جستجوی مقالات مرتبط با کلیدواژه « کرمانشاه » در نشریات گروه « زمین شناسی »

Zagros is very active in terms of seismicity and is the most seismic region of Iran. In the book on the history of earthquakes in Iran, two major earthquakes have been reported on 1st January 958 Mw 6.3, and 1st April 1150 Mw 6.1 (Ambraseys & Melville, 1982). It is well-known that the historical earthquakes consist of valuable information for identifying the hazard of earthquakes, completing the earthquake catalogs, better understanding the Zagros area, and better preparing for this natural phenomenon; on 12th November 2017, an earthquake with a magnitude of 7.3 occurred at a distance of 10 km from the Ezgleh and about 37 km northwest of Sarpolzahab city in Kermanshah province, located at the Iran-Iraq border. The earthquake location was close to historical earthquakes. In this regard, we used the empirical Green's function method to simulate the historical earthquake. Empirical Green's function evaluates parameters of strong ground motion such as time history, frequency content, effective duration, P and S wave arrival time, the Earth response spectrum, and the maximum acceleration of the earth that occurred during the earthquake. Empirical Green's function method is one of the most common and simple simulation methods for generating strong ground motion with geological heterogeneity effects, which is used to model ground motions using foreshocks and aftershocks. In this study, the simulation of one of the Sarpolzahab earthquake aftershocks was conducted by small aftershocks recorded in the Ezgeleh region, using the empirical function method. The temporary network data of the International Institute of Seismology and Earthquake Engineering was used for this study. The simulation results show that there is a good similarity between the waveforms, the Fourier amplitude spectra, and the simulated response spectra observed at the existing stations and that the errors are acceptable. The parameters of the acquired model consist of rupture velocity of 2.6 to 3.5 km/sec equivalent to 0.8 to 0.9 times the S-wave speed and healing velocity equal to 0.95 times the rupture velocity. The dimensions of the fault grids were 0.05x0.05 and the scalar seismic moment of the aftershock was 1.04×1023 Nm. In the simulation, asperities were not considered. The source time function was Kostrov-ramp and fault roughness was taken into account. Furthermore, the waveforms, Fourier amplitude spectra, and response spectra for the mentioned historical earthquakes were constructed with the results obtained from the reference earthquake for simulation. The results are reasonable; however, some errors are unavoidable.

The Garou Formation (Aptian – Cenomanian) is one of the hydrocarbon-generating formations in the Zagros Basin. The lithology of the Garou Formation in the study area has been alternative to clay-limestone and shale which is dominated by shale facies. This study has been selected as the source rock of gas shale for organic geochemistry studies of Garou Formation and 26 intact and non-aerated rock samples were taken through the water transfer tunnel of this formation, NW Kermanshah. The samples were analyzed by Rock-Eval 6 pyrolysis method. Based on studies, the dominant kerogen type III is the Garau Formation was recognized. In terms of genetic potential, the Garu Formation is poor to relatively good source rock, but its hydrocarbon potential ranks poor. The reflection of vitrinite in most of the Garau Formation specimens is more than 1.3 percentage and indicating a source rock in the gas production stage, which is confirmed by Tmax more than 440 C°. Furthermore, the thermal history model of the Garau Formation in the study area suggests that this formation entered to catagenetic range in Paleogene and reached high thermal maturity in the late Neogene. The existing methane and carbon dioxide in the tunnel with a concentration of more than 1800 ppm can be attributed to the generation of gaseous hydrocarbons according to the results of thermal history modeling that this volume of exhaust gas is related to the shales of the Garau Formation.

Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic pollutants composed of two or more benzene rings. These compounds have attracted widespread attention due to their high carcinogenicity and mutagenicity in humans. In this study, 21 street dust samples were collected from various land uses in Kermanshah to investigate pollution and potential sources of PAHs. The samples were analyzed using gas chromatography-mass spectrometer (ICP-MS) after preparation. Also, in order to accurate identification of pollution sources, isomeric ratios were used. The results showed that all 16 PAH compounds identified by the United States Environmental Protection Agency (USEPA) as dangerous carcinogenic compounds are present in the street dust of Kermanshah metropolis. The concentration of total PAHs varies from 22.8 to 2820.98 μg / kg dry weight, with an average concentration of 1140.79 μg / kg. In addition, the toxic equivalency quotient (TEQ) in street dust samples of Kermanshah metropolis ranges from 18.54 μg / kg to 196.64 μg / kg, indicating the difference in concentration and toxicity of these compounds in different parts of the city. The results also show that the potential risk of carcinogenicity in adults and children through dermal contact is greater than direct ingestion and respiration pathways. In general, considering the isomeric ratios and principal component analysis, the combustion of fossil fuels, oil products and emissions from vehicles and traffic are the most important sources of PAHs in Kermanshah metropolis.

The pillow lavas and dyke swarm of Harsin-Nurabad and Miyanrahan are part of Kermanshah Ophiolite complex. Diabasic dykes with ophitic, doleritic and glomeroporphyritic textures consist of zoned plagioclase and clinopyroxen and pillow lavas have intergranular and microporphyritic textures with hyalomicrolitic matrix and consist of plagioclase, augite-diopside and pseudomorphic olivines.The resalts of N-MORB-normalized multielement and chondrite-normalized REE patterns indicate that these rocks not formed in supra-subduction zone but overall geochemistry of Gashor pillow baslte and diabasic dykes resembles that of alkaline basalts generated at within-plate ocean island settings (OIB), meanwhile Tamark and Miyanrahan pillow baslte show P-MORB geochemical signature. MORB evidence in studied rocks is interpreted to be the partial melting of an OIB-type enriched source led to the production of the Gashor and diabasic dykes alkaline basalts whereas the partial melting of MORB-type mantle heterogeneously modified by OIB-type components resulted in the production of Tamark and Miyanrahan P-MORBs. Therefore, it may be considered that, southern Neo-Tethys was characterized by an intermediate rifted margin type where asymmetrical rifting, exhumed sub-continental upper mantle provided combination of continental margin- and plume-type in the investigated ophiolites.

In this study, the Late Paleocene Taleh Zang Formation in the southwest of Kermanshah hasbeeninvestigatedfor elemental geochemistry and effective diagenetic processes during burial. The thickness of the studied section is 282 meters that mainly composed of shallow marine limestones with interbedded of marl and dolomite. The main diagenetic processes affecting the TalehZangFormation include micritization, various types of porosity, cementation, dolomitization and compaction. Due to the texture and the abundance of unstable skeletal particles (green algae and bivalve), porosity and cementation aremorecommon among the identified processes. Microscopic and geochemical studies have shown that these processes have taken place in eogenesis and early mesogenesis stages in marine, meteoric and shallow burial environments. Evidences indicate that the carbonates of the TalehZangFormation didnot tolerate deep burial after the deposition during diagenesis. Fluids that affected the lower parts of the formation during burial were mainly marine. Moreover, tothetop ofthe sequence in addition to seawater less meteoric fluids have affected the marine carbonates of the Taleh Zang Formation during diagenesis. The high amounts of Sr/Mn (mean27/51) and Sr/Ca (mean 1/61) and also low Mn (mean 27ppm) and Fe (mean 78ppm) values indicate close digenetic system with low water/rock interaction for the carbonate samples of the TalehZangFormation.

Some researchers defined environment pollution as any change in properties of the environment members in a way that makes not only natural performance and biological balance disordered but also jeopardizes the benefits and the life of living creatures directly and indirectly. For centuries, different heavy metals, whether anthropogenic or earth-made, have been releasing into water and soil resources through different natural processes and industrial activities. In fact, studying water pollution to heavy metals can provide a good way to improve the quality of water, decrease disease, and increase safety and health. One of the natural water polluting activities is the weathering and oxidation processes on ophiolite rocks of special regions. Controlling chemistry processes and water composition, like weathering and dissolution, ion exchange, and absorption-desorption processes, can have high importance.

