List of Articles Tectoni

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  1 - The role of the active tectonics in geomorphic anomalies of Gorgan Rud - Gharasu basin
   Agh- Atabai  Nemati معصومه  روستائی
  The study area is located in north of eastern Alborz range. In this study, it was evaluated the pattern of neotectonic in eastern Alborz and the distribution of seismicity and geomorphic pattern of Southern Golestan province. To assess tectonic activities in 22 separat More

  The study area is located in north of eastern Alborz range. In this study, it was evaluated the pattern of neotectonic in eastern Alborz and the distribution of seismicity and geomorphic pattern of Southern Golestan province. To assess tectonic activities in 22 separated subbasins, we have analysed neotectonic indices: the stream– gradient index (SL), drainage basin asymmetry (Af), reveres symmetry of topography (T), hypsometric integral (Hi), drainage basin shape (Bs) and mountain front sinuosity (Smf). The results of the analysis is accumulated and expressed as an index of relative active tectonics (Iat), which divided into four classes from relatively low to highest tectonic activity. The high class values of tectonic activity for Iat mainly occur in the south and southwest of the Gorganrud- Gharasu drainage basin, while the rest of the study area has classes of Iat suggesting moderate to low tectonic activity. The rate of tectonic activity in this area will increase from north to south. This increase can be related to the position of peaks steam gradient index along the faults and segment faults. Also value of drainage basin asymmetry is calculated for all of the subcatechments greater or less than 50 that shows tilt for each stream toward West or East. The results of this study show that the distribution of seismicity, geomorphic and tectonic movements of studied area has been affected especially by Khazar and North Alborz faults movement and thrust fault in north of Gorgan. Areas with high tectonic activity and the high measure of tilting indicate that there may be a thrust fault, with a NNE-SSW approximate trend. On the other hand, this seismicity trend may be related to a deep and relatively young thrust splay in north of the Alborz range front. Manuscript profile
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  2 - Temporal evolution of faults in Ziaran region, shoutwestern of central Alborz
  Elham Asadi Mehmandosti
  Ziaran area is located in the southwestern part of the central Alborz range (northern Iran) where a complete series of rocks from Paleozoic to Tertiary are exposed. Thus, the area is suitable for temporal evolution of structures in this part of the range. The study area More

  Ziaran area is located in the southwestern part of the central Alborz range (northern Iran) where a complete series of rocks from Paleozoic to Tertiary are exposed. Thus, the area is suitable for temporal evolution of structures in this part of the range. The study area is bounded by the Taleghan Fault to the south, the Tekie Fault to the east, and the Ahurak Fault (Western continuation of the North Qazvin Fault) to the North. In this research, kinematic analysis of these faults and other related structures are presented to elucidate their structural evolution during Tertiary, considering the relationship between present structure and the dominant Tertiary deformation phases. The data obtained from analysis of the Taeghan Fault implies the basement involvement nature of the fault and its evolution during the inversion of an initial normal fault since Late Cretaceous (at least). This inversion led to thrusting of the Paleozoic and Mesozoic rocks over the Eocene units. Based on E-W strikes of the Taleghan and Ahurak faults and their reverse components, it might be suggested that they have been formed as result of a N–S compression phase before the Miocene. During the Miocene, the final collision between the Arabian Plate and Central Iran has occurred (with approximate oblique trend of SSW-NNE). This change of trend resulted in variation on the main faults kinematics across the area such as change in kinematics of the Taleghan Fault to left lateral strike-slip and that of the Ahurak Fault to right lateral strike-slip. Due to SSW motions of the Caspian basin toward the central Iran, left lateral transperssion tectonics have dominant since Pliocene. This movement led to reactivation of the basement faults and their effect have resulted in formation of several left lateral strike slip faults, as its riddle shear faults inside the study area. Manuscript profile
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  3 - Active Tectonics Zonation in Saveh Area, SW Tehran
  bijan abdollahi Hossein Hajialibeigi
  Geomorphic indexes can be a useful tool for investigating the impact of active tectonics and the identification of related anomalies, especially in areas that quantitative research work has been done. The study area is a part of the Central Iranian structural-sedimentar More

