مجله پژوهش های دانش زمین
پیاپی 55 (پاییز 1402)

The Fars and Hormuzgan Zones is eastern domain of the Zagros Belt which characterized by the outcrops and sub-crops of Precambrian-Cambrian Hormuz Salt. Deep-seated extensional faults played a major role in controlling the distribution and thickness variations of the Hormuz series and played important role in triggering and localizing the salt walls and diapirs This suggests that part of halokinesis could have been localized along the Precambrian-Cambrian extensional faults. Differential loading is the most probable principal mechanism for initiating and driving halokinesis in the Hormuz Salt Basin in Early Paleozoic. Therefore, it is expected that dissimilar types of the earlier salt related structures have their own influences on the geometry of present-day structures. Therefore, objective of this study is understanding role of the Hormuz Salt as basal décollement on long term sedimentation and relatively short term shortening happened by the Zagros Orogeny. The presence of anomalies in buried salt domes plays an important role in this inequality, and for example, sigmoid-shaped anticlines can be mentioned. We used sand box modelling technique for better understanding geometry of the hidden earlier structures which were masked by the Zagros Orogeny.

Sandbox modelling We arranged a sand box model to review structural evolution of the study area. In this experiment, we tried to simulate behavior of a viscous layer representing the Hormuz Salt at different stages (prior to Zagros shortening and simultaneous with it).  This modeling was done with the objective of revealing role of the pre-exist Hormuz Salt bodies in geometry of the study area structures. The apparatus for this experiment is consists of four plates at four side of the sand box with the size of 20 × 25 cm. (figure 9). At the first stage of experiment we attempted to construct two column of Corn starch cream whit 3 cm diameter in sand layer to simulate expected pre- exist Hormuz salt. Three experiments were performed to indicate the effect of anomalies from the moving wall. In all three tests, one of the anomalies (right anomalies) was 10 cm from the wall and another anomalies (left anomalies) were placed at 2.5, 5 and 15 cm, respectively. The distance between two anomalies is 6.5 centimeters. Both anomalies with the same distance from lateral fixed walls. (figure10). Finally pattern of circles overlaid on the flat surface of the last dry sand layer. These patterns were drawn to describe the magnitude and orientation of the strain axes when the reference circle of unit radius is deformed. Total thickness of dry sand layers is 3 cm. In the last stage, shortening applied by the moving wall with a rate of 1 mm/min. This stage simulates superimposition of the Zagros Orogeny on the paleo-structures which were formed earlier than onset of the Zagros movements. The result after applying ~ 16% shortening (4 cm displacement of the moving wall) is shown in figure 10 and 11.

Role of the basal and intermediate detachments of the Zagros Belt in deformation development in form of folds and thrusts have widely been discussed and the Hormuz Salt efficiently controlled fold wavelength in the Fars and Hormuzgan area. For instance, divergence reflectors (growth strata) beneath the syncline between Naura & Firouzabad anticlines denote early Hormuz Salt movement due to halokinesis (Fig. 7).  In addition, pre-exist Hormuz Salt body make weakness area. Deformation at the deeper (beneath the Hormuz Salt) and shallower (above the Hormuz Salt) levels are different. Results of the sandbox experiment confirm this matter as deformation in corn starch cream column and sand. Folding and thrusting happened at both sides of this column zone. In contrast, sigmoidal shape happened.

When the Zagros Orogeny shortened the belt, the localized Hormuz Salt bodies mainly affected geometry of the shallow structures. Therefore, structural evolution of the study area is simply summarized in two pre-Zagros halokinesis and the Zagros shortening stages. In fact, the Zagros compressional forces facilitated salt movement in form of salt diapirs as seen in the experiment. The results of this study also emphasis on importance of pre-exist salt body to unconventional shape folding whit one or both narrow and linear plunges.

