List of articles (by subject) Geoscience Fields in relation with Petroleum Geology
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Open Access Article
1 - Biostratigraphy, microfacies and sequence stratigraphy of the Asmari Formation (based on Cyclolog) in the Qaleh Nar Oli field, Zagros Basin
adel neisi ali Ghobeishav Mohammad Allahkarampour-DillIn this research, biostratigraphy, microfacies, sedimentary environments and sequence stratigraphy (using by Cyclolog software) of the Asmari Formation are carried out. These studies are done on the basis of 580 samples (core and cutting) from 430 meters thickness of th MoreIn this research, biostratigraphy, microfacies, sedimentary environments and sequence stratigraphy (using by Cyclolog software) of the Asmari Formation are carried out. These studies are done on the basis of 580 samples (core and cutting) from 430 meters thickness of the formation from the well #2 of the Qaleh-Nar oilfield. Paleontological studies are led to identification of 23 genera and 28 species of the benthic and planktonic foraminifera. According to these microfossils, four assemblage zones have been recognized which confirm the age of Oligocene (Rupelian – Chattian) and Early Miocene (Aquitanian – Burdigalian) for the whole formation. Paleoenvironmental studies demonstrate 9 different microfacies that were deposited in the outer ramp (open marine) in the lower Asmari part, middle ramp (open marine to shoal) in the middle Asmari part and the inner ramp environment (tidal flat to lagoon) in the upper Asmari part. The sequence stratigraphy on the well #2 and the auxiliary well numbers 1, 3, 5, 6 and 7 of the Qaleh-Nar oilfield using by Cyclolog software reveals 7 positive breaks and 9 negative break levels alternatively. Some of the positive breaks define sequence boundaries and some of the negative breaks present the maximum flooding surfaces. In addition, a number of positive levels specify the major chronozone (stage boundaries). Comparison of the quintuple reservoir zones of the Asmari Formation in the Qaleh-Nar oilfield with the mentioned break levels suggests a fine correlation with these levels; however this correlation is invalid for other levels. Manuscript profile -
Open Access Article
2 - Biostratigraphy and sedimentary environment of Asmari Formation in Davan section, North of Kazerun
masood khoshnood Hosyen Vaziri moghadamThis research concentrates on biostratigraphy, microfasies and Sedimentary environment of the Asmari Formation at Davan village in 10 Km north of Kazerun. Micropalaeontological study led to recognition of 25 genera and 15 species of foraminifera. Based on biostratigraph MoreThis research concentrates on biostratigraphy, microfasies and Sedimentary environment of the Asmari Formation at Davan village in 10 Km north of Kazerun. Micropalaeontological study led to recognition of 25 genera and 15 species of foraminifera. Based on biostratigraphic study 3 biozones (1-Nummulites vascus – Nummulites fichteli assemblage zone, 2 -Lepdocyclina-Operculina- Ditrupa Assemblage Zone, 3- Archaias asmaricus- Archaias hensoni- Miogypsinoides complanatus Assemblage Zone) are determined. As a result, the age of the Asmari Formation is Oligocene (Rupelian – Chattian) at the study area. Depositional texture, petrographic analyses and fauna led to identification of 9 carbonate microfacies related to open marine, slope, bar and lagoon. These depositional environments correspond to inner, middle, and outer ramp. Manuscript profile -
Open Access Article
3 - Fracture analysis of the Asmari Formation of Dara anticline, as analog model for other Asmari subsurface hydrocarbon reservoirs
saeed mohammadi asl Ali Farzipour Saein Ghodratollah ShafieiThe quality of the Asmari Formation, as the reservoir rock of almost three-quarters of the explored oil In Southwest Iran, is often affected by the fractures system. In this paper, in order to study fracture patterns in the Asmari Formation, as well as to present an ana MoreThe quality of the Asmari Formation, as the reservoir rock of almost three-quarters of the explored oil In Southwest Iran, is often affected by the fractures system. In this paper, in order to study fracture patterns in the Asmari Formation, as well as to present an analog model for other Asmari reservoirs, the Dara anticline in South Dezful depression, which has extensive outcrops of the Asmari Formation, has been studied. During field studies, eleven stations on the anticline, in its different structural positions, have been investigated. In the southwestern limb, four fracture sets trending AZ40-50,AZ130-140,AZ10-20,AZ80-90, in the northeastern limb four fracture sets trending AZ130-140,AZ50-60,AZ170-180,AZ110-120, and in its hinge area, three fracture sets with AZ50-60,AZ130-140,AZ0-10 trends have been identified. From the structural perspective, all the identified fracture sets are associated with folding. In this study, the relative formation time of the identified fractures relative to folding, has been diagnosed as before or simultaneously with folding. Based on field studies, fractures density in the Dara anticline, the Asmari outcrop, ranges from 11.75 to 2 fractures per meter. Indeed, variation range of the fracture length is 1 to 25 m and most fractures have a length of lower than 5 meters. Also, in this study it was found that there is a negative logarithmic relationship between fracture density and sedimentary layers thickness. Manuscript profile -
Open Access Article
4 - Structural Modeling and Estimation of Tectonic Stresses at Lali Oilfield in Dezful Embayment
Nasrin kianizadeh Behzad Zamani Rahym khadkhodayi Hoseyn TalebiStructural geological study is one of the most important stages of an oilfield exploration and production (E&P) program, since a knowledge of existing structures can play a fundamental role in the oilfield development plan. The main purpose of this study is to create MoreStructural geological study is one of the most important stages of an oilfield exploration and production (E&P) program, since a knowledge of existing structures can play a fundamental role in the oilfield development plan. The main purpose of this study is to create three-dimensional (3D) structural models to determine direction of tectonic stresses at Lali oilfield using subsurface geophysical data. The study area is located within the so-called Dezful Embayment (northern Khuzestan Province, Iran). Accordingly, in order to provide a 3D model of the reservoir, geostatistical tools in Petrel Software were utilized. Incorporating density log data into several coded formulations in MS Excel Software, the reservoir had its modulus of elasticity calculated. Subsequently, maximum and minimum horizontal stresses were calculated using poroelastic equations. Fault modeling results showed that, fault dip increases with increasing the depth towards the center of the field. Obtained values of stress using the poroelastic equations show that σ_H>σ_h>σ_v, confirming a regional reverse stress regime, which is consistent with previous studies in this area. Also, the formal stress ratios (Φ = (σ2-σ3) / (σ1-σ3)) obtained from poroelastic equations and inverse analysis method were found to be well-correlated across the area. Finally, average azimuth of the reverse faults on the southern limb (as calculated by Petrel) and the fractures on the limb (as obtained from FMI images and core samples) were found to be N305 and N315, respectively (average = N310). Thus, N040E was inferred to be the average direction of principal stress, i.e. principal stress is mostly directed along a NE-SW axis (perpendicular to the general trend of Zagros Orogeny); this is probably a result of the activities of youngest Zagros orogeny phase. The agreement between the obtained principal stress directions by fractures, faults, and focal mechanism of earthquakes across the World Stress Map (WSM) confirms the validity of this study. Manuscript profile -
