds, and NE-dipping thrusts in the Phanerozoic sedimentary strata covering the Afro-Arabian basement, above a detachment zone of the Infracambrian–Cambrian Hormuz evaporite (Kadinsky-Cade and Barzangi, 1982; Alavi, 1994). In this research, Firstly, all available information for the area of interest was collected and compiled by using geological and topographic maps, satellite images as well as fieldwork. Then, all data were converted to digital format and consequently different layers were created, such as tectonic elements, lithology, slope, elevation and drainage density. The relationship between the number of springs and distance from structural elements is generated by cross operation between springs layer and structural elements layer using buffer and distance operation in the GIS environment. In order to identify the relationship between the amount of slope and the number of springs, the topo-spring layer was crossed with the slope map in the GIS. Springs layer was, also, crossed with 400 m altitude zones of a DEM (digital elevation model) to present the relationship between the elevation levels and the number of springs.
Results and discussion:  The springs at large distance from the main structural elements can be explained by local geologic conditions, including fracturing not mapped at the scale used. The result of topo-spring layer on the the slope map is showing that there is a good correlation between slope class and the frequency of springs located in each class and represent that the number of springs is a function of slope. The output of the existence of springs on different elevation levels clears that the vast majority of springs are in 1400-2200 meter. Springs at high altitude indicate local geologic control. Drainage density has been measured as total stream length per unit area of each basin. The results reveal that high drainage density is correspondent with impermeable sub surface units and mountainous relief, whereas, the low drainage density reveals that the subsurface material are permeable and low relief which results in more infiltration capacity in the basins.
Conclusion: According to the results, there is a tendency for springs to occur at short distances from structural elements. It can be concluded that many of tectonic elements, are conduits of water. However, the water surface is not necessarily on the element itself.  Most of the springs are either faulted ones or identified with major faults through the study area. It has been proved not only by correspondence between the location of springs and the trend of main faults such as Sabz Pushan and Sarvestan, but also by the huge differences in the amount of wells’ discharge. Furthermore, it is concluded that there exists an entwined relationship between the abundance of water resources and structural elements.

Abstract The study area with almost 13000 km², Qom-Saveh basin, is located in most northern boundary of the Central Iran, where Eocene-Oligocene volcanic rocks and associated sediments as well as Qom Formation crops out between the dextral Koshk-Nosrat fault in the north and the Talkhab fault in the south. The Koshk-Nosrat, Saveh, Indes, Tafresh, Nobaran, Talkhab, Alborza and Koh Qermez fault zone are the most important faults, are delineated in geological maps with 1:100,000 Scale. The faults are covered by the Quaternary alluvium in the major part of its length, so morphotectonical characteristics gives more evidences about the regional activity.
Materials and Methods
Three morphotectonic indices, Stream Length-Gradient (SL), Mountain Front Sinuosity (Smf) and Valley height ratio (Vf), are used to determine the tectonic activities of 175 adjacent catchment draining in the study area, which are determined by ArcGIS 10.1 and Arc hydro software. The SL index depended to the gradient of the rivers and high value indicate higher exhumation in the basin so it can confirm activities of faults with higher dip displacement than lateral component. Smf index related to activities of faults in front of mountains and lower value indicate higher activities of faults than erosional process. The Vf index depended to of dip slip fault movements, therefore less Vf value shows higher uplift than erosion and makes V shape valley in the area.
Results and Discussion
The morphotectonic analysis consist of high SL value (>950) in south of Indes and Tafresh faults, which indicate a high exhumation in these area. Measurements on 396 mountain front for calculation of smf index, indicate low value of the index on main part of Nobaran, Indes, Alborz, Saveh, Koh Qermez, Tafresh and Kosh-Nosrat faults (<1.10), which points to high activities of the faults. Usually, faults in southern part of the study area such as Tafresh does not show such a value and activities. 40 valley, distributed all over the study area, are chosen to calculate vf index. The calculation indicate valleys related to Koh Qermez fault zone, and all over the Indes fault (whithin the study area) have lowest value of vf (<0.5), which points to high uplifting in these basins.  
Fieldwork studies and satellite image processing are done to control the results obtained from the morphotectonic indices. High resolution satellite images of Google Earth and Bing have used to determine deflection and offsets of streams and rivers. Usually, main rivers near to all of the main faults of the study area show a systematic right-deflection and offsets, which suggest right lateral component activities of the faults. The right-deflection are observed on fieldworks and minimum offsets of the streams and Quaternary sediments are about 2m. Usually, Small streams and youngest Quaternary alluvial near to the Koshk-Nosrat and Nobaran Faults (NW segment of Indes fault) show a small left-deflection and offsets, which indicate the last activities of the faults are sinistral in these faults.
South of Koshk-Nosrat fault, in hanging wall, several NW-SE reverse faults are recorded in Quaternary terraces with total displacements of 5 to 10 cm. since the strike of the Quaternary faults are parallel to the Koshk-nosrat fault and have same dip directions (to south) so most probably the Quaternary faults are splayed out from the Kosh-Nosrat fault.
A clear WNW-ESE lineation with streams deflection and effected on morphology of Quaternary sediments is visible in north of Nobaran Fault in satellite images. Just adjust to the lineation several almost N-S reverse faults with dipping 30ºE with total displacements of 20 to 30cm is recorded in Quaternary terraces. Normal faults, almost parallel to the Quaternary reverse faults but with opposite dips (52W), are extended in hanging wall of the reverse faults. The total displacement of the normal faults are much less than the reverse faults (5-7cm). The reverse faults are created by activities of the lateral component of a branch of the Nobaran fault. The normal faults should form by activities of reverse fault by moving material toward foreland (west) and so breed normal faults by collapse in soft Quaternary sediments.
Conclusion
In general based on morphotectonic indices and fieldwork data and observations all the study area but south eastern part (fault zone around Qom city) and Talkhab fault, are active. The most activities of faults are seen in Koshk-Nosrat, where reverse faults cuts Quaternary sediments, Koh Qermez fault zone, Indes and its NW continuation (Nobaran fault), where reverse and normal faults cuts Quaternary sediments clearly, Saveh and Tafresh in order.

