Original Research Paper
Sedimentology
AFSHIN KARIMKHAMI BAHADOR; SADAT FEIZNIA; Mohsen Aleali; Mehran Arian
Abstract
To prepare sedimentological data, 98 surface sampling stations have been designed from the seabed in the continental shelf in the southern part of the Caspian Sea and along the coast of Iran. Indicators such as the type and amount of sediment load transported to the sedimentation environment, the energy ...
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To prepare sedimentological data, 98 surface sampling stations have been designed from the seabed in the continental shelf in the southern part of the Caspian Sea and along the coast of Iran. Indicators such as the type and amount of sediment load transported to the sedimentation environment, the energy of waves and sea currents, as well as how the slope of the seabed changes, play a role in the production and diversity of the sedimentary facies. 9 sedimentary facies are the most abundant in the surface deposits of this area and on average, in the sediments of the continental shelf, there are 1% by weight of coarse-grained particles, 25% by weight of medium-grained particles and 74% by weight of fine-grained particles. The composition of sedimentary facies in this area is controlled by indicators such as the size of sedimentary particles, the amount of sedimentary load carried to the environment, the energy of waves and sea currents, and how the slope of the seabed changes. In the marine environment of the study area, sub-sedimentary environments, Backshore, Foreshore, Shoreface, Offshore transition zone and Offshore can be identified. The two facies of slightly gravelly Mud and Mud are more abundant than other facies.
Original Research Paper
Petrology
Behnaz Bakhtiari; Nahid Shabanian; Alireza Davoudian; Hossein Azizi
Abstract
ABSTRACTThe Muteh–Golpaygan Metamorphic Complex is located within the center of the Sanandaj-Sirjan Metamorphic Zone. The strain parameter measurements including strain ratio in the XZ principal plane of strain ellipsoid (RXZ), strain ellipsoid shape (K), and strain intensity (D) exhibit constrictional ...
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ABSTRACTThe Muteh–Golpaygan Metamorphic Complex is located within the center of the Sanandaj-Sirjan Metamorphic Zone. The strain parameter measurements including strain ratio in the XZ principal plane of strain ellipsoid (RXZ), strain ellipsoid shape (K), and strain intensity (D) exhibit constrictional to the plane-strain shape of the strain ellipsoids in the amphibole mineral for the deformed amphibolitic rocks in the Muteh–Golpaygan Metamorphic Complex. Several kinematic shear sense indicators consist of the asymmetric fold, kink fold, boddin, S/C fabrics, oblique grain shape, and mineral fishes show a dextral shear sense. The quantitative kinematic analyses highlight that Wk varies between 0.6 and 0.93, implying a general shear flow with 42% < simple shear <74% and 26% < pure shear <58%.
Original Research Paper
Geological Environment and Engineering
Neda Khajooee; Sourosh Modabberi; Behnoush Khosh manesh zadeh; Fatemeh Razavian
Abstract
Population growth and increasing urbanization expose people to higher degrees of urban pollutants, especially when they need to spend long time in enclosed environments with inadequate ventilation. This study is the first research on inorganic pollutants in indoor dust particles of Tehran city, which ...
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Population growth and increasing urbanization expose people to higher degrees of urban pollutants, especially when they need to spend long time in enclosed environments with inadequate ventilation. This study is the first research on inorganic pollutants in indoor dust particles of Tehran city, which applies geochemical indices to estimate the intensity of dust pollution by potentially toxic elements. A number of 31 indoor dust samples were passively collected from inside the residential and office buildings in the central and densely populated districts of the city and were analyzed by ICP-Ms at the Taragona University of Spain. Single geochemical indices of Contamination Factor, Geoaccumulation Index, Enrichment Factor, and cumulative indices of Pollution Load and Potential Ecological Risk Indices were calculated. The results of elemental analysis showed that the concentration of arsenic, cadmium, copper, mercury, lead and zinc in Tehran indoor dust is higher than that in some cities in the world. On the other hand, cobalt, chromium, nickel and vanadium present low concentrations in the analyzed indoor dust samples. This result was confirmed by the cumulative indices as well as the contamination factor. In contrast, some other factors showed low to medium degree of pollution for the above-mentioned elements.
