H Ghaderi Fijani; M Khanehbad; R Moussavi Harami; A. Mahboubi
Abstract
The elongated Elyato River catchment, covering about 52.89 Km2 areas, is located in southwestern Fariman. To understand the grain size variation and effective factors in downstream fining, 35 samples from central axis of Longitudinal Bars have been collected and analyzed. The results indicate that the ...
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The elongated Elyato River catchment, covering about 52.89 Km2 areas, is located in southwestern Fariman. To understand the grain size variation and effective factors in downstream fining, 35 samples from central axis of Longitudinal Bars have been collected and analyzed. The results indicate that the grain size decreases downstream as exponential. The lithological and geomorphological changes and faulting are effective in the slope percentage changes downstream. Based on petrographic studies, sediments on the river’s substrate are igneous rock fragments such as gabbro and serpentine group. However, based on sedimentological studies, we show that the sediments of Longitudinal Bars are mostly poorly and very poorly sorted, near symmetrical to very positive skewness and mesokurtic and platy kurtic kurtosis. Six sedimentary facies including grain supported gravel (Gcm), matrix supported gravel (Gmm), grain supported gravel with horizontal bedding (Gh), massive sand (Sm), laminated mud (Fl) and massive mud (Fm) are recognized along the wall of the studied river. These sedimentary facies have formed in 3 architectural elements including channel (CH), Gravel bars and bed form (GB) and fine grain clastic deposits (FF). Based on sedimentary facies and architectural elements, sedimentary model for this river is proposed as gravelly braided river system.
N. Sarbaz; A. Mahboubi; R. Moussavi-Harami; M. Khanehbad
Abstract
The Koppeh- Dagh Basin in the northeast Iran formed after closure of the Paleotethys in the south of Turan plate. Kashafrud Formation in the Navia Section (west of Bojnourd) with a thickness of 749 m is composed of silici-clastic rocks (conglomerate, sandstone and shale). In order to interpret provenance ...
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The Koppeh- Dagh Basin in the northeast Iran formed after closure of the Paleotethys in the south of Turan plate. Kashafrud Formation in the Navia Section (west of Bojnourd) with a thickness of 749 m is composed of silici-clastic rocks (conglomerate, sandstone and shale). In order to interpret provenance of this formation in the study section, 12 shale samples have been geochemically analyzed. The samples are rich in quartz and clay minerals, with respect to (UCC) depletion in Na2O, CaO, MgO, Cu, Nb and Sr and enrichment in Ni, Co, V, Y and U. Plotting TiO2 versus Al2O3, Zr versus TiO2, as well as ternary diagram (SiO2/20), (k2O+ Na2O), (MgO+ TiO2+ FeO) and diagram Al2O3, (Cao+ Na2O+ K2O), (FeO + MgO) suggest that the original source of this formation was probably from intermediate igneous rocks. Calculated PIA and CIA indicate high chemical weathering and semi- humid climatic condition in the source area. Prepared discrimation diagram using the major oxides (SiO2 versus K2O/Na2O and ternary diagrams SiO2/20, Na2O+ K2O, TiO2+ MgO+ Fe2O3), shows that the shales of this formation were plotted in the passive continental margin. Paleogeographic reconstruction for this formation, during the Middle Jurassic shows that sedimentation of this formation is mainly controlled by intracontinental subsiding basin and the source of these sediments was from the southeast of the Kopph-Dagh Basin.
Stratigraphy and Palaeontology
M. Allameh; A. Mahboubi; R. Moussavi-Harami; M. Khanehbad
Abstract
The Aitamir Formation (Albian-Cenomanian) composed of siliciclastic rocks and several carbonate horizons. In order to study depositional environment and sequence stratigraghy, two stratigraghic sections studied in east Koppeht Dagh basin near the Baghak and Shurijeh villages. Field and petrograghic studies ...