Open Access Article
5 - Improve the detection of buried channel, using Artificial Neural Networks and seismic attributes
Alireza Ghazanfari Abdolrahim Javaherian Mojtaba Seddigh ArabaniChannels are one of the most important stratigraphic and morphological events. If channels place in a suitable position such as enclosed in impermeable place can make suitable oil and gas reservoir; So identifying channels are crucial. Different tools such as filters, s MoreChannels are one of the most important stratigraphic and morphological events. If channels place in a suitable position such as enclosed in impermeable place can make suitable oil and gas reservoir; So identifying channels are crucial. Different tools such as filters, seismic attributes, artificial neural networks, and meta-attributes have played an important role in this regard. In this paper dip-steering cube, dip-steer median filter, dip-steer diffusion filter, and fault enhancement filter, have been used. Then, various seismic attributes such as similarity, texture, spectral decomposition, energy and polar dip have been defined and studied. Therefore, work on F3 real seismic data of Dutch part of the North sea for detecting channels has been started by detecting suitable attributes. For identifying the channel in data, it has been used from compilation and combination of seismic attributes using supervised ANN (multi-layer perceptron), and development of mata-attributes, then recombine meta-attributes created along the channel, and using different interpretation point, for eliminating the impact of facies and lithology changes along the channel. Among the advantages and the reasons for using this kind of neural network (supervised), which increases the effect of the neural network and improves the result, is the ability to train the network by specifying the channel and non-channel points used in this paper. Finally, using the above methods, the identification of the channel examined in the above seismic data has been improved, and the channel has been properly detected and extracted throughout its entire length. Manuscript profile -
Open Access Article
6 - Facies, thickness variations and reservoir characterisation of Arab formation (Surmeh) in the Eastern part of the Persian Gulf
Ali reza BashariThe Kimmerigian-Tithonian) Arab Zone are the prolific hydrocarbon bearing resrvoirs in the eastern part of the Persian Gulf,offshore,Iran.They were deposited in an arid climate which dominate during late Jurassic. The Berriasian to Thitonian Hith formation wich o MoreThe Kimmerigian-Tithonian) Arab Zone are the prolific hydrocarbon bearing resrvoirs in the eastern part of the Persian Gulf,offshore,Iran.They were deposited in an arid climate which dominate during late Jurassic. The Berriasian to Thitonian Hith formation wich overlies the Arab reservoir constitutes the cap rock,wich just to the east gradually pinches out and form a N-S feather adge. The study reveals that Arab zones form a massive to interbedded anhydrite with varying proportion of limestone and dolomite and generally have regressive units which was deposited on a broad carbonate platform .This formations are thick in center (Salman field) and mostly consist of intertidal pack/grainstones with high porosity/permeability,good cap rock and also close to the source rock,which has the most hydrocarbon potential, but towards east the layers getting thinner with unsuitable cap rock and are away from source rock ,so as a result Arab formation in this part of the Persian Gulf doesn,t seem to be attractive. This study reveals that there is still some undrilled structure within this area which could be attractive for further Exploration drilling. Manuscript profile -
Open Access Article
7 - Calculation of elasticity modulus and rock strength parameters and their relationship with porosity in Dalan formation in one of the well in south pars gas field
Reza Khoshnevis Zadeh Alireza Hajian Ehsan LarkiThe elastic parameters of the rock include the Young modulus, the Poisson ratio, the bulk modulus and the shear modulus. Young modulus with the unconfined compressive strength of rock, are two key parameters in the definition of intact rock. Elastic modulus represents t MoreThe elastic parameters of the rock include the Young modulus, the Poisson ratio, the bulk modulus and the shear modulus. Young modulus with the unconfined compressive strength of rock, are two key parameters in the definition of intact rock. Elastic modulus represents the amount of rock rigidity and is known as the stress-strain chart slope. These parameters represent of rock strength to failure, are important parameters for the stability analysis of wellbore stability. According to the unavailability and cost of core data, and also attended to this fact that the data from the core are not continuous and not available at all points in the well, the uses of DSI logs is one of the best methods for calculating elastic modules. Using these logs, you can also study elastic moduli continuously in a well. In this study, elastic dynamic parameters were calculated using the DSI and density logs for the Dalan Formation. Attention to the fact that the calculated parameters using the velocity of the sound waves are of the type of dynamic parameters, these parameters were have converted to the static modules using appropriate empirical relationships. The rock strength Parameters were calculated using the experimental relationships commonly used in the oil industry to determine rock strength parameters. These parameters were calculated according to static elastic modulus as well as porosity and shale volume. Comparing the values of elastic modulus and rock strength parameters with porosity showed that porosity with elastic modulus and rock strength parameters has an inverse relationship, so that with increases the porosity, the elastic modulus and rock strength parameters have been reduced. Manuscript profile -
Open Access Article
8 - Biostratigraphy of the Gurpi Formation Based on Planktonic foraminifera with emphasis on the Cretaceous-Paleogene boundary in Jahangirabad Section, Kabirkuh Anticline, SW Iran
Alireza Ashouri Samira Rahimi Abass Sadeghi Abbas GhaderiIn this research, biostratigraphy of the Gurpi Formation in Jahangirabad section, SW Iran, has been studied .The thickness of the Gurpi Formation in this section is 263 and consists mainly of argillaceous limestone and limestone. The lower boundary with the Ilam Formati MoreIn this research, biostratigraphy of the Gurpi Formation in Jahangirabad section, SW Iran, has been studied .The thickness of the Gurpi Formation in this section is 263 and consists mainly of argillaceous limestone and limestone. The lower boundary with the Ilam Formation is comformable with sharp lithology and upper boundary with the Pabdeh Formation is gradational. In this study, 76 species belong to 17 genera and 8 biozones of planktonic foraminifera were recognized. The biozones consist of Globotruncana ventricosa Zone, Radotruncana calcarata Zone, Globotruncanella havanensis Zone, Globotruncana aegyptica Zone, Gansserina gansseri Zone, Contusotruncana contuosa Zone, Abathomphalus mayaroensis Zone and Pseudoguembelina hariaensis. The age of the Gurpi Formation in this section based on these biozones is Middle Campanian to Late Maastrichtian in this section. Manuscript profile -
Open Access Article
9 - Biostratigraphy and microfacies analysis of the Shahbazan and Asmari formations (through Eocene to Oligocene) in the carbonate deposits of northwest Dezful Embayment, Zagros Sedimentary Basin
