List of Articles Microfacies

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  1 - Microfacies, sedimentary environment and sequence stratigraphy of the Qom Formation in East Siyah Kuh surface section (South of Garmsar)
  Mahmoud Jalali Mahmoud Jalali محمد حسين  آدابي
  This paper represents the sequence stratigraphic analysis of the Oligo-Miocene shallow water carbonate succession of the Qom Formation, east of Kuh Siah outcrop (South of Garmmsar). The study is based on the lithosratigraphy, biostratigraphic framework (in the contex More

  This paper represents the sequence stratigraphic analysis of the Oligo-Miocene shallow water carbonate succession of the Qom Formation, east of Kuh Siah outcrop (South of Garmmsar). The study is based on the lithosratigraphy, biostratigraphic framework (in the context of European standard biozonation), microfacies, paleoenvironmental interpretation and sequence srtatgraphic concepts. In this section, only f to c1 members of the Qom Formation can be differentiated. The biostrtigraphic results revealed that the benthic foraminiferal composition of the studied section has close affinities with coeval assemblages in Western Tethys and the Middle East. The larger foraminifera associations in the Qom Formation mark the SBZ 23 to 25 zones, referring to a time span from the late Chattian to Burdigalian. Based on the micropaleontological studies, the age of late Chattian (SBZ 23) is ascribed to c1 member which previously considered as Aquitanian, in East of Siah Kuh surface section. Sedimentary environment of the Qom Formation is related to a carbonate ramp platform. Based on sedimentary texture and percentage of skeletal and non skeletal allochems, 1 lithofacies and 13 microfacies from inner to outer ramp were determined. The sequence stratigraphic studies led to the determination of four 3rd order sequences. The first sequence with the Chattian age includes c1 and c2 members. The second sequence with the Aquitanian age includes c3, c4 and d members. The e and f members belong to third and fourth sequences with the age of Burdigalian. Manuscript profile
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  2 - Microfacies, Sedimentary Environment and Sequence Stratigraphy of the Qom Formation, Deh Namak, Northwest of Garmsar
  Jahanbakhsh Daneshian  Asadi Mehmandosti yousef ramezani
  Deh Namak section is exposed along the most northern point of the Qom Formation, where the Central Iran zone and Alborz zone come together. The study of microfacies, sedimentary environments and sequence stratigraphic features of the Qom Formation in this area can h More

  Deh Namak section is exposed along the most northern point of the Qom Formation, where the Central Iran zone and Alborz zone come together. 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 the northern part, bordering the Alborz zone. 166 samples of the Qom Formation in Deh Namak section in the northwest of Garmsar are investigated. Microfacies analysis of these sedimentary rocks indicates that according to sedimentary environment they consist of nine microfacies belonging to four facies belts including tidal flat, agoon, shoal/reef sediments and slope of platform. Due to the absence of the gravitational and turbidity sediments and abundance of reef/shoal sediments, a rimmed carbonate shelf depositional environment is suggested in which more sediments were precipitated in shallow water. In this model, deep facies of the basin did not spread and the deepest facies belong to the slope. Also, sequence stratigraphic studies show that the Deh Namak section is composed of four sedimentary sequences of third- order, two types II and one type I sequence boundaries were recognized in this formation. Manuscript profile
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  3 - Microfacies and sedimentary environment of the Maastrichtian deposits in Jorbat Stratigraphic section, west of Kopet Dagh
  Yadolah Ezampanah Mahmoud Jalali محمد حسين  آدابي امیرمحمد  جمالي
  To determine microfacies and depositional subenvironments of the Maastrichtian deposits in the western part of the Kopet-Dagh Basin, one stratigraphic section, has been selected and analysed. In this section which is located 9.5 kms N-NW of Jorbat, Maastrichtian deposit More

