فهرست مطالب abbas charchi

Kupal Oil Field is one of the important oil fields in the Zagros Basin, located in the eastern part of the Dezful embayment, adjacent to Aghajari Oil Field and Marun Oil Field. Some characteristics of the fold elements, such as the fold interval angle and axial surface, were determined in the Asmari folded horizon using the interpreted seismic profiles. Based on the deviation of the axial surface from the vertical surface and determination of shear angle and shear strain, minimum and maximum quadratic stretch and strain ratio (R) values were calculated in different parts of the anticline. With application of graphical functions the amounts of fold aspect ratio were determined along the anticline. Base on the results, the amounts of shear strain varies from 0.01 to 0.09 in deferent parts of anticline. Also results show the amounts of strain ratio in range of 1.25 to 1.38 and shortening about 5% to 17% in different parts of the kupal anticline oil field.

Issues related to air and aerosols have been one of the major environmental problems for the people of the world and the region in recent years. The present study was conducted with the aim of investigating suspended particles on the surface and vegetation of Khuzestanprovince in the period from 2000to2020.In this regard, in order to achieve the goal of the research, three aerosol optical depth products AOD,vegetation index product NDVI and land surface temperature product LSTwere used and the relationship between these parameters was investigated.The results obtained for the time period of the research show an almost similar general trend for all four periods.The results show that in the very low class, low AOD values ​​are associated with high vegetation values. For the low class, the area of ​​the AOD index has increased, but still the vegetation has a larger area percentage.
In the medium class, with the increase in the area of ​​the AOD index, the area value of the vegetation index has decreased greatly, and the area value of the average temperature class shows a slight increase. For the high class, the area value of the surface temperature index is higher than the AOD and vegetation indices. Finally, in the very high class,

Determination of crustal direction and velocity movement is important for understanding the recent strain fields and tectonic events. Different global tectonic models have been suggested for direction and velocity study of crustal movement. In this research using Nuvel1, GSRM and ITRF models the crust movement velocity and movement direction have been mapped for Borazjan fault system. In order to comparison the result of global models with recent strain fields the results of twelve earthquake focal mechanisms evaluated for Borazjan fault system. Comparison of fault slip direction data in the Borazjan fault system with the ITRF, GSRM and Nuvel1 models reveals 58.3, 25 and 16.7 percent similarity respectively. Therefore, it can be concluded that the ITRF model has more adaptation to the slip direction in the Borazjan fault system than other models. Therefore, it can be concluded that the ITRF model has more adaptation to the slip direction in the Borazjan fault system than other models.

The only outcrop of Asmari formation in the Dezful embayment is visible in the Asmari anticline. In order to estimate the strain parameters and shortening values, 26 geological cross sections were prepared perpendicular to the anticline axis. Based on the, interlimb angle measurements, the interlimb angles of the northern and central parts of the anticline show smaller angles than the southern parts. Determination of strain ratio (R) values indicates the strain values between 1.12 - 1.52. The zoning map of strain ratio values shows higher strain values in the northern and central parts of the anticline. Using geological cross sections and measuring the base length of the folded layer of Asmari formation (L0) and the straight length of the layer (L1), the percentage of shortening values were calculated in each section. The results show the occurrence of 1.8% to 12% shortening in different parts of the anticline. Shortening map of the Asmari anticline shows more shortening amounts in the northern and central parts of the anticline than the southern parts.

Proper water resources management relies on recognizing and evaluating the factors affecting the quantity and quality of the water resources. In the present study, the hydraulic relationship between the karstic structures of the Izeh territory located has been assessed using hydrogeochemical and isotopic information of water resources. To investigate the number of 31 water samples (17 wells, 8 springs and 6 rain samples) in the areas of Kamarderaz, Mongasht, Shavish-Tanosh, Anticlines and the Naal-e-Asbi (Horseshoe) Syncline were taken on June 1398 and June 1400, and hydrogeochemical as well as isotopes δ18O and δ2H were examined until to the hydrogeological and hydraulic behavior of this complex karstic system. The results of hydrogeochemical analysis of the specimens showed that the concentration of ions is influenced by the dissolution of calcareous rocks. The isotopic content of groundwater samples is from 5.62 to 3.49- ‰ and from 20.97 to 12.29- ‰ for δ18O and δ2H. Investigating the isotopic content of water wells and springs of the region indicates three groups of water. The first group of indentation springs is fed from altitudes and snow from altitudes. Fast water in the canal system caused a low latency in these springs. The second group is enriched more than the first group, and in addition to precipitation, the mixing of underground water is also effective in providing their water. The third group has longer than other samples due to evaporation and distances longer than the feeding site and the enrichment system. The decrease in Sr+2 and incremental Ba+2 of dolomitic limestone samples (Shavish-Tanosh and Mongasht) to water samples of chemistry and hinges, as well as structural and isotopic data indicate the probability of nutrition. The karstic aquifers of the region are from the anticline, as well as the hydraulic relationship between these structures.