sepedeh Gholampoor-moghahi Hosyen Vaziri moghadam Naser Arzani Afshin ArmoonAbstract In this research based on petrography study of 320 thin sections (cutting samples), biostratigraphy, microfacies and depositional environment analysis has been done to determine the boundary between the Shahbazan and Asmari formations in well No. 1 of the Bala MoreAbstract In this research based on petrography study of 320 thin sections (cutting samples), biostratigraphy, microfacies and depositional environment analysis has been done to determine the boundary between the Shahbazan and Asmari formations in well No. 1 of the Balarud Oil Field, located in the north of Dezful embayment. The Shahbazan Formation with 460 meters thick with mainly composed of dolomite along with interlayers of limestone, shale and anhydrite in the studied well. The lower boundary of this formation with the Pabdeh Formation is conformable and its upper boundary with the Asmari Formation is marked by an unconformity. The Asmari Formation with thickness of 140 meters mainly consists of limestone and shale with the interlayers of dolomite; its upper boundary to the Gachsaran Formation is conformable. Biostratigraphy studies documented a high diversity of shallow-water benthic and rare planktonic foraminiferas and led to the determining of one assemblage zone in the Shahbazan Formation (15 genera and 8 species) that indicates age of the Priabonain. Three assemblage zones also were recognized in the Asmari Formation (12 genera and 8 species) that, shows the age of the Asmari Formation from Mid-Rupelian to the Chattian, Aquitanian and Burdigalin. Based on biostratigraphy studies, the boundary between Shahbazan and Asmari formations and the position of an unconformity between them were determined. The facies analysis led to recognition of eight microfacies for the Shahbazan Formation which belong to three facies belts of inner (tidal flat and lagoon), middle and outer ramp, deposited on a ramp-type carbonate platform. Also four microfacies were recognized in the Asmari Formation which are related to the inner carbonate platform. Manuscript profile -
Open Access Article
10 - Impact of shale oil revolution on falling of Oil and Gas prices Technical report
Ali reza BashariThe rapid development of shale gas resources in the US has transformed the world gas-market outlook. Despite this, the consensus was for a long time that shale gas would not be a ‘game changer’ in the world as it has been in the US. Shale gas is extracted from solid roc MoreThe rapid development of shale gas resources in the US has transformed the world gas-market outlook. Despite this, the consensus was for a long time that shale gas would not be a ‘game changer’ in the world as it has been in the US. Shale gas is extracted from solid rock using a process called hydraulic fracturing, or ‘fracking’. Static shows, in USA, production rates decline, for the most of well on average, 80 0r 85 percent over the three years. In order to maintain current level of shale gas production, Hughes estimates that the high rates of deterioration of such wells across the US will require the drilling of 7,000 new wells a year at cost of $42 billion annually. For the maintenance of overall production of shale oil, some 6,000 new wells would need to be drilled every year, an endeavor that would cost $ 35 billion. A number of environmental concerns have been raised about fracking, including the potential for seismic events, air pollution, surface and groundwater contamination, and greenhouse gas emissions. There is no doubt that shale revolution has been a game-changer in short term, but the implication shows that it is not sustainable in long-term. Manuscript profile -
Open Access Article
11 - Biostratigraphy and microfacies of the Asmari Formation in north flank of Khami anticline (north of Gachsaran)
Mona Rahim Abadi Hossein Vaziri-Moghaddam Ali Seyrafian farzad SotohianIn the present study, biostratigraphy, microfacies and sedimentary environment of the Asmari Formation in north flank of the Khami anticline in the north of the Gachsaran province is investigated. The Asmari Formation at the study section with a thickness of 276 meters MoreIn the present study, biostratigraphy, microfacies and sedimentary environment of the Asmari Formation in north flank of the Khami anticline in the north of the Gachsaran province is investigated. The Asmari Formation at the study section with a thickness of 276 meters is a thin, medium and thick to massive limestone, nodular limestone, marl, marly limestone, dolomite and dolomitic limestone. In this study 166 thin sections are studied and 23 genera and 24 species of foraminifera have been identified and 3 biozones are introduced. 1- Archaias asmaricus-Archaias hensoni-Miogypsinoides complanatus Assemblage zone. (Chattian) 2- Indeterminate zone (Aqutanian) 3- Borelis melo curdica-Borelis melo melo Assemblage zone. (Burdigalian) Thus, the age of the Asmari Formation at the study area is Chattian to Burdigalian (Oligo-Miocene). Based on study of thin sections and by considering the sediment texture, distribution of skeletal and non-skeletal grains, 12 microfacies are recognized which were deposited in open marine, bar, semi-restricted and restricted lagoon. Four platform types for the Asmari Formation at the study area in comparison with the recent studies on Asmari Formation including: 1-Rupelian-lower Chattian: Distally steepend ramp, 2-middle Chattian-upper Chattian: open shelf, 3-Aqiutanian: homoclinal ramp, 4-lower Burdigalian: carbonate platform. Manuscript profile -
Open Access Article
12 - Evidence of transpressional tectonics in NW of central Iran sedimentary basins based on reflective data and geomorphic indices
Mohammad Mokhtari S.Ahmad Alavi Leila MahshadniaThe depressed basins of northwest central Iran are located in the structural Step and between Soltanieh-Ipac-Koshk-e-Nosrat and Qom –Zefreh system (the Indes - Qom –Khurabad faults). The main process of deformation within the basin with extension and compression of spec MoreThe depressed basins of northwest central Iran are located in the structural Step and between Soltanieh-Ipac-Koshk-e-Nosrat and Qom –Zefreh system (the Indes - Qom –Khurabad faults). The main process of deformation within the basin with extension and compression of specific structures are comparable and verifiable using experimental models. The extensional structures include roll-over folds and normal faults, resulting in deep sedimentary basins during deposition of the lower and upper red formations. The younger structures, includes back-thrusts and for-thrusts, shortcut, and pop up structures represents the reversal of tectonic of primary extensional basin. These sedimentary basins have been created in relation to the growth faults and hanging wall blocks So In the presence of roll-over fold and antithetic and synthetic faults therefore are suitable for entrapment of hydrocarbons during migration. The active structural features have been identified using combination of geomorphic characteristic and seismic reflection data. Accordingly, none of the old normal faults in the Saveh- Qom and Aran basin show at the present any extensional movement and the fault activity of boundary faults and extensional folding are compressional. The active parts are: hanging wall of Saveh, restraining bending at the end of Indes fault that has stream Length-Gradient (SL) index and high value hypsometric index (Hi). The central part of Saveh-Qom and Aran basin, although show high Hi but the SL is low. This situation is due to the moderating effects of the thick lower and upper red formations and evaporative layer within the basin. In the Aran basin due to incomplete coverage of seismic lines the absence of normal faults cannot be definitively confirmed. However, the center of Aran basin as of Qom-Saveh formed push up which marks the compression of this basin and also activity of reverse and thrust faults. Based on the existing surface and subsurface data set, active deformation in this area now is transpression basin and the interior domains are in the uplift. Manuscript profile -
Open Access Article