After field study and making related maps, the samples from the region’s wells and springs were gathered through a field operation. Since the concentration-aqueous concentration of the elements is affected more by evaporation during the dry season, the samples were gathered at the end of September, the time before precipitation when dry summer is finished. Plastic containers with half-liter capacity were used for the samples. Before gathering, the containers were filled and emptied 3 times. After that, 10cc nitric acid was added to the samples for each liter; and then they were sent to Zar Azma Mineral Company for analysis of their heavy elements. Concentration total of 28 light and heavy elements were measured in the water samples by ICP-MS analysis.

Dendrogram diagram and Pearson correlation were applied to classify the samples based on intergroup similarities, to find the probable source of the elements, and to study the correlation among the elements. It can be seen that Cr has a rather high positive correlation (0.54) with Si indicating the fact that they both have the same source, from Si minerals. This table reveals that there is a high correlation between Ca, S, and Sr on one hand, and a high correlation between Cr and Si and somewhat with Mg, on the other hand. Moreover, there is a rather high positive correlation between Ni and P and somewhat between Ni and Mg. These correlations can prove the fact that the elements have the same source. According to ArcGIS maps, the most concentration of calcium, Sr, and S is recorded for zone 1 including Hezarkhani and Yadabad. Moreover, the lowest concentration of these three elements is recorded for Aliabad and Ch-pavleh. These elements are expected to be originated mostly from conglomerate and limestone deposits. It turns out that the second controlling factor of groundwater chemistry includes the weathering and dissolution of source rock of Cr, Mg, and Si. The same-value maps of sampling points have been classified based on the concentration of Cr, Si, and Mg, revealing that the points of highest and lowest concentration of these elements are geographically the same. This fact proves a high correlation and a similar source of these elements. Therefore it can be seen that the highest concentration of these elements is recorded for Ch-pavleh, while the lowest concentration for Aliabad and Gashour. Since chromium has a high positive correlation with Si, it can be concluded that chromium has a silicate source. Based on the geological map of the region, the important silicate source is peridotite. In fact, peridotites, as a representative of the ophiolite collection of the region, can be considered as the source of Cr entrance to the regional waters. Moreover, as these peridotites include ferromagnesian minerals, they are also regarded as the source of Mg entrance to regional waters. Therefore, peridotites are considered as the common source of Si, Cr, and somewhat Mg entrance to regional waters. The existence of Cr- spinel in the geochemistry of peridotite rocks in Ch-pavleh can also prove silicate and peridotite sources of Cr in the region water.

Pearson correlation among elements was calculated to recognize the elements with the most correlation. According to that, the elements with higher correlation are suggested to have the same source. Factor analysis revealed that controlling factors of water chemistry have the highest correlation with the elements which have the highest correlation. Dissolution and weathering of these elements’ source rock are considered the important factors. Besides, focusing on water-rock interaction, the most essential minerals participating in the actions with water were recognized. Same-value maps were applied to determine the source of the elements. Moreover, according to these maps, it is revealed that the elements with the highest correlation come from the same geographical setting.   Based on these stages, the important controlling factors of water chemistry were recognized as the following: weathering and dissolution of conglomerate deposits to the dissolution of gypsum as the common source of calcium, strontium, and sulfide, weathering and dissolution of peridotites, especially ferromagnesian ( as the common source of magnesium and nickel) and chrome-bearing spinel (a common source of chromium, cilice, and magnesium), dissolution of chalcedony, barite, and calcite as three minerals with the highest saturation index.

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.

Sahneh, Harsin-Nourabad ophiolits (Kermanshah Provience) located in outer Zagros ophiolitic zone and are parts of the Cretaceous ophiolitic belt, as remnants of southern branch of the Neo-Tethys Ocean obducted over the Arabic–Tauric platform from Oman to northwestern Syria, Cyprus and Antalya. Calculation of Fe/Mg separation coefficient of olivine indicates the mantle origin of this mineral. Textural evidence of ultramafic rocks displays clear evidence of cooling with decompression, partial melting and melt-rock reactions. Tectonomagmatic discrimination diagrams show that peridotite samples are located in olivine- spinel mantle array and SSZ peridotite field. Based on geothermobarometry calibration the temperature and pressure of crystallization of harzburgite and lherzolite rocks were 1100 to 1500 ° C and 12 to 18 Kbar and the wehrlite sample was 1200 to 1500 ° C and 21 to 23 Kbar, which corresponds to the SSZ tectonic environment.