With the formation of plate tectonics theory, it became possible to describe many geological phenomena. During the development of this theory, many scientists and researchers tried to use different methods to quantitatively and qualitatively express the amount and direction of crustal motion. Determination of crustal direction and velocity movement is important for understanding the recent stress and strain fields and tectonics events. Different global tectonic models have been suggested for study the direction and velocity of crustal movement. In this research using global plate motion model (NUVEL1), international terrestrial reference frame (ITRF) and global strain rate model (GSRM) models the velocity and direction mapped for Khuzestan province. In order to comparison the result of global models with recent stress and strain fields the results of twenty earthquake focal mechanisms evaluated for Khuzestan province. The results reveal that the direction of crustal movement shows the best correlation with ITRF global model. Therefore, the ITRF global model can be introduced as more valid model for obtaining and analysing data in the future studies.

In the present study, an attempt has been made to identify the seismic risk zoning of Khuzestan province due to its location in the seismic state of Zagros. To achieve the desired goal, geological data, analytical hierarchy process (AHP), and GIS decision support system was used. The information layers used in this study were: digital elevation models (DEM), land slope, faults density, earthquakes density of the last 20 years, the distance of faults (buffer), the distance of earthquakes of the last 20 years (buffer), and interpolation (IDW) layer of earthquakes of the last 20 years’ province. The results of this study that the northeastern and northern parts of Khuzestan province have the highest seismic risk that the cities of Masjed Soleyman, Andika, and Izeh have high earthquake potential, Dezful, Lali, and Gutvand have moderate earthquake potential. A few cities such as Ahvaz, Abadan, and Dasht -e- Azadegan plain have low earthquake potential. The earthquakes of the last 10 years in Khuzestan province also showed good overlap with high-risk points. The reason for the high risk of earthquakes in these areas can be considered as the existence of many faults, many human activities such as dam construction, extraction from groundwater aquifers in areas with active faults, and the release of seismic energy of active faults.

The faults and fractures play crucial roles in conducting groundwater flow and providing high recharge zones for aquifers. The hard rock formations are exposed on the ground surface of the west of Yazd Province in Iran and build a reliable groundwater source for consumption. This study aims to provide a hydro-tectonic conceptual model of the region using remote sensing techniques and GIS. The geological map, groundwater resource data, geophysical reports, hydrogeological reports, and Landsat ETM satellite images are collected and evaluated by field visits. The lineaments densities of the area have been extracted and projected on various maps. The results demonstrate that the likelihood of groundwater flow is correlated positively with the region's main geological structures and groundwater resource availability. Finally, to conclude, the hydrotectonics model of the area consists of several distinctive and non-distinctive aquifers because of the presence of hydrogeological and tectonic barriers, water-conducting passages, and even neutral fractures.

In this research, seismotectonic analysis has been done Guriyeh area (subsidiary of Shooshtar city, Khuzestan province, Iran) with radius of 25Km. In this research, nine months of Guriyeh earthquake swarm from 2017-11-15 to 2018-7-20 has been studied. The main purpose of this study is to provied evidences to prove the activity of new seismic trends and finally, the need to strengthen historic and dilapidated buildings in this area. Seismogenic history, field evidences, epicenter locations (in the form of seismic bunch) and their migration trend toward Southwest (N30E), indicate the activity of Northeast-Southwest seismic trend in the vicinity of Northwest-Southeast seismic trend (Zagros trend) and their conformity with location of surface and subsurface faults in this region. It also expresses the focal mechanism provided for earthquakes in this region, the compression mechanism and some cases with oblique right-slip component, for faults causing seismogenic in this area. The main collected evidence indicates reactivation of Sardarabad fault, subsurface fault(UGC-FAULT) and magnetic lineament (MGL-1). To continue, seismic hazard analysis has been done using deterministic approach for this region, and maximum seismogenic power (MSmax), 7.14 in Richter scale for the subsurface fault(UGC-FAULT) and peak ground horizontal acceleration(PGA)of 0.27g for the magnetic lineament (MGL-1) were calculated.