Original Research Paper
Sedimentology
Alireza Vaezi; Vahid Tavakoli; Abdolmajid Naderi Beni
Abstract
In the present study in order to reconstruct the paleoenvironmental and climatic changes of Jiroft during the last 4000 years, several evidences of sedimentology and biogeochemistry on a sedimentary core have been investigated. Around. 3950 cal yr BP, low values of Ti/Al, Si/Al, C/N and CPI along with ...
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In the present study in order to reconstruct the paleoenvironmental and climatic changes of Jiroft during the last 4000 years, several evidences of sedimentology and biogeochemistry on a sedimentary core have been investigated. Around. 3950 cal yr BP, low values of Ti/Al, Si/Al, C/N and CPI along with high values of δ13COM, and Paq indicate a wet period in Jiroft. The evidence indicates a relative decrease in humidity between about 3900 and 3293 cal yr BP. Between 3293 and 2897 cal yr BP, Jiroft was dry and dusty. The results show very dry conditions with a significant increase in the amount of dust around 3200 cal yr BP. A long wet period from about 2897 to 2302 cal yr BP can be recognized with high Paq values. The highest Ti/Al values along with the lowest δ13COM values indicate increased wind activity and dry conditions between 2100 and 1650 cal yr BP. Jiroft experienced wet conditions between 1540 and 1315 cal yr BP. With the relative decrease of rainfall, a semi-humid climate prevailed in Jiroft between 1315 and 854 cal yr BP.
Original Research Paper
Economic Geology
Alireza Zarasvandi; Mohsen Rezaei; Mansour Adelpour; Hadis Parvaneh
Abstract
Parkam (Sara) and Abdar porphyry Cu deposits containing mainly dioritic and quartz dioritic stocks are located in the southern part of Urumieh-Dokhtar Magmatic Belt (UDMB). The aim of this study is to characterize the phyllic alteration using sericite and sulfide (i.e., pyrite and chalcopyrite) chemistry. ...
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Parkam (Sara) and Abdar porphyry Cu deposits containing mainly dioritic and quartz dioritic stocks are located in the southern part of Urumieh-Dokhtar Magmatic Belt (UDMB). The aim of this study is to characterize the phyllic alteration using sericite and sulfide (i.e., pyrite and chalcopyrite) chemistry. Results imply for higher concentrations of Zn, Ag, Au, and As in the chalcopyrite samples (averages in wt. %; 0.07, 0.007, 0.012, and 0.043; respectively). Comparably, pyrite samples exhibit higher concentrations of Re, Te, Co, and Mo (averages in wt. %; 0.01, 0.003, 0.09, 0.07; respectively. Gold concentration in the pyrite samples is analogous to those reported previously for Meiduk porphyry Cu-Mo systems wherein gold occurs as inclusions, and/or nanoparticles (probably as Au0 or Au-telluride). In the both deposits, fine-grained micas are K-rich. Additionally, sericite samples exhibit an increasing trend of Si with Fe2+, Mg2+, and Al3+ substitution in the octahedral sites confirming the changes to celedontie - endmember. In accordance with other mineralized porphyry systems (i.e., Copper Cliff and Copper Flat deposits), most of the data follow the trend of ideal tschermak substitution occurring by the increasing of positive charges in the tetrahedral site of white mica owing to the increasing of Si substitution
Original Research Paper
Hydrology
Soraya Nouri Sangarab; Asghar Asghari Moghaddam; nasser jabraeeli andrian
Abstract
Recently, due to the trend of decreasing rainfall and increasing groundwater pumping rate, there have been concerns about the risks caused by the decrease in the volume of aquifer reserves and the drop in the groundwater level, and as a consequence the land subsidence. Also, in Ajabshir plain due to ...