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.

Nosud water transfer tunnel with a length of 45 km has been constructed to guide and transfer water in the northwest of Kermanshah. The tunnel passes through several anticlines and synclines and as soon as its axis enters the Garo and Gurpi formations, gases with a volume of more than 400 ppm are drained into the tunnel, which is mainly related to the Azgleh and Kurdish Qasman anticlines. In the Zagros Basin, the Garou and Gurpi Formations are known as high potential oil source rocks. In the study area, despite the predominant type III kerogen, which is mainly of dry origin, a large volume of gases, mainly methane and carbon dioxide, are found. Due to the expansion of Garo and Gurpi formations in the region, gas-prone zones in the tunnel axis are divided into four parts A, B, C, D, which is the largest volume of gas produced in the Kurdish anticline of Qasman and is related to zone D. The gases produced from these areas along with a large volume of water are led into the tunnel through tectonic fractures, which are mainly joints and faults, among which faults play a very important role in the Kurdish anticline of Qasman and the anticline of the herd.

The Garau Formation (Apthian – Cenomanian) is one of the hydrocarbon-generating formations in the Zagros Basin. Investing hydrocarbon potential of the Garau Fm., 14 samples were taken through the Nosoud water-transfer tunnel, NW Kermanshah. The samples were analyzed by selected from Rock- Eval 3 pyrolysis method. The results show that kerogen type III is the most abundant in the Garau Fm. According to the Tmax, the organic matter of Garau Fm. is thermally matured in the study area. The HI vs TOC values indicate a CD organic facies representing an oxidizing environment of plant organic origin in this formation at the study area. In terms of genetic potential, the Garau Fm. is a poor to relatively good source rock, but its hydrocarbon potential ranks poor. The vitrinite reflectance is more than 1.3 in the most samples, which indicates gas production stage that is also confirmed by Tmax more than 440 C°. Furthermore, thermal history model of the Garau Fm. in the study area suggests this formation entered to catagenetic stage in Paleogene and reached to high thermal maturity in late Neogene. The existing methane and carbon dioxide in the tunnel with a concentration of more than 870 ppm can be attributed to the generation of gaseous hydrocarbons according to the results of thermal modeling.

The studied zone is in the Northern part of  Zagros Suture Zone (Kermanshah). The presence of deep sea sediments, oceanic crust remnants, platform carbonates, igneous and metamorphosed rocks of active margin and carbonate sequence of passive margin that are assembled in the studied area show a compressional tectonic regime from the late Cretaceous up to the present. As a result of convergent regime, a very complicated structural zone is developed. The main purpose of this study is stress characteristic analysis in Zagros Suture Zone (Kermanshah).To recognize and study the arrangement of stress axes a great amount of data were gathered from the folds axial surface and the faults which are appeared within the rocks specially the radiolaritic rocks. The data includes characteristics of fault surface geometry, fault slip and lineation slip. The stress recording patterns for data in this study is Multiple Inverse Method and comparison with stress position by using folds axial surface.  By studying folds it was obtained the situation of main stress σ1, σ2 and σ3 respectively as 029, 127, 234 and by using the method Multiple Inverse Method, the situation of main stress is obtained as 059, 304, 194. Based on the investigations in the study area and measurements on Cretaceous rocks, the results show that the main stress direction since Cretaceous up to the present is northeastern with minor changes. The estimations of stress direction were the same in both folds and faults. As a result, the shortening direction has been constant, so the shortening faults all show one direction of stress.