Abstract Khur area as the study area is located in the northern part of Central Iran Micro continent. The Central Iran contains three smaller tectonic blocks that consist Lut, Tabas and Yazd blocks. The Khur area is located in the Yazd block and Anarak-Khur sub zone and is surrounded by the GreatKavir Fault (Dorouneh Fault) to the north. The Chupanan Fault is considered as a major branch of the Great Kavir Fault and is the most important fault of the north Khur area. Reason to absence of great systematical earthquake data along the Chupanan fault, checking of seismicity of the area based on earthquake catalog is impossible. In this research, according to the several morphotectonic evidences along the Chupanan fault and its branches, including the displacement of large and small streams and alluvial fans, activity of the faults during Quaternary period is studied.

Method

The methods used in this research, can be classified into several parts: Satellite images interpretation, field observations, structural analysis. In this research, Satellite images (SAS Planet, Google Earth, ETM and DEM) were used and processed and several faults were identified for the first time. For processing and detection of faults, we used ER Mapper, Global Mapper and Oasis Montaj software's. During geological and structural fields, every observed fault trace was mapped as accurately as the scale of the maps allowed. Fault traces were identified mainly in places where they cut competent rocks. Based on length and role of the faults, faults were separated into principal displacement zones, and minor, secondary faults. Shear sense along the faults was recognized during field studies from analysis of slickenlines and drag of beds along faults. Fault data analyzed by using FaultKinwin5 and Dips software.
For checking the tectonic activity of the Chupanan Fault zone and Khur area, Earthquake events data during the period between 1958 and 2015were calculated and then the seismic map is compared with distribution of the study area faults. A few earthquakes with magnitude approximately Mw=5 along the major and map-scale faults have been recorded.

Result

Field studies and satellite image interpretations indicated that the study area is cut by several sets of faults with different orientations. The distributions of the faults are classified in NE-SW, NW-SE, E-W and N-S. Our analysis showed that the most important set of faults have NE-SW direction and stretched parallel to the Chupanan Fault and have sinistral strike-slip component of movement along the fault planes. The Chupanan Fault has the greatest length and is an active fault because the fault and its branches faults are displaced and cut streams, alluvial fans and terraces and other Quaternary deposits. Chupanan Fault is divided into two major segments to the north and south. The northern segment is an ENE-WSW-trending sinistral fault that disruption and displaced Proterozoic to Quaternary rock units and sediments and streams. Based on several observed offsets along the fault we tried to reconstruct the movement of the fault during the time. The fault slip rate according to the amount of horizontal displacement and the age of tectonic movement was calculated. Reconstruction and calculated slip rate for the northern segment of Chupanan Fault is about 0.09 mm/yr that calculated based on 71 meters offset during 0.790 million years. In the northern Arusan village, the NW-SE-trending faults are displaced Pleistocene sediments about 250 and 500 meters and the calculated slip rates are about 2 and 4 mm/yr, respectively.

Conclusion

According to the geometry and mechanism of the faults several structures such as pull- apart basin were observed. Abbas Abad basin is one of the examples of structures related to sinistral strike-slip movement of Chupanan fault and its branches faults.
The presented morphotectonic evidences in the Khur area indicate that the major movement of the Chupanan fault during Pleistocene is sinistral strike-slip. By considering the horizontal offsets along the Chupanan fault zone in different parts of the area, maximum slip rate is measured about 4mm/yr in the north Arusan village area. By considering faults long, high rate of faults slip rates and large earthquakes recorded around this area, there is the possibility of destructive earthquakes with a long return period. According to this evidence, tectonically, the Khur area in the Central Iran is active.