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Recently, due to the trend of decreasing rainfall and increasing groundwater pumping rate, there have been concerns about the risks caused by the decrease in the volume of aquifer reserves and the drop in the groundwater level, and as a consequence the land subsidence. Also, in Ajabshir plain due to a gradual decrease in the water level, it is necessary to estimate the subsidence and investigate the subsidence potential to prevent its harmful risks in the future. For this purpose, using the ALPRIFT framework, which includes seven layers of parameters affecting subsidence, the subsidence potential map was zoned. Using Sentinel-1 satellite images, the subsidence during the years 2020-2021 was estimated to be 2.4 cm, which had a significant correlation with the groundwater level of the water year 1399-1400 and subsidence potential. In addition, artificial intelligence optimization methods including fuzzy logic (Sugeno) and genetic algorithm were used in order to fix the defects of applying expert opinions and increase the correlation between subsidence (Insar) and ALPRIFT, among these models, fuzzy logic method provided the best correlation between the two subsidence maps and ALPRIFT. The correlation between subsidence with ALPRIFT, ALPRIFT-GA and ALPRIFT-SFL was obtained as 0.46, 0.62 and 0.72 respectively
Original Research Paper
Petrology
Afsaneh Naseri Esfandagheh; Mohammad Rahgoshay; Sasan Bagheri
Abstract
The Haji-Abad-Esfandagheh-Faryab ophiolitic belt is one of the most famous chromite-bearing occurrences in the south of Iran. In recent years, the ophiolitic belt of Haji-Abad-Esfandagheh-Faryab has been the focus of attention of many geologists interested in ophiolitic complexes and economic geology. ...
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The Haji-Abad-Esfandagheh-Faryab ophiolitic belt is one of the most famous chromite-bearing occurrences in the south of Iran. In recent years, the ophiolitic belt of Haji-Abad-Esfandagheh-Faryab has been the focus of attention of many geologists interested in ophiolitic complexes and economic geology. Golashkard ultramafic unit includes dunite, highly serpentinized harzburgites, chromitite and wehrlite layers in the Faryab ophiolitic complex located in the southeast of Sanandaj-Sirjan as one of the chromite-bearing areas of the Haji-Abad-Esfandagheh-Faryab ophiolitic belt. Ultramafic rocks and chromitites of Golashkard area consist of 20 to more than 50% of chromite. The studied chromites have variable massive, banded and scattered textures. The geochemistry of Golashkard ultramafic rocks shows that the average Cr# enrichment of chromite in serpentinite rocks (probably dunite and harzburgite) and wehrlite is to Cr/ (Cr + Al) ×100= 70-80 and in chromitite is relatively higher (Cr/ (Cr + Al) ×100= 81). Based on the lithological and mineral chemistry characteristics, Golashkard ultramafic rocks are part of mantle related to ophiolite, which was produced by a homogeneous boninitic melt in the suprasubduction zone and formed high chromium chromitites and related peridotites.
Original Research Paper
Tectonics
Mohammad Hossein Tahriri; Hamid Saffari
Abstract
The Doruneh fault system with more than 700 km length, after the main Zagros fault, is known as the largest fault in Iran. In this research, this fault system is divided into three main parts because the mechanisms of its different parts are different. The western part is reported to have a left lateral ...
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The Doruneh fault system with more than 700 km length, after the main Zagros fault, is known as the largest fault in Iran. In this research, this fault system is divided into three main parts because the mechanisms of its different parts are different. The western part is reported to have a left lateral strike-slip mechanism with a reverse component, the middle part is a left lateral strike-slip mechanism, and the eastern part is reported to have a reverse mechanism. In this study, seismicity parameters and their temporal and spatial changes along this fault system are analyzed using seismic data collected from 1980 to 2023 and based on the maximum likelihood method. In this regard, the temporal changes of b-value shows two significant drops, which indicate two relatively strong Torbat-e Heydarieh earthquakes in 2010 and the Freeman earthquake in 2017. Despite the fact that the scientific community is not yet able to accurately predict earthquakes, but according to the studied method and with the continuous monitoring and analysis of various earthquake parameters, especially b-value, it is not far from expected to predict the occurrence of possible earthquakes in the future.