  To determine microfacies and depositional subenvironments of the Maastrichtian deposits in the western part of the Kopet-Dagh Basin, one stratigraphic section, has been selected and analysed. In this section which is located 9.5 kms N-NW of Jorbat, Maastrichtian deposits are composed of two formations including Kalat (282 m thickness) and Chakhmaghlo (77 m thickness). The Kalat Formation consists of bioclastic and sandy limestone and the Chakhmaghlo Formation is composed of shale, marl, limestone and argillaceous limestone. Based on field observations and also petrographic studies, the lower boundary of the Kalat Formation with the Abderaz Formation is disconformable. The lower boundary of the Chakhmaghlo Formation with the Kalat Formation is gradual and conformable, while its upper contact with the Paleocene Pesteligh Formation is disconformable. Petrographic studies in Maastrichtian deposits led to recognition of 16 microfacies. These microfacies deposited in 5 facies belts including tidal flat, lagoon, shoal, reef and fore reef subenvironments in a carbonate platform. Manuscript profile
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  4 - The Study of Overburden Pressure Effect on Cementation Factor in Hydraulic Flow Units of Carbonate Rocks
  حبیب اله  صدیقی کاظم سعادت محمد رضا  اصفهانی عزت اله  کاظم زاده
  Abstract Analyze of parameters which influence the petrophysical Properties of reservoir rocks is necessary in dynamic model simulation of reservoirs. According to the relation of cementation factor and reservoir pressure changes, cementation factor is the most effec More

  Abstract Analyze of parameters which influence the petrophysical Properties of reservoir rocks is necessary in dynamic model simulation of reservoirs. According to the relation of cementation factor and reservoir pressure changes, cementation factor is the most effective parameter in water saturation determination in the mentioned model, so the study of the effect of pressure on cementation factor is necessary. In this study, firstly carbonate core samples of a gas reservoir, in the south of Iran was classified by hydraulic flow unit delineation method. Then their cementation factors were determined by Archie equation and best fit curve method at ambient, 800, 2000, 3500, and 5000 psi pressures. The changes in cementation factor values due to increasing overburden pressure were evaluated in each hydraulic flow unit and their relationship with flow zone indicator (FZI) were studied by experimental equations (for 4 flow units 0.95<R2<0.99). In this study a relation between flow zone indicator for each hydraulic flow unit and cementation factor changes, due to the different pressures, were also obtained. The experimental results of studied reservoir cores shows that with increasing flow zone indicator the changes in cementation factors decreases. Manuscript profile
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  5 - Lithostratigraphy and Sedimentary Environment of the Jahrum Formation in two Anticlines of Jahrum and Tudej
  رضا  صادقی محمد حسین  خواجوئی مریم  جوکار
  Abstract In this study two stratigraphic sections named Tang-e Ab as type section and Tang-e Nimbashi analyzed in order to study lithostratigraphy and microfacies of Jahrum Formation in Fars province. Both sections, Tang-e Ab in northern flank of Jahrum Anticline (Ea More

  Abstract In this study two stratigraphic sections named Tang-e Ab as type section and Tang-e Nimbashi analyzed in order to study lithostratigraphy and microfacies of Jahrum Formation in Fars province. Both sections, Tang-e Ab in northern flank of Jahrum Anticline (East of Jahrom) and Tang-e Nimbashi in northern flank of Tudej Anticline (West of Estahban) located in Interior Fars Sub-Zone at Zagros folded belt. Tang-e Ab section included 450 meters of conglomerate, limestone, nodular marly limestone, dolomitic limestone and dolostone with thin, medium, thick and very thick bedding and Tang-e Nimbashi section included 562 meters of limestone, marly Limestone, nodular marly limestone, dolomitic limestone and dolostone with very thin, thin, medium, thick and very thick bedding. The result of field and laboratory observations is determination of 10 lithostratigraphic unit and 10 microfacies class in Tang-e Ab and 7 lithostratigraphic unit and 11 microfacies class in Tang-e Nimbashi, in both Sections 3 sub-environments included: open marine, lagoon and peritidal and sedimentary settings corresponded on a carbonate platform of homoclinal ramp. Manuscript profile
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  6 - Microfacies and palaeoecology of the Asmari Formation in southeast flank of the Khami anticline (east of Gachsaran) and Correlation with two other sections of the Asmari Formation in the Zagros Basin
  همتا رنجبر علی رحمانی
  Abstract In order to characterize the features of facies and depositional environment conditions of the Asmari Formation in southeast flank of the Khami anticline with a thickness of 270 m has been studied. the Field and laboratory studies, led to the identification More

