نشریه زمین شناسی کاربردی پیشرفته
سال یازدهم شماره 41 (پاییز 1400)

The Koushk Zn-Pb shale-hosted massive sulfide deposit is located in the north east of Bafq area within the sequence of lithostratigraphical Rizu unit in the Central Iran (Posht-Badam block). During this study, for the first time in Iran, unknown pink vein minerals are contemporaneous with quartz, located in most of the north and south Pahno stratigraphic units has been introduced as Kutnohorite mineral in the Koushk deposit. Kutnohorite is a type of manganese carbonate with the chemical formula "CaMn2+(CO3)2", belong to the dolomite group. Sampling and geochemical analyses of volcanic-sedimentary host rocks (rhyolite, tuff, shale and dolomite) indicate that high amounts of chlorite, sericite, clinochlore, and euhedral pyrite minerals are found with kutnohorite-quartz veins and associated with galena and sphalerite ores at north Pahno section of the Koushk deposit. According to determining the types of alteration associated with kutnohorite-bearing zone using Ishikawa and chlorite-carbonate-pyrite (CCPI) indices showed that this mineral is an indicator and exploratory key in the Zn-Pb shale-hosted massive sulfide deposits such as the Koushk ore deposit.

In this study, the potential for heat generation and maturation was investigated using 1D modeling of the sedimentary basin and evaluation of rock-eval experiments performed on Faraghun Formation in well No. 2 of the Nar gas field. In this study, the feasibility of creating a pattern between the Chilean-charcoal layers of the Permian Faraghun Formation was considered as the source stone. Based on Tmax values and Vitrinite reflection coefficient, most of the samples related to these intermediates are in the range of the beginning of the oil window, and the 1D modeling confirms this hypothesis. By assigning a heat flux of 52 MW/M^2, the best adaptation was obtained with the data of the vitreous reflection coefficient, and the correction of intra-well temperatures and the modeling accuracy was confirmed. The results of Rock-Eval experiments and 1D modeling showed that the intermediate layers of the Chilean Formation of Permian Fraghun are capable of producing hydrocarbons and have reached the peak of the oil window about 69 million years ago. / 04 produced megatons of hydrocarbons. The history of burial and heat also shows that between the Chilean-charcoal layers of Faraghun Formation, they are located at the depth of burial necessary for thermal maturation and hydrocarbon production. Therefore, relying on these results, among the Chilean- charcoal -forming layers, the extrasolar rock is considered to be a source of weakness to good but immature hydrocarbon potential, which can be considered as a source of possible unconventional hydrocarbons.

In order to study, biostratigraphy, Sedimentary environment and biogeochemistry of Garau Formation studied at one stratigraphical section at the KhorramAbad anticline. This section has a thickness of 137.5 meters. Study of microfacies sections of the Early Cretaceous Formation of the Garau Formation and study of paleontological and histological characteristics of specimens including abundance of skeletal and non-skeletal alocomas, cement, detrital particles and matrix resulted in the identification of 8 microfacies in the deep-sea region in the study area. Also the proposed sedimentary model of the Garau Formation is based on carbonate platform microfacies determined by ramp type. In this research, the geochemical characteristics of the Garau Formation in the Khorramabad anticline were done by Rock-eval method. Based on the analysis of existing data, type III kerogen was studied. The TOC of samples from this rock unit is relatively weak and varies from about 0.24 to 1.28 . Garau Formation samples in Khorramabad anticline have low potential for hydrocarbon production. Since the hydrogen index of the Garau Formation samples is between 50-250 mgHc/gRock, so the potential of the Garau Formation in these samples seems to be more focused on the production of light (gas) hydrocarbons.

In the present study, calcareous nannofossil of the Gurpi Formation have been studied from well No. 123 of Marun oil field in the Zagros sedimentary basin. In this study, thirty-eight nannoplankton species belonging to eighteen genera were introduced from the Gurpi Formation deposits. Based on index calcareous nannofossil species, the Gurpi Formaation deposit was subdivided into nine calcareous nannofossil biozones, including CC17- CC25 zones (Sissingh, 1977) and UC12-UC20 (Burnett, 1998). The identified biozones are assigned to the Late Santonian-Late Maastrichtian ages for the studied interval. In order to paleoecology and Paleoenvironment studies, the diversity, abundance, size and extent of preservation of nannofossil taxa were also investigated. The distribution and abundance of some species such as Micula decussata, Micula murus and Watznaueria barnesiae indicate that the temperature and environmental stress have increased towards the end of the Formation. Also, the sedimentary environment of Gurpi Formation during the Late Cretaceous was mainly in low to mid-latitudes based on calcareous nannofossil assemblages.

