جستجوی مقالات مرتبط با کلیدواژه « ایران » در نشریات گروه « زمین شناسی »

Gneissic domes are evidence of vertical movements in both compressional and extensional tectonic regimes in orogenic systems. These domes are evidence of mutual interaction between gravitational and tectonic forces in the continental crust. Gneissic domes have unique structures in deformed regions. These domes include a complex of deformed metamorphic rocks and intrusive masses covered with the upper layers of the crust. The Toutak gneissic dome is located in the high-pressure-low-temperature Sanandaj-Sirjan metamorphic belt and is an example of gneissic domes in the Zagros orogenic system. The purpose of this research is to determine the deformation temperature based on the petrofabric characteristics of quartz minerals in the mylonite rocks exposed in the Toutak gneissic dome. The temperature obtained from the quartz c-axis pattern shows the temperature range from 260±50 to 565±50 °C for the deformation. The asymmetry of quartz c-axis patterns indicates the occurrence of dextral shear during the deformation.

Masteroon area is located in the northeast of Azna city, in the Sanandaj-Sirjan zone. The rocks units include a relatively uniform sequence of slate and phyllite with a granodiorite intrusive mass that includes pegmatitic complex. The most important minerals include quartz, alkaline feldspar, plagioclase, tourmaline and muscovite. Quartz is high pure and does not have any other elements. EPMA shows the albite-type feldspar with a lesser extent than orthose-type with a less than 550⁰C crystallization temperature. This can be due to the result of below the freezing of the feldspars composition during the cooling of the mass. The available tourmalines are of schorl and alkaline type with a deficiency in the X position, and their numerous and abundant presence, automorphism and absence of chemical zoning, indicate that tourmalines are magmatic. Muscovites are present in two forms: coarse-grained in pegmatites and fine-grained in joints and cracks, and the coarse-grains does not stretch to phengite.

The Pargeh pluton is located in the northeast of Qazvin. The rocks of this pluton mainly include monzogabbro and olivine gabbro, which mineralogically contain olivine, clinopyroxene, plagioclase, biotite and alkali feldspar. Geochemically, they have features of potassic alkaline magmas with enrichment in large ion lithophile elements (LILE: Ba, U, Pb, Sr) and depletion in high field strength elements (HFSE: Nb, Ti, Zr), which are similar to subduction zone magmatism and mantle-derived magmas. Chondrite-normalized REE plots show enrichment in light REE (LREE) (4.43< (La/Yb) N <8.58)) and slight negative anomalies (Eu/Eu* = 0.82-0.99). The studied gabbroic rocks have resulted from fractional crystallization of a parental magma which formed by partial melting of depleted lithospheric mantle with spinel-peridotite composition. The primary ratios of 87Sr/86Sr and 143Nd/144Nd (0.70493-0.70525 and 0.51272-0.51269) are compatible with the parental magma formation in the mantle wedge. The values of ɛNd(i) (1.47 to 1.92) are in the range of mantle-derived melts. We suggest that Pargeh gabbroic rocks are part of the Alborz magmatic belt, which according to the geochemical data, their tectonic setting is consistent with a post-collisional, back-arc extensional environment.