13 - Analysis Correlation of Seismo-Tectonic in Bakharden-Quchan Zone with Geometry Disorders of Earthquakes
Javad Biglari abbas kangi abdolreza jafarianThe most seismic activities have observed around and along major fault systems of this zone in NE Iran that involving of an array active right lateral-strike slip faults have distributed by trending NW-SE. neotectonic activity and mechanism changing of faults to reverse MoreThe most seismic activities have observed around and along major fault systems of this zone in NE Iran that involving of an array active right lateral-strike slip faults have distributed by trending NW-SE. neotectonic activity and mechanism changing of faults to reverse trusting faults have caused to increase stress, shortening and increasing seismicity with high density of earthquakes in their ends bending. Structural relation faults between this zone and Binaloud through Meshkan thrusting-transfer zone which is major motion engine of Bakharden-Quchan zone to put it constantly under neotectonic stresses convergence of Arabia-Eurasia plates since last phase Alpine orogeny. In this paper Fractal analysis through box counting method has done and D values change between 0-2. If D closes to zero, faults an earthquakes are focusing in a point with high tension and if D closes to 2 is shown low tension, dispersal faults and earthquakes in whole of region. Both surface/volume fractal dimension distribution show higher seismicity activity in Central and Western parts of Kopeh Dagh in NE Iran. Manuscript profile -
Open Access Article
14 - Investigation of main planktonic foraminifera bio-events at the base of the Coniacian and Santonian stages in the Surgah Formation, Maleh-Kuh and Sarkan wells, South west of Khoram Abad
Mohammad Hadadi Meysam Shafiee Ardestani Mohammad Vahidinia Mohammad GharaeeIn this study Surgah Formation at Maleh-Kuh and Sarkan section in south west of Khoram Abad have been studied based on bio-event models. Surgah Formation at Sarkan well no.1and Maleh-Kuh has 46 and 82-meter thickness respectively and was placed on the Sarvak Formation a MoreIn this study Surgah Formation at Maleh-Kuh and Sarkan section in south west of Khoram Abad have been studied based on bio-event models. Surgah Formation at Sarkan well no.1and Maleh-Kuh has 46 and 82-meter thickness respectively and was placed on the Sarvak Formation and under the Ilam Formation. In this study Surgah Formation were composed of shale, limy shale with glauconite and pyrite. In this section two Turonian-Coniacian and Coniacian-Santonian boundaries were recognized in Dicarinella concavata Interval Zone. Based of Heterohelix moremani and FODs Dicarinella concavata and Dicarinella primitiva were detected Turonian-Coniacian boundary. Finally based on LoDs Dicarinella primitiva and Marginotruncana marginata were distinguished Coniacian - Santonian boundary in this section. Manuscript profile -
Open Access Article
15 - Biostratigraphy and microfacies of the Dariyan Formation in east of Gachsaran (Anneh anticline)
Samaneh Solymani-Ahmadi Hosyen Vaziri moghadam Ali TaheriIn this study, biostratigraphy, micofacies and sedimentary environment of Dariyan Formation in Anneh Anticline, near Hosein-Abad village (east of Gachsaran city) were investigated. Dariyan Formation at this study were consisted of 196 meters of thick, medium and thin MoreIn this study, biostratigraphy, micofacies and sedimentary environment of Dariyan Formation in Anneh Anticline, near Hosein-Abad village (east of Gachsaran city) were investigated. Dariyan Formation at this study were consisted of 196 meters of thick, medium and thin layers of limestone, with orbitolinids, marl and marly limestone. The Daryian Formation is divided into the upper and lower parts, based on the existence of tongue with thin layer of limestone and laminated shale along with interlayer chert, with a large amount of radiolarids and planktonic foraminifera. In study area, Dariyan Formation conformably overlies the Gadvan Formation and is overlain by Kazhdumi Formation. A total of 114 thin sections were extracted from the study area and 22 benthonic foraminifera and 3 planktonic foraminifera have been identified in 4 biozones and 1 subzone: Praeorbitolina cormyi zone, Palorbitolinoides cf. orbiculata subzone, Hedbergella spp. Assemblage zone, Mesorbitolina texana zone, Mesorbitolina gr. subconcava zone. Based on identified zones in the study section, the age of Dariyan Formation is designated between Early Aptian to Albian. Sedimentary environment study of Dariyan Formation in Anneh Anticline led to identification of 9 microfacies related to open marine and lagoon. Due to the lack of a barrier facies, slumping and storm deposits, lump and grapston, an open shelf sedimentary environment was suggested for deposition of the Dariyan Formation in Anneh anticline. Manuscript profile -
Open Access Article
16 - Biostratigraphy, Paleobathymetry, and identification of new planktonic foraminiferal species of the Abderaz Formation at Qalezo section, west of the Kopeh-Dagh sedimentary basin
Meysam Shafiee Ardestani Mohammad Vahidinia Fatemeh FarazifarIn this study, Abderaz Formation at Qalezo section in the west of the Kopeh-Dagh sedimentary basin has been studied. It has consisted mainly of massive limestone, Marl and chalky limestone units at the mentioned section. Abderaz Formation at Qalezo section, the lower co MoreIn this study, Abderaz Formation at Qalezo section in the west of the Kopeh-Dagh sedimentary basin has been studied. It has consisted mainly of massive limestone, Marl and chalky limestone units at the mentioned section. Abderaz Formation at Qalezo section, the lower contact with Aitamir Formation is paraconform and the upper contact with Abtalkh Formation is conformed and continuous. The thickness of Abderaz Formation, 216 meters, has been measured. In this investigation have been identified 55 planktonic foraminifera species belong to 15 genera, in a frame of 4 biozones have been recognized. Finally, based on this research was distinguished from latest Early Turonian-Late Santonian ages for this section. In this study four planktonic foraminifera species, Dicarinella bouldinensis (Pessagno 1967), Dicarinella takayanagii Hasegawa 1999, Marginotruncana desioi (Gandolfi 1955), Marginotruncana caronae Peryt 1980 have been introduced for the first time in Iran. Also in this research planktonic foraminifera test geometric in Abderaz Formation at Qalezo section has been studied for sea-level changes. In Lower-Middle Turonian substages, the high frequency of the M1 group and low frequency of M3 group displayed fall seal level at this time. In Late Turonian frequencies of M3 group with accompany of %P was shown rise sea level. In the Coniacian and Santonian stages, the M1 group is dominant and the M3 group is low frequency and all of the mentioned evidence were demonstrates fall sea level. Also, the depth average of the studied section based on Depth = e (3.58718 + (0.03534 × %P)) has been calculating 146 meters which were shown these sediments deposited in Outer Neritic environment. Manuscript profile -
Open Access Article
17 - Interpretation of sedimentary environment and factors affecting reservoir quality in upper Sarvak Formation in one the oil fields of Abadan plain