Reservoir characterization and the identification of the main factors controlling the quality of the reservoir has an important contribution to providing a real image of reservoir properties. The Sarvak Formation is one of the most important reservoir rocks in the Zagros sedimentary basin and the studied well is divided into three core facies based on layering, texture, fossils, and sedimentary structure. In this study, first, using the porosity and permeability data of a well in this formation, hydraulic flow units were determined based on the flow zone indicator and then compared with the results of thin sections studies, effective factors on the quality of each flow unit were identified. The results of determining the hydraulic flow units based on the flow zone indicator indicate the existence of four flow units A, B, C, and D in Sarvak Formation, which increase the reservoir quality from units A to D, respectively. Then, the electrofacies of Sarvak Formation were determined using well log data which resulted in five electrofacies. By comparing electrofacies with flow units and the results of microscopic section studies, it was observed that Sarvak Formation has a high heterogeneity in the studied well due to various diagenetic processes such as dissolution, cementation, and dolomitization that using the concept of flow units and electrofacies and comparing with the results of microscopic section studies, it is possible to separate different parts of this reservoir that have the same flow characteristics and generalize the results to non-core wells in the study field.

Seymareh Dam site is located in 40 km northwest of Darreh Shahr City and in Ilam Province. In this study, the origin of the downstream brines of Seymareh Dam with the results of chemical and using two computational methods of Schoeller's Index Base Exchange and weight ratio (Na/Cl)-Cl and two graphical methods of Hounslow and Sulin graph were studied. The results of these methods show a lot of conformity. In this study, part of the aquifer has been contaminated with oil brines, and the polluted water is drained through springs into the Seymareh River, which has reduced the quality of the river's water for agricultural purposes. Based on the equivalence maps of the Index Basic Exchange and the water type, a hydraulic connection has been established between the oil brines and the aquifer through the observation wells. Based on the interpretation of the results, the study area has been affected by the oil spills in the Seymareh Dam area, and the Gachsaran Formation in the area has also increased the salinity of water resources, including sulfate. Based on this, until 1396, the area of polluted aquifer was 1.8 km2. Examining the quality of irrigation water of Seymareh River in the period of 2011 to 2017 shows that since 2013, the quality of river water based on Wilcox classification is not suitable for irrigation. Based on the regression of SAR and EC diagrams with respect to time, it is predicted that in 1401 the quality of river water will reach C4-S4.

The Chaharston-Deshwan fault area is located to the northwest of the city of Salmas in the Sanandaj–Sirjan zone.The area consist highly deformed rocks which have been emerge clearly in a dextral shear zone. Mesoscopic and microscopic scale analysis carried out for determining the deformation history of the area. Thus tectonics structures and microstructures measured and analyzed based on field study and statistical method. Then fitting structural models were offered for each of them. According to the results, it can be concluded that four different deformation phases were efficacious in formation of the analyzed structures.The most important deformation mechanism including: foliation, S-C fabrics, mineral fish, Z drag folds, mantled porphyroclasts throughout the field area indicate dextral deformation. The most reliable shear sense markers in high grade shear zones are shear bands, mineral fish, mantled porphyroclasts, sigmoid and asymmetric bounding. This shear sense indicators indicate that the Chaharsoton-Deshwan area deformed via dextral transpression tectonic regime.

The Shamsabad manganese-bearing iron deposit is located 36 km south-east of Arak city, in the Sanandaj-Sirjan Zone. In order to determine the origin and ore-forming processes of the deposit, in addition to petrographic and mineralogical studies, geochemical studies for major, trace and rare earth elements (using LA-ICP-MS method) were done on ore samples. The ore is lens form and strataband, occurring in thick-bedded to massive, orbitolina-bearing Early Cretaceous limestones. Hematite, limonite, goethite and pyrolusite are the main ore minerals. Hematite is more abundant than other minerals. The colloform texture and lamination of the ore are evidences for volcanic-sedimentary origin of the deposit, and deposition in a marine environment. The presence of todorukite as a primary mineral is indicative of the hydrothermal mediated mineralization. The high Mn/Fe and Si/Al ratios, As, Ba, Cu, Pb and Zn enrichments, and depletion of Co and Ni are similar to hydrothermal deposits. The normalized REE patterns and low ΣREE values (31.40 ppm in average) support that Shamsabad deposit is of hydrothermal origin. Negative Ce and positive Eu anomalies indicate that low temperature hydrothermal fluids have an important role in mineralization. The Co/Ni, Co/Zn, La/Ce, LaN/NdN, DyN/YbN, Y/Ho ratios, and the discriminative diagrams for trace element concentrations are in the range of hydrothermal deposits. this study, it is suggested that the Shamsabad deposit is deposited from submarine hydrothermal fluids.

In recent years, the long period of droughts and dust storms have caused dust particles to enter the west of the country. The large population, development of industrial centers and the existence of various sources of urban pollutants may increase the pollution load of dust particles in Kermanshah Metropolis. In this study, concentration of six heavy metals (Cd, Cr, Cu, Pb, Zn, and Ni) was investigated in street dust of this city. For this purpose, 21 street dust samples were collected and analyzed by ICP-MS. The results showed high concentrations of Cd, Cu, Pb and Zn with a mean values of 0.34, 128, 98.71 and 282.24 mg/kg, respectively. Enrichment factor, pollution load index, potential ecological risk index and health hazard index were used to investigate the contamination level of dust particles. The results of these indices indicated relatively high levels of lead, zinc, copper and cadmium in most parts of the city. Also, 42.85% of the sampling sites have low ecological risk index and 52.30% of the stations show moderate risk index. The highest hazard quotient (HQ) was calculated for the ingestion pathway, particularly for Cr and Pb. However, the risk index values for all the studied heavy metals were below unity for children except for lead in three stations. Principal component analysis (PCA) showed that chromium and nickel were predominantly originated from geogenic sources and other elements were highly affected by anthropogenic sources.