In the context of global warming and climate change, carbon dioxide (CO2) is known as one of the most important greenhouse gases that has significant effects on the global warming. It is considered as one of the consequences of the accumulation of greenhouse gases. It is very important to control the amount of CO2 emissions and reduce the effects of human activity on climate warming and understanding the spatial and temporal distribution of atmospheric CO2. Due to the coarse horizontal resolution of global transport models, simulation of CO2 concentration in hourly/weekly time intervals and with a good vertical resolution in continental or coastal sites is one of the most important environmental challenges especially in the Middle East.   While compiling information on CO2 emission from different sources, regional numerical simulation with spatial resolution of 30 and 10 km of atmospheric CO2 concentration was carried out using the Weather Research and Forecasting-Chemistry (WRF-GHG) model. XCO2 information retrieved from GOSAT satellite observations was used as accuracy control information and evaluation of simulated results in CO2 column concentration in hot (August) and cold (February) seasons compared to the output results of TM3 global model.  The performance of simulations in predicting the concentration of greenhouse gas carbon dioxide (CO2) for the study period of February and August in 2010 showed that the spatial and temporal variability of meteorological variables have been simulated well with the correlation coefficients of 86-92%, 75-67% and 76-82% for temperature, wind and relative humidity, respectively. The evaluation results showed that the WRF-GHG model performs better than the TM3 global model in terms of statistical errors. On average, the skewness error values in both hot and cold seasons are -0.79 and 0.45 (-0.85 and 1.12) in the regional (global) model, respectively. The evaluation results showed that the difference between the simulated concentrations and XCO2 observations from the GOSAT satellite could be caused by the underestimation of emissions produced by human activities, oceanic emissions, and exploitation of fossil fuels. This study showed that the WRF-GHG model is able to simulate well many important features of the atmospheric variables fields in Southwest Asia (Middle East-Iran region); then its application for future studies in this region is assured.

Earthquake descriptions documented in various reports are one of the most important datasets to assess the macroseismic intensity distribution of an earthquake and preparing different intensity maps. This information consists of building damages and earthquake environmental effects as macroseismic data points (MDPs). Extracting the macroseismic parameters of the earthquake will be possible using these MDPs. Each location with any information can be considered as a point of the intensity map.    In this study, Ardekul Ghaen earthquake (10 May 1997) was selected to show the effect of using complete dataset to assess the intensity values and prepare the earthquake intensity map. There are several reports for this earthquake. Researchers in different fields in their reports mentioned to various descriptions of this earthquake effects consisting of descriptions on different types of building damages, descriptions on various environmental effects, and information from people who felt the earthquake. For this study, the descriptions published in different reports were collected separately for the cities and the rural areas (MDPs) affected by the earthquake. Totally, about more than 100 locations with various effects from the earthquake were reported for this earthquake. Since the descriptions of all reports were not complete, the intensity values were assessed using all descriptions reported by different references for each MDPs. As the main dataset of this study is MDPs with their intensity values, complete descriptions of each MDP reported by different references were considered for reassessing the intensity values of MDPs. However, the intensity maps were separately prepared for each selected report using their reported MDPs. On the other hands, depending on the reported MDPs, the intensity maps of each report will be different from others. For this study, to show that the effect of completeness of the earthquake reports on estimating the results depends on their datasets, five reports were selected from different reports published. The intensity maps of this earthquake were separately plotted based on each of the selected reports. According to this study, the best report should be the one with more complete information of each MDP affected by the earthquake. It consists of all descriptions related to the building damages or the environmental effects. Thereafter, the earthquake intensity values can be assessed with more accuracy. Moreover, the intensity map of the selected earthquake will also be plotted with more details. If there are enough MDPs, the macroseismic parameters of the earthquake can be also estimated. More MDPs and complete description for each one, more accuracy and high quality estimations.

One of the most important problems in mining is the flow of groundwater into the pit mines. The location and amount of these waters are often dependent on the permeable zones. Therefore, geostatistical methods can be used to identify these zones. Hence, geostatistical research has been done on variable data of the rock quality designation (RQD) to identify permeable zones in the area of Takht e- Gonbad copper mine pit, Sirjan. This mine is located in Kerman province, northeast of the Sirjan city and it is an open-pit type. A total of 69 exploration boreholes have been dug in the area around the pit. During the drilling, the variable data of the RQD was recorded during a spatial distance of 3 m along the entire length of the boreholes. Identifying areas with high permeability in the rock units of the region, especially in the subsurface of the aquifer, is necessary to carry out the drainage plan in the future. In this research, geostatistical simulation methods have been used to identify permeable zones. The results of the preliminary statistics showed that the RQD has an increasing trend with increasing depth. The spatial continuity of the RQD based on the directional variogram and the spherical model was estimated about 81 meters, and was greater in the east-west direction. Finally, by geostatistical simulation, the areas with high permeability in the region have been determined which are mainly located in the northeast and southwest of the pit.

