دانشگاه تهران Geopersia 2228-7817 1 1 2011 03 01 Prediction of shear and Compressional Wave Velocities from petrophysical data utilizing genetic algorithms technique: A case study in Hendijan and Abuzar fields located in Persian Gulf Prediction of shear and Compressional Wave Velocities from petrophysical data utilizing genetic algorithms technique: A case study in Hendijan and Abuzar fields located in Persian Gulf 1 17 22161 10.22059/jgeope.2011.22161 EN Iman Moatazedian Hossein Rahimpour-Bonab 0000-0003-3647-2897 Ali Kadkhodaie-Ilkhchi Mohammad Reza Rajoli Journal Article 1970 01 01 Shear and Compressional Wave Velocities along with other Petrophysical Logs, are considered as upmost important data for Hydrocarbon reservoirs characterization. Shear Wave Velocity (Vs) in Well Logging is commonly measured by some sort of Dipole Logging Tools, which are able to acquire Shear Waves as well as Compressional Waves such as Sonic Scanner, DSI (Dipole Shear Sonic imager) by Schlumberger and MDA (Monopole-Dipole Array) by Weatherford Company. Usually in Old Wells, there is lack of Shear Velocity data, or in other Wells, only some intervals may have Vs data. Shear Wave Velocity is of high importance in Geophysical studies such as AVO (Amplitude Variation with Offset) and VSP (Vertical Seismic Profiling) and along with Compressional Wave Velocity, it can be used for identification of Fluid Type, Lithology and Mechanical Rock Properties. Genetic Algorithms Technique as a subset of Evolutionary Computing is an important part of Intelligent Systems for solving Optimization Problems. In this study, Compressional and Shear Wave Velocities were modeled by Genetic Algorithms Technique in Ghar member of Asmari Formation, Hendijan Field. For measuring the accuracy of the method, predicted values were compared with the real data in Ghar member of Asmari Formation, Abuzar Field. Shear and Compressional Wave Velocities along with other Petrophysical Logs, are considered as upmost important data for Hydrocarbon reservoirs characterization. Shear Wave Velocity (Vs) in Well Logging is commonly measured by some sort of Dipole Logging Tools, which are able to acquire Shear Waves as well as Compressional Waves such as Sonic Scanner, DSI (Dipole Shear Sonic imager) by Schlumberger and MDA (Monopole-Dipole Array) by Weatherford Company. Usually in Old Wells, there is lack of Shear Velocity data, or in other Wells, only some intervals may have Vs data. Shear Wave Velocity is of high importance in Geophysical studies such as AVO (Amplitude Variation with Offset) and VSP (Vertical Seismic Profiling) and along with Compressional Wave Velocity, it can be used for identification of Fluid Type, Lithology and Mechanical Rock Properties. Genetic Algorithms Technique as a subset of Evolutionary Computing is an important part of Intelligent Systems for solving Optimization Problems. In this study, Compressional and Shear Wave Velocities were modeled by Genetic Algorithms Technique in Ghar member of Asmari Formation, Hendijan Field. For measuring the accuracy of the method, predicted values were compared with the real data in Ghar member of Asmari Formation, Abuzar Field.