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The Aitamir Formation (Albian-Cenomanian) composed of siliciclastic rocks and several carbonate horizons. In order to study depositional environment and sequence stratigraghy, two stratigraghic sections studied in east Koppeht Dagh basin near the Baghak and Shurijeh villages. Field and petrograghic studies led to siliciclastic and carbonate facies that deposited in lagoon, barrier, shoreface and open marine environments. Sequence stratigraghy analysis led to identification of three depositional sequences in both sections. Comparision of interpreted sea level curves at studied area with Albian-Cenomanian global curve shows similarities and differences that can be relatedto tectonic setting and sedimentation rate.
A Ramezani Akbari; H Rahimpor-Bonab; M.R Kamali; R Moussavi-Harami; A Kadkhodaie
Abstract
The Fahliyan Formation of Khami Group is hosting important hydrocarbon reserves in Iran and also is a main reservoir rock in the Abadan Plain oil fields which is Neocomian in age. In the studied wells its thickness is about 440 meters. In the Abadan Plain, the Fahliyan Formation transitionally overlies ...
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The Fahliyan Formation of Khami Group is hosting important hydrocarbon reserves in Iran and also is a main reservoir rock in the Abadan Plain oil fields which is Neocomian in age. In the studied wells its thickness is about 440 meters. In the Abadan Plain, the Fahliyan Formation transitionally overlies the argillaceous limestone of the Garau Formation and its upper boundary changes into marl and argillaceous limestone of the Gadvan Formation. According to thin sections examinations prepared from cuttings and cores plus electrofacies analysis 11 microfacies and 2 lithofacies are recognized. This formation consists of two carbonate and mixed carbonate-siliciclastic (mixed zone) members. The Lower Fahliyan was deposited in carbonate ramp environment while, the Upper Fahliyan was deposited in a mixed carbonate–siliciclastic environment. To determine electrofacies, the rock types were modeled with using MRGC method. Best correlation between petrographical and electrofacies is 12 cluster model (in MRGC method). These results suggest that the electrofacies model is in agreement with heterogenetic rock type such as mixed carbonate–siliciclastic environment observed in petrography. Also, in homogenous rock type such as carbonate ramp environment electherofacies can’t completely determine geological facies. Based on petrographical and electrofacies this formation is composed of three third order sequences with type sb2 sequence boundaries. But, the third sequence in mixed carbonate–siliciclastic zone is terminated with sb1 sequence boundary just below the Gadvan Formation.
M Tajbakhshian; M.H Mahmudy; A Mahboubi; R Moussavi Harami; I Ejlali
Abstract
Hydrogeochemistry of surface and ground waters is a useful way to identify performing reactions in aquifers and also in recognizing effective natural and anthropogenic polluting factors in these sources. In order to study surface and ground waters quality of shahid Hashemi- Nejad gas refinery region, ...
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Hydrogeochemistry of surface and ground waters is a useful way to identify performing reactions in aquifers and also in recognizing effective natural and anthropogenic polluting factors in these sources. In order to study surface and ground waters quality of shahid Hashemi- Nejad gas refinery region, located 35 km south of Sarakhs town, 17 water samples were collected. Parameters of pH, temperature, electrical conductivity and total dissolved solids were measured in the field, and water samples were analyzed for major anions and cations concentrations in geochemical lab. Using Piper diagram, sodium sulfate and sodium chloride type and facies were determined for the water samples. Ca2+/Mg2+v.as Mg2+ ,Ca2+/Ca2++Mg2+v.as SO42-/SO42-+HCO3- compound diagrams, total hardness and PCO2 proved carbonates dissolution. Na+/Na++Cl-, Ca2+/Ca2++SO42-,HCO3-/Σ anions, HCO3-/SiO2 , SiO2/Na++K+-Cl-, Na++K+and SO42-+Cl-ionic ratios determined factors such as ion exchange, dissolution of Gypsum, Halite and sulfates of sodium-potassium, and weathering of carbonates and silicates as the most important effective parameters on chemical composition of water sources in this area. In Log(aCa2+/a(H+)2)andLog(aMg2+/a(H+)2) v.asLog (aNa+/a(H+)2) diagrams, which are used for specifying soluble silicate minerals in water, all water samples showed the dissolution of Kaolinite except two samples which were located at clinochlore mineral zone. Calculating saturation indices using PHREEQC software proved that Calcite and Dolomite mineral had supersaturation, Halite and Anhydrite undersaturation and Gypsum mineral supersaturation, undersaturation and equilibrium states in all samples. Schoeller and Wilcox diagrams pointed unsuitable quality for drinking and agricultural usages for these water sources. In fact, because of formations presence with high solubility that lay out in large amount of surface, water resources in this area have not suitable quality, and on the other hand shallow water level and high temperature intensify it. Based on obtained results, natural factors have major role in quality area’s water resources.