In this research, we investigate the seismic hazard associated with the Kheyrabad blind thrust fault at the north of Birjand, Eastern Iran. Field measurements from a structural transect through the Kheyrabad anticline indicate fault-propagation folding above a 38° northeastward-dipping blind thrust fault which probably reaches into a horizontal detachment at a depth of ~500 meters. In this research, in order to evaluate the seismic risk of Khayrabad blind fault have been investigated, parameters such as average slip rate, maximum earthquake (Mmax) and its recurrence. Obtaining estimates of the slip-rate on the blind fault, and of the rate of crustal shortening are difficult, but we assume that transport of material on the horizontal decollement at depth is balanced by extrusion of material at the surface, we can produce approximate measurements of slip-rate and shortening by using area balancing. In this method, the rates of fault slip, horizontal shortening, and uplift have been estimated as 0.75, 0.59, and 0.46 mm/yr, respectively. Using the regression equation between earthquake magnitude and rupture area, magnitude of the maximum earthquake is estimated at 4.7. Also, using the empirical relationships between magnitude, coseismic displacement and slip rate, the recurrence of this earthquake is predicted to be 577 years. According to the obtained slip rate (0.75 mm/yr), the activity grade of Khairabad blind fault is considered moderate.

Many examples of tear faults are observed in Tabas block. These faults are usually seen in belts with active folds. In this research, an example of the mentioned faults has been studied. The axis of the Kamarmahdi anticline has a north-south trend. In the north of Kamarmehdi anticline, there is a fault with an approximate trend of N75E which does not have a clear shear sense on the ground, and the geological structures on both sides of this fault are also different. This research has been done to determine the shear direction of the said fault. For determining the shear sense of this fault, a geological map with a scale of 1:1000, was prepared and the boundary of the rock units and the folding axis are taken as a guide to calculate the fault shear direction. The amount of heave (143m) and throw (331m) of fault was determined after preparing the geological cross sections on both sides of the tear fault, using AutoCAD software. By determining the movement direction of the fault, the existence of the tear fault and its displacement has been proven, and the movement pattern of the formation of the tear fault has been presented.

Temperature is a key atmospheric variable and has a direct effect on other atmospheric variables including precipitation. The average global temperature has increased in recent decades, which causes an increase in evapotranspiration, an increase in climate extremes, drought, and wildfires. Examining the performance of different versions of ERA5 can help in choosing the best version of ERA5 in climate studies of the country. This research examines Iran's temperature based on deterministic and probabilistic versions of the ECMWF-ERA5 reanalysis, which replaces the previous releases.

The data used in this study is the average monthly air temperature which we examined in two ERA5 deterministic and probabilistic datasets. To investigate the impact of horizontal resolution on temperature estimation, two horizontal resolutions of 0.25o and 0.5o from the deterministic and probabilistic versions of ERA5 have been used. Also, the multi-member Ensemble of Data Assimilations (EDA) version with a horizontal resolution of 0.5o has been used to compare ERA5 probabilistic dataset versus its deterministic version. Before evaluating the data of three different versions of ERA5, a multi-member ensemble dataset was generated from 10 different members of the probabilistic version of ERA5, which are presented as Member0 to Member9.

The results showed that ERA5 correctly estimates the spatial distribution of average temperature in Iran. However, in Iran's higher latitudes and regions with complex topography, the performance of ERA5 in temperature estimation is worse than in arid and semi-arid interior regions. In addition to the complex topography, the ERA5 performance is affected by certain complex geographical features such as the southern coast of the Caspian Sea. The worse performance of ERA5 temperature in the coastal areas of the north of the country and Zagros may reflect some shortcomings in the accurate representation of the geographical features of these areas, such as the air-sea interaction and the simultaneous interaction of local moist currents with the coastline and the complex topography of Alborz and Zagros.