  Geomorphic indexes can be a useful tool for investigating the impact of active tectonics and the identification of related anomalies, especially in areas that quantitative research work has been done. The study area is a part of the Central Iranian structural-sedimentary zone, located in the Saveh area. By studying the geological and topographic maps and using digital elevation data, it was evaluated the rate of relative active tectonics of this area, using some of the geomorphic indexes such as Hi, Re ,Bs, AF, Vf, Vc, V, SL, Smf and Iat. These indexes which have been measured and compared in eight fronts and nine basins (Shur-payeinii, Lar, Bidlu, Amirabad, Shur-baleii, Eshtehard, Buin Zahra, Arab and Kharrud) resulted to present the active tectonic zonation map for the study area. The measured Hi index shows the relative maturity of all basins and the Arab basin has the most relative tectonic activity compared to other basins. The Re index shows the highest elongation for Lar, Bidlu and Kharrud basins and the least elongation for Shur-payeinii basin. The AF index shows the highest uplift for the Bidlu basin, which is located on the right side of this basin. Vf, Vc and V indexes represent the lowest rate of activity in the valleys which are located on the border between the Shur-baleii and Amirabad basins, the southern part is the Lar basin and the border between Amirabad and Bidlu basins. The Kharrud, Buin Zahra and Arab basins are the most active basins based on the SL index. The Smf index indicates the high activity for all basins. According to active tectonic zonation map, it is possible to show that on the border between the Eshtehard, Shur-baleii, Lar, Bidlu and Amirabad basins which are located in 1 class, have the highest degree of activity. These basins are affected by behavior Jaru, Gomorkan, Ipak, Takidagh, and Alishar faults. Other parts along the mountain fronts are also located in 2 class and are active. The low-lying areas (Kharrud, Buin Zahra and Arab basins) located in 3 class, have the least degree of activity. The highest rate of SL index is for Kharrud, Buin Zahra and Arab basins. This high rate resulted to the seismic and active Ipak fault. According to Smf index, Amirabad basin is the most active basins. Vf index represent the lowest rate which are located on the border between the Shur-baleii and Amirabad basins. This border is located on Jaru and Gomorkan faults. Manuscript profile
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  4 - Geochemistry and petrology of Qareh-Dash rhyolites from Shahindej- NW Iran: Geochemical features of post- collision volcanism
  Masoumeh Ahangari معصومه  نظری Mohsen Moazzen
  20.1001.1.17357128.1399.14.56.4.7
  Qareh-Dash rhyolites from the Shahindej area are peraluminous rocks with high SiO2 and K2O contents. These rocks are mainly composed of quartz, K- feldspar and rare plagioclase phenocrysts in a fine-grained K-feldspar rich matrix. Geochemically, Qareh-Dash rhyolites sho More

  Qareh-Dash rhyolites from the Shahindej area are peraluminous rocks with high SiO2 and K2O contents. These rocks are mainly composed of quartz, K- feldspar and rare plagioclase phenocrysts in a fine-grained K-feldspar rich matrix. Geochemically, Qareh-Dash rhyolites show enrichment in LREEs and LILEs and depletion in HREEs. Field studies, textural and petrographical relations, along with whole rock geochemistry, demonstrate that the parental magma of the Qareh-Dash rhyolites was originated from the crust. The composition of the parental magma was modified due to fractional crystallization of plagioclase and titanomagnetite evidenced by negative Eu, Sr and Ti anomalies in multielement diagrams. The chemical characteristics of Qareh- Dash rhyolites such as Rb/Nb, K/Rb, Rb/Sr, Rb/Ba and Ga/Al ratios are similar to A-Type granites/ rhyolites associated with post- collision tectonic settings. According to Precambrian age for the Qareh-Dash rhyolites, formation of these rocks might be related to extensional phases which were probably taken place after closure of proto- Thetys Ocean. Manuscript profile
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  5 - Investigation of tectonics, fault data and their relationship with mineralization and alteration in Asbkhan, Heris area (East Azerbaijan Province - Northwest Iran)
  N. Yadegari Seyed Ghafor Alavi Mohsen Moayyed
  20.1001.1.17357128.1402.17.65.3.5
  The study area is located in the south of Qushadagh mountain range, in the north of Asbkhan village, Heris township and in East Azarbaijan province. In terms of structural geology of Iran, this area is located in the main zone of Central Iran and Alborz-Azerbaijan sub-z More

