نشریه زمین شناسی کاربردی پیشرفته
سال یازدهم شماره 42 (زمستان 1400)

The Lashotor stone quarry complex as the part of the Sanandaj-Sirjan structural zone is located in the south of the Isfahan city. The Cretaceous calcareous units are the main lithological unit extended in the area. Unscientific extraction is caused to produce many wastes in this stone quarry Complex. Investigation and modelling of structural discontinuities is an essential step in the mining to wastes reduction and economic efficiency improvements. Blocks with different geometric characteristics (number and volume of each block) resulted from the intersections between discontinuities and the faces directions. So, the attitudes of discontinuities (i.e. bedding, joints and stylolites) and their spacing and direction of the cutting step of each face were measured during field survey. The dominant strike of discontinuities are stylolites, which are parallel to the bedding planes based on rose diagrams of the strike direction obtained from field measurements. The average spacing of the stylolites is ~1-1.2 meters. Based on the results of the Modeling Using 3DEC software and the percentage of non-economic blocks was calculated and the volume-cumulative percentage diagrams the current faces were not extracted in correct directions. Therefore, modeling was repeated for different directions of the faces until reaching an optimal direction in order to reduce the waste and increase the efficiency. Finally, the best extraction direction was suggested.

The brittleness is an important rock property and effective in rock excavation. Recognition of the relationship between drillability and brittleness will increase performance the rock excavations. In this study, the number of 16 samples has been studied rock mechanical properties of granite, granodiorite, dolomite, hornfels and marble in the area of Glass water conveyance tunnel project in the margin of Naghadeh city. The number of 16 brittleness indices were calculated with stress-strain curve, modulus and rocks strength properties. In addition, Sievers’ J-miniature drill test and the brittleness test are carried out and DRI values were calculated. The statistical relationships between the brittleness indices and the drilling rate index are showed a strong correlation between B3 brittleness index (R2= 0.76 and RMSE= 1.02 coefficients) and B4 brittleness index (R2= 0.79 and RMSE= 0.95 respectively) with rocks drilling rate index. The statistical relationships are compared with study former between the brittleness indices and the drilling rate index of rocks. The Precision and accuracy of relationships are confirmed with relationships former. In addition, a model was presented with multiple regression analysis. It can use for the assessment of rock drillability.

Sarkuh porphyry copper deposit is located 6 km southwest of Sarcheshmeh deposit in the Kerman section of Urumieh-Dokhtar magmatic arc. The aim of this study is characterizing the behavior of rare earth elements and trace elements to assess the magmatic features of deposit. In this deposit, intrusive rocks are mainly composed of granodiorite and granite that undergone by intense hydrofracturing that lead to the formation three main stages of hydrothermal evolution and mineralization. They include (1) pre-ore stage occurring roughly in potassic alteration and dominated by quartz + biotite, and quartz + k-feldspar veins, (2) main ore stage characterized by quartz + biotite + chlorite ± magnetite ± pyrite ± chalcopyrite in potassic alteration, and later quartz + pyrite + chalcopyrite ± bornite ± chalcocite ± sercite in potassic – phyllic transition, and (3) late stage barren quartz ± calcite veins in phyllic alteration. The data show that there is an elevated Lan/Ybn values ranging between 14.83 and 56.57 (average; 27.21) with low negative and/or minor positive Eu anomalies (Eu/Eu * = 0.77 _ 1.35; average; 1.01). Also Sr/Y vs. Y and La/Yb vs. Yb diagrams reflect the adakite affinity of Sarkuh porphyry intrusions. Charactering the magmatic system of Sarkuh deposit proved that the lack of significant plagioclase fractionation which is casual for Sr removal, and on the other hand Y removal by fractionation of hydrous minerals under high magmatic water conditions (>4 wt. % H2O) provided a suitable condition for increasing the Sr/Y ratio in the Sarkuh deposit.