Comparing different versions of ERA5 with observational data showed that the deterministic version of ERA5 with a resolution of 0.5o systematically underestimates the temperature in Iran, which is -7.41% for the area-averaged of the country. On the other hand, the deterministic version with a resolution of 0.5o overestimates the temperature of Iran by 12.01% in the area-averaged of the country.Examining three different versions of the ERA5 dataset for two deterministic and probabilistic versions showed that the deterministic version of ERA5 with a horizontal resolution of 0.25o with an area-averaged bias of 1.07 oC and a percentage of bias of 9.36% shows the best estimate of Iran's temperature. The monthly distribution of Iran's average temperature based on the ERA5 deterministic version with a resolution of 0.25o showed that the minimum temperature of Iran is -10.49 oC in January and the maximum temperature is 39.83 oC in July. The temperature in all months and the annual average follow the topography in Iran. The minimum temperature is negative in 5 months of the year (January, February, March, November, and December) in Iran.

Rock beds containing plant macrofossils of Norian in Alborz region belong to two stratigraphic units of Lalehband and Shahmirzad. The same beds in Kopeh-Dagh area belong to Mian-Kuhi Formation and in Central Iran belong to Qadir submember in Tabas region and Dehroud member in Kerman region. In general, plant diversity and vegetative cover during the Norian stage is less than Rhaetian especially Jurassic (Shemshak group) and the highest plant diversity of Norian in the Alborz basin is related to the phyllum of Pteridospermophytes (seed ferns) and in the Central Iran basin is related to the phyllum of Pteridophyta (ferns) indicating the higher humidity of the mentioned time in Central Iran basin and the drier climate in Alborz basin. The highest diversity of vegetation in Norian sediments throughout Iran belongs to the seed ferns (Pteridospermophyta) and the lowest diversity belongs to Ginkgophytes so that they comprise 32% (one third of the vegetation) and 6.5% of the total vegetation, respectively. Plant-covered areas throughout Alborz were interconnected during the Norian period and there was no extensive separation between them. The plant macrofossils assemblage in both Alborz and Central Iran basins confirms the relatively humid subtropical to tropical climate for the Norian but less humidity compared to the Rhaetian. Also, the vegetation of Norian in Alborz was less dense and scattered than Central Iran during Norian.

Volcanic rocks with adakitic nature, are outcropped, in the south of Rudbar city as a part of the Alborz magmatic zone and the northern part of the Alborz zone. Most of the rock units in this area are volcanic and pyroclastic belonging to the Tertiary age and specifically Middle Eocene. For this study, we present new data to understand the origin and tectonic setting of the adakitic early Cenozoic magmatism in the southern part of the western Alborz orogenic belt.

Regional Geology:

Based on the 1:100,000 Guilan geological map (Nazari and Salamati, 1998), the predominant geological units of the region include the Paleozoic, Mesozoic, and Cenozoic stratigraphic units. The volcanic activity resulting from the subduction of an oceanic crust beneath the active continental margin of Alborz began in Paleocene and its peak is attributed to the Lutsin period (Nazari and Salamati, 1998).

Following microscopic studies, 11 samples were analyzed at Actlabs Lab in Canada by ICP-MS method. IGPET and GCDKIT software were applied to draw diagrams and interpret the data. Petrography and Whole rocks chemistry The studied lavas consist mainly of dacite to trachy-dacite, rhyodacite, and rarely rhyolite. Abundant plagioclase as phenocrysts and microlites and rare amphibole, biotite, and quartz with hyaloporphyritic, microlithic porphyry to felsitic porphyry and microfelsitic textures are the dominant petrographic features of these rocks. Geochemically, they are characterized by mean value of 61.87 wt%< SiO2<66.54, 1.1 wt%<MgO<2.8 wt%,10 ppm<Y<14 ppm, 1.4 ppm<Yb<1.7 ppm, 450 ppm<Sr<1887 ppm as well as the average amounts of Sr/Y: 103.8, 10.5<(La/Yb)N<14.09 and 5.1<Yb/Lu<6.5. Thus, the overall geochemical data point to HAS characteristics of the rocks under study.  On normalized spider diagram to chondrite, MORB, and primitive mantle, all rocks demonstrate subparallel trend, linear and homogeneous REE profiles with LILE and LREE enrichment together Ta, Nb, and Ti negative anomalies. As the tectonic diagrams display, all the studied samples are plotted in an arc volcanic granite field formed in a subduction environment in an active continental margin. Moreover, all the obtained geochemical data point to a high silica adakitic magma as the parent magma.