M Shahraki; M.H Mahmudy Gharaie; R Moussavi-Harami; A Ahmadi
Abstract
In this research the catchment of the Sarbaz river, SE Iran, has been studied to determine sediment provenance and its possible pollution potential. 30 sediment samples collected from the riverbed were analyzed for major and trace elements, using combined XRF and AAS methods. Based on major and trace ...
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In this research the catchment of the Sarbaz river, SE Iran, has been studied to determine sediment provenance and its possible pollution potential. 30 sediment samples collected from the riverbed were analyzed for major and trace elements, using combined XRF and AAS methods. Based on major and trace element data and identification charts the sediments are identified to be of litharenite composition. Quartz-rich sedimentary and intermediate igneous origin and island arc tectonic setting is proposed for the sediments, mainly inferred from discrimination diagrams. Regarding the hazardous potential of metals and metalloids, As, Cd, Co, Cr, Cu, Fe, Mn, Hg, Ni, Pb, Se, V and Zn were studied from 30 locations. Pb, Cd and As concentrations measured respectively in 7, 10 and 20 locations are more than concentrations of the same elements in the world riverbeds. In this research, the polluted sediments were evaluated using the geo-accumulation index (Igeo). Based on this index, Cd, Pb, Zn and Cu show some degrees of pollution, while other elements are evaluated to be less pollutant. Statistic analysis show strong correlation between studied elements. Volcanic activity in north of the Makran zone can readily justify the common origin of the contaminants in the catchment of the Sarbaz river. Chromium is most probably originated from the nearby Makran ophiolites. It is concluded that geological factors have mainly been the controlling factors for the sediment pollution in the Sarbaz catchment.
A Bayet-Goll; R Moussavi-Harami; A Mahboubi
Abstract
Carbonate deposits of members 1 to 2 of the Mila Group (Middle Cambrian) in Central Alborz that call the Deh-Sufiyan Formation in this research, were studied in Shahmirzad, Tueh-Darvar, Mila-Kuh and Deh-Molla sections. The Unit 2 of Deh-Sufiyan Formatrion in Central Alborz of Northern Iran consists mainly ...
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Carbonate deposits of members 1 to 2 of the Mila Group (Middle Cambrian) in Central Alborz that call the Deh-Sufiyan Formation in this research, were studied in Shahmirzad, Tueh-Darvar, Mila-Kuh and Deh-Molla sections. The Unit 2 of Deh-Sufiyan Formatrion in Central Alborz of Northern Iran consists mainly of shallow marine carbonates and contains a variety of limestone conglomerates. Limestone conglomerate is an important component of Unit 2 of Deh-Sufiyan Formatrion, but its origins remain enigmatic. These limestone conglomerates have a diverse set of characteristics that range from clast to matrix supported with scattered flat pebbles. These conglomerates are largely comprised of oligomictic, rounded lime–mudstone clasts of various sizes and shape (equant, oval, discoidal, tabular, and irregular). According to composition and characteristic sedimentary structures and fabric, limestone conglomerates in the Unit 2 of Deh-Sufiyan Formatrion consist of: (1) Intraformational limestone conglomerate beds were formed by depositional processes (2) Limestone pseudoconglomerate beds were produced by diagenetic processes. The common characteristics of the Unit 2 of Deh-Sufiyan Formatrion pseudoconglomerates, such as oligomictic lithology of lime–mudstone clasts, mosaic fabric, disorganized/edgewise fabric, variable and gradational fabric, transitions from adjacent or underlying facies and the complete lack of depositional structures, are typical of pseudoconglomerates formed by early diagenetic sediment deformation under shallow burial conditions. These characteristics are different from those of intraformational limestone conglomerate showing primary depositional features such as normal or inverse grading, internal stratification, (hummocky) cross-stratification and sharp erosional bases. Diagenetic conglomerates in ribbon rocks resulted from soft-sediment deformation of ribbon rocks during early diagenesis. In contrast, the dimension and thickness, sizes of the clasts, clast-rich beds, size ingredient of matrix, tendency to amalgamate with amalgamation scours within depositional conglomerates suggest that high energy and strong erosion above storm wave base was responsible for the disintegration of the carbonate material.