In this paper, the biological evolution of the carbonate platform of the Taleh Zang Formation with Paleocene age in the Kermanshah region has been investigated in two stages (time interval) concentrating on fossil debris (such as algae, corals, and benthic foraminifera). For this purpose, two suitable stratigraphic of this formation in the south (Kaboutar Bala section) and southwest (Barikeh section) of Kermanshah were selected, sampled, and studied. For a broader view, the results of this study have been compared with other parts of Tethys basin around the world. The depositional environment of the studied deposits of the Taleh Zang Formation is a carbonate ramp and is probably a form a low gradient ramp due to underdeveloped coral constructions. The gradient of this platform increases from the northwest (Barikeh section) to the southwest (Kaboutar Bala section). Four biofacies were recognized in the studied successions, which include green algae, coral, green algae and benthic foraminifera as well as benthic foraminifera and green algal biofacies. In the lower parts of the Taleh Zang Formation, the presence of algal and coral biofacies (patch reefs) indicates the first stage of carbonate biological evolution of this formation, in that such biofacies has been identified in the Paleocene sequences of other Tethys sectors. Throughout the time and in the upper parts of the Taleh Zang Formation, corals have disappeared and the abundance of green algae is greatly reduced. By the presence of benthic foraminifera with low amounts of green algae, the second stage of the biological evolution of the carbonate platform of the Taleh Zang Formation in the Kermanshah region is formed. In the Early Eocene in Kermanshah region and in the studied successions, due to the seawater regression, the production of carbonates in the Taleh Zang Formation stopped and the detrital red sediments of the Kashkan Formation replaced the carbonates of the Taleh Zang Formation. However, the carbonate production of this formation continued in other areas of the Zagros sedimentary basin (Lorestan province) until the Middle Eocene.

In karstification phenomenon of carbonate formations various factors are involved which the most important of them are lithology, precipitation, stratigraphic characteristics, structural factors and the topography of the region. Thick and massive limestones have much higher potential for the development of karst and, as a result, the formation of karst features. In this research, four important karstic springs have been investigated, the name of these springs are Ravansar, Kabotarlaneh, Sahneh and Kashanbeh. The catchment areas of these springs are located in the different geological formations with various lithologies and ages. The discharge of springs and its variability depends significantly on the lithology of the aforementioned formations. The average annual discharge of the Ravansar, Darband Sahneh, Kashanbeh, and Kabotarlaneh springs in the hydrological year 2016–2017 is 1932, 462, 166 and 771 lit/s, respectively. Moreover, the coefficients of variation of these karst springs are 1.07, 0.30, 0.49 and 0.48 and the maximum to minimum ratio of these springs were calculated 20, 2, 7 and 4, respectively. The Ravansar and Kabotarlaneh springs have three discharge coefficients, while the springs of the Sahneh and Kashanbeh have two, which are related to stratigraphy and lithology of their basins. The largest of the aquifer storage from these springs is dedicated to the Ravansar spring, and the smallest is Kashanbeh; the discharge of these springs also confirms it.

Contamination of seven heavy metals (Cu, Pb, Zn, Fe, Al, V, Ni) and PAH compounds, and physicochemical characteristics were studied in sediments of Qarasoo River, Kermanshah. The results of contamination factor (CF), pollution load index (PLI) and enrichment factor indicated severe contamination of sediments, particularly for lead, zinc and copper in some segments of the river. Also, sampling stations near the city including oil refinery and industrial town had much higher PAH concentrations than the upstream. Based on toxic equivalency factor (TEF) and comparison of PAHs concentration with effect range low (ERL) revealed inappropriate situation of Qarasoo sediments. Among the various compounds, 3-rings PAHs are dominant with maximum concentration, same as heavy metals, in oil refinery station. Based on principal component analysis (PCA) and geochemical indices effluents of Kermanshah oil refinery are the main source of contamination of low molecular weight PAHs with petrogenic origin and copper, vanadium and nickel. In addition, organic matter and pH have also shown strong correlation with this component, confirming the role of the refinery in increasing their concentration in the Qarasoo River. Other important anthropogenic sources in the Qarasoo River include urban and industrial effluent, traffic and illegal waste disposal in the river margins.