The studied area lies in Alborz Mountain, which owing to the collision of two Eurasian and Arabian plates, where a Neo-Tethyan oceanic lithosphere (Southern Caspian Sea Ocean or SCO)” is subducted beneath the Central Iranian continental lithosphere (Salavati et al, 2013), is an active deformation zone. The studied rocks formed in arc and subduction zones setting. Adakitic rocks in the arc setting can be produced by partial melting of a hot and young subducted oceanic slab and subduction of a very young oceanic crust (<5Ma) at depths of about 25 to 90 km is required to produce adakitic magma in the arc setting (Thorkelsona and Breitsprecher, 2005). In the north of the investigated area and south part of the Caspian Sea, an Alpian oceanic belonging late Cretaceous age was reported and named “Southern Caspian Sea Ocean (Salavati et al., 2013), which was subducted toward the south. Adakitic activity and not-adakitic magmatism continued to migrate toward the trench supporting a slab window model. The proposed tectonomagmatic model "Ridge-Trench", indicates that the studied lavas were generated in the Neothetyan supra-subduction zone. Based on this model, in the south of Guilan Province, SCO oceanic crust (and likely its ridge) has subducted towards the south the first because of a pressure change that might be caused by the extension and thinning of the overlying crust. A slab window was formed therefore in the source region, and partial melting occurred by asthenospheric upwelling. It looks like the adakitic rocks imply a deep source with a low magma source melting degree.

The overall petrological and geochemical features of the studied lavas gave rise to the following conclusions A new group of extrusive rocks, with remarkable geochemical characteristics of adakitic rocks, is outcropped in the south of Guilan Province .These rocks are characterized by HFSE and HREE depletion relative to LILE and LREE and negative Nb, Ta, and Ti anomalies, suggesting the parent magmas were affected by subduction-related geochemical processes. On tectonic diagrams, the studied adakitic rocks plotted on an Active Continental Margin setting and they show HAS characteristics produced by 5% to 10% partial melting of an amphibolite garnet source from a hot and young Cenozoic slab subduction. All the geological and geochemical data indicate that the early Cenozoic adakitic magmas in the south of Guilan Province were generated in an extensional tectonic setting (Slab window setting) when the active spreading center of the Neo-Tethys oceanic (Southern Caspian Sea Ocean) subducted toward the south and produced a slab window. According to the proposed model, the active spreading center of the Neo-Tethys oceanic crust (Southern Caspian Sea Ocean) subducted toward the south and produced a slab window in the subducted oceanic lithosphere.

Climate change has significantly increased the frequency and intensity of heat stress and has more effects than increasing average temperature. This study has investigated the spatial distribution of the universal thermal climate index (UTCI) during historical and future periods in Iran. The UTCI (°C) refers to “the isothermal air temperature of the reference condition that would elicit the same dynamic response (strain) of the physiological model” (Jendritzky et al., 2012). In this way, the UTCI is an equivalent temperature, similar to PT. The thermal impact of the meteorological conditions is compared to the one of a standardized reference “indoor” environment with RH = 50% (Ta < 29 °C), WS = 0.5 m s−1, pa = 20 hPa (Ta < 29 °C), and Tmrt = Ta (Shin et al. 2022). Three variables of daily temperature, relative humidity, and wind speed from two sets of data, including 124 meteorological stations and five models from the Coupled Model Intercomparison Project phase 6 (CMIP6) model, including GFDL-ESM4, IPSL-CM6A-LR, MPI-ESM1-2-HR, MRI-ESM2-0, and UKESM1-0-LL were investigated with a horizontal resolution of 0.5o. Then, an ensemble model (CMIP6-MME) was generated from these five models using the independent weighted mean (IWM) method. The performances of individual models and the generated ensemble model were examined by Taylor's diagram. The results showed that the multi-model ensemble has higher performance than individual models for all three variables. The results revealed that the spatial distribution of the seasonal averages of the UTCI index has significant variability in Iran, and the variability of this index is affected by the latitude, complex topography, and distance to water resources in Iran. In general, heat stress will increase significantly in Iran by the end of the century. So, we will witness a significant decrease in areas with no heat stress until the end of this century. On the contrary, strong to very strong heat stress events will increase significantly in the country at the end of the century. While the areas with no thermal stress show a spatial displacement to mountainous regions and higher latitudes. These results show that effective adaptation methods should be taken to adapt to global warming and reduce its consequences to avoid the adverse effect of increasing heat stress events in Iran. The results show the overall increasing trend of Iran's heat stress in the near and far future. The highest increase in heat stress anomalies (13.3 degrees Celsius in winter during the far future period under the SSP5-8.5 scenario) can be found in the northwest and west of the country. The increasing intensity of heat stress in the western and northwestern parts of Iran may be related to elevation-dependent warming (EDW).