M.R Rahmani; R Moussavi – Harami; M Arian
Abstract
Dariyan formation is one of the oil reservoirs in the south pars field. This formation has been studied in wells SPO-1, SPO -2 and Spo-3. Thickness of Dariyan formation in mentioned wells are 109, 113 and 114 meters respectively. Based on the studies of thin sections from the Dariyan formation of three ...
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Dariyan formation is one of the oil reservoirs in the south pars field. This formation has been studied in wells SPO-1, SPO -2 and Spo-3. Thickness of Dariyan formation in mentioned wells are 109, 113 and 114 meters respectively. Based on the studies of thin sections from the Dariyan formation of three above mentioned wells, nine carbonate and one detrital facies have been identified within four facies associations including tidal flat (Mudstone), lagoon (Bioclast mudstone to wackstone, Bioclast peloid wackstone to packstone, Bioclast peloid packstone to grainstone, Algal boundstone), Mid ramp (Echinoid mollusk wackstone to packstone, Orbitolina wackstone to packstone, Framestone, Floatstone) and outer ramp (Shale). Facies studies indicate that Dariyan formation has been deposited in a homoclinal ramp.The Dariyan formation has been affected by four diagenetic stages, including marine, meteoric, burial and uplift. The most important identified diagenetic processes are micritization, bioturbation, geopetal, physical and chemical compaction, cementation, neomorphism, replacement, dissolution, fracturing and filling. Among the all diagenesis process, dissolution and fracturing are the major processes improving reservoir quality. In Contrary, physical compaction and especially cementation are the main processes redusing reservoir quality. Dissolution process with generating secondary porosity consists of vuggy and moldic, has important effect on increasing of porosity. Most of the dissolution features have been produced during the meteoric diagenesis and less through burial diagenesis. Dissolution process with develop the vuggy pores caused to connect them in some case and also affected on fractures , stylolites and previous diagenetic cements in upper and lower members of daryian formation which eventually has been increased permeability and reservoir quality. Also, Fracturing, the main other diagenetic process with connect the some individual vuggy and moldic pores together has effective role to increase the permeability and reservoir quality in upper and lower parts of Dariyan formation.
M Karavan; A Mahboubi; H Vaziri-Moghaddam; R Moussavi-Harami
Abstract
The Oligocene Qom Formation deposits in NW Central Iran (NE Delijan) are widespread in NE-SW trend.Four members of the Qom Formation (unknown, a, b& c1) in the study area consist of mainly marly limestone, limestone, sandy limestone and a minor amounts of sandstone. It disconformablyoverliesthe Lower ...