The Zagros sedimentary Basin has long been considered by geologists because of the presence of the hydrocarbon reservoirs and source rocks. Variable sedimentology and facies studies in this basin especially in Jurassic and Cretaceous successions have displayed their high potential as hydrocarbon source rocks. The Sargelu Formation is one of these successions that consist of abundant thin-shelled bivalves. Pelagic disarticulated bivalves concentrations in the deep marine sediments have been introduced as filaments that have recorded in variable middle Jurassic sediments around the world. In this study diversity and abundance of the Posidonia-dominated faceis have applied to differentiation of the sub-environments and reconstruction of the palaeoecological conditions of the Sargelu Formation. Because of the importance of the Sargelu sediments as source rocks, the achieved results are useful for reconstruction of the paleogeographical condition and hydrocarbon exploration in the Zagros Basin.  

The studied outcrops of the Sargelu Formation throughout Zagros fold-thrust belt including the Lorestan Zone consists of Tange-Havandeh, Kezi, Dowdan, Bizel, Tange-Mastan and Homajgah. To evaluation and determination of the sedimentary facies and sedimentary environment of the Sargelu sediments, a detailed sedimentary parameters include sediment/package/layers thickness, bedding boundaries (gradational, sharp, erosional), sedimentary structures, variable grain size, type and preservation mode of macrofossils (fragmented, whole, disarticulated, articulated) were recorded in the field. Based on microscopic asses on 500 thin-section, eight carbonate facies were identified in the Sargelu sediments in the studied area. Carbonate facies were classified/named according to Dunham (1962) classification. Identification of the facies/facies associations and their sedimentary environments were based on Wilson (1975) and Flugel (2010) scheme. 

Based on the microscopic and field analysis, eight facies have been identified in the Sargelu sediments that were related to two facies associations including basin to outer ramp of a distally steepened ramp system. Mud-dominated, fine-grained facies (calcareous shale, mudstone, pelagic bivalve wackestone/floatstone) including pelagic and hemi-pelagic deposits were deposited in the basin environment below SWB, characterized by long time of the low sedimentation rate, low water circulation and low oxygen level, displayed by high abundance of the organic material in this sediments (Pomar et al, 2012; Bayet-Goll et al, 2018; Sharafi et al, 2016, 2019). Outer ramp association consists of thin- to medium-bedded dark limestone including abundant Posidonia-dominated shell concentration with sharp-based, chaotic to preferentially parallel bed orientation of the skeletal elements and fining up-ward fabrics. These special features display periodically activity of the turbidity currents during deposition of the shell concentration and higher sedimentation rate and relatively favorable environmental conditions (with respect to the oxygen and nutrients) for the benthic communities, displayed by abundance bioturbation in these sediments.

Facies analysis of Sargelu Formation exposed in Lorestan Zone led to identification of two facies associations, representing basin to outer ramp of a distally steepened ramp system. Basin deposits in central Lorestan Zone include pelagic and hemi-pelagic deposits, displayed by mud-dominated, fine-grained facies. These sediments were deposited in an anoxic to dysoxic, relatively deep, sea-floor environment as revealed by the presence of: a) organic-rich shales and limestones, b) undisrupted lamination in most facies, c) absence benthic fauna. In contrast, Posidonia pelagic bivalves are interpreted as the result of the proliferation of this bivalve during periods of favorable environmental conditions on the sea floor. Thin to medium beds of graded wackestone/packstone to rudstone/floatstone and accumulations of thin shells of Posidonia pelagic bivalves indicate sporadic reworking of the sea floor by turbidity currents. Disarticulation, fragmentation, and reorientation of Posidonia pelagic bivalves can be indicative of reworking, by turbidity currents which periodically interrupted periods of lower-energy suspension sedimentation.

The Kopeh Dagh sedimentary basin is an intercontinental basin formed following the closure of the Paleo-tethys ocean due to a collision between the two continents of Iran and Turan and in has arisen the Early Cimmerian orogenic phase. Deposition of shallow carbonates during the Lower Cretaceous (Barmin-Apsin) in the Kopet Dagh sedimentary basin has been introduced as the Tirgan Formation. This formation is located in three studied sections on the Shurijeh detrital siliceous formation and below the limestone-marni formation of Sarcheshmeh.