The faults and fractures play crucial roles in conducting groundwater flow and providing high recharge zones for aquifers. The hard rock formations are exposed on the ground surface of the west of Yazd Province in Iran and build a reliable groundwater source for consumption. This study aims to provide a hydro-tectonic conceptual model of the region using remote sensing techniques and GIS. The geological map, groundwater resource data, geophysical reports, hydrogeological reports, and Landsat ETM satellite images are collected and evaluated by field visits. The lineaments densities of the area have been extracted and projected on various maps. The results demonstrate that the likelihood of groundwater flow is correlated positively with the region's main geological structures and groundwater resource availability. Finally, to conclude, the hydrotectonics model of the area consists of several distinctive and non-distinctive aquifers because of the presence of hydrogeological and tectonic barriers, water-conducting passages, and even neutral fractures.

The effect of Shushtar fault in the northern Dezful Embayment cases to several geomorphologic features that can be used to identification of geology and morphotectonic properties of the this fault. The Geomorphic indices including mountain front sinuosity (Smf), valley floor width to valley height ratio (Vf), basin shape index (Bs), stream length–gradient index (SL) and basin asymmetry index (Af) have been calculated for determination of various tectonic activities along the Shushtar fault. The mountain front sinuosity (Smf) index was calculated about 1.007 to 1.584 respectively in the active and inactive parts of the Shushtar fault. The stream length–gradient (SL) index was calculated between 898.11 in the high active tectonic and 242.8 in the low active tectonic parts of the study area. The basin shape (Bs) index has been calculated between 9.62 for the very active parts and, 2.04 for the low active parts of the fault. The amounts of valley floor width to valley height ratio (Vf) index show the range between 1 to 10.5 in the active parts with V shape valley morphology and inactive parts with U shape valley morphology respectively. Also the basin asymmetry index (Af) was calculated between 359.3 in the high active tectonic and 3.7 in the low active tectonic parts of the study area. With application of the GIS techniques and the overlaying the Smf, Bs, Vf, SL and Af data layers the area was divided into three different tectonic zones and quantitative active tectonic zoning map was prepared for the study area. In this active tectonic map, classes 1 to 3 respectively show the highest to lowest tectonic activity along the Shushtar fault. Results reveal that the Shushtar fault in the central and northwestern parts shows the medium tectonic activity and in the southeastern parts shows the low tectonic activity manner. Also results show the high tectonic activity in the some northwestern parts near the Shushtar city.

The calcareous terrain of Ilam-Sarvak Formation at Leylia-Keynow Anticlines in the northeast of Khuzestan province has formed a very rich karst aquifer under the influence of geological structures. Many dolines at the heights of these anticlines, and also karstic springs such as Sousan spring with super-high discharge, springs of Tange-Sard and Dare-kool with a relatively high discharge indicate that the regional karst is well developed. Studies of geological structures show that the study area is affected by the basement faults of the Izeh and Balaroud shear zones. As a result, in addition to the development of fractures, the anticlines of the area have been merged with each other through structural interferences. The aquifer (anticline) of the Leylia-Keynow is the result of the same structural development, which, based on water budget estimation, can also be linked to the adjacent aquifers (or anticlines). The fault structure of another important in the study area is Mafaroun thrust fault which has played a substantial role on occurrence of above springs by placing the Ilam-Sarvak Formation in front of the Pabdeh-Gurpi impenetrable Formation, as well as creating high fracturing. Field surveys also show that faults and fractures are more frequent in the study area. These types of fractures and faults play a key role in controlling the pattern of general flow and water transfer. In sum, these results indicate that the karstic aquifer in the study area is controlled by a specific hydrotectonic regime.

The Geomorphic indices including mountain front sinuosity (Smf), valley floor width to valley height ratio (Vf), basin shape index (Bs), and stream length–gradient index (SL) have been calculated for determination of various tectonic activities along the Aghajari fault. The mountain front sinuosity (Smf) index was calculated about 1.007 to 1.58 respectively in the active and inactive parts of the Aghajari fault. The basin shape (Bs) index has been calculated between 7.83 for the very active parts and, 1.18 for the low active parts of the fault. The amounts of valley floor width to valley height ratio (Vf) index show the range between 0.21 to 5.29 in the active parts with V shape valley morphology and inactive parts with U shape valley morphology respectively. The stream length–gradient (SL) index was calculated between 1414.58 in the high active tectonic and 385.14 in the low active tectonic parts of the study area. With application of the GIS techniques and the overlaying the Smf, Bs, Vf and SL data layers the area was divided into three different tectonic zones and quantitative active tectonic zoning map was prepared for the study area. In this active tectonic map, classes 1 to 3 respectively show the highest to lowest tectonic activity along the Aghajari fault. Results reveal that the Aghajari fault in the central and southeastern parts except for some small areas shows the medium tectonic activity and in the northwestern parts shows the low tectonic activity manner.