Mohammad Hossein Saberi Bahman Zarenezhad الهام اسدی Nasim RahmaniThe Sarvak Formation of the Albian-Turonian Formation is one of the most important hydrocarbon reservoirs in south and southwest of Iran. In this study, in order to assess the reservoir quality, from a petrographic study and porosity and permeability data, an important MoreThe Sarvak Formation of the Albian-Turonian Formation is one of the most important hydrocarbon reservoirs in south and southwest of Iran. In this study, in order to assess the reservoir quality, from a petrographic study and porosity and permeability data, an important well in one of the oil fields of Abadan plain has been used. Based on microscopic studies, 13 microfacies have been identified in the form of Four facies tidal flat, lagoon, shoal and open marine for Sarvak Formation deposits in the studied oil field, indicating that the upper part of the Sarvak Formation is deposited in a homoclinal carbonate ramp. Among the identified diagenetic processes, dissolution, cementation, dolomitization, fracturing, compaction, neomorphism, micritization, bioturbation, pyritization, hematitization, phosphatization and silicification are mentioned. Diagenetic processes of Sarvak Formation occurred in three marine, meteoric and burial environments. Among the dissolution and fracturing diagenetic processes, the most important role has been in increasing the reservoir quality, and cementation and compaction have been the most important factors in reducing reservoir quality. Sequence stratigraphy studies identified third order sedimentary sequences of the age of Turonian, Late Cenomanian, and Middle Cenomanian, and studied the facies and diagenetic processes within its framework. Correlation of porosity and permeability data of the core showed that the reservoir quality in this formation was influenced by facies and diagenetic processes. So that the microfacies containing the rudist have the highest reservoir quality. Due to the diagenetic processes, sedimentary and porosity and permeability data, the facies shoal and open marine to the land have the best reservoir quality. Manuscript profile -
Open Access Article
18 - Interpretation of sedimentary environment and factors affecting reservoir quality in upper Sarvak Formation in one the oil fields of Abadan plain
The Sarvak Formation of the Albian-Turonian Formation is one of the most important hydrocarbon reservoirs in south and southwest of Iran. In this study, in order to assess the reservoir quality, from a petrographic study and porosity and permeability data, an important MoreThe Sarvak Formation of the Albian-Turonian Formation is one of the most important hydrocarbon reservoirs in south and southwest of Iran. In this study, in order to assess the reservoir quality, from a petrographic study and porosity and permeability data, an important well in one of the oil fields of Abadan plain has been used. Based on microscopic studies, 13 microfacies have been identified in the form of Four facies tidal flat, lagoon, shoal and open marine for Sarvak Formation deposits in the studied oil field, indicating that the upper part of the Sarvak Formation is deposited in a homoclinal carbonate ramp. Among the identified diagenetic processes, dissolution, cementation, dolomitization, fracturing, compaction, neomorphism, micritization, bioturbation, pyritization, hematitization, phosphatization and silicification are mentioned. Diagenetic processes of Sarvak Formation occurred in three marine, meteoric and burial environments. Among the dissolution and fracturing diagenetic processes, the most important role has been in increasing the reservoir quality, and cementation and compaction have been the most important factors in reducing reservoir quality. Sequence stratigraphy studies identified third order sedimentary sequences of the age of Turonian, Late Cenomanian, and Middle Cenomanian, and studied the facies and diagenetic processes within its framework. Correlation of porosity and permeability data of the core showed that the reservoir quality in this formation was influenced by facies and diagenetic processes. So that the microfacies containing the rudist have the highest reservoir quality. Due to the diagenetic processes, sedimentary and porosity and permeability data, the facies shoal and open marine to the land have the best reservoir quality. Manuscript profile -
Open Access Article
19 - Interpretation of sedimentary environment and factors affecting reservoir quality in upper Sarvak Formation in one the oil fields of Abadan plain
Arad Kiani Mohammad Hossein Saberi Bahman Zare nejad Elham Asadi Nasim RahmaniThe Sarvak Formation of the Albian-Turonian Formation is one of the most important hydrocarbon reservoirs in south and southwest of Iran. In this study, in order to assess the reservoir quality, from a petrographic study and porosity and permeability data, an importan MoreThe Sarvak Formation of the Albian-Turonian Formation is one of the most important hydrocarbon reservoirs in south and southwest of Iran. In this study, in order to assess the reservoir quality, from a petrographic study and porosity and permeability data, an important well in one of the oil fields of Abadan plain has been used. Based on microscopic studies, 13 microfacies have been identified in the form of Four facies tidal flat, lagoon, shoal and open marine for Sarvak Formation deposits in the studied oil field, indicating that the upper part of the Sarvak Formation is deposited in a homoclinal carbonate ramp. Among the identified diagenetic processes, dissolution, cementation, dolomitization, fracturing, compaction, neomorphism, micritization, bioturbation, pyritization, hematitization, phosphatization and silicification are mentioned. Diagenetic processes of Sarvak Formation occurred in three marine, meteoric and burial environments. Among the dissolution and fracturing diagenetic processes, the most important role has been in increasing the reservoir quality, and cementation and compaction have been the most important factors in reducing reservoir quality. Sequence stratigraphy studies identified third order sedimentary sequences of the age of Turonian, Late Cenomanian, and Middle Cenomanian, and studied the facies and diagenetic processes within its framework. Correlation of porosity and permeability data of the core showed that the reservoir quality in this formation was influenced by facies and diagenetic processes. So that the microfacies containing the rudist have the highest reservoir quality. Due to the diagenetic processes, sedimentary and porosity and permeability data, the facies shoal and open marine to the land have the best reservoir quality. Manuscript profile -
Open Access Article
20 - Microfacies, Sedimentary environment and Sequence stratigraphy of Anarak section (Late Devonian-Early Carboniferous), central Iran
ٍٍElahe Sattari Hosyen vaziri-Moghadam Ali Bahrami Ali Taheri sandra kaiser Peter KoneigshofAnarak section in northeast Isfahan, central Iran is evaluated regarding to sedimentary environment and sequence stratigraphy. Field studies and micro-facies analysis led to the identification of 12 micro-facies related to the open marine, the shoal, the lagoon and the MoreAnarak section in northeast Isfahan, central Iran is evaluated regarding to sedimentary environment and sequence stratigraphy. Field studies and micro-facies analysis led to the identification of 12 micro-facies related to the open marine, the shoal, the lagoon and the tidal flat environments. Micro-facieses gradual change, lack of calciturbidite and lack of expanded barrier reef indicate the deposition of a sedimentary interval in a homoclinal ramp environment. Two type 3 sequences were identified by sequence stratigraphic study. Both of these sequences are separable TST and HST packages. The age of first sequence is Late Devonian (Bahram Formation) and its thickness is 42.3 meters and the second sequence with a thickness of 70.7 meters is Late Devonian-Early Carboniferous (Upper part of Bahram Formation and Shishtu2 Formation). The sequence boundary between first and second sequences is the second type boundary due to the lack of evidence for exposure. Manuscript profile -
Open Access Article
21 - Reconstruction of the sedimentary environment of the Tarbur Formation based on microfacies and microtaphofacies analysis in the Murak area (southwest of Semirom)