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The Oligocene Qom Formation deposits in NW Central Iran (NE Delijan) are widespread in NE-SW trend.Four members of the Qom Formation (unknown, a, b& c1) in the study area consist of mainly marly limestone, limestone, sandy limestone and a minor amounts of sandstone. It disconformablyoverliesthe Lower Red Formation and the upper boundary is covered by the recent alluvium. Based on the benthic foraminifers assemblage, these deposits are attributed to Oligocene (Rupelian- Chattian). Petrographic considerationled to identification of 12 carbonatemicrofacies and one sandstone facies that may have been deposited in a homoclinal ramp and in 4 sub environments including tidal flat, lagoon, bioclastic bar and open marine. Sequence stratigraphy analysis led to identification of 8 3rdordersdepositional sequences bounded by type I and type II sequence boundaries. Comparison between interpreted relative sea level curve with global sea level curve showsreasonable correlation with the lower and upper sequence boundaries of this formation and also Rupelian- Chattianboundary and the differences in other sequence boundaries can be related to local tectonic activity in the sedimentary basin of Qom Formation and the local sea level changes.
A. Bayet-Goll; R. Moussavi-Harami; A. Mahboubi
Abstract
Trace fossils are abundant in the clastic succession throughout the Shirgesht Formation of Kalmard Block, Central Iran. At certain horizons there are beds full of Cruziana and Rusophycus. This study presents an evaluation of the arthropod ichnotaxa of the Cruziana and Rusophycus from the Ordovician succession ...
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Trace fossils are abundant in the clastic succession throughout the Shirgesht Formation of Kalmard Block, Central Iran. At certain horizons there are beds full of Cruziana and Rusophycus. This study presents an evaluation of the arthropod ichnotaxa of the Cruziana and Rusophycus from the Ordovician succession Shirgesht Formation. Apart from the broad range in morphology and size, Cruziana from Shirgesht Formation show higher behavioral diversity using food sources than has ever been documented in a single section. It consists of a straight, or gently curved, ploughed furrow usually a few centimetres across, which is divided lengthwise into two lobes, each of which is braided transversely by a series of scratches. These vary in arrangement and profile according to ichnospecies. Overall characteristics of recognized ichnospecies suggest that with the exception of C. semiplicata, the ichnofaunas contain all the members of the Cruziana rugosa Group throughout the clastic successions in Shirgesht Formation. It consists of the five members of C. rugosa, C. furcifera, C. goldfussi C. rouaulti and C. yini. The Shirgesht Formation material therefore indicates that these arthropod ichnofossil assemblages are suitable for Cruziana ichnostratigraphy in Shirgesht Formation. Accordingly, the present assemblage could represent the Early to middle Ordovician age. The arthropod traces also, occur with other biogenic sedimentary structures in a fine to medium grained sandstone with minor mudstone interbeds of the Shirgesht Formation. The substrate composition and ichnological evidence places the arthropod ichnofossil-rich unit in the Cruziana ichnofacies.
M. Motamedalshariati; A. Sadeghi; H. Vaziri Moghadam; R. Moussavi Harami
Abstract
A stratigraphic section in west of Maraveh Tappeh town has been selected and measured in order to study the Aitamir Formation in north west of Kopeh Dagh. The Aitamir Formation with 1070 m thickness, consists of sandstone in the lower part and shale and marl in the upper part. The lower and upper boundaries ...
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A stratigraphic section in west of Maraveh Tappeh town has been selected and measured in order to study the Aitamir Formation in north west of Kopeh Dagh. The Aitamir Formation with 1070 m thickness, consists of sandstone in the lower part and shale and marl in the upper part. The lower and upper boundaries of the Aitamir Formation with Sanganeh and Abdraz Formations are conformable. The biostratigraphic studies led to identification of 34 genera and 58 species of planktonic and benthonic foraminifera. Based on foraminifera assemblage three biozones are suggested as follows: Rotalipora appenninica zone, Rotalipora brotzeni zone, Whiteinella aumalensis –Dicarinella canaliculata zone. These biozones coincidence with global biozones. Based on foraminiferal fauna, a Late Albian to Late Cenomanian age is suggested for the upper shale member of Aitamir Formation.
A. Bayat Gol; N. Abbassi; A. Mahboubi; R. Moussavi-Harami; H. Amin Rasouli
Abstract
Some of Paleozoic sediments from Alborz and Central Iran subzones from Mid-Iran zone evaluated for distinction of Palaeophycus and Planolites ichnofossils. These sediments include Shale Member of Lalun Formation, Shirgesht Formation, member 5 of Mila Formation and Geiroud Formation. A diverse ichnofauna ...