دانشگاه تهران Geopersia 2228-7817 1 1 2011 03 01 Review of age, Rb-Sr geochemistry and petrogenesis of Jurassic to Quaternary igneous rocks in Lut Block, Eastern Iran Review of age, Rb-Sr geochemistry and petrogenesis of Jurassic to Quaternary igneous rocks in Lut Block, Eastern Iran 19 54 22162 10.22059/jgeope.2011.22162 EN Mohammad Hassan Karimpour Chak Stern Lang Farmer Said Saadat Journal Article 1970 01 01 The Lut Block (Eastern Iran) extends over 900 km in a north-south direction and is only 200 km wide in an east-west direction. It is confined by the Nayband fault and Shotori Range on the west. The eastern edge is bordered by the Sistan suture zone and Nehbandan Fault. The northern termination of Lut Block is the depression of Kavir-e-Namak and the Great Kavir Fault. The Makran arc, including the Bazman volcanic complex and the Jaz-Murian-Depression, define the southern edge. Sixty-five percent of the exposed rocks within the Lut Block are volcanic and plutonic rocks. Klateh Ahani, Shah Kuh and Surkh Kuh granitoids (Middle Jurassic,165-162 Ma) are among the oldest rocks exposed within the Lut Block. Based on mineralogy, low values of magnetic susceptibility [(1 to 50) × 10-5 SI], and high initial 87Sr/86Sr = 0.7073-0.709, Klateh Ahani, Shah Kuh and Surkh Kuh granitoids are classified as belonging to the ilmenite-series of reduced S-type granitoids. They formed in a continental collision tectonic setting and the magma originated from with the continental crust. The next episode of magmatism was in the Late Cretaceous. . The Lut Block (Eastern Iran) extends over 900 km in a north-south direction and is only 200 km wide in an east-west direction. It is confined by the Nayband fault and Shotori Range on the west. The eastern edge is bordered by the Sistan suture zone and Nehbandan Fault. The northern termination of Lut Block is the depression of Kavir-e-Namak and the Great Kavir Fault. The Makran arc, including the Bazman volcanic complex and the Jaz-Murian-Depression, define the southern edge. Sixty-five percent of the exposed rocks within the Lut Block are volcanic and plutonic rocks. Klateh Ahani, Shah Kuh and Surkh Kuh granitoids (Middle Jurassic,165-162 Ma) are among the oldest rocks exposed within the Lut Block. Based on mineralogy, low values of magnetic susceptibility [(1 to 50) × 10-5 SI], and high initial 87Sr/86Sr = 0.7073-0.709, Klateh Ahani, Shah Kuh and Surkh Kuh granitoids are classified as belonging to the ilmenite-series of reduced S-type granitoids. They formed in a continental collision tectonic setting and the magma originated from with the continental crust. The next episode of magmatism was in the Late Cretaceous. .

دانشگاه تهران Geopersia 2228-7817 1 1 2011 03 01 The effect of rock types on pore volume compressibility of limestone and dolomite samples The effect of rock types on pore volume compressibility of limestone and dolomite samples 37 82 22163 10.22059/jgeope.2011.22163 EN Hesam Al Vaki Aloki Bakhtiari Amin Moosavi Ezatollah Kazemzadeh Kamran Goshtasbi Mohammad Reza Esfahani Jafar Vali Journal Article 1970 01 01 Determination of porosity, permeability, and pore volume compressibility of reservoir rocks and those variations with effective stress changes are of great interest in petroleum engineering. This paper has studied the influence of pore types of carbonate reservoir rocks on pore volume compressibility as well as Klinkenberg permeability and porosity at different stress values. In the current study pore volume compressibility tests have been done on 38 limestone and 8 dolomite samples. The experiments show the importance of rock type description of the reservoir rocks. Carbonate rocks with touching vug pores have different behavior from the other studied carbonates in this paper. This complex behavior is related to the role of connecting paths closure on the characteristics of hydraulic conductivity of the rock while there is no more changes in porosity or volume change. It means that the planar connecting paths have more effect on hydraulic conductivity of this rock type, while it has not more effect on porosity. Also, in all rock types excluding touching vuggy pores limestone, increasing the initial porosity leads to increase the permeability at the same effective stress value. Determination of porosity, permeability, and pore volume compressibility of reservoir rocks and those variations with effective stress changes are of great interest in petroleum engineering. This paper has studied the influence of pore types of carbonate reservoir rocks on pore volume compressibility as well as Klinkenberg permeability and porosity at different stress values. In the current study pore volume compressibility tests have been done on 38 limestone and 8 dolomite samples. The experiments show the importance of rock type description of the reservoir rocks. Carbonate rocks with touching vug pores have different behavior from the other studied carbonates in this paper. This complex behavior is related to the role of connecting paths closure on the characteristics of hydraulic conductivity of the rock while there is no more changes in porosity or volume change. It means that the planar connecting paths have more effect on hydraulic conductivity of this rock type, while it has not more effect on porosity. Also, in all rock types excluding touching vuggy pores limestone, increasing the initial porosity leads to increase the permeability at the same effective stress value.