Hossein Ghanbarloo Hosyen Vaziri moghadamReconstruction of the sedimentary environment of the Middle-Upper Maastrichtian deposits (Tarbur Formation) in the Murak area (southwest of Semirom) was performed based on Microfacies and microtaphofacies analysis. The formation with 239 m thickness consists of limeston MoreReconstruction of the sedimentary environment of the Middle-Upper Maastrichtian deposits (Tarbur Formation) in the Murak area (southwest of Semirom) was performed based on Microfacies and microtaphofacies analysis. The formation with 239 m thickness consists of limestone and shale. Meanwhile, the Tarbur deposits overlie the Gurpi Formation and is covered by the Paleocene deposits. Seven and five microfacies and microtaphofacies were recognized based on the main components and sedimentological and taphonomical features, respectively. In addition, these microfacies and microtaphofacies were deposited in homonicnal carbonate ramp. From the viewpoint of vertical distribution and interpretation of microfacies and microtaphofacies, the Tarbur deposits were formed in the energetic environment (under the influence of the storm waves) in the study area. Therefore, communities of rudist are absent and the green algae (Dasycladales) are abundant in the study area. Concerning the high rate of detrital grain input and increasing of nutrients, the bryozoans were performed the encrusting more than other organisms. Manuscript profile -
Open Access Article
22 - (Biostratigraphy and microfacies of the Asmari Formation in south flank of Mish anticline (northeast of Gachsaran
Saber Ahmadi Ali seyrafian Hosyen vaziri-MoghadamAsmari Formation at the section of the south flank of Mish anticline (northeast of Gachsaran), located 22 km northeast of Basht city, in vicinity village Kalagh ¬Neshin is investigated and has a thickness of 281 meters. In this research, biostratigraphy and microfacies MoreAsmari Formation at the section of the south flank of Mish anticline (northeast of Gachsaran), located 22 km northeast of Basht city, in vicinity village Kalagh ¬Neshin is investigated and has a thickness of 281 meters. In this research, biostratigraphy and microfacies of the Asmari Formation in this section were studied and the results were compared with 5 section of Asmari Formation in similar regions and close to it. By studying on 172 microscopic sections, 3 the biozone for Asmari Formation in the section the study was carried out and the section studied given that is: Lepidocyclina – Operculina – Ditrupa assemblage zone. Archaias asmaricus – Archaias hensoni – Miogypsinoides complanatus assemblage zone. Indeterminate zone. According to the study of benthic foraminifera and biozones, the cut off age is from the late Oligocene (Rupelian-Chattian) to the early Miocene (Aquitanian). Microfacies studies led to identify 10 microfacies and 4 subfacial belonging to the open marine and lagoon (semi-closed and enclosed) environments, which includes the external, intermediate, and interior parts of a hemocalinal ramp. Manuscript profile -
Open Access Article
23 - Microfacies analysis, Sedimentary Environment and Sequence Stratigraphy of the Qom Formation in the Naraq area
Alireza Ashouri Asma Aftabi arani Jahanbakhsh Daneshian Abbas Ghaderi Mohammad Reza Aria NasabNaraq section is located at the South of the Qom sedimentary basin in Central Iran. The study of microfacies sedimentary environments and sequence stratigraphic features of the Qom Formation in this area can help to understand the situation of the Qom sedimentary basin. MoreNaraq section is located at the South of the Qom sedimentary basin in Central Iran. The study of microfacies sedimentary environments and sequence stratigraphic features of the Qom Formation in this area can help to understand the situation of the Qom sedimentary basin. In this study, 111 samples of the Qom Formation in Naraq section in the northwest of Naraq are investigated. Based on field observation and thin-section studies, 6 microfacies related to the lagoon, reef and slope parts of carbonate platform have been recognized.Due to the presence of slope microfacies and skeletal and non-skeletal grains that are transported from the shallow to this environment and the existence of SMF9, bioturbation, Also the presence of barrier / reef sediments, a carbonate shelf depositional environment is suggested for the Qom Formation in Naragh section. In this model, marls of b member of the Qom Formation show more relative depth. Also sequence stratigraphic studies show that the Naraq section is composed of three sedimentary sequences of third- order three types I and one type II sequence boundaries were recognized in this formation. Manuscript profile -
Open Access Article
24 - Biostratigraphy of Dariyan Formation in Lar Anticline (north east Gachsaran) and Lower Cretaceous sediments in Kolah Ghazi section (South west Isfahan)
Mahdie Shirzad Hosyen Vaziri moghadam Ali BahramiIn order to identify foraminifera and determine the age of Dariyan Formation and the lower Cretaceous sediments of Central Iran, a section of Dariyan Formation in Lar Anticline (northeast Gachsaran) (with a thickness of 111m, thick, medium and thin layer of limestone, m MoreIn order to identify foraminifera and determine the age of Dariyan Formation and the lower Cretaceous sediments of Central Iran, a section of Dariyan Formation in Lar Anticline (northeast Gachsaran) (with a thickness of 111m, thick, medium and thin layer of limestone, marl and marly limestone) and Kolah Ghazi section (south west Isfahan) (with a thickness of 260m, thick to medium layer limestone and shale) were studied. Based on biostratigraphic studies of Lar Anticline section, 28 benthonic foraminifera and 4 planktonic foraminifera have been identified in 4 biozones contains: Hedbergellids - Orbitolinids assemblage zone, Mesorbitolina texana zone, Mesorbitolina gr. subconcava zone, Favusella washitensis rang zone. Based on biostratigraphic of Lower Cretaseous sediments in Kuh-e-Kolah Ghazi, 21 benthonic foraminifera and 1 planktonic foraminifera have been identified and consequently 2 biozones are recognized contains: Mesorbitolina texana zone, Mesorbitolina gr. subconcava zonethe studied areas were correlated with some sections of the Dariyan in Kuh-e-Fahliyan, Kuh-e- Mangasht and Meymand. Accordingly, the sedimentation of two studied sections in Lar Anticline and Kuh-e-Kolah Ghazi were started from Late Aptian which were later than the other sections, and the end of sedimentation in the Kuh-e-Kolah Ghazi was earlier than the other sections in the Late Aptian age, while the end of sedimentation of Dariyan Formation in other sections was in Early Albian age Manuscript profile -
Open Access Article
25 - Foramniferal morphogroups of the Qom Formation in E Sirjan and SW Kashan: implication for paleoenvironmental and paleoecological interpretations
Ebrahim MohammadiThe Qom Formation is the main reservoir and source rock of hydrocarbons in central Iran. Foraminifera are now central to our ability to date, correlate and analyse the sedimentary basins that are currently key to the economic wellbeing of the world. Morphogroup analysis MoreThe Qom Formation is the main reservoir and source rock of hydrocarbons in central Iran. Foraminifera are now central to our ability to date, correlate and analyse the sedimentary basins that are currently key to the economic wellbeing of the world. Morphogroup analysis, due to independence of species level taxonomy, as wel as permit to comparison of assemblages of differing ages, is a useful tool for ecological and palaeoecological interpretation. It is independent of species level taxonomy and is thus relatively elementary to translate from one worker to another. Foramniferal study of the Qom Formation in the Bujan (eastern Sirjan; with Rupelin-Chattian in age and 156 m thickness) and Varkan (southwestern Kashan; with Rupelin in age and 190 m thickness) sections resulted in identification of seven morphogroups. The morphogroups were distinguished according to test/shell morphology and architecture (general shape, mode of coiling, and arrangement and number of chambers), inferred life habitat either living on the surface of the sediments or within the sediments (epifaunal and infaunal), and feeding strategy (suspension-feeder, herbivore, etc.). Generaly, epifaunal morphogroups were dominated in both study sections. The morphogroup analyses showed variations in the percentage of the dominant morphotypes, suggesting fluctuations in the paleoecological conditions. In the Bujan section, the Rupelin deposits are dominated by calcareous porcelaneous morphogroups; while the Chattian deposits are dominated by hyaline morphogroups, which indicates the lower and upper parts were deposited in inner ramp (lagoonal environments) and middle ramps, respectively. This significant change through time reffers to gradual increasing of the basin depth, decreasing the light intensity, reducing the salinity and decreacing the nutrient level. De dominance of the hyaline morphogroups throughout of the Varkan section is indicative of the deposition in middle ramp environments with normal salinity under meso-photic to oligo-photic conditions. Manuscript profile -