In this research, this formation uses petrographic studies and geochemical analyzes to evaluate the sedimentary model, primary carbonate mineralogy and diagenetic processes in Shirvan (197.7 m), Quchan (464.4 m) and Chenaran (127.8) sections. 720 thin sections were prepared for petrographic studies. To separate ferroan calcite and dolomite from nonferroan samples, the samples were stained with potassium ferrocyanide solution (Dickson, 1996). In order to name carbonate rocks, the method (Dunham, 1962) and detrital rocks, classification (Folk, 1980) were used. The method (Flugel, 2010) was also used to interpret the facies and present the sedimentary model. For geochemical studies, 41 samples were analyzed by ICP-OES method in Iran-Karaj Mineral Processing Research Center (Emidro Company) for elemental analysis and by ICP-MS method in Science Laboratory Center of Ottawa University of Canada for carbon isotope and oxygen.

Petrographic studies led to the identification of 18 microfacies that were deposited in four facies belts open marin, lagoon, Barrier and tidal flat. The frequency of tidal facies along with barrier facies and the absence of large reef barrier and turbidite sediments indicate the deposition of this formation in a ramp system with a carbonate slope. Diagenetic processes in this formation include: cementation, micritization, dissolution, compaction, dolomitization, fracture, stylolitification and silicification. The abundance of skeletal and non-skeletal components of calcite along with calcite cement, abundance and presence of dolomite with high content of stransiom refers to the initial mineralization of calcite in the carbonates of Tirgan Formation in time. Also, the values ​​of major (Mg, Ca) and minor elements (Sr, Na, Mn, Fe) and the isotopic range of oxygen 18 and carbon 13 of the limestones of Tirgan Formation, also indicate the composition of primary calcite mineralogy in these areas. This value also shows the impact of the burial diagenesis environment on these deposits in a semi-closed diagenesis system with a low water-to-rock ratio. The average diagenetic temperature of seawater at the time of sedimentation of carbonates of Tirgan Formation using the heaviest oxygen isotope in calcareous samples is estimated to be 18.21 ° C.

Comparison of the data obtained from the three studied sections and the information provided from the eastern and western regions, shows an increase in temperature and thus an increase in strontium to the west, which it is indicates a change in the mineralogical composition from calcite to aragonite from east to west basin

Qarah Gol study area is located in Ahar- Arasbaran metallogenic zone in Ardabil province, 50 km from Meshginshahr city in Moradloo section. According to field studies, the main exposed rock units in the region include volcanic, plutonic and pyroclastic igneous rocks, microdiorite masses have injected into volcanic and igneous rocks and caused alteration and mineralization on a weak scale. Mineralized silica veins are often formed in parallel band and are sometimes seen as stockwork veins. In the subduction zones, productive, semi-productive and fertile magma are found together, and the identification of these masses is very important from the point of view of exploration. Fertile granitoid magmas are generally formed in pre-collisional subduction setting (Gammons and Williams Jones, 1997; Li et al, 2016; Shafiei et al, 2009; Shahabpour, 1992). While productive granitoid magmas are formed in post-collision tectonic setting (Li et al, 2016). Many processes have been proposed for the origin of granitoids in collisional or accretionary orogenic environments, it is thought that the melting of young thickened mafic lower crust or the partial crystallization of hydrous basaltic magma is the key factor in the production of various types of productive magmas, While partial melting of the young thin mafic lower crust is considered as a process that can produce fertile magmas (Hollings et al, 2005).