Original Research Paper
Sedimentology
Hoda bavi; Reza Moussavi-Haramia; Mohamad Hosein Mahmudy Gharaie; Hamed Zand-Moghadam; Asadollah Mahboubi; Mohammad Reza Tohidi
Abstract
The geochemical separation pattern and environmental behavior of ΣREE have been investigated in five different sedimentary systems related to Dar-e-Allo copper mine. For this purpose, the total concentration and sequential patterns of ΣREE elements were determined using multi-acid digestion ...
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The geochemical separation pattern and environmental behavior of ΣREE have been investigated in five different sedimentary systems related to Dar-e-Allo copper mine. For this purpose, the total concentration and sequential patterns of ΣREE elements were determined using multi-acid digestion and mBCR selective extraction method. The normalization patterns of ΣREE are drawn based on the NASC and UCC. concentration changes in the five sedimentary systems are very similar and the concentration of LREEs is higher than that HREEs, Opposite of the changes in the concentration of ΣREEs, more enrichment is seen in HREEs compared to LREEs. The geochemical separation patterns of ΣREEs in natural sediment and samples containing iron and manganese oxides is mainly dominated by the residual fraction. considering the different conditions of formation and stability in the samples taken from the waterways leading to the mine, evaporite deposits and sediments washed from the rock dump, the separation pattern of ΣREEs is controlled mainly with two parts soluble in Acid and reducible fraction. The trend of mobility and bioavailability from LREEs to HREEs increases with an upward slope. These results show that speciation, geochemical segregation pattern and environmental behavior for ΣREE lead to misinterpretation without considering key environmental factors.
Original Research Paper
Economic Geology
Sholeh Malekshahi; Masoumeh Khalajmasoumi; Hadi Mohammad Doost; Mona Sojdehee; Shahrzad Aboutorab
Abstract
Sarkuh Porphyry Copper deposit is located about 6 km southwest of Sarcheshmeh porphyry copper deposit. Alterations in the region include advanced potassic, propylitic, phyllic and argillic. Copper mineralization is mainly associated with porphyry granodiorite mass. Minerals include chalcopyrite, pyrite, ...
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Sarkuh Porphyry Copper deposit is located about 6 km southwest of Sarcheshmeh porphyry copper deposit. Alterations in the region include advanced potassic, propylitic, phyllic and argillic. Copper mineralization is mainly associated with porphyry granodiorite mass. Minerals include chalcopyrite, pyrite, magnetite and some molybdenite. Fluid inclusion studies were performed on quartz from the sulfide viens of the potassic fraction and showed that the main mineralization phase was present with a homogenization temperature between 250 and 527 ° C and a salinity between 13.6 and 52.9 wt ٪ NaCl, has a high salinity in Sarkuh deposit, between +1 Up to 2.7 which indicates the magmatic source of sulfur. The stable isotope data of oxygen on quartz vessels show a positive range between 7.6 to +3.3 with a minimum of +5.5. Shows magma for hydrothermal fluids. Also, due to the limited openness of the sulfur isotopic composition, it can be concluded that the sulfur isotopic mixture is subject to change or is not controlled by other sources or if its amount is very small.
Original Research Paper
Economic Geology
Maryam Khosravi; Wenchao Yu; Jintao u Zhou
Abstract
The Gano bauxite deposit is located 90 km northeast of Semnan city in the eastern Alborz Mountains, northern Iran. The bauxite ores occur as stratiform discrete lenses with a length of 6 km and thickness of 2–20 m along the contact between carbonates of the Elika Formation and shale, sandstone, ...