Drought is a natural phenomenon that is mainly caused by less than normal precipitation over a long period that occurs in almost all climates. Since the late 1970s, the occurrence of drought has increased globally due to increased evaporation (caused by global warming). This phenomenon occurs slowly and can be short-term or terminated within a few months or continue for several years. drought has increased significantly in Iran in recent decades. The increase in droughts has many negative consequences in different areas of agriculture, water resources, and wildfire. The purpose of this study is to investigate the drought situation in the vegetation areas of Iran using the Keetch-Byram drought index (KBDI). For this purpose, the KBDI drought index derived from the data set of the European Centre for Medium-Range Weather Forecasts (ECMWF) fifth edition (ERA5) with a horizontal resolution of 0.25o during the period of 1981-2020 has been used. Also, the combined product of surface soil moisture (SSM) from microwave sensors AMI-WS (ERS-1 and ERS-2 satellites) and ASCAT (MetOpA-B satellite) with a horizontal resolution of 0.25 o to evaluate the KBDI drought index results as well as the moisture condition. The results showed that the khalij-Omani and Irani-Turani vegetation areas have very low soil moisture and high drought in Iran. The amount of soil moisture in these areas is low and the area-averaged is equal to 12.65% and 18.42%, respectively, which has been somewhat constant in all months, in other words, dryness is the predominant climate feature of these areas. The monthly analysis of the KBDI index shows the spread of drought severity towards the west, i.e., the vegetation area of Zagros, in the hot months of the year. A decrease in soil moisture and dryness can be observed in a major part of Iran from early spring to mid-autumn. Also, in the Zagros region, from mid-summer to mid-autumn, increasing values of the drought index and decreasing soil moisture can be observed. The minimum drought index is in the vegetation areas of Hyrkani and Arsbaran. The correspondence between the results of the surface soil moisture (SSM) of the satellite product and the KBDI drought index obtained from ECMWF-ERA5 shows the appropriate efficiency of the KBDI drought index in identifying drought centers in Iran and investigating the spatio-temporal patterns of drought occurrence. frequent low-intensity drought may favor more drought-tolerant species and adapt forests and grasslands to future conditions without the need for management measures.

Earthquakes with a large magnitude affect people, man-made buildings and environments. This information can be a dataset of the earthquake description consisting of people’s feelings, the building damages, and the effects on the earth. For the building damages, different types of buildings should be considered to find the best dataset of the earthquake. For the effects on the earth, various environmental effects such as the displacements, landslides, rock falls, liquefactions, surface and chemical changes on the rivers and springs, etc. should be considered; more information of more situations, more accurate exports of the earthquake. According to global research in this field, using this information can be useful to assess the macroseismic intensity of the affected areas and the epicentral earthquake. Moreover, having a good dataset of these descriptions, the macroseismic parameters of the earthquake can also be estimated. It can be useful especially for the earthquakes with low or/ and lack of information in the earthquake catalogs and also paleo-earthquakes. This study concentrates on the Tabas earthquake, which occurred on September 16, 1978, in the Tabas region located in eastern Iran. This was a shallow earthquake felt in a region with 1130000km2 total affected area. Such as every large earthquake, several phenomena were observed related to this event. For example, it destroyed 1500 building units and 30 Qantas. Although the epicenter of the earthquake was located in a situation with a poor population, it destroyed or severely damaged 90 villages and slightly damaged other 50 villages. The surface rupture of this event was extended for about 85km with no connection on the surface with a trust mechanism. Moreover, 150cm vertical displacement and 300cm horizontal displacement were reported for this event. According to these descriptions of Tabas earthquake with magnitude more than 6, occurring more earthquakes in the past can be usual for this region; then, more investigation on this field is necessary. Therefore, in this study, primarily investigation on this region was started using the available maps (e.g. geology map) and images (e.g. Landsat) and for the following researches the locations near Ali Abad in NW of Tabas were suggested for the field study and sampling to date their absolute ages.