  Abstract In order to characterize the features of facies and depositional environment conditions of the Asmari Formation in southeast flank of the Khami anticline with a thickness of 270 m has been studied. the Field and laboratory studies, led to the identification 12 microfacies (nummulitidae lepidocyclina packestone/rodestone, corallinacea benthic foraminifera (perforate) packstone, bioclast neorotalia packestone, ooid grainstone, bioclast grainstone, miliolid neorotalia nummulitidae packestone, miliolid corallinacea coral floatstone/grainstone, bioclast benthic foraminifera (imperforate) packstone/grainstone, miliolid packstone/grainstone, sandy mudstone, intraclast mudstone) that deposited in continental slope, shoal, lagoon and tidal flat. In three different salinity facies environment from 34 psu to over 50 psu in oligoophotic to euphotic environment and oligotrophy-weak mesotrophy to eutrophy conditions in a homoclinal carbonate ramp platform recognized for the Asmari Formation at this study area. Correlation of the Asmari Formation in 3 section, A water salinity environmental correlation of the Asmari Formaion from Firozabad to east and north of Gachsaran reveals that 1- during Rupelian the Asmari Formation deposited in a normal water salinity environment, 2- while normal salinity water condition prevailed in Gachsaran area during Chattian, the Fars area was under higher marine salinity environment. Higher salinity environment developed during Aquitanian and Burdigalian in Gachsaran area. Manuscript profile
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  7 - Microfacies and palaeoecology of the Asmari Formation in southeast flank of the Khami anticline (east of Gachsaran) and Correlation with two other sections of the Asmari Formation in the Zagros Basin
  همتا رنجبر علی رحمانی
  Abstract In order to characterize the features of facies and depositional environment conditions of the Asmari Formation in southeast flank of the Khami anticline with a thickness of 270 m has been studied. the Field and laboratory studies, led to the identification More

  Abstract In order to characterize the features of facies and depositional environment conditions of the Asmari Formation in southeast flank of the Khami anticline with a thickness of 270 m has been studied. the Field and laboratory studies, led to the identification 12 microfacies (nummulitidae lepidocyclina packestone/rodestone, corallinacea benthic foraminifera (perforate) packstone, bioclast neorotalia packestone, ooid grainstone, bioclast grainstone, miliolid neorotalia nummulitidae packestone, miliolid corallinacea coral floatstone/grainstone, bioclast benthic foraminifera (imperforate) packstone/grainstone, miliolid packstone/grainstone, sandy mudstone, intraclast mudstone) that deposited in continental slope, shoal, lagoon and tidal flat. In three different salinity facies environment from 34 psu to over 50 psu in oligoophotic to euphotic environment and oligotrophy-weak mesotrophy to eutrophy conditions in a homoclinal carbonate ramp platform recognized for the Asmari Formation at this study area. Correlation of the Asmari Formation in 3 section, A water salinity environmental correlation of the Asmari Formaion from Firozabad to east and north of Gachsaran reveals that 1- during Rupelian the Asmari Formation deposited in a normal water salinity environment, 2- while normal salinity water condition prevailed in Gachsaran area during Chattian, the Fars area was under higher marine salinity environment. Higher salinity environment developed during Aquitanian and Burdigalian in Gachsaran area. Manuscript profile
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  8 - Oligocene microfacies and sedimentary environment of the Asmari Formation at northwest of Deris village, west of Fars province: correlation with three other sections in Zagros Basin
  samir Akhzari Ali Seyrafian
  In this disquisition, Oligocene (Rupelian-Chattian) microfacies and sedimentary environment of the Asmari Formation at the northwest of Deris village, located in interior Fars zone of the Zagros Basin have been interpreted. The coordinates of such section are N: 29o 4 More