In this research, 14 thin sections of surface samples and 28 thin sections of drilling cores were prepared for the petrologic study at Mineral Research and Processing Center. To determine the texture and paragenesis of ores, 30 polished thin sections and 20 polished sections of the samples were prepared. The rocks collected from surface samples and drilling cores were analyzed in order to investigate rare earth elements, 23 surface lithogeochemical samples were studied by ICP-MS. method. Also 14 core samples were studied by XRF for main oxides.

Productive granitoids in the UDMB display lower values of Ni (9–31 ppm) and Cr (14–36 ppm) than barren granitoids (Ni = 11–73 ppm; Cr = 21–81 ppm)) (Sepidbar et al, 2018). The low values of Ni (5–19.6 ppm) and Cr (14–30.2 ppm) in the igneous rocks of the Qarah Gol are comparable to their values in other productive magmas in this belt and indicate that this magma originates from partial melting of the thick lower crust. Also, the productive magma has a higher LREE/HREE ratio than the barren magma, which is also seen in the samples of Qarah Gol area. In productive magmas, pattern of trace elements normalized to N-MORB is characterized by enrichment in Cs, Rb, Ba and Pb and depletion in Nb, Ta, Th, Zr, Hf and Ti. In fact, productive porphyries, unlike the barren type, usually show negative anomalies of Nb, Ta and Ti. This process shows that garnet is present as a residual phase in the magma chamber of origin of the rocks and indicates the formation at a pressure (>15kbar) equivalent to a crustal thickness of 45-55 km (Palin et al, 2016).

According to geochemical results, the average concentration of copper is 138.21 ppm. Petrological observations and geochemical data show that the graniteoids of Qarah Gol area are calc alkalines type I related to subduction zone which is linked to porphyry copper mineralization. To identify the tectonic environment of the study area, diagrams of La/Yb versus Th/Yb and ZR3-Nb50-Ce/P2O5 can be used. These results show that the study area is located in post-continental collision. Also, the use of La / Yb versus Sm / Yb diagram shows that the samples were made from partial melting of 10 to 20% garnet peridotite. Based on Ce against Ce / Yb diagram, the melting depth of 100 to 110 km is estimated. Productive magma has a higher LREE / HREE ratio than barren magma, which is evident in samples of the Qarah Gol area. The values of Eu / Eu* igneous rocks in the range of Qarah Gol are between 0.7 to 1.07 and in this respect it is similar to the magmas that produce in the Urmia-Dokhtar belt.

The Asmari Formation in southwest Iran is the youngest and most important hydrocarbon reservoir in Iran. Asmari Formation in Ahvaz oil field in the studied wells consists of limestone, dolomite, dolomitic limestone, sandy dolomite and sandstone, siltstone and shale. Asmari formation in Ahvaz oil field is divided into ten zones in terms of stratigraphic characteristics (Mc Coard, 1974). Diagenetic process along with sedimentary processes are considered as one of the main processes controlling reservoir quality in carbonate reservoirs of the world (Schlager, 2005; Ahr, 2008). In some cases, similar facies are subjected to similar diagenesis processes and have similar reservoir quality and produce similar rock types, but most of the time due to the high impact of diagenetic processes the porosity-permeability distribution in these reservoirs is completely reversed (Gomes et al, 2008). Therefore, it is necessary to carry out detailed diagenesis studies and investigate the effects of diagenesis on reservoir changes and evolutions in all systematic and fundamental studies of carbonate reservoirs and hybrid reservoirs (Lucia, 2007; Ahr, 2008).

This study was conducted on wells No. X, Y and Z of Ahvaz oil field. In this study, 1100 thin sections of the drilling cores of the mentioned wells were studied. The types of facies and their governing diagenesis processes have been identified using microscopic thin-section studies of drill cores. Types of microfacies were named based on Dunham's method (Dunham, 1962). Wilson's classification (Wilson, 1975) and Buxton and Pedley (Buxton and Pedley, 1989) were also used to determine the sedimentary environment of microfacies. In order to distinguish limestone from dolomite, all thin sections were stained with alizarin red solution according to Dickson's method (1965). From digital well and porosity data (resulting from helium gas core testing) and core permeability (resulting from mercury saturation core testing) in order to distribute different units (reservoir and non-reservoir) in the studied wells and drawing the two-dimensional model of their distribution using Geolog, Excel software was used. In this discussion, firstly, the most important diagenesis processes affecting the reservoir changes and evolutions of the Asmari formation in Ahvaz oil field are discussed, and then the distribution of different reservoir and non-reservoir units in wells No Z, Y, X of this field was studied using flow hydraulic units in any rock type. Finally, the control of diagenesis processes on the distribution of these units in different parts of this formation has been discussed.