دانشگاه تهران Geopersia 2228-7817 1 1 2011 03 01 Geochemistry and genesis of Mehredjan bentonite deposit, southeast of Khoor, Isfehan province Geochemistry and genesis of Mehredjan bentonite deposit, southeast of Khoor, Isfehan province 47 104 22164 10.22059/jgeope.2011.22164 EN Ali Abedini Ali Asghar Calagari Masoomeh Akbari Journal Article 1970 01 01 Mehredjan bentonite deposit is located ~33 km southeast of Khoor in Isfehan province. It includes 15 discrete outcrops and occurs as layered and massive forms within a volcano-clastic sequence. Bentonitization process was accompanied with development of minerals such as montmorillonite, quartz, cristobalite, calcite, kaolinite, halite, albite, orthoclase, and muscovite. The collected field and laboratory data indicate that this deposit was developed by authigenic alteration of tuffs ranging in composition from trachyandesite, through andesite to basaltic andesite in a shallow marine environment. The distribution patterns of REEs normalized to chondrite in both bentonite and enclosing tuffs illustrate similar trend indicating the fractionation and enrichment of LREEs relative to HREEs and negative anomalies for Eu. Geochemical data revealed that transformation of tuffs into bentonite took place in an open system where leaching and fixation processes were two basic regulating factors in concentrating of common trace and rare earth elements. By pointing to the obtained results, factors such as differences of alteration intensity of protolith, physico-chemical conditions of alteration environment, adsorbing mechanism, structural incorporation, existing of organic matters, effects of diagenesis, carbonate complexation, ionic exchange, physical concentrations, and existing of resistant minerals played important roles in development of Mehredjan bentonite. . Mehredjan bentonite deposit is located ~33 km southeast of Khoor in Isfehan province. It includes 15 discrete outcrops and occurs as layered and massive forms within a volcano-clastic sequence. Bentonitization process was accompanied with development of minerals such as montmorillonite, quartz, cristobalite, calcite, kaolinite, halite, albite, orthoclase, and muscovite. The collected field and laboratory data indicate that this deposit was developed by authigenic alteration of tuffs ranging in composition from trachyandesite, through andesite to basaltic andesite in a shallow marine environment. The distribution patterns of REEs normalized to chondrite in both bentonite and enclosing tuffs illustrate similar trend indicating the fractionation and enrichment of LREEs relative to HREEs and negative anomalies for Eu. Geochemical data revealed that transformation of tuffs into bentonite took place in an open system where leaching and fixation processes were two basic regulating factors in concentrating of common trace and rare earth elements. By pointing to the obtained results, factors such as differences of alteration intensity of protolith, physico-chemical conditions of alteration environment, adsorbing mechanism, structural incorporation, existing of organic matters, effects of diagenesis, carbonate complexation, ionic exchange, physical concentrations, and existing of resistant minerals played important roles in development of Mehredjan bentonite. .

دانشگاه تهران Geopersia 2228-7817 1 1 2011 03 01 The field and microstructural study of Malayer plutonic rocks,west of Iran The field and microstructural study of Malayer plutonic rocks,west of Iran 59 127 22165 10.22059/jgeope.2011.22165 EN Vahid Ahadnejad Mohammad-Vali Valizadeh Reza Deevsalar Jamal Rasouli Journal Article 1970 01 01 A detail field and microscopic characteristics of Malayer Plutonic Rocks (162-187Ma), west of Iran, are discussed in details to evaluate relationships between deformation and pluton emplacement. The studied rocks were injected into the slate, phyllite and schists of so called "Hamadan phyllites and slates" in the Sanandaj-Sirjan zone. Studies have shown that there is a continuity from magmatic to solid-state deformation and latter deformation overprint the magmatic structures. The brittle deformation such as deformed granite sheets, (sub)mylonites and migmatites occurred in the region is subjected to tectonic forces after cooling the pluton and imply the persistency of regional deformation. The continuity from liquid to solid state deformation suggests a syntectonic emplacement of pluton. These features display a shearing deformation in the pluton. Porphyroclasts in the sheared rocks show dextral shear sense. Overall microtectonic features show that the pluton was emplaced synchronously with respect to the regional scale deformation in the high-strain environment. A detail field and microscopic characteristics of Malayer Plutonic Rocks (162-187Ma), west of Iran, are discussed in details to evaluate relationships between deformation and pluton emplacement. The studied rocks were injected into the slate, phyllite and schists of so called "Hamadan phyllites and slates" in the Sanandaj-Sirjan zone. Studies have shown that there is a continuity from magmatic to solid-state deformation and latter deformation overprint the magmatic structures. The brittle deformation such as deformed granite sheets, (sub)mylonites and migmatites occurred in the region is subjected to tectonic forces after cooling the pluton and imply the persistency of regional deformation. The continuity from liquid to solid state deformation suggests a syntectonic emplacement of pluton. These features display a shearing deformation in the pluton. Porphyroclasts in the sheared rocks show dextral shear sense. Overall microtectonic features show that the pluton was emplaced synchronously with respect to the regional scale deformation in the high-strain environment.