  In this disquisition, Oligocene (Rupelian-Chattian) microfacies and sedimentary environment of the Asmari Formation at the northwest of Deris village, located in interior Fars zone of the Zagros Basin have been interpreted. The coordinates of such section are N: 29o 41' 59'', E: 51 o 32' 26''. The Asmari Formation deposits in this section are divided into 5 lithological units and consist of 460 m thin, medium, thick and massive bedded, gray and cream to gray limestone, slightly dolomitic with nodular and marly interbedded. By study of hyaline benthic foraminifera genera and non-foraminifera, and also recognition of some properties such as skeletal ingredient associations and sedimentary textures of thin sections, 14 microfacies have been introduced for the Asmari Formation. Gradual perpendicular changes of these microfacies represent that settling the Asmari Formation deposits took place in a homoclinal rapm. This homoclinal ramp consists of middle ramp and inner ramp, that are separated by shoal environment. Middle ramp is recognized by presence and dominition hyaline benthic foraminifera, coralline red algae and echinoids. The most significant skeletal debris of inner ramp are porcelainous foraminifera. To compare the thickness, age and sedimentary environment, zonal correlation of the Asmari Formation done in Deris section with three other sections (Naura anticline, Dill anticline and Dehloran) in the Zagros Basin. This correlation represent that the age of the Asmari Formation gets younger to the deeper parts of the foreland basin of the Zagros. Manuscript profile
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  9 - Microfacies and depositional environment of the Asmari Formation in the Izeh zone
  Mohammad.reza Taheri Ali asghar Gabishavi
  In this study, microfacies features of the Asmari Formation have been studied. The study area is located in the Izeh zone, in the vicinity of Izeh city. Accordingly four outcrop sections (Halayjan, Kuh Shur, Kuh-e Bad and Gharibi Ha) have been sampled and investigated. More

  In this study, microfacies features of the Asmari Formation have been studied. The study area is located in the Izeh zone, in the vicinity of Izeh city. Accordingly four outcrop sections (Halayjan, Kuh Shur, Kuh-e Bad and Gharibi Ha) have been sampled and investigated. Due to unique tectonical characteristic and lateral as well as spatial variations of the outcrops, different facies have been deposited across the Asmari Formation platform in the study area. Based on the sedimentary structures, texture, skeletal and non-skeletal grains, 11 microfacies have been recognized which have been deposited in three different sub environments including open marine, shoal and lagoon. Based on this reaserch, for the Asmari Formation, three independent depositional models have been considered during the Chattian, Aquitanian and Burdigalian. On the basis of the results of this study, during the Chattian, Aquitanian and Burdigalian the Asmari Formation has been deposited in a homoclinal ramp system. During the Burdigalian toward the NE of study area (Gharibi Ha section), the shallow water deposits are abruptly overlain by pelagic limestone. Therefore, during the Burdigalian toward the NE of study area, probably, the carbonate ramp has been changed to drowned carbonate platform. It is interpreted as the result of a regional tilting that started in the late of the Burdigalian. During the Chattian in the Gharibi Ha area, the base of the carbonate Asmari Formation transits into the marl-dominated Pabdeh Formation towards the Halayjan area which could be concerned as an analogue to investigate about the stratigraphic oil traps potential in the Izeh zone. Manuscript profile
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  10 - Biostratigraphy, microfacies and sedimentary environment of the Asmari Formation at Somghan area and correlation with other sections in the Zagros basin
  Mehrnaz Rahimzadeh Ali Seyrafian Ali Rahmani
  The difference in the depositional setting of the Zagros, causes multiple carbonate facies.The Asmari Formation deposited in the foreland basin during Oligo-Miocene time. In this study, biostratiography and microfacies of the Asmari Formation at Nowdan anticline next to More

  The difference in the depositional setting of the Zagros, causes multiple carbonate facies.The Asmari Formation deposited in the foreland basin during Oligo-Miocene time. In this study, biostratiography and microfacies of the Asmari Formation at Nowdan anticline next to Somghan village (39 Km north of Kazerun) are studied. The thickness of the Asmari Formation is 302 meters and its upper and lower boundries are coverd. Field work studies resulted to recognize 4 lithostratigraphic units (unit 1: thin to medium bedded limestone, unit 2: thick and some thin and medium bedded limestone, unit 3: thin and thick bedded nudular limestone, unit 4: thin bedded nudular limestone). Based on microscopic studies, 20 genera and 19 species of benthic foraminifera were identified and two biozones related to the Oligocene were identified. Based on textural and faunal studies, nine microfacies related lagoon and open marine were differentiated. Also in this study, to reconstract geometry and to analyze the role of Qatar-Kazerun fault during Oligocene, 11 sections of the Asmari Formation were examined. Manuscript profile
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  11 - 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-Dill
  In 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 More