Most of the diagenesis processes of the Asmari Formation in the studied field (especially the types affecting the reservoir quality) have occurred under conditions where the diagenesis environment was affected by the sedimentary environment. Dissolution and dolomitization, which have been widely occurring in the studied facies, have played the greatest role in increasing the reservoir quality. These two processes, the development of which depended on the sedimentary environment, are the most important diagenetic processes controlling the reservoir quality. Dolomitization in the Asmari reservoir is very early and late diagenetic processes that and has had a dual effect (constructive and destructive) on the reservoir quality of the Asmari Formation, raising the reservoir quality in the limestone and in the Sandstones are in the form of cement and have lowered the quality of the reservoir. Although the carbonate cement appears to fill the voids in the rocks and reduce their porosity, it has a positive effect on the reservoir quality due to the fact that it occurs continuously immediately after deposition and prevents compaction in the facies. Anhydrite cement is the most important diagenetic process with a negative impact on reservoir quality. The expansion of coarse-grained clastic facies are the best reservoir-prone facies, and the diagenesis processes of these facies have been mainly affected by their sedimentary environment. Based on this, environmental conditions can be mentioned as the main factor controlling the reservoir quality. In the studied field, the higher the lateral expansion and thickness of the sandstone facies, the better its reservoir quality. The contribution of environmental conditions in controlling the reservoir quality of carbonate facies is less than that of clastic and mixed facies, but due to the early diagenesis of most of the diagenesis processes in these facies, the superior role of environmental conditions in controlling the reservoir quality is evident.

In the survey, eight hydraulic flow units were identified, the best of which are the 7th and 8th hydraulic flow units. These hydraulic flow units correspond to the rock type of loose sand. The worst hydraulic flow units 1 and 2, which corresponds to the dolomudstone rock type.

Aland Chai basin which is located in Khoy County and North West of Iran is one of the high erodibility susceptibility basins due to its unique topographic location and receiving appropriate rainfall throughout the year, especially in spring. The primary purpose of the present study is to investigate and analyze the role of hydrogeomorphic indicators in the sensitivity to erodibility of the sub-basins of the Aland Chai basin located in Khoy County. For this purpose, 12 hydrogeomorphic parameters including Drainage density, Stream frequency, Bifurcation ratio, Drainage texture, Texture ratio, Infiltration Number, Compactness coefficient, Elongation ratio, Circulatory ratio, Form factor, Relief, and Gradient have been used. Study Area Aland Chai basin with an area of 1147.30 km2 is located in the Northwest of Iran and the Western Azerbaijan province. This basin is located between 38°- 30¢-14² and 38°- 48¢-22² N and between 44°- 15¢- 13² and 45°- 01¢-02² E. Basin elevation variations are from 1093m in the Aland Chai River bed to 3638m above sea level in the Avrin Mountain. This basin is one of the sub-basins of the Aras River basin, which surface water flows into the Aras River after joining the grand Qotour River.