Sulfur springs are distinguished from other groundwater sources by their specific therapeutic, thermal and hydrochemical properties. Golgir, Meydavood, Naft Sefid, pole Zal, Grasab JaOrdo, Mashrageh, Grab Behbahan, and Baba Ahmad Springs are low-temperature sulfur springs in Zagros area of Khuzestan. These springs have temperatures between 22 and 35 °C and appear along with the Zagros thrust. By analyzing the hydrochemical data of sulfur springs on two periods (December 2017 and May 2018) and applying the hydrochemical methods, principal component analysis (PCA) and hierarchical clustering (AHC), it has been tried to identify the factors affecting the chemical quality of the springs. The first factor includes the electrical conductivity, Na, Cl, K, Ca, Mg, As and Cd variables, this factor is due to the interaction of aquifer and water materials, as well as high correlation between the main ions, arsenic and cadmium indicates that these elements have similar origin.The second factor includes the SO4, NO3, and S variables. According to the results of TOC analysis, this factor can be attributed to the influence of oil brines. Piper diagrams and hierarchical Q-mode clustering were used to classify the springs studied. The Piper diagram separated these springs into three groups and the hierarchical Q-mode clustering method, taking into account further parameters of sulfur springs in four groups.

The application of Experimental modeling is an important key to understanding the complex tectonic phenomena, specially the extremely complex salt structures. In this study, using an analogue sandbox modeler, the salt structures of Zagros and their effect on the general shortening of Zagros had been simulated, considering the low density and creep of the salt. The study area was divided into three subregions, according to the existence or the lack of salt structures and the thickness of Hormuz salt series. At the western part of the region the lack of salt series was assumed, and gradually the thickness of Hormuz salt series increases until it reaches the Qatar-Kazerun Fault System (KFS), then at the eastern part there is a thick layer of Hormuz salt series. For every subregion, a model was designed, considering the low density of salt and its creep. Finally, a schematic outline proposed to describe the existence and distribution of salt structures at Zagros. According to this outline the KFS is an important agent of general thickness changes at the base, because at its eastern part there is an abundance of salt structures, but conversely, at its western part except of a few buried small salt structures there is no sign of Hormuz salt structures.

This research focuses on seismotectonic setting and seismic risk analysis of Dezful and Susa cities for 50 km radius. It helps to the safety of critical structures, and optimum siting of new projects in these cities. Results of the study lead to protect lives and decrease economic risks when a probable earthquake will occur in the area. For these purposes, geological investigations, and recognition of faults, as well as their geometry in this region carried out. Moreover, the seismic background of these cities evaluated. The ground motion parameters estimate by probabilistic seismic hazard analysis in defferent probability. For return periods of 25, 50, 100, and 200 years, results show that the maximum magnitude of design base earthquake (DBE) is 5.4, 5.6, 5.9, 6.1 Richter, respectively. For Dezful city, the maximum acceleration of design base earthquake and maximum credible earthquake calculate 0.22 and 0.33g, respectively, using Donovan equation. In addition, these parameters, for Susa city, estimate equal to 0.24 and 0.36g. The seismic zonation maps revealed that the highest risk of the area located in middle and northern parts. Therefore, it is necessary to retrofit the historical and worn-out urban structures.

Ramhormoz Fault has been located in the Dezful embayment and it is active from point of tectonics. The Geomorphic indices including mountain front sinuosity (Smf), valley floor width to valley height ratio (Vf), basin shape index (Bs), and stream length–gradient index (SL) have been calculated for determination of various tectonic activities along the Ramhormoz fault. The mountain front sinuosity (Smf) index was calculated about 1.003 to 1.14 respectively in the active and inactive parts of the Ramhormoz fault. The amounts of valley floor width to valley height ratio (Vf) index show the range between 0.37 to 13.48 in the active parts with V shape valley morphology and inactive parts with U shape valley morphology respectively. The basin shape (Bs) index has been calculated between 6.5 for the very active parts and, 0.5 for the low active parts of the fault. The stream length–gradient (SL) index was calculated between the range of 227-14.5 for the active and inactive parts of the fault respectively. The overlaying of the data layers was made and the active tectonic map of the study area was created with application of the GIS techniques. According to the active tectonic map the Ramhormoz fault was divided to the three classes of tectonic activity zones. Class 1 shows the high tectonic activity and class 3 shows the low tectonic activity parts. Results show more tectonic activity in the central and south west parts of the hanging wall respect to the other parts of the Ramhormoz fault.