  In 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
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  12 - Electro-facies analysis of the Sarvak Formation (Middle Cretaceous) and compliance with sedimentary microfacies in an oil field, SW Iran.
  zahra Eghbalkiani Taher Goli ALI HOSSEIN JALILIAN Rahym Kadghodaii
  Electro-facies analysis is a sure method in clustering petrophysical logs analysis that can well indicates the changes of geologic charactereristics of the different lithostratigraphic units as well. Petrographic studies of 120 prepared thin sections of the upper parts More

  Electro-facies analysis is a sure method in clustering petrophysical logs analysis that can well indicates the changes of geologic charactereristics of the different lithostratigraphic units as well. Petrographic studies of 120 prepared thin sections of the upper parts of the Sarvak Formation in studied oilfield, Southwestern Iran, has resulted in definition of 6 microfacies sedimentary types. These data suggested that the middle Creataceous sediments in the studied area were predominantly deposited in two subenviornments of patch organic barrier and lagoon corresponding to inner and shallow a homoclinal ramp. In addition, using petrophysical logs in the studied well, 10 electrical facies were determined. By analyzing the data petrophysical in Geolog software, 10 electerical facies were optimized and then their number was reduced to six. According to good adaptation of optimized electerical facies with sedimentary microfacies, we would generalized obtained dresults to all parts of the Sarvak Formation. Study of porosity changes in the electrical diagrams such as CGR corrected Gamma, and sonic curves in mentioned well, indicated a significant reduction in facies porosity of 1 to 6. In addition, the results showed that the reservoir quality reductionin studied microfacies is corresponded to Bioclastic Rudist debris floatstone/ Rudstone, Benthic foraminifera Rudist debris wackestone / packstone, Benthic Foraminifera peloid Grainstone/Packstone, with High diversity benthic foraminifera wackestone / packstone, Peloid bioclastic wackestone /packstone with Low diversity benthic Foraminifera and Mudestone/Wackestone, respectively. In this study, we concluded that comparison and correlation sedimentary facies with electric microfacies provide an efficient method to study the quality of the hydrocarbon reservoir system that especially can be used in other wells with no core. Manuscript profile
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  13 - The impact of microfacies and diagenesis characteristics on the reservoir quality of Asmari Formation in the Gevarzin gas field, Zagros basin, south Iran
  Karim  Mombani   Ahmad Yahyaei
  Asmari Formation from the Gavarzin gas field have erosional unconformity boundary on marl and pelagic limestones of Pabdeh Formation and gradually change to evaporate cap rock of Gachsaran Formation. Cores studies from the one of wells of Gavarzin field is 183 m in thic More

  Asmari Formation from the Gavarzin gas field have erosional unconformity boundary on marl and pelagic limestones of Pabdeh Formation and gradually change to evaporate cap rock of Gachsaran Formation. Cores studies from the one of wells of Gavarzin field is 183 m in thickness, which includes 1.30 m from the top of Pabdeh, 162.4 m from the Asmari Formation and 19.30 m from the base layers of Gachsaran. Asmari Formation includes alternation of limestone, calcite dolomitic, claystone and shale with green marl. Petrology and facies analysis of the sequence of these formations identified 12 microfacies, a carbonate ramp from deep-sea to sabkha environments and formed in a retrograded sequence. This ramp includes deep environments, open sea, patch reef, bio-, clastic-bars, lagoon and tidal environments, which confirms a changing environment due to rapid facies changes and deposition of evaporative sediments in Gachsaran as a restricted environment. Diagenesis processes are considered as the main factors in carbonate reservoir quality of Gavarzin field. The diagenesis history of the Asmari carbonates of the studied cores is summarized as A) marine phreatic diagenesis, bioturbation, micritization and cementation processes occurred. B) vadose zone diagenesis, where the crystallization, cementation, and dissolution occurred. C) burial diagenesis, comprises compression-induced, pressure dissolution and fracturing are common. The microfacies show a wide varieties of reservoir characteristics and therefore a heterogeneous reservoir has been formed. Micro-fractures, however have strongly influence on the reservoir quality in the section. The simultaneous presence of dissolved spaces and fractures in the reservoir the permeability greatly increased. The best reservoir quality in the Grainstone/Packston facies are coated grains with moldic porosity that were created by the leaching of Ooid-bearing Packston lithology during the diagenesis of atmospheric waters. Manuscript profile
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  14 - 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 moghadam
  Reconstruction 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 More