During weathering, a significant proportion of the elements specially base and rare metals would migrate. Origin of sediments has been studied only through empirical methods or isotopes such as Cs137, which has always been a controversy about the results of these methods. Detecting the rules for migration and distribution of some metal elements in environments with different lithologies, can provide an appropriate and precise method for determining the origin of sediments. The existence of isolated and combined igneous, sedimentary and metamorphic rocks along with various weathering phenomena in north of the Shahrekord city provided an appropriate opportunity for this innovative research. In this research, the origin of sediments are determined using the result of XRD and ICP-MS analyses on the samples from igneous, sedimentary, metamorphic rocks and their associated sediments and statistical analysis of the enrichments and depletions of migratory metals. Based on the results of this study, Rb, Ni, Sr, Pb, Nb, and Zr in igneous rocks, U, Pb, Ba, W, Nb, Ni, and Zr in sedimentary rocks and Zr, Rb, V, Ba, Co, Nb, and Ni in metamorphic rocks can be used as indicators for determination of sediment origin.

Various reasons of surface water resources scarcity, and consequently, the excessive removal of groundwater resources has posed a serious threat to these resources. Reduction of groundwater surface, land subsidence and Sinkholes, are the harmful effects of large-scale exploitation and the lower recharge of groundwater resources which become a social challenge. Therefore, the sustainable management of these water resources is a vital necessity. Storage and recharge of groundwater aquifers is a potential solution to achieve future water supply goals. In this paper, the potential of infiltration areas to recharge groundwater was investigated by using the maximum entropy model (MaxENT). The Jackknife test was used to determine the most effective factors on ground water supply. Based on Jackknife graph, soil texture and lithology factors were the most important factors influencing the prediction of areas with potential infiltration. The map of the maximum entropy model was classified to four classes with low, medium, high and very high permeability. The greatest potential was observed in the middle part of the watershed, which is the plains. Areas with low slope gradient, sandy soil texture with quaternary sediments showed the highest potential. Study area included 0.02 % very high recharge potential, 3.1 %, 0.7 % and 96.18% with high, moderate and low recharge potential, respectively. The precision of prediction of the final map of the model results was evaluated using some indices with good to excellent grade. According to the results, the plain areas of the Marboreh watershed are suitable to groundwater recharge.

Geochemical composition and uranium occurrences in Tahlab aquifer, southeastern Iran, were studied in order to understand the source of U and geochemical processes controlling chemistry of Tahlab aquifer. Also the contamination and health risk assessment of uranium for drinking purposes in 16 sampling wells were investigated. Sulfate, Cl, K and EC for all water samples reveal higher concentrations than the drinking water standard values. Piper diagram of major ions indicated that the water is mostly Na-SO4-Cl type with sulfate and sodium as the dominant anion and cation respectively. The hydrogochemical signature of the investigated groundwater samples suggests that they are mostly affected by a hydrothermal source related to deep circulation waters from Taftan volcano. The results of saturation index (SI) show that the Tahlab aquifer groundwater samples are oversaturated with respect to quartz, chalcedony, hematite, uraninite (68.75% of samples), caffinite (43.75) and U4O9 (31.25%). Principal component analysis (PCA) results and high positive factor loading of U, V, HCO3 and Si revealed that the geogenic activities were major source of uranium in Tahlab aquifer and suggests that the U concentration is controlled by Si-bearing minerals. The results of hazard quotient (HQ) for adults were higher than one in the 81.25% of the groundwater samples, indicating that groundwater of this area may not be safe for drinking purposes. Health risk assessment shows that the consumption of uranium contaminated groundwater poses an emerging health threat to the populations in the study area, and hence needs regular monitoring and management measures.