In the current study, a geomorphometric ranking method was used considering two groups of hydrogeomorphic parameters to rank the parameters. The first groups are the parameters that have a direct relationship with the erodibility of the sub-basins. These parameters include Drainage density, Stream frequency, Bifurcation ratio, Drainage texture, Infiltration number, Relief, and Gradient. The second group includes 4 parameters of Compactness coefficient, Elongation ratio, Circulatory ratio, and Form factor, which have an inverse relationship with erodibility sensitivity. Next, in order to standardize the geomorphometric rating of each of the parameters, equation 1 is used for the first group and equation 2 for the second group. Equation 1) .Equation 2)

Hydrogeomorphic analysis of basins plays an important role in analyzing the hydrological behavior of basin. In this study, 12 hydrogeomorphic parameters were analyzed from three aspects of drainage network characteristics, shape parameters, and relief characteristics of the basin in order to investigate the role of these parameters in the sensitivity of the Aland Chai basin to erosion. In the next step, the information of each sub-basin based on 22 hydrogeomorphic parameters were prepared using the geomorphological laws of Horton, Schumm, and Strahler in ArcGIS software. In the following, the final map prioritizing the sub-basins in terms of sensitivity to erosion in 5 classes of very high (<43), high (39-42), medium (33-38), low (30-33) and very low (>30) sensitivity was prepared.

The results of erosion susceptibility of sub-basins using hydrogeomorphic parameters also showed that 5 sub-basins (sub-basins 1, 2, 3, 4, and 11) have high susceptibility. Land use changes were investigated in the Aland Chai basin between 1985 and 2020. To prepare a land use map, Landsat time-series images and supervised classification method with Maximum Likelihood Algorithm in ENVI software were used. The results of this part of the study showed that the area of ​​the Rangeland had a decreasing trend between 1985 and 2020. In contrast, with the physical development of Khoy and Firouraq cities during the statistical period under study, we are witnessing an increasing trend in the area of ​​built-up areas. Agricultural and garden classes have also increased in 2000, 2010, and 2020 compared to 1985, but the largest increase in agricultural land and garden area is related to 2000. From 2000 with the physical development of Khoy city (development of settlements and facilities) and the expansion of surrounding villages and the integration of some villages with Khoy city (such as Badal Abad village) and the conversion of agricultural lands into urban areas, we see a downward trend in agricultural lands and gardens. The study of the relationship between land use changes in each sub-basin and their erodibility showed that in the sub-basins upstream of Aland Chai basin, land use change (an increase of agricultural lands) or inappropriate and excessive use of area capacity, it is effective in intensifying erodibility of sub-basins.

Seismic hazards have always been a growing concern because of the potential consequences in urban areas. However, seismic assessment needs to focus on vulnerable areas of cities. Urban-scale seismic risk assessment is an essential activity to assess the potential consequences of large earthquakes. This method includes a series of systematic research steps that begin with the identification of seismic hazard, continue with the assessment of the vulnerability of buildings and end with the development of hazard plans and appropriate mitigation plans. The Impact of Seismic Scenarios on the Ardabil City, the ultimate goal of this study is to provide up-to-date information on the seismic vulnerability assessment of the urban operational plan. The main goal of the action plan is to provide a rapid and effective response that minimizes potential damage to people, property and the environment, and returns basic services to people in the shortest possible time.

In this study, a method based on the vulnerability index has been used to assess the expected damage in Ardabil. This method introduces a vulnerability index to display and determine whether a building belongs to a particular vulnerability class. This method uses the mean of quasi-experimental vulnerability functions, which for a given vulnerability index is strongly associated with seismicity and expected damage. Risk analysis for seismic scenarios defined by seismic intensities V, V-VI, VI, VI-VII and VII has been performed to design seismic emergency plans. According to the country's seismic Codes, the basic peak ground acceleration for a 475-year return period is 0.04 g, which corresponds to an intensity of VII. Thus, the expected physical damage is quantified and its impact on population and other quantities, such as debris and economic cost, are studied.