In this study, for determination of dolomitization model of the Taleh Zang Formation, 2 suitable outcrops have been used in the South and Southwest of Kermanshah city. The Barikeh section in southwest of Kermanshah city, with a thickness of 282 m conformably overlies the Amiran Formation and is overlain by the Kashkan Formation. The thickness of the dolomites in this section reaches to about 40 m which are present in the lower part of the TalehZang Formation. The Kaboutar Bala section with a thickness of 65 m,like the Barikeh section conformably overlies the Amiran Formation and is overlain by the Kashkan Formation with a disconformity surface. The existing dolomites in this section are also occur in the upper part of the Taleh Zang Formation which has 12 m thickness. Based on the fieldwork evidences, petrographic studies (polarizan microscope, SEM and CL) and geochemical analysis (AAS), four different types of dolomite have been distinguished in the Taleh Zang Formation which include dolomicrite, dolomicrosparaite, dolosparaite and pore-filling dolomite cement. In these dolomites, there is no evidence of the saddle dolomite and dolomicrosparaite have the highest amount of porosity among all types of dolomites. Based on Energy Dispersive X-ray (EDX) analysis, the smectite clay mineral was identified among the upper dolomites sequence in the Kaboutar Bala section. Dolomitization model of the Taleh Zang Formation in the upper part of the section (Kaboutar Bala section) is sabkha type evaporation model and in the lower part of the section (Barikeh section) is shallow burial model.

In this study, for the first time depositional conditions, sequence stratigraphy and elemental geochemistry of the Taleh Zang Formation with Paleocene to Lower Eocene age in the Kermanshah province (Kaboutar Bala section) have been evaluated. In this section, the Taleh Zang Formation conformably overlies the Amiran Formation and is overlain by the Kashkan Formation with a disconformity surface. Field and microscopic studies led to recognition of six microfacies within the succession. Gradual microfacies change, the absence of calciturbidites and lack of extensive barrier reefs with considerable thickness, confirms a carbonate ramp. Sequence stratigraphic studies led to the identification of one-third order depositional sequence which includes TST and HST facies association. The lower boundary of this sequence, specified as type II and the upper boundary with evidences of subaerial exposure is type I. The maximum flooding surface (MFS) is determined with bioclastic coral corallinacea floatstone/rudstone microfacies of proximal middle ramp. The results of geochemical analysis of major elements (Ca, Mg) and minor elements (Sr, Na, Mn and Fe) indicate that the original carbonate mineralogy is aragonite and diagenetic system is semi-close to open system. Trend of elements changes along this stratigraphic section shows that in the HST sediments, the amount of Sr is decreased, while Fe and Mn are increased due to more meteoric diagenetic effect.

The Taleh Zang Formation is part of Lower Paleogene (Upper Paleocene–Middle Eocene) in the Lorestan zone of Zagros basin (Aghanabati 2010). At the type locality, this formation conformably overlies Cretaceous beds of marl and siltstone belonging to the Amiran Formation and is overlain by the Kashkan Formation with an unconformity (Aghanabati 2010). The thickness of the Taleh Zang Formation is very variable, as in some areas, this formation is absent and the Kashkan Formation directly overlies the Amiran Formation (Rajabi et al. 2011). In this paper the carbonate deposits of the Taleh Zang Formation in the Kermanshah province (Kaboutar Bala section) have been studied for the first time. The previous study of the Taleh Zang Formation in the Kermanshah province are focused on the biostratigraphy and also the components of this current study is different from other sections in the Lorestan zone (such as the absence of larger benthic foraminifera e.g. nummulitidae, alveolinidae and discocyclinidae and presence of corals and algae). So in this research for the first time depositional conditions, sequence stratigraphy and elemental geochemistry of the Taleh Zang Formation in the Kermanshah province (Kaboutar Bala section) have been evaluated.
 