Open Access Article
26 - Biocorrelation, Biostratigraphy and determination basal of the Aptian stage at Tirgan Formation , west of Kopeh-Dagh sedimentary basin, NE Iran
Atefeh Chenarani Meysam Shafiee Ardestani Mohammad VahidiniaTirgan Formation (Lower Cretaceous) in the Kopeh-Dagh sedimentary basin consists mainly of Oolitic, Orbitolina, dolomitic limestones that conformably overlies the Shurijeh and Sarcheshmeh formations, respectively. Upper contact of Tirgan Formation at Jozak section with MoreTirgan Formation (Lower Cretaceous) in the Kopeh-Dagh sedimentary basin consists mainly of Oolitic, Orbitolina, dolomitic limestones that conformably overlies the Shurijeh and Sarcheshmeh formations, respectively. Upper contact of Tirgan Formation at Jozak section with Abderaz Formation is faulty and were placed under white chalky limestone of the Abderaz Formation. Two stratigraphic sections at Estarkhi and Jozak were measured and sampled. Biostratigraphicic studies lead to two benthic foraminifera and calcareous green algae fossil assemblages have been identified. Twenty one genera and 24 species of benthic foraminifera and 16 genera and 26 species of calcareous green alge at Estarkhi section, 21 genera and 26 species of benthic foraminifera and 10 genera and 10 species of calcareous green alge at Jozak section in west of Kopeh-Dagh sedimentary basin have been identified. This study has been suggested the Barremian- Early Aptian( Bedulian) stage for the Tirgan Formation at these localities that is corresponded with age of central and east basin. Also based on paleobio-events study were determined base of the Aptian stage in east of the kopeh-Dagh sedimentary basin base of FA(First Appearance) Dictyoconus pachymarginalis and LA(Last Appearance) Montseciella arabica and in center and west of the basin base of the FAs Palorbitolina lenticularis, Salpingoporella muehlbergii. Manuscript profile -
Open Access Article
27 - Qom Formation, Microfacies, Depositional sequence, Maragh area.
Amrolah Safari Hossein Ghanbarloo Ebrahim MohammadiThe Qom Formation is located at the Maragh area (20 kilometers southwest of Kashan). The formation with 216 m thickness contains shale and limestones. Volcanic rocks unconformably are covered by the Qom Formation. The upper boundary of the Qom Formation with the Upper R MoreThe Qom Formation is located at the Maragh area (20 kilometers southwest of Kashan). The formation with 216 m thickness contains shale and limestones. Volcanic rocks unconformably are covered by the Qom Formation. The upper boundary of the Qom Formation with the Upper Red Formation is also unconformable. Nine microfacies and terrigenous facies were identified based on the main components and sedimentological features. These microfacies and terrigenous facies were deposited on an open-shelf carbonate platform. Three environments were recognized in this carbonate platform. These environments include the inner shelf (restricted and semi-restricted lagoon), middle shelf, and outer shelf. In addition, three third-order and one incomplete depositional sequences were identified based on the vertical distribution of microfacies. Manuscript profile -
Open Access Article
28 - Comparison of the function of conventional neural networks for estimating porosity in one of the southeastern Iranian oil fields
Farshad Toffighi parviz armani Ali Chehrazi َAndisheh AlimoradiIn the oil industry, artificial intelligence is used to identify relationships, optimize, estimate and classify porosity. One of the most important steps in evaluating the petrophysical parameters of the reservoir is to identify the porosity properties. The main purpose MoreIn the oil industry, artificial intelligence is used to identify relationships, optimize, estimate and classify porosity. One of the most important steps in evaluating the petrophysical parameters of the reservoir is to identify the porosity properties. The main purpose of this study is to compare the accuracy and generalizability of three multilayer feed neural networks (MLFNs), radius base function networks (RBFNs) and probabilistic neural networks (PNNs) to estimate porosity using seismic properties. In this regard, geological data of 7 wells were evaluated from an offshore oil field in Hindijan in the northwest of the Persian Gulf basin. Acoustic impedance was estimated using model-based inversion method and then the mentioned neural networks were designed using optimal seismic properties and evaluated by stepwise regression method. Finally, it became clear that the MLFN model did not work well for estimating porosity. PNN has the best performance accuracy in porosity interpolation, but RBFN generalizability is better. Manuscript profile -
Open Access Article
29 - Early Triassic conodonts of the Sorkh-Shale Formation in Rabat-Shor section of (West of Tabas, East of Central Iran); investigation of their alteration index concerning the hydrocarbon production capacity
Abeer Issa Abbas Ghaderi Mohammad Khanehbad Tea Kolar-JurkovšekSorkh Shale Formation in Rabat-e-Shur stratigraphic section, west of the Tabas Depression, has been biostratigraphically investigated in this research. The Sorkh Shale Formation, with 48 meters thickness in this section, consists of shale, marl, and marly limestones, wh MoreSorkh Shale Formation in Rabat-e-Shur stratigraphic section, west of the Tabas Depression, has been biostratigraphically investigated in this research. The Sorkh Shale Formation, with 48 meters thickness in this section, consists of shale, marl, and marly limestones, which are underlain by the Permian Jamal Formation and are overlain by the Triassic Shotori Formation dolomites. Nine conodont species belonging to four genera, Ellisonia, Hadrodontina, Parachirognathus, and Pachycladina were identified for the first time from this formation. The mentioned conodont assemblage is divided into three biozones: Hadrodontina aequabilis, Hadrodontina anceps, and Pachycladina obliqua. These taxa are in good agreement with the previously reported euryhaline assemblages from the near-shore and shallow water Western Tethyan realms in the south and east of Europe in the Early Triassic (Late Griesbachian-Middle Smithian). These conodont biozones are used for a better understanding of the distribution and affinities of the Early Triassic conodonts in West Asia, their paleobiogeographical rank, their significant role in the Early Triassic chronostratigraphy and their importance in bio-correlation of different section worldwide. Examination of the conodont alteration index of the obtained taxa from the Sorkh Shale Formation demonstrates CAI=5 during the late Griesbachian, CAI=4 in the Smithian, and CAI=6-8 in the Dienerian substages which is placed in the barren Zone for hydrocarbon production. Manuscript profile -