دانشگاه تهران Geopersia 2228-7817 1 1 2011 03 01 Sequence stratigraphy and depositional environment of the Oligocene deposits at Firozabad section, southwest of Iran based on microfacies analysis Sequence stratigraphy and depositional environment of the Oligocene deposits at Firozabad section, southwest of Iran based on microfacies analysis 71 152 22166 10.22059/jgeope.2011.22166 EN Hossein Vaziri-Moghaddam Behnaz Kalanat Azizollah Taheri Journal Article 1970 01 01 The Asmari Formation was deposited in the foreland basin of southwest Iran (Zagros Basin). Carbonate sequences of the Asmari Formation consist mainly of large benthic foraminifera along with other skeletal and non-skeletal components. Three assemblage zones have been recognized by distribution of these large foraminifera in the study area that indicate Oligocene age (Rupelian-Chattian). Absence of turbidite deposits, reefal belt and gradual facies changes indicate that the Asmari Formation was deposited in a carbonate ramp environment. Based on analysis of large benthic foraminiferal assemblages and microfacies features nine different microfacies have been recognized, which can be grouped into three depositional environments: inner, middle and outer ramp. Based on the microfacies analysis and sequence stratigraphic studies, two third-order sequences in Firozabad section were identified. The Asmari Formation was deposited in the foreland basin of southwest Iran (Zagros Basin). Carbonate sequences of the Asmari Formation consist mainly of large benthic foraminifera along with other skeletal and non-skeletal components. Three assemblage zones have been recognized by distribution of these large foraminifera in the study area that indicate Oligocene age (Rupelian-Chattian). Absence of turbidite deposits, reefal belt and gradual facies changes indicate that the Asmari Formation was deposited in a carbonate ramp environment. Based on analysis of large benthic foraminiferal assemblages and microfacies features nine different microfacies have been recognized, which can be grouped into three depositional environments: inner, middle and outer ramp. Based on the microfacies analysis and sequence stratigraphic studies, two third-order sequences in Firozabad section were identified.

دانشگاه تهران Geopersia 2228-7817 1 1 2011 03 01 Introducing some echinoderms from the Tirgan Formation, Kopeh-Dagh Basin, NE of Iran Introducing some echinoderms from the Tirgan Formation, Kopeh-Dagh Basin, NE of Iran 83 176 22167 10.22059/jgeope.2011.22167 EN Morteza Taherpour Khalilabad Ali Asghar Aryaei Alireza Ashouri Abbas Ghaderi Journal Article 1970 01 01 A stratigraphic section from the Tirgan Formation was selected in Arkan village nearby Bojnourd city in order to study echinoderm fauna systematically. Many specimens of echinoderms, especially toxasteridae which is associated with brachiopods were collected and studied systematically in this paper. Microscopie slides were also prepared and studied. All slides contain benthic foraminifers and calcareous algae as well as gastropod and coral fragments. Based upon diagnostic micro and macro fossils, a Barremian-Aptian age is assigned to the Tirgan Formation which suggests Urgonien facies type indicating shallow water of open marine environment The Urgonien is named after the village with this name in the east of Tarascon, France. This facies type is characteristic of shallow-water carbonate facies which was accumulated along the Tethys northern shelf from the Barremian to the late Albian. The facies consists of hard, white-gray limestones which contains Orbitolina (foraminifers) and transitional sediments – detrital or siliceous limestones (Foury, 1968). A stratigraphic section from the Tirgan Formation was selected in Arkan village nearby Bojnourd city in order to study echinoderm fauna systematically. Many specimens of echinoderms, especially toxasteridae which is associated with brachiopods were collected and studied systematically in this paper. Microscopie slides were also prepared and studied. All slides contain benthic foraminifers and calcareous algae as well as gastropod and coral fragments. Based upon diagnostic micro and macro fossils, a Barremian-Aptian age is assigned to the Tirgan Formation which suggests Urgonien facies type indicating shallow water of open marine environment The Urgonien is named after the village with this name in the east of Tarascon, France. This facies type is characteristic of shallow-water carbonate facies which was accumulated along the Tethys northern shelf from the Barremian to the late Albian. The facies consists of hard, white-gray limestones which contains Orbitolina (foraminifers) and transitional sediments – detrital or siliceous limestones (Foury, 1968).