For the present study, one surface section of the Taleh Zang Formation in the south of the Kermanshah region (Kaboutar Bala section) has been studied. The section measured a total thickness of 65 m and consists of limestone, dolomitic limestone, dolostone and minor amount of marl. During the fieldwork studies, 33 rock samples from carbonate deposits (limestone and dolostone) have been taken for petrographic studies. In order to differentiate ferroan and non-ferroan calcite from ferroan and non-ferroan dolomite in thin sections, the staining method of Dickson (1965) was applied. According to the methods of some researchers such as Haq et al. (1987) and Posamentier et al. (1988), depositional sequences were recognized. Elemental geochemistry analysis were performed form 12 samples of carbonates at the geochemistry laboratory of Shahid Beheshti University, Iran.
 

Based on the field and petrographic studies, the microfacies and depositional environment of the Taleh Zang Formation were recognized. This formation in the Kaboutar Bala section have been made of six microfacies which occur in four facies belts. The tidal flat sediment is composed of dolomicrite with ranging in size from 4 to 16 µm and contain silt-size quartz grains. Many researchers believe that dolomicrite forms during very early diagenesis in supratidal to intertidal environments (e.g. Sibley and Gregg 1987; Adabi 2009). From the shoreline towards the seas, the lagoon facies belt consists of two microfacies; bioclastic benthic foraminifera peloidal wackestone, and bioclastic benthic foraminifera dasycladacea wackestone to packstone. The lack of marine biota and abundant components of restricted biota (such as miliolids and dasycladacea), represent a restricted conditions in the lagoon environment (Bachmann and Hirsch 2006; Adabi et al. 2015; Kahsnitz et al. 2018). Barrier facies belt is composed of coral boundstone microfacies with limited lateral extension. The main components of this microfacies are only corals. The dominance of coral colonies indicate a high energy environment in the barrier facies belt (Vescogni et al. 2016; Ghafari et al. 2017). The open marine facies belt includes coral floatstone and bioclastic coral corallinacea floatstone/rudstone microfacies. The common coral debris may have derived from erosion of pre-existing coral colonies (in the barrier facies belt) by currents and/or storms (Roozpeykar and Maghfouri Moghaddam 2015; Shabafrooz et al. 2015). Gradual microfacies change, the absence of calciturbidites and lack of extensive barrier reefs with considerable thickness, confirms a carbonate ramp .
Based on the sequence stratigraphic studies, one depositional sequence was identified in the studied sequence. The lower boundary of this sequence is located at the base of the formation and specified as type II. The upper boundary with evidences of subaerial exposure and the presence of siliciclastic Kashkan Formation specified as type I. The MFS is determined with bioclastic coral corallinacea floatstone/rudstone microfacies belonging to the proximal middle ramp.
Geochemical analysis in limestone parts of the formation including Ca (37.57–39.25%), Mg (0.25–1.3%), Sr (964–1833 ppm), Na (65–160 ppm), Mn (161–421 ppm) and Fe (281–2107 ppm), and their variations indicate that the original carbonate mineralogy is aragonite and diagenetic system is semi-close to open system.
Variation trends of elements along the stratigraphic column shows that the amounts of elements in the TST and HST are different from each other. Generally in the HST sediments, the amount of Sr is decreased, while Fe and Mn are increased due to more meteoric diagenetic effect at this part of the sequence.

In the Northern part of Suture Zone (Kermanshah) the deep sea sediments, oceanic crust remnants, platform carbonates, igneous and metamorphosed rock of active margin and carbonate sequence of passive margin are assembled in this studied area. This convergent area has provided a very complicated structural zone. The main purpose of this study is stress characteristic analysis. A great data has gathered from the faults which are appeared within the rocks specially the radiolaritic rocks. The data includes characteristics of fault surface geometry, fault slip and lineation slip related. By using the method Right Dihedral, the position of main stress was obtained. The great number of reverse faults have a NW- SW trend, while the strike- slip faults, show a NE- SW direction. The Normal faults with a different displacements appeared younger than the other faults. The result of this study that we obtained the situation of main stress σ1, σ2 and σ3 respectively is 059, 305 and 195.