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The Gano bauxite deposit is located 90 km northeast of Semnan city in the eastern Alborz Mountains, northern Iran. The bauxite ores occur as stratiform discrete lenses with a length of 6 km and thickness of 2–20 m along the contact between carbonates of the Elika Formation and shale, sandstone, siltstone, and coal of the Shemshak Formation. Mineralogical analyses revealed that the bauxite ores consist of diaspore, hematite, kaolinite, chlorite, anatase, illite, zunyite, goethite, quartz, and dolomite minerals. An increase in oxidation, the possible presentence of secondary phosphate minerals, fluctuations of groundwater table level, and the role of carbonate bedrock as an active buffer played an important role in the extent of Ce anomaly in the ores (0.79–12.25). The pH variations of weathering solutions, fluctuations of the groundwater table level, the role of carbonate bedrock as a geochemical barrier, and simultaneous precipitation of Fe-bearing minerals and preferential scavenging of LREE(La–Eu) by hematite played an important role in the distribution and fractionation of rare earth elements in the bauxite ores. According to geochemical considerations (Eu/Eu* vs. TiO2/Al2O3 and Sm/Nd bivariate diagrams), the Gano bauxite deposit probably derived from the weathering of intermediate igneous rocks.
Original Research Paper
Economic Geology
Shohreh Hassanpour; Susan Ebrahimi
Abstract
Astmal deposit is located in the northwest of Iran and is structurally located in the Arasbaran Magmatic zone. Skarn mineralization related to the Eocene-Oligocene granodiorite rocks which have been permeated to the Upper Cretaceous rocks. Mineralization has formed in the exoskarn zone, and the metasomatic ...
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Astmal deposit is located in the northwest of Iran and is structurally located in the Arasbaran Magmatic zone. Skarn mineralization related to the Eocene-Oligocene granodiorite rocks which have been permeated to the Upper Cretaceous rocks. Mineralization has formed in the exoskarn zone, and the metasomatic process has started immediately after the penetration of the granodiorite into the limestone. Significant amounts of Si, Mg, and Fe elements lead to the development of anhydrous calc-silicate minerals with medium to coarse grains, and also significant amounts of Cu, Fe elements along with volatile substances such as CO2, H2S are added to the skarn system. As a result, hydrated calcsilicates (epidote, tremolite, and actinolite), sulfides (pyrite and chalcopyrite), oxides (magnetite and hematite) and carbonates (calcite) have replaced anhydrous calcsilicates. The results of δ34S isotope analysis on pyrite and chalcopyrite ores are in the range of -1.8 to +6.1 ‰, which indicates the magmatic source of sulfide. Also, the results of δ18O and δD isotope data on magnetite, sericite and epidote minerals, which are in the range of -56 to -73 ‰ for hydrogen and -0.5 to +6.8 ‰ for oxygen, indicate a mixture of magmatic fluids associated to the small amounts of meteoric fluids.
Original Research Paper
Economic Geology
Maryam Emami Jafari; Saeid alirezaei; iraj rasa; Jochen Kolb
Abstract
The Hired gold deposit in the Lut block, east Iran, is closely associated with an Eocene intermediate-mafic intrusive complex consisting of granodiorite to diorite, hornblende monzonite, and gabbro-diorite intruded into Eocene volcanic rocks. The intrusions are distinguished by high contents of CaO,FeOt, ...