دانشگاه تهران Geopersia 2228-7817 1 1 2011 03 01 cover cover 3 22168 10.22059/jgeope.2011.22168 EN Cover Cover Journal Article 1970 01 01 EDITOR’S NOTE Geopersia is published biannually by the College of Science, University of Tehran, Iran. The College of Science published “Journal of Science”, which covered all fields of basic science, from 1968 to 2010. It was then decided that the College’s journals should be more specialized, and hence publication of Geopersia was launched. Geopersia aims to publish peer-reviewed original research articles related to geology sciences that timely and sufficiently reflect progress in these sciences. The research topics may relate to Petroleum Geology, Sedimentology, Stratigraphy, Seismology Geochemistry, Petrology, tectonics, and all other areas of Geology. Authors are encouraged to submit their valuable manuscripts to our Geopersia for possible publication. Articles printed in Geopersia will also be published electronically and will be available online. More details about Geopersia could be found in our home page at: http://jgeope.ut.ac.ir or http://journals.ut.ac.ir EDITOR’S NOTE Geopersia is published biannually by the College of Science, University of Tehran, Iran. The College of Science published “Journal of Science”, which covered all fields of basic science, from 1968 to 2010. It was then decided that the College’s journals should be more specialized, and hence publication of Geopersia was launched. Geopersia aims to publish peer-reviewed original research articles related to geology sciences that timely and sufficiently reflect progress in these sciences. The research topics may relate to Petroleum Geology, Sedimentology, Stratigraphy, Seismology Geochemistry, Petrology, tectonics, and all other areas of Geology. Authors are encouraged to submit their valuable manuscripts to our Geopersia for possible publication. Articles printed in Geopersia will also be published electronically and will be available online. More details about Geopersia could be found in our home page at: http://jgeope.ut.ac.ir or http://journals.ut.ac.ir

دانشگاه تهران Geopersia 2228-7817 1 1 2011 03 01 Editors note Editors note 1 1 22169 10.22059/jgeope.2011.22169 EN Editor Note Journal Article 1970 01 01 EDITOR’S NOTE Geopersia is published biannually by the College of Science, University of Tehran, Iran. The College of Science published “Journal of Science”, which covered all fields of basic science, from 1968 to 2010. It was then decided that the College’s journals should be more specialized, and hence publication of Geopersia was launched. Geopersia aims to publish peer-reviewed original research articles related to geology sciences that timely and sufficiently reflect progress in these sciences. The research topics may relate to Petroleum Geology, Sedimentology, Stratigraphy, Seismology Geochemistry, Petrology, tectonics, and all other areas of Geology. Authors are encouraged to submit their valuable manuscripts to our Geopersia for possible publication. Articles printed in Geopersia will also be published electronically and will be available online. More details about Geopersia could be found in our home page at: http://jgeope.ut.ac.ir or http://journals.ut.ac.ir EDITOR’S NOTE Geopersia is published biannually by the College of Science, University of Tehran, Iran. The College of Science published “Journal of Science”, which covered all fields of basic science, from 1968 to 2010. It was then decided that the College’s journals should be more specialized, and hence publication of Geopersia was launched. Geopersia aims to publish peer-reviewed original research articles related to geology sciences that timely and sufficiently reflect progress in these sciences. The research topics may relate to Petroleum Geology, Sedimentology, Stratigraphy, Seismology Geochemistry, Petrology, tectonics, and all other areas of Geology. Authors are encouraged to submit their valuable manuscripts to our Geopersia for possible publication. Articles printed in Geopersia will also be published electronically and will be available online. More details about Geopersia could be found in our home page at: http://jgeope.ut.ac.ir or http://journals.ut.ac.ir