Senjedeh gold mine is located 60 km southwest of Delijan in the central part of the Sanandaj-Sirjan zone (SSZ). This is one of the active mines of the Muteh mineral area. The gold mineralization in the study area occurred as quartz- sulfide veins and veinlets along N40W tending, NE dipping normal faults in metarhyolite host rock. The most important hydrothermal alteration types are sericitization, kaolinitization, silicification and sulfidization, which silicified and sulfide alterations are developed in the inner parts of the fault zones adjacent to the mineralized zones. Five group of fluid inclusion can be identified based on fluid inclusion petrography in Senjedeh, which main primary fluid inclusion is the two-phase fluid (L + V) with dominant phases of (H2O) and (CO2). Evidences from fluid inclusion microthermometry studies indicate the contribution of CO2 bearing ore-forming fluids. They are characterized by the mean homogenization temperature of 300oC, and average salinity of 11 % wt NaCl. They are genetically linked to the generation of metamorphic fluids that are typically characterized by low salinity and mixed H2O–CO2 compositions. Results from petrography, temperature and fluid inclusion homogenization (homogenization to fluid) indicate that released fluids during progressive metamorphism have been mixed with magmatic fluids and meteoritic water, which penetrateed up to a few kilometers through faults. These processes are responsible for alteration and mineralization along normal faults. Based on the evidences of geology, alteration and microthermometry, and comparing with Iran and world's gold deposits, this mine can be considered as an orogenic gold mineralization.

Changuleh sulfur and thermal springs having an average annual discharge of about 1500 lit/s are discharged from the Anaran anticline located in the west of Ilam province. The purpose of this study is to determine the source of salinity, temperature and sulfide hydrogen of these springs. For this purpose, field studies and monitoring of springs, including measurement of discharge, temperature, acidity, amount of hydrogen sulfide and dissolved oxygen and measurement of main ions, measurement of Deuterium, oxygen 18 and sulfur 34 stable isotopes were performed. Silica geothermometry was used to estimate the reservoirs temperature and relationships between stable isotopes with local meteoric water lines were performed. Geological studies showed that the faults in the Anaran anticline have caused hydraulic connection between Ilam and Sarvak karstic formations and deep seated evaporite formation. SO4/Cl and TDS/Br ratios showed that the salinity of Changuleh sulfur springs is the dissolution of evaporite formations. Stable isotope sulfur 34 analysis also revealed that the source of sulfate is evaporite formations. Analysis of Deuterium, oxygen 18 stable isotopes demonstrated that the origin of these springs is the local precipitation. Silica geothermometer studies showed that the temperature of the Changuleh sulfur reservoirs is about 50 to 55°C. Origin of hydrogen sulfide (H2S) is related to the activity of sulfate reducing bacteria. The hydrograph of the springs showed that the rainfall affects the discharge of the springs about 2 months after precipitation. In other words, infiltrating rainfall has a deep circulation along faults and the temperature of springs increases.

The use of hydraulic flow units as a method to determine the quality of the reservoir and also the use in the zoning of hydrocarbon reservoirs has a very high role in the development of reservoirs. The most reliable data in the discussion of reservoir study are obtained from the core, which due to the high cost of core retrieval, there is a small amount of this data in each field, however, the data from the core may Can play a decisive role in the study of the reservoir. In the present study, core porosity and permeability data were investigated and 6 hydraulic flow units (HFU) were identified using the regional flow index method, which were separated based on reservoir quality. Then 6 electrofacies were determined using petrophysical logs by self-organized method. The conformity of the electrofacies and the designated hydraulic flow units indicated a good convergence between them and an increase in reservoir quality from unit 1 to unit 6. The results of this study can be used as input for the construction of field facies models in the modeling process and locating new wells.