While temperature is an important climatic variable in the majority of the fields such as hydrological and climatological modelling, spatial and temporal separation of this variable is a weakness all over the world which makes challenges in its usages. Lots of studies have been conducted to solve this problem; using Temperature Laps Rate (TLR) is one popular way to handle this challenge. Although TLR is an effective tool to interpolate temperature,an insufficient number of stations or inefficient spatial distribution of the stations could make calculated TLRs very uncertain. To cope with this discontinuity in temperature, satellite-sensed temperature data have been utilized. In comparison to station-based temperature, satellite-sensed temperature data is a well choice to map the temporal and spatial pattern of temperature in a wide area. With recent developments in Moderate-resolution Imaging Spectroradiometer (MODIS), Land Surface Temperature (LST) data has been successfully employed in several areas such as earth surface radiation, evaporation, urban heat islands, climate change, hydrological modeling, sea surface and air temperature estimation. Iran is located in the arid and semi-arid region that has been always faces with water shortages. This has been worthen with global warming which has caused increases in water demand, too. Thus, having temperature data with good spatial resolution has been always a need and challenge in the area and lots of the fields. In this study, an approach was introduced to estimate TLR utilizing MODIS LST with good spatial resolution. These estimated TLRs were then used to downscale ERA5, CFS, and MERRA2 daily reanalysis temperature data sets to 1 km spatial resolution. The downscaled data was compared with the recorded data at the stations in different climate regions and elevation clusters. The results showed that improvements resulted in all climate regions and elevation levels. On average 15, 18, and 4 percent improvements were seen in RMSE, MAE, and NSE, respectively.

Quaternary volcanic activity, as the last magmatic effort in Iran, is the evolution of large volcanic cones such as Damavand, Sahand, Sablan, Taftan and Bazman, as well as lava flows such as Mako basalts and Lot block. Sablan, a young member of the Cenozoic volcanic complex, belongs to the Alborz magmatic arc (AMA). In Sablan Mountain, there is a collection of volcanic rocks with the composition of andesite, basaltic andesite, dacite, rhyodacite and trachy andesite. The texture of these rocks is mostly porphyritic with microlithic clay, porous porphyritic, sometimes glomeroporphyric, sieve and trachytic. Among the main minerals, plagioclase and one or more mafic minerals such as hornblende and pyroxene can be mentioned. Secondary minerals include opaque minerals, edengsite, chlorite and calcite. In the normalized multi-element diagrams, relative enrichment of K, Ba, Rb and relative depletion of Ti, Ta, and Nb indicate magmatism affected by subduction processes. In terms of the chemical composition of these rocks, the main elements such as K2O, Na2O, MgO, Al2O3, SiO2 Mg# and K2O/Na2O and the composition of rare elements such as Cr, Ni, Yb, Y, Sr, Rb Sr/Y and La/Yb are in the range Adakite stones are placed. In addition, the geochemistry of these rocks, including the concentration of Cr, MgO, Th, Rb, Th/Ce, and K2O/Na2O, is in better agreement with the adakites derived from partial melting of the subducted oceanic sheet. According to the petrographic diagrams, the adakitic magma forming these rocks was formed from the partial melting of an eclogitic source rock or amphibolite garnet resulting from the metamorphism of the subducted Neotethys oceanic plate under Central Iran. Keywords: petrology, PULL PARAT, petrogenesis, Iran.