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The Hired gold deposit in the Lut block, east Iran, is closely associated with an Eocene intermediate-mafic intrusive complex consisting of granodiorite to diorite, hornblende monzonite, and gabbro-diorite intruded into Eocene volcanic rocks. The intrusions are distinguished by high contents of CaO,FeOt, and MgO and rather low K2O+Na2O implying they crystallized from weakly differentiated magmas. This, and the relatively high Mg# (36.36 to 52.32) imply the involvement of a mantle source in the production of the parent magma. The intrusions are metaluminous, calc-alkaline to high-K calc-alkaline, and distinguished by the occurrence of ilmenite as an accessory mineral. Mineralization occurs in veins and veinlets and disseminations in the granodiorite intrusion and in the volcanic rocks closely associated with tourmaline, silicic, and carbonate alterations, and is distinguished by abundant pyrrhotite, arsenopyrite, pyrite, and minor chalcopyrite, galena and sphalerite. Gold occurs mostly as submicroscopic grains in the pyrite and arsenopyrite. The mineralogical and geochemical attributes of the intrusive complex, and the ore mineralogy, allow the Hired to be classified as a gold deposit related to reduced I-type granitoids.The reducing nature of the parent magma can be explained by introduction of reduced crustal materials into the source area, and/or assimilation of carbonaceous metasedimentary rocks.
Original Research Paper
Economic Geology
Mahdi Ghorbani Dehnavi; Azadeh Malekzadeh Shafaroudi; Mohammad Hasan Karimpour
Abstract
Chahnar Pb-Zn deposit is located south of Rutchun plain, 110 km SW Baft, within Sanandaj- Sirjan Zone. Mineralization occurs at calitic-dolomitic marble of Rutchun complex as epigenetic with structural control. Paragenetic minerals are galena and minor sphalerite and pyrite associated with quartz, and ...
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Chahnar Pb-Zn deposit is located south of Rutchun plain, 110 km SW Baft, within Sanandaj- Sirjan Zone. Mineralization occurs at calitic-dolomitic marble of Rutchun complex as epigenetic with structural control. Paragenetic minerals are galena and minor sphalerite and pyrite associated with quartz, and minor calcite and dolomite, as gangue minerals. These minerals show veinlets, open space filling, berrecia, and dessiminated textures. Galena can be seen in the form of coarse graine crystal and cuboctahedral texture and fine graine crystal. Silicification and carbonatization are the most important alteration zones. Galena chemistry indicates galena is Ag, As, Cd and Zn -rich and Sn, Bi-poor. Sb/Bi ratio in galena is close to 3, which is indicator of low temperature deposits. Host rock type, stratabound and epigenetic mineralization, postsedimentary fault controlling, texture, ore types and gangue minerals, and lack of significant correlation between mineralization and igneous activities, chemistry of galena, indicate that Chahnar deposit is similar to MVT deposits, although it has some differences with this deposits type.
Original Research Paper
Stratigraphy and Palaeontology
Kamyar Younesi; Anoshiravan Lotfali Kani; Hormoz Ghalavand
Abstract
A conformable transition between Sarvak and Surgah formations in Lurestan sedimentary basin reveals the potential of studying the Turonian–Coniacian boundary within Surgah Formation. Two sections of the Surgah Formation at Posht-e-Jangal and Pasan anticlines situated on the southeast of the Lurestan ...
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A conformable transition between Sarvak and Surgah formations in Lurestan sedimentary basin reveals the potential of studying the Turonian–Coniacian boundary within Surgah Formation. Two sections of the Surgah Formation at Posht-e-Jangal and Pasan anticlines situated on the southeast of the Lurestan sedimentary basin have been studied on the basis of calcareous nannofossils, and based on the observed distribution of nannoflora, the presence of CC12 to CC16 nannofossil biozones is documented which points to the latest Turonian to Coniacian age for the base of this formation, while the top is estimated approximately at earliest Santonian. Due to the absence of Micula staurophora, however, separation of CC13 and CC14 biozones is not possible and therefore, the Turonian–Coniacian boundary is placed somewhere within the said undivided interval. The FO of Calculites obscurus as the marker event for the top of CC16 biozone is not identified but on the basis of suspected LO of Lithastrinus septenarius as the marker event of the top of UC11 and onset of UC12, the record of early Santonian beds seems probable.
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