The primary objective of the current study is to produce karstification potentiality maps in northeast of Khuzestan province, Iran, using both fuzzy logic and AHP models as an additional tool in hydrogeological research. Geographic Information Systems (GIS) and Remote Sensing (RS) are used to create two maps depicting the development of the karstification, consisting of five classes, showing the karstification potentiality ranging from very high to very low. The extractions of these maps are based on the study of input data such as: lithology, lineament density, elevation, slope, rainfall, temperature, drainage density and vegetation cover. Eventually, two maps based on weighted spatial modeling system are created. The verification results show that the fuzzy logic model outperformed AHP model for the study area. Based on hydrogeological survey, hydrodynamic characteristics perceived at the outlet of major springs consisting of Dare-Anari (DA), Abshekaloo (AS) and Sarhooni (SH) revealed poorly and well developed karstified systems. The collected data indicated that one of the main factors for karst development in the area is tectonic activity and occurrence of lineaments in various scales.

To study of petroleum reservoirs which their productions are function of their fractured system, fractures assessment is necessary and important in oil production optimization and field development. The purpose of this research is recognition of a quick method for identification of fractured zones using petrophysical logs which are handy in all wells, and their effects on porosity and permeability of Asmari reservoir of Balarood oil field. The result shows that although some factors such as lithology and reservoir fluids effects on petrophysical logs, requiring minor corrections to logs by means of mathematical methods such as derivation can be used to determine fractured zones on logs, which show great consistency with image logs and velocity deviation log. Results show that zones of abundant bearing fractures can be easily recognized on first stage of derivation on petrophysical logs. Derivation process of any log is defined as a function for that log. Tectonic information and geological prospective of oil field will have an apparent contribution in identification of fractured zones. In addition, fractures and porous zones have had effective impact on the reservoir rock properties. The results indicated that the production in the Asmari reservoir of this field is a combination of fractures and rock matrix and fracture analysis can be done by using petrophysical logs in old drilled wells without image logs as well. As six logs RHOB, NPHI, GR, DT, PEF, CAL have vital role in petrophysical studies, these six tools are the best logs to diagnosis of fractured zones due to their responses against the fracture along with doing some corrections in these logs.

The Dehdasht bauxite deposits are located 40 km northeast of Dehdasht in Kohgilouye and Boyer-Ahmad Province. It is a part of the Irano-Hymalayan karstic bauxite belt located in the upper part of karstic depressions of Santonian-Turonian Sarvak carbonate formation. The aim of this study is to determine various geneses of pisoliths and prevalent processes in bauxitization. For this purpose، laboratory experiments were carried out including qualitative mineralogical investigation by X-Ray Diffraction (XRD) and petrographic study of thin section. Bauxitization processes led to the formation of bohemite، diaspore، calcite، kaolinite، anatase، rutile، goethite، hematite and chlorite in these deposits. Bauxitization was developed by destruction of kaolinite and deferruginization and caused aluminium concentration in the deposits. Mineralogically، these deposits vary based on the presence of pyrite in the gray horizon in some deposits such as Mandan. Minerals were formed due to three stages of weathering، diagenetic and epigenetic processes. Based on quantitative mineralogical results of the bauxite horizons، depositional/diagenetic environments of the study area vary from vadose to phreatic. Micromorphological investigations show pisoliths with simple، vitreous، complex and oolithic cores and also discolored and broken pisoliths. Therefore، the deposits can be divided into three types: autochthonous، allochthonous and para-autochtonous. Dissolution features and kaolinization، deferruginization and diaspore formation in fractures demonstrate diagenetic and epigenetic processes that occurred after the formation of the deposits. Investigation of encrust particles frequency shows that particles with 50-200 micron in diameter، have the most frequency and simple fabric of ooliths shows short-term formation. Comparison of the frequency of encrust particles as well as TiO2/Al2O3 variation diagrams، indicates that some deposits such as Mandan had lengthier bauxitization time.

Earthquake is main the problem in Izeh city (NE Khuzestan Province). This city is seismically an active area.The earthquakes with magnitude of 4 to 5 in Richter scale occurred in this region during 1382, 1383 and 1386. In order to evaluate the earthquake hazard in this area distribution of active faults was investigated. In this paper, the faults around Izeh city as far as 55 Km were studied. According to calculations, the magnitude of earthquake resulted from the activity of these faults range from 6 to 7.4 in Richter scale. The maximumhorizontal acceleration and vertical accelerations resulting from these earthquakes are 0.33 gand 0.16 g, respectively. Therefore, the problem of earthquake critical management and the process of urban development in Izeh area requires special attention.