Design and construction of engineering structures in karstic areas can face numerous problems due to the dimensions and geometry of karstic structures and existence of unpredictable locations and cavities. Therefore, comprehensive investigations may help to avoid hazardous areas, plan preventively and take effective and corrective course of actions. In this study, due to the karstic conditions of the foundation of the Khorramabad's artificial waterfall, different methods were used to evaluate the engineering geological features of the karst and analyze the rock slope stability. These methods include determination of the physical, mechanical, hydraulic and solubility properties of the rock samples obtained from the boreholes drilled in the rock slope. In addition, karst geomorphology and rock engineering classification were studied for karst development and engineering judgement. To determine and analyze possible landslides in the rock slope, Dips, Roclab, Rockplane, Swedge and Slide softwares were used in static state and in contact with surface water flow. According to the results, the region is a young karst in terms of karst maturity and the solubility velocity constant of the limestone is 6.99×10-5 m / s. Also, possible slips detected in the rock slope are of plate, wedge and mass types, whose long-term stability will be provided by anchors and shotcrete. However, due to the stabilization costs, environmental problems causing by cement injection in karstic dissolved cavities and increase in landslides risk causing by surface water flow, it was recommended that preventive planning be considered for the construction of the waterfall at the proposed site.

In this study, the Asmari reservoir in 39 wells in one of the oil fields of southwestern Zagros, located in the Dezful region, was investigated using well log tomography of Gamma ray logs and core porosity data. For this purpose, two-dimensional and three-dimensional models of gamma and core porosity logs in 4 reservoir zones of Asmari Formation have been designed by Petrel software. Among the slice of Gama log and porosity data, 2 slice were selected from the upper and lower sections of the zones, and a total of 8 tomographic sections from 10 key wells were prepared and compared with each other. The results of gamma logs and porosity tomography models are very close and compatible with each other and show that there is an inverse relationship between gamma values and porosity in the slices made by Asmari Formation in the studied wells. Also, with increasing dolomitization in the zones, the petrophysical characteristics have changed and the amount of porosity has increased. Based on the well log tomography model of the studied oil field, it was found that zone 2 with the lowest gamma value and the highest dolomite value, has higher porosity than other zones and can be the main target of production wells in the field. Since drilling wells is expensive and time consuming, it is possible to achieve very close and accurate results of well drilling using well log tomography. Therefore, tomography studies can be very useful before increasing excavations in the area for general information.

Acid matrix treatment is one of the key jobs to increase and maintain the long-term well productivity. Matrix acidizing of deep slanted wells in heterogeneous reservoirs is a challenging task. Thus, performance evaluation of pre- and post- stimulation job is of great importance. This study presents the analysis of well test data using deconvolution and also conventional pressure transient analysis (PTA), combined with the interpretation of surface well testing, data from production logging tool (PLT), and petrophysical logs to evaluate the performance of matrix acidizing and well deliverability improvement in a gas-condensate multi-layered carbonate reservoir. This evaluation can be used to optimize the acid matrix treatment strategy in offset wells and, consequently to perform an effective remediation in future wells. The diagnosis results using the surface data has indicated a successful acid matrix treatment job with having an improved total productivity index by a factor of three. Furthermore, it has shown that the wellhead flowing pressure has increased by 623 psi and drawdown has decreased to one third. Additionally, taking advantage of combining PLT and PTA analysis for multilayer systems, it has been found out that, the acid treatment has mostly affected the deepest reservoir layer with higher pressure. Hence, the unfavorable skin effect of different reservoir layers have not been removed uniformly, which needs to be considered in designing the future acid job for offset wells to control acid diversion in the reservoir towards less affected intervals.

The study area is Tasuj region, in East Azarbayjan Province, which consists of the mountainous and Tasuj plain. The purpose of this study is identification the areas with high potential for subsidence, earthquake and landslide in the Tasuj region, based on the factors affecting their occurrence and using the hierarchical analysis process (AHP) method. In this study, the effect of groundwater drawdown and the risk of subsidence due to it were evaluated. The average amount of water table drawdown in the study area was calculated about 6 meters and areas with high subsidence risk were identified. For the mentioned hazard zoning, 15 criteria, such as water table, water table drawdown, slope, aspect, distance of stream, land use, elevation, lithology, distance of fault, earthquake depth, fault length, distance of epicenter, earthquake magnitude, distance of road and rainfall were used. According to the results of this study, the criteria of water table, distance of faults and lithology, respectively, have the greatest effect on the risk of subsidence, earthquake and the potential for landslide occurrence. Also, most of the areas associated with high risk of subsidence, earthquake and landslide are located in the central and southern parts of the plain, eastern and northern parts of the region and mountainous and steep areas in the north and east of the region, respectively. Therefore, by studying the resulting zoning maps and identifying high-risk points in the basin, their harmful effects on natural resources and other parts can be reduced.