High vulnerability causes significant direct physical damage to buildings, even for low-intensity earthquakes. As a result, the expected physical damage in the case of moderate earthquakes is significant. For a magnitude V earthquake, the damage is not expected to be significant, but for a magnitude VII scenario, all five areas and the dilapidated textures within them will experience a level of damage that is slightly higher. Among the five urban areas, Region 2 will have the greatest economic impact due to its high-altitude density, and will cost approximately 261 billion rials for the VII intensity scenario. The economic impact of the earthquake for the five regions is from 101 billion rials for the earthquake with magnitude V-VI to 844 for the earthquake with magnitude VII. Due to the impact of a seismic crisis, there is a significant volume of expected debris production. In addition, under such circumstances, 29% of the total citizens of Ardabil become homeless.

The city of Ardabil is in the range of moderate to high seismic hazard, which in the current seismic norm of the country has been identified by a specific earthquake with a magnitude of VII and a related acceleration of 0.04g. The city and its environs have a relatively high seismic risk, mainly due to the large population and old and vulnerable buildings. Vulnerability of buildings in Ardabil shows an average value of 0.59 for concrete buildings and 0.93 for masonry buildings. Therefore, masonry structures are predicted to have a higher degree of damage, because the pattern of vulnerability is transferred to the pattern of damage. The vulnerability index of regions 1 (0.950) and 3 (0.850) is higher than other regions. On the other hand, due to the increase in infrastructure and services in areas, one to four vulnerable elements are constantly increasing. Therefore, the only way to reduce seismic risk with a vulnerability reduction approach is through strict measures of seismic regulations and raising public awareness.

Considering that local satisfaction is closely related to viability it can be expected that the environment and neighborhood relations in the neighborhoods of Tabriz have a significant impact on viability. Therefore, in this study, satisfaction with the urban environment and neighborhood relations in urban areas as factors affecting viability in the city of Tabriz has been studied. In this regard, the improvement of urban environments should be prioritized in a way that increases access to urban facilities and encourages residents to interact with each other. Considering that the neighborhood relations factor is known as an influential factor on viability, at present, this research presents an empirical analysis of the city of Tabriz. Tabriz is an example of a city that has experienced rapid urbanization and is becoming a model of development for many cities in Iran. Reflection on the factors affecting the residents' satisfaction with the viability of the city of Tabriz can have important consequences for many developing cities in our country. Therefore, to fill the existing knowledge gap, research questions are posed as follows: 1) How do satisfaction with the urban environment and neighborhood relations in the neighborhoods of Tabriz affect the viability? (2) What is the relationship between the neighborhood in terms of the mediating effect between satisfaction with the urban environment and viability?       

This article has been done using descriptive-analytical and survey method and using library and field tools. The data collection was done with a questionnaire, the statistical population of the eight city of Tabriz zone is 29384 people based on the statistical yearbook of 2016 and the sample size was 379 people, which was obtained based on Cochran's formula. In addition, respondents were randomly selected. Survey questions were created and modified based on a review of previous studies. Items were ranked using a five-point Likert scale. First, satisfaction with the urban environment was ranked in terms of accessibility, pleasantness and safety. The access factor was measured through the level of satisfaction with access to public institutions, cultural facilities, commercial facilities and medical facilities. Access was assessed for human perception and emotion. The pleasant factor was also measured in terms of satisfaction with green parks and the surrounding natural environment. The safety factor was measured in terms of safety from natural disasters, crime, etc. According to previous studies, the section on neighborhood relations included questions about the reliability of relationships between neighbors and the repetition and quality of their social interactions, and so on. In this study, accessibility, pleasantness and safety, which are sub-components of urban environmental satisfaction, were organized as exogenous variables, while neighborhood relations were classified as a mediator and viability was considered as an endogenous variable. All analyzes were performed using SPSS and AMOS software. On the other hand, structural equation (SEM) can determine the direct and indirect effects on the dependent variable. At this time, the indirect effects can be calculated by the mediator.

The results showed that by comparing the total effect of each factor on viability, the access factor had the greatest impact. In addition, the indirect effect of neighborhood relationships between safety and viability was found to be greatest. This means that greater satisfaction in neighborhood relationships can increase the impact of safety on viability. It was also found that the higher the satisfaction of the urban environment, the more positive effect it has on viability.