The Golmandeh Metamorphic Complex is located in the Central East Iranian Microcontinent. In this research, structural and microstructural studies have been performed to determine the nature of the deformation in the Golmandeh metamorphic complex. The presence of microstructures such as mica fish, rotating porphyroclasts, and the S/C structure all indicate the top-to-northeast sense of shear. Based on the dynamic recrystallization studies, the deformation temperature in the Golmandeh Metamorphic Complex is estimated between 500 and 650° C. This condition correspond to amphibolite metamorphic facies. Using the Rigid Grain Net (RGN) method, the mean kinematic vorticity number was estimated to be 0.75. Based on the results of kinematic studies, the deformation regime in the Golmandeh Metamorphic Complex was determined as a general shear with contribution of 55% simple shear and 45% pure shear component.

The city of Ardabil is surrounded by faults, including the large seismic fault of Astara, which throughout seismic history of the region, several earthquakes have occurred along that. The focal depth of most earthquakes is low and close to the surface (5 to 30 km) at Ardabil. In this research, 7 linear sources and 23 regional sources have been identified. After aggregating historical and instrumental earthquake information, the reliability and completeness of the catalog should be evaluated. Due to the lack of reports of small earthquakes in historical data and the new periods of instrumental data, there is always an incomplete seismic catalog for a region. Because the existing catalog covers a long period of time, it contains temporal and spatial heterogeneities. The Stepp method is used to calculate the completeness of the catalog. Most earthquakes in this region have a depth of less than 40 and according to the cumulative distribution diagram, also most earthquakes have a focal depth of less than 20 km.

To carry out this research, the recorded earthquake data of the region taken from 4 sites IIEES, ISC, NEIC and University Geophysics Tehran, and Matlab, Zmap, Kijko and Ez-frisk software were used. Seismic device data used in the region includes details related to the earthquake spring, such as: date, time, latitude and longitude, magnitude and related seismic information, which are used to determine the seismic source of the faults. Data analysis for earthquake risk has been done using Ez-frsik software. In this study, the earthquake catalog for northwestern Iran has been examined in three-time series:A: historical earthquakes (period before 1900 AD); B: Systematic earthquakes of the first period (1900 to 1963) and C: Systematic earthquakes of the second period (1963 to 2020).

Kijko and Sellevoll method was used to determine the seismicity parameters of Ardabil region. This method has useful capabilities in using the list of heterogeneous earthquakes which is consistent with the characteristics of seismic data of Iran. The functions used in the Kijko program include the distribution of final values for earthquakes before the 20th century, which are often large but with high error, and the Gutenberg-Richter function for recorded earthquakes and using the statistical method of maximum likelihood estimation. In this method, it is also possible to simultaneously use historical and recorded earthquakes by making appropriate classifications by considering the magnitude error, threshold magnitude, and maximum magnitude differently for each category. It is also possible to somehow include the effect of seismic absences or lack of information in the calculations. The estimated seismicity parameters, including the maximum magnitude of the earthquake (Mmax), the coefficient β and the annual volume λ in the 100 km area using the Kijko method, are:Mmax=7.7, β=1.86, λ=0.9The probability of the event or return period of earthquakes is another parameter that are calculated by this software. The return period increases greatly with the increase and the probability of an earthquake event decreases in a certain period of time. For example, in a 100-year period, the probability of an earthquake with a magnitude of 6 is 90%.

Graphs show an increase in the return period of earthquakes, so the probability of an earthquake event in a certain period of time decreases. Earthquake risk map for PGA was performed on bedrock with 1% damping for a return period of 475 years in a set of networked points at 0.05 ° × 0.05 intervals. According to the acceleration set for the city of Ardabil, this area is divided into 4 micro-zones. The results show that the acceleration values ​​in this range for PGA vary from 0.19 in the north to 0.21 in the southwest. It should be noted that the acceleration values ​​are the same throughout each designated area, so the city of Ardabil can be introduced as one of the cities with moderate risk in seismic activity.