In this investigation, the foraminifera and oligosteginids of Sarvak Formation (Late Albian-Middle Turonian) at the Khumi Anticline section (East of Izeh Zone) has been studied. It consists of limestone of 213m thick which overlies the Kazhdumi Formation conformably and underlies the Gurpi Formation unconformably at Khumi Anticline. The biostratigraphy of Sarvak Formation in this section indicates 80 genera and 39 species (19 genera and 49 species of plankton foraminifers, 17 genera and 22 species of benthic foraminifers and 8 genera and 4 species of oligosteginids). Based on received paleontological data 8 biozones and 2 subzones in study area were established: Pseudothalmanninella subticinensis Partial range Zone (Late Albian), Pseudothalmanninella ticinensis Interval Zone (Late Albian), Thalmanninella appenninica Interval Zone (Latest Albian), Rotalipora globotruncanoides Interval Zone (Early Cenomanian), Thalmanninella reicheli Total range Zone (Early to Middle Cenomanian), Rotalipora cushmani Total range Zone (Middle to Late Cenomanian), Whiteinella archaeocretacea Partial range Zone (Latest Cenomanian to Early Turonian), Whiteinella archaeocretacea Interval subzone (Latest Cenomanian), Dicarinella hagni Interval subzone (Early Turonian), Helvetoglobotruncana helvetica Interval range Zone (Early Turonian- Middle Turonian). Based on these biozones the age of Sarvak Formation in Marin section is Albian-Middle Turonian.

The water-oriented development of countries calls for the enforcement of the regulations on the Clean Development Mechanism (CDM) through integrated water resources management (IWRM). The simulation of the most important drainage basin in the Middle East, which consists of six reservoir dams with a cumulative PV capacity of over 10500MW, was the goal of this study. The simulations of the groundwater and surface water resources were carried out separately by using the MODFLOW and WEAP models and coupling these models with a link file. The multi-objective function optimization process, which involved the maximization of the supply of hydropower and demand and minimization of aquifer drawdown, was carried out using the NSGA-II genetic algorithm. Afterward, all the system and policy components influencing the integrated water resources system were assessed. These components included inter-basin water transfer, combined use of water resources, variation of irrigation network efficiencies, and the effect of water shortage, According to the model results, the inter-basin water transfer with a scenario of 1.5 billion cubic meters increase will reduce about 10% of the average annual production of hydropower in the basin. Finally, the model showed the best scenario for attaining the CDM objectives.

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 Pabdeh Formation (Paleocene – Oligocene) is one of the hydrocarbon-generating formations in the Zagros basin that investigating hydrocarbon potential of the Pabdeh Formation, 30 samples were taken through the Ezgeleh section, NW Kermanshah. The samples were analyzed by Rock-Eval 6 pyrolysis method. The results show that kerogen type mixed of II and III is the most abundant type II in the Pabdeh Formation. That reason for this could the dominance of marine facies that make up this formation. In terms of genetic potential and hydrocarbon potential, this instrument is a medium relatively good rock. The reflection of vitrinite in most of the Pabdeh Formation specimens is lower than 1.3 indicating a submature source rock but 20 percent of the samples have entered the oil window and liquid hydrocarbons stage, which is also confirmed by Tmax more than 450 C°. HI vs TOC values indicate for this Pabdeh Formation a C and BC organic facies and to a lesser extend B and AB, wich this facies diversity can be due to the diversity of organic materials of continental and marine origin, and its deposition mainly in relatively regenerative environments such as pro – delta, to outer shelf, and upper part of the continental slope are done, and if it goes through the stages of thermal maturation, it will be able to produce condensate and gas.