Therefore, in order to improve the quality of viability in the city of Tabriz, more attention should be paid to satisfaction with the urban environment and neighborhood relations.

Investigating the geomorphology of glaciers and the changes in their past climatic conditions is one of the major topics of mountainous territories. The border areas of Iran and Iraq, which are located along the Mako-Bane Mountain range, have many evidences of glacial traces; But due to the border and security situation and the difficulty of commuting, it has been far from the eyes of researchers. This research has been done to investigate the evidence of glaciers in the past climate of Kona Goorg valley in the northwest of Piranshahr by using field observations and laboratory work and reconstruction of temperature and precipitation. Also, the identification of the sequence of new and old terraces in this area and their comparison and correspondence with the terraces of the Zevka river, the main branch of the Little Zab river, have also been investigated.

The data used in this research included topographic maps, Landsat 8 images, climatic data, field observations and sampling. The studied area and elevation data were measured and extracted from 1:50000 topographic maps and during repeated visits with GPS. There were 4 general stages of field operations. The first stage of the field visit includes: identifying and recording the location of landforms, extent of glaciers, identifying evidence of glaciers such as cirques and glacial valleys, moraines and their extent and on the edge of the valleys and taking photographs. has been in the second stage, sediment samples were taken from the Kona Goorg valley and photographed. The third stage was the collection of rock samples, completion of field data and evidence of glacier activity in the Quaternary.

The results obtained by Porter's method, the snow-boundary area of the region is 2563.6 meters, and with the method of the maximum height of lateral moraine, the height is 2571 meters. The temperature and precipitation anomalies are 6.45 degrees Celsius and 233.8 mm, respectively. Granulation of the samples, where coarse and medium gravel make up the largest percentage. XRD test showed that chlorite and illite minerals are the most abundant in the surface sample and kaolin mineral is more abundant in the deep sample. Glacial evidences include layers and outcrops of Brecia stone on the edges of glacial valleys in the form of antidotes, the side moraines are stretched up to a height of 2272 meters. The glaciers in the form of new terraces, which are probably related to the Wurm period, are located on both sides of the valley at a lower altitude, and the old terraces are located at a higher altitude (2606 meters) with a difference of 60 to 80 meters from the valley floor. have height A mass of cemented glacial deposites was observed in the left part of the glacier valley with a length of 570 meters and a width of 180 meters, which probably belongs to the older ice ages. The northern valley of the region extends to a height of 2720 meters and the southern valley to a height of 2686 meters and has preserved its U-shaped shape to some extent. One of the main property of Kona Goorg cirques is its elongated shape. In the northern valley, they extend from an altitude of 2720 meters to an altitude of 2900 meters, with a length of 600 to 700 meters. Three alluvial terraces have been identified on the edge of the river.

In general, evidences and effects of glaciers related to paleoclimate in the study area show that the study area was affected by glacier activity in the late Pleistocene and even in the Holocene. The mountain slopes and especially the edges of the valleys are covered with a huge amount of glacial deposites. Numerous field visits clearly revealed the existence of a sequence of glacial periods. The remains of terraces and glacial drifts at lower altitudes than the glacier cirques show three cross-sections of slope change, which in some slopes are cemented glacial deposites in the middle of piles of new moraine, it has an exterior. These conditions are consistent with the alluvial reservoirs (glacial melt water) of the main branch of the Little Zab river near Mashkan village. These terraces are in line with the findings of Jedari Aywazi's research on the rivers of the lake Urmia basin, which all have 3 to 4 alluvium terraces. is correspond. The granulation and XRD test of the glacial sediment samples confirmed the poorly sorted, angularity and superior volume of the gravel sizes, which is indicative of severe physical weathering. Putting these data together with the reconstruction of temperature and precipitation is indicative of the changes. An increase in precipitation and a decrease in temperature in the past compared to the present.