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Some of Paleozoic sediments from Alborz and Central Iran subzones from Mid-Iran zone evaluated for distinction of Palaeophycus and Planolites ichnofossils. These sediments include Shale Member of Lalun Formation, Shirgesht Formation, member 5 of Mila Formation and Geiroud Formation. A diverse ichnofauna has been found in these Formations, so Planolites and Palaeophycus are abundant between them. Ichnotaxa diagnosis and some determination problems of these ichnogenera was discussed here. Overall characteristics of Palaeophycus suggest dwelling structure made by predator or suspension-feeder and passive sedimentation in the open burrow. Planolites, on the other hand imply active backfilling structure in ephemeral burrows, which constructed by a mobile deposite-feeder. Planolites include unlined burrows with infilled sediments differ texturally from host rock. Whereas Palaeophycus is lined burrow filled by same sediments of surrounding matrix. Accordingly, Palaeophycus assemblage members made by opportunistic communities with r-selected population strategies in physically-controlled and unstable environment, whereas ichnofossils of Planolites assemblage are related to benthic communities with displaying K-selected or climax strategies in the stable environments and rather predictable conditions. Recognized ichnospecies of Planolites are P. montanus, P. annularis, P. terraenovae and P.beverleyensis. and ichnospecies of Palaeophycus include P. heberti, P. tubularis, P. striatus. P. sulcatus and P. alternates.
L. Fateh Bahari; M.H. Mahmoudi Gharaei; A. Mahboubi; R. Moussavi-Harami
Abstract
Ab-Deraz Formation (Turonian to Santonian) is a marly - Carbonates sequence consists of three marl-chalky limestones intervals. This formation widely crops out in Kopet-Dagh Basin in NE of Iran. Chalk and calcareous marl couplets show decimeter to meter scale cycles. Carbonate content of chalky beds ...
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Ab-Deraz Formation (Turonian to Santonian) is a marly - Carbonates sequence consists of three marl-chalky limestones intervals. This formation widely crops out in Kopet-Dagh Basin in NE of Iran. Chalk and calcareous marl couplets show decimeter to meter scale cycles. Carbonate content of chalky beds are 80-95% in rhythmic couplets, and about 65-80% in calcareous marly beds. The Ab-Deraz Formation is studied in tow Hamam-Ghale and Padeha outcrops, and also in well No.56 of Khangiran. Three dominate frequency of sediments are identified based on gamma ray log, which are related to three type of Milankovitch cycles including the long eccentricity (413 ka), eccentricity (100 ka) and precession (21-23 ka) cycles. Biostratigraphic age determination based on foraminifera is comparable with orbital chronology calculated by on eeccentricity cycles counting. These cycles are also correlated with carbonate contents in studied sections.
R. Moussavi-Harami; A. Mahboubi; A. Kheradmand; H. Zandmoghadam
Abstract
For interpretation of paragenetic sequence and post depositional history of siliciclastic sediments of Dahu Formation (Late Camberian), two stratigraphy sections were measured at Dahuieh (type section) and Gazuieh in the NE and E of Zarand, with the thickness of 240 and 227 meters, respectively. The ...
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For interpretation of paragenetic sequence and post depositional history of siliciclastic sediments of Dahu Formation (Late Camberian), two stratigraphy sections were measured at Dahuieh (type section) and Gazuieh in the NE and E of Zarand, with the thickness of 240 and 227 meters, respectively. The diagenetic processes affected these sediments, during three stages eogenesis, mesogenesis and telogenesis, including compaction, cementation, alteration, dissolution, fracturing and vein filling. Clay mineral study within sandstone and mud rocks of Dahu Formation led to identification of two groups of clay as illite and cholerite. Illite form 90% of clay minerals in these sediments that are mostly formed during burials and clay mineral diagenesis as well as alteration and dissolution of potassium feldspar. The interpreted paragenetic sequence shows that a large number of diagenetic processes act in the mesogenetic stage. Physical compaction and hematite cement have operated in eogenetic stage, while other processes such as chemical compaction, silica and dolomite cement, feldspar alteration, sericitization, ilitization and chloritization, dissolution of feldspars and cherts have occurred in mesogenetic stage. The fractures and calcite vein filling have formed in telogenetic stage during uplifting. We hope that this information can be used for evaluation of post depositional and burial history of similar sediments in local and regional scale.