Open Access Article
30 - Strain and shortening amount analysis in the Asmari anticline, Khuzestan province
Babak Samani Abbas Charchi Narges KhatibThe only outcrop of Asmari formation in the Dezful embayment is visible in the Asmari anticline. In order to estimate the strain parameters and shortening values, 26 geological cross sections were prepared perpendicular to the anticline axis. Based on the, interlimb ang MoreThe only outcrop of Asmari formation in the Dezful embayment is visible in the Asmari anticline. In order to estimate the strain parameters and shortening values, 26 geological cross sections were prepared perpendicular to the anticline axis. Based on the, interlimb angle measurements, the interlimb angles of the northern and central parts of the anticline show smaller angles than the southern parts. Determination of strain ratio (R) values indicates the strain values between 1.12 - 1.52. The zoning map of strain ratio values shows higher strain values in the northern and central parts of the anticline. Using geological cross sections and measuring the base length of the folded layer of Asmari formation (L0) and the straight length of the layer (L1), the percentage of shortening values were calculated in each section. The results show the occurrence of 1.8% to 12% shortening in different parts of the anticline. Shortening map of the Asmari anticline shows more shortening amounts in the northern and central parts of the anticline than the southern parts. Manuscript profile -
Open Access Article
31 - Biostratigraphy and Lithostratigraphy of Pabdeh Formation is based on planktonic foraminifera in the section of Jahangirabad (south Ilam_ Zagros basin)
somaye taherizade Mohammad Vahidinia mohammadhossein mahmoudi gharaiiAfter the Late Cretaceous and during the Paleogene, with the sea level rising, the Zagros sedimentary basin is covered with a progressive sea in which the Pabdeh Formation is deposited. The dual function of this formation as a source of oil and its reservoir capacity MoreAfter the Late Cretaceous and during the Paleogene, with the sea level rising, the Zagros sedimentary basin is covered with a progressive sea in which the Pabdeh Formation is deposited. The dual function of this formation as a source of oil and its reservoir capacity due to the diversity of lithology and its location between the two reservoirs Asmari and Bangistan, and the age of this formation is one of the issues that has attracted the attention of geologists. In order to study the stratigraphic and biostratigraphic rock of the Pabdeh Formation, the Jahangirabad section in the northwest of Zagros sedimentary basin has been selected and sampled. 320 samples were taken, of which 230 samples were prepared by washing method, and 90 samples were prepared by thin section method and examined. Based on studies conducted in the Jahangirabad section, 25 genera and 110 species have been identified, and based on the identified fossils, 27 biozones and 7 sub-biozones have been identified. Based on the identified biozones, the age of the Pabdeh Formation in the Jahangirabad Danian Early-Late Chattian section has been obtained. Pabdeh Formation deposits in the Jahangirabad section have a thickness of 676 m (beginning of purple shale to anhydrite Kalhor) which includes units of purple shale (2 parts), marl limestone with lower limestone, limestone, and marl limestone with limestone It is high. In this section, the lower boundary of the Pabdeh Formation is continuous with shales and marls of Gurpi Formation, and its upper boundary is with continuous limestone of Asmari Formation. Manuscript profile -
Open Access Article
32 - Biostratigraphy, biofacies and CAI of the late Devonian deposits in Kale-Sardar section, North-east Tabas, based on conodont fauna
Mina Ramshini ٍٍElahe Sattari Ali Bahrami Hosyen Vaziri moghadamKale-Sardar section, is located at the vicinity of Niaz village, 15 kilometers east of Tabas town. This section consists of 80 m thick and from Late Devonian deposits as known as Shishtu formation that upper part of this section has cut by a fault by Frasnian’s deposits MoreKale-Sardar section, is located at the vicinity of Niaz village, 15 kilometers east of Tabas town. This section consists of 80 m thick and from Late Devonian deposits as known as Shishtu formation that upper part of this section has cut by a fault by Frasnian’s deposits. The entire studied thickness is subdivided into 12 lithostratigraphic units and in order to study of conodont elements, 27 species and subspecies belonging to 7 genera were recognized, that due to these revealed conodont elements, Shishtu formation’s age in the studied section spans from Eifelian to late Frasnian. The Frasnian-Famennian bio event in studied section is located between two intervals linguiformis Zone and Lower to Middle triangularis zones which is located at the top of the dark Frasnian shales and at the base of the thin limestones of the Famennian layer. The microfacies determined in studied section are subdivided into siliciclastic-carbonate and carbonate facies, which were deposited from the shore to the deep part of the marine environment. Gradual changes in facies within stratigraphical sequence, sedimentological hiatus due to sudden change in sedimentary environment’s slope, absence of reef facies (related to Wilson’s 5th facies zone) and presence of discontinuous bioclastic barrier (existence of semi-enclosed lagoon), convey that studied sediments were deposited in a homoclinal carbonate ramp. Manuscript profile -
Open Access Article
33 - Biostratigraphy and paleoecology of Family Gavelinellidae in Sanganeh and Aitamir Formations at the Kopeh-Dagh basin
Maryam Motamedalshariati Mahmoud JalaliThe sedimentary basin of Kopeh-Dagh is located in the northeast of Iran. This sedimentary basin has been of interest for a long time because of hydrocarbon materials. Gavelinellids are the most abundant and dominant groups of benthic foraminifera in epicontinenal seas d MoreThe sedimentary basin of Kopeh-Dagh is located in the northeast of Iran. This sedimentary basin has been of interest for a long time because of hydrocarbon materials. Gavelinellids are the most abundant and dominant groups of benthic foraminifera in epicontinenal seas during Cretaceous period which belong to Rotaliinacean foraminifera. They have shown a wide biogeographical distribution and dispersion in many areas of Tethys. Their evolutionary trend during the Cretaceous time was success. The high concentration of marine sedimentary rocks and the absence of igneous activities in the Kope-Dagh sedimentary basinhave caused it to be considered the most suitable basin for the formation and accumulation of hydrocarbons after the Zagros sedimentary basin. This basin has suitable layers of carbonate rocks and porous sandstones to store hydrocarbon materials, also thick layers of shales in this basin can act as suitable source and cap rocks. In this research some genera and species from this family in Sanganeh and Aitamir Formations at five stratigraphic sections including Marave Tappeh, Takal kuh, Sheykh, Gadvecanlou and Kalat from point of biostratigraphical and paleoecological applications have been investigated. In this study, four biozones including Gavelinella flandrini-Gaudryina cf. praedividens assemblage zone, Berthelina intermedia assemblage zone, Berthelina cenomanica Assemblage Zone, Berthelina intermedia-Osangularia schloenbachi Assemblage Zone have been introduced. Based on the reported genera and species of the Gavellinidae family, it can be stated that the studied formations were deposited in the middle and outer part of the continental shelf to the upper part of the continental slope and in aerobic to semi-aerobic environments. The presence of more planktonic foraminifera than benthic foraminifera in the Aitamir Formation, the depth of the basin increases. Manuscript profile