Asmari Formation is the first known carbonate reservoir rock in the world and the largest oil reservoir rock in the Zagros sedimentary basin. This formation has a significant expansion in the Dezful Embayment and Izeh areas. In this study, the main focus has been on the stratigraphic position of Basal Anhydrite of Asmari Formation. In this study, the main focus on the stratigraphic position of the basal anhydrite section has been the rule of Asmari Formation, so in three stratigraphic sections (surface sections of Putu mountain and Bangestan mountain as well as subsurface section of well 19 of Parsi oil field) An attempt has been made to study the status of this sequence. Based on field descriptions and lithographic changes, these sections have been done from old to new.Due to the similarity of these rock units, both in terms of location and time, in the study area, the features of the facies and their environment have been briefly reconsidered from old to new.The transition from the sequence of green marls and dolomite limestone consisting of marine facies related to the relatively deep and low-energy marine environment environment, to the sequence of medium limestone of the packstone - grainstone ooid and Favreina facies it shows the shallowness of the sedimentary basin of the end parts of Pabdeh Formation towards the base of Asmari Formation, which is ultimately associated with the formation of planar stromatolite facies.

The Yamaghan deposit is located in the southeast of Zanjan, within the Tarom subzone of Alborz magmatic belt in NW Iran. The rocks of the area are a collection of Eocene volcano-sedimentary units. Cu (Ag) mineralization in the deposit has occurred as stratabound in the mega porphyritic andesite unit. The main sulfide ores of chalcocite, bornite, chalcopyrite together with pyrite are seen as dissemination, open-space filling, vein-veinlet and replacement textures. Silver sulfide (acanthite) has also been identified based on microprobe studies. Propylitic and mineralization-related alteration types are observed in the deposit. The homogenization temperature of mineralizing fluids was measured in the range 230-390°C, average salinity being 15% NaCl equiv. The Yamaghan deposit formed in three main stages, the first stage occurred at temperatures lower than 100°C during diagenesis, forming framboidal pyrites in the host rock of mega porphyritic andesite. The second stage occurred at temperatures more than 300°C and caused the formation of copper sulfide minerals due to the replacement of pyrite in the first stage. During this replacement, excess iron in pyrite formed as hematite in the place of ores. In the third (or supergene) stage, secondary minerals such as secondary chalcocite, covellite, digenite and copper carbonate minerals such as malachite and azurite formed due to the influence of meteoric water. Based on the geology, host rock, mineralogy, structure and texture, and fluid inclusion data, the Yamaghan copper deposit is similar to Manto-type copper deposits around the world forming through hydrothermal processes.

Due to the necessity of identification and need assessment phase in the creation and the development of Geodatabase and Geographic Information System (GIS), designing a concept model is being introduced as its first phase of the study. Conceptual data modeling using ERD (Entity-Relationship Diagram) method, by defining entities, attributes, and the relationship between spatial and non-spatial entities. In this study, using the ERD method, a spatial database structure is designed for geochemical data of oil wells. Petroleum geochemical data is used for oilfield exploration, management, production, and development. In an oilfield, the most basic spatial entity is the wells. Other spatial entities in this study are field boundaries, sectors, and formations. Non-spatial entities were defined in separate tables, including oil samples and parameters derived from the geochemical analysis of samples in the Gachsaran oilfield. The ER diagram was designed using SAP Power Designer Software by establishing a 1 to N relationship between the well and all entities as well as determining the primary key and foreign key for each relationship. 11 entities were identified to create the data model.The result of applying the conceptual model before creating the Geodatabase is the logical structure of the database; also, spatial data modeling ensures the success of creating and developing a Geodatabase and WebGIS. As a result, the designed conceptual model simplifies the creation of a spatial database for display, processing, query and analysis of geochemical data of oil wells.

One of the hazardous area in Golestan province is Vatan-Farsian area which selected as case study. In this research, main and minor faults were determined by using Remote Sensing techniques together field surveys and then, mapped in GIS environment. The Geohazards were distinguished and categorized into: Faulting, Seismicity, Landslides, Slope movements and Erosion. The location of Geohazards were defined by image processing together field surveys and enter to GIS environment as data layers. Then, these layers overlaid on extracted faults and finally, the relationship between them are investigated. The results shown that maximum density of fractures occurred along fault zones. Also, the faults have potential to occurred earthquakes with magnitude < 4. Many of landslides aligned as wide strip with East-West trend between Tilabad and Susara faults. Some rock falls taken placed along Qeshlaq and Vatan faults. Many of sliding occurred in floor of fault scarps. But, the creeps have weaken relationship with fault zones. The weathering shown in Qeshlaq, Farsian faults and in a fault which controlled the Tillabad river trend. Sloppy erosions show in fault scarps. River erosions haven’t any direct relationship with faults. So, the result shown that faults caused to taken placed and/or defined the location of Geohazards.