  Reconstruction 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
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  15 - (Biostratigraphy and microfacies of the Asmari Formation in south flank of Mish anticline (northeast of Gachsaran
  Saber Ahmadi Ali seyrafian Hosyen vaziri-Moghadam
  Asmari 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 More

  Asmari 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
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  16 - Microfacies and Sequence stratigraphy of the the Qom Formation in Kuh-e Charkheh (Natanz), Western Zefreh and Varton sections, northeastern Isfahan
  Amir Pedramara Mehdi Yazdi Zahra Maleki Ali Bahrami
  In this research, the deposits of the Oligocene-Miocene Qom Formation in Kuh-e Charkheh (Natanz), Western Zefreh and Varton sections, northeastern Isfahan were studied. According to the field observations and thin section analysis in Carbonate part of the mentioned sect More

  In this research, the deposits of the Oligocene-Miocene Qom Formation in Kuh-e Charkheh (Natanz), Western Zefreh and Varton sections, northeastern Isfahan were studied. According to the field observations and thin section analysis in Carbonate part of the mentioned sections, 8 microfacies were identified, which were deposited from shallow part of lagoon to open marine and the sedimentary environment of 3 sections due to absence of reef and presence of bioclastic barrier and absence of spillage, the homoclinal carbonate ramp was detected. According to the sequence stratigraphic studies, each of the studied sections has two 3rd sequences. In Kuh-e Charkheh section, both sequences include of TST and HST, which are separated by sequence boundary SB2. In the western Zefreh section, the first sequence includes of TST and HST that is separated from the second sequence (include of LST, TST and HST) with sequence boundary SB1. In the Varton section, the first sequence is aggredation type and separated from the second sequence, which include TST and HST by a sequence boundary SB2. Manuscript profile
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  17 - Reservoir quality evaluation of the Asmari Formation in the framework of sequence stratigraphy in one of the Iranian SW oilfield
  Ebrahim Sfidari A. Hakymi-Zanuz
  The Oligo-Miocene Asmari Formation forms the main reservoir rock of many Dezful Embayment fields. Microfacies analysis, diagenetic features, and sequence stratigraphic evaluation of the Asmari Formation were carried out based on the petrographic investigation, petrophys More

  The Oligo-Miocene Asmari Formation forms the main reservoir rock of many Dezful Embayment fields. Microfacies analysis, diagenetic features, and sequence stratigraphic evaluation of the Asmari Formation were carried out based on the petrographic investigation, petrophysical logs, and core measurement porosity and permeability data. Petrographic analyses led to the identification of twelve microfacies indicating five subenvironments including tidal flat, lagoon, barrier (belonging to inner ramp), middle ramp, and outer ramp, all of which are representing a homoclinal ramp. Tidal flat, lagoonal, and barrier microfacies are mostly present in the upper parts of the Asmari Formation, while middle and outer ramp microfacies were largely developed in the middle part. Cementation, compaction, dolomitization, dissolution, and fracturing are the main diagenetic processes in this formation. Compaction and cementation have negatively affected reservoir quality while fracturing, dolomitization, and dissolution contributed to reservoir quality enhancement. The sequence stratigraphic studies represent three 3rd order sequences of early Aquitanian, late Aquitanian, and early Burdigalian age based on the main features of microfaces, their depositional environments, and shallowing and deepening-upward trends. Microfacies of the Transgressive System Tract (TST) have been affected by compaction, dissolution (moldic), cementation, and slightly dolomitization in the middle to outer ramp parts. The Highstand System Tract in the inner ramp part has been affected by dolomitization, dissolution, and fracturing close to the sequence boundaries, and has a better reservoir quality than the Transgressive System Tract. Manuscript profile