  The study area is located in the south of Qushadagh mountain range, in the north of Asbkhan village, Heris township and in East Azarbaijan province. In terms of structural geology of Iran, this area is located in the main zone of Central Iran and Alborz-Azerbaijan sub-zone. The geological units of the region are including Eocene igneous and pyroclastic rocks with combination of andesitic, Trachyandesitic, basaltic, tuffic and ignembritic. The semi-deep intrusive mass with Oligocene age, with the combination of quartz diorite, diorite and quartz monzonite in the form of stock and dyke is exposed in the area. Structural studies, including fault plates, slickenside on them, and the joints system in various lithologies, indicate at least two general stress directions in the range, Which can be created following one tectonic regime or two tectonic regimes. If we consider the tectonic regime as a phase and consider the tensors with different directions as the result of rotation in the fault plates, We can introduce a general strike-slip regime with a general north-south trend that controls the existing structures of the region. At the same time, the infiltration of intrusive masses has caused the disintegration of these structures and made the issue more complicated. In general, faults with a northwest-southeast trend and a right on strike-slip mechanism, form the main structures of the area.Other faults are controlled by the main structures following the Riddle fractures system. Based on the system of joints in four different lithologies, lithological units from old to new include: basaltic andesite, quartz diorite, quartz monzonite (porphyry mass) and diorite, which from old to new reduces the diversity of the joints system. The northwest-southeast tectonic system has been involved in the development of argillic alteration and the northeast-southwest system has been important in the development of siliceous and mineralized veins. Manuscript profile
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  6 - Investigation of the relationship between tectonic morphological indices and seismic acceleration in Indes, Aipak, Avaj and Kushk-e-Nusrat fault zones (northwest of Saveh)
  bahar Rezaei nahal Mohsen Pourkermani M. Zare M. Dehbozorgi R. Nozaem
  The northwest zone of Saveh city is located in the Indes, Kooshk e Nosrat, Avaj, and Aipak fault zones. Indes, Kooshk e Nosrat, Avaj, and Aipak faults are considered the major faults in central Iran, which are also active in the Quaternary, and their last movements are More

  The northwest zone of Saveh city is located in the Indes, Kooshk e Nosrat, Avaj, and Aipak fault zones. Indes, Kooshk e Nosrat, Avaj, and Aipak faults are considered the major faults in central Iran, which are also active in the Quaternary, and their last movements are attributed to the present time. Therefore, the estimation of morphometry to identify the effect of active tectonics on the tectonic evolution of drainage basins seems necessary. In this study, six important morphotectonic indices were analyzed including the longitudinal gradient of the river, asymmetry of the drainage basin, hypsometric integral, drainage basin shape, the ratio of the floor width to the valley height, and mountain front. To model the formation of basins in the studied area, Arc Hydro software (Arc GIS add-ins) was used based on data derived from a digital elevation model. Then, 6 morphotectonic indices were compiled and classified on each of the basins. Finally, the Active Tectonic Index (IAT) was calculated, according to which the study area was classified into 4 categories including very high, high, intermediate, and low tectonic activity. According to the IAT index, 5% of the study area shows very high tectonic activity, 25% of the studied area has high tectonic activity, 65% of it has average tectonic activity and about 5% of the tectonic activity is low. Moreover, seismic acceleration was prepared to confirm the result of morphological indices in the estimation and analysis of active tectonics in the region. In this study, the highest level of tectonic activity can be seen in the north-eastern part of the area. In most sectors, the level of activity is high and intermediate, which is related to the activity of Kooshk-e-Nosrat, Aipak, and Avaj faults. Manuscript profile