M.R Poorsoltani; R. Mousavi harami; Y. Lasemi
M. Khoddami; A. Mahboubi; R. Moussavi-Harami; S. Feiznia
Abstract
The Lateshur Watershed is a part of Central Iranian drainage basin located northeast of the city of Pakdasht in northeastern TehranProvince. This watershed has an elongate form and its surface area is more than 22.2 square kilometer. It is a part of central Alborz zone and geologically is composed of ...
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The Lateshur Watershed is a part of Central Iranian drainage basin located northeast of the city of Pakdasht in northeastern TehranProvince. This watershed has an elongate form and its surface area is more than 22.2 square kilometer. It is a part of central Alborz zone and geologically is composed of Neogen red beds units, Hezardareh Formation and Quaternary alluviums. Geomorphologic studies show that this watershed is within an anticline and surrounded by DahanehMountains in the south and Gara-aghajMountains in the north respectively. Structural and lithological variability have a very important role in the formation of this watershed; therefore, the watershed has the same trend as structures (NW-SE). Based on this study, the LateshurRiver has a braided pattern with gravelly bed. Sedimentological studies along rivers in Lateshur basin show that three basic factor (sudden changes in slope gradient, floods events and distributaries) are the main reasons for changes in texture of bed load sediments within the channel as well as the break in sedimentary links. Lithofacies identified in this watershed include gravelly (Gmm, Gmg, Gcm, Gt), sandy (Sp, Sm, St, Sh) and muddy (Fl, Fr). Based on lithofacies, Boundary surface and current direction architecture elements identified in main river of Lateshur basins include: (1) Gravel bars and Bed forms [Element GB], (2) Lateral Accretion deposits [Element LA], (3) Sandy bed forms [Element SB] and (4) Fine grain classtic deposits [Element FF]. Also, based an lithofacies and architectural elements, Facies models have been purposed for the Lateshur river from upstream toward downstream as fallows: Shallow gravel braided river, Gravel wandering river, Gravel bed meandering river, Sandy meandering rive and Fining grain meandering river.
M. R. Poursoltani; R. Moussavi Harami; Y. Lasemi
Abstract
The KopetDaghBasin of northeast Iran formed in the NeotethysOcean after the closure of Paleotethys in the south of Turan plate. A thick sequence of Jurassic to Miocene sediments has been deposited in this basin without any major break. The siliciclastic Kashafrud Formation ...
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The KopetDaghBasin of northeast Iran formed in the NeotethysOcean after the closure of Paleotethys in the south of Turan plate. A thick sequence of Jurassic to Miocene sediments has been deposited in this basin without any major break. The siliciclastic Kashafrud Formation (Middle Jurassic), overlying unconformably on Triassic rocks and ultrabasic rocks comprises nearly 2 km of turbidite and fluvio-deltaic facies, consists of sandstone, shale and conglomerate. Trace-fossil assemblages are presented in some units with different environments. The most important ichnofossils in this formation are Skolithos, Palaeophycus tabularizes,Belerhaphe, Thalassinoides suevicus, Psilonichnus , Planololites beverleyensis, Rhizocoralium jenese, Scolicia, Conichnus, Lophactenium, Palaeophycus striatus,Taenidium. It is interpreted, based on identified ichnofossils, the Kashafrud Formation may have been deposited in fluvio-deltaic and deep water (turbidity conditions) environment. We hope that these data can help in a better understanding of palaeogeography and tectonic setting of the region during Middle Jurassic.