Volume 23, Issue 89 , December 2013, Pages 1-1
Volume 23, Issue 89 , December 2013, Pages 2-2
Volume 23, Issue 89 , December 2013, Pages 3-3
Original Research Paper
K Shirani; A Seif; A Nasr
Abstract
Regarding their nature and their variety, and hazards that landslides have for humans life and properties, landslides have always been the center of attention and study by scientist from different fields of study such as: geology, engineering geology, geomorphologies, these phenomena are a complex activity ...
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Regarding their nature and their variety, and hazards that landslides have for humans life and properties, landslides have always been the center of attention and study by scientist from different fields of study such as: geology, engineering geology, geomorphologies, these phenomena are a complex activity and different factors and variables could be effective in this occurrence, numerous studies have been done to recognize the effective factors, classification, zooming and modeling. Accordingly, we have tried to study the landslides in Kahredan basin in northern part of Semirom, DenaMountain in Zagros zone suburban area in Esfahan province and provide a landslide hazard zonation map by using the statistical method and the hazard map which has the most accuracy and precision will be selected. So finally we specify the order of effective parameters in landslides. According, by selecting following six parameters: slope aspect, lithology, land use, rainfall and distance from drainage, we provided the distribution of landslides map by using following four methods.
Information value, linear regression, discriminate analysis and area density. The best landslide hazard zonation map has been statistical method of information value which is capable of using in planning and urban developments. Effective parameters in landslides according to their importance are, lithology, distance from drainage, land use, slope and rainfall.
Original Research Paper
M Kianpour; M Sayari; A Uromeihy; M.R Nikudel
Abstract
Shear strength is one of the most important properties of mudrocks and shales in rock engineering and engineering geology. Because of the difficulty to obtain undisturbed samples of shales as required for determination of shear strength parameters, it is also the most difficult to evaluate. This research ...
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Shear strength is one of the most important properties of mudrocks and shales in rock engineering and engineering geology. Because of the difficulty to obtain undisturbed samples of shales as required for determination of shear strength parameters, it is also the most difficult to evaluate. This research investigated properties that can be used to predict the shear strength parameters of Shemshak formation shales. Thirty samples of shales from various depths were collected from boreholes in Shemshak formation in the site of Siahbishe pumped storage powerhouse. Shear strength parameters (c and ϕ), tensile strength (TS), quartz percent (Qz %), porosity (n) and density (ρ) were determined in lab for each sample. Data were analyzed statistically and with fuzzy inference system to determine the relationships between shear strength parameters with other properties. Results show that cohesion and friction angle of shales can be meaningfully predicted from a few engineering properties by fuzzy inference system. The adjusted R2 values between measured and predicted values for cohesion and friction angle are 0.95 and 0.84 respectively. Also the variation of regression coefficient (R2), performance indices (VAF) and root mean square error (RMSE) with were calculated as for the shear strength parameters, obtained from the multiple regression modeland the fuzzyinference system, revealed that the prediction performance and accuracy of the fuzzy models are high and multiple regression equations not have performance in prediction of shear strength parameters of shales.
Original Research Paper
D Raeisi; S Dargahi; S.H Moeinzadeh; M Arvin; B Bahrambeigi
Abstract
Gandom-Berian area, located on southern part of the Kavir-e Lut, covers an area around 480 km2 and morphologically is a covered messa by very dark basaltic lava flows. Their major minerals are olivine and clinopyroxene phenocrysts along with plagioclase microlites and their main textures are microlitic ...
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Gandom-Berian area, located on southern part of the Kavir-e Lut, covers an area around 480 km2 and morphologically is a covered messa by very dark basaltic lava flows. Their major minerals are olivine and clinopyroxene phenocrysts along with plagioclase microlites and their main textures are microlitic porphyry to glomeroporphiry with interestal to intergranular groundmass. The in line position of volcanic cones along the line of movements of Nayband fault show its effect on the formation of Gandom-Berian basaltic magma. The genetic realationship of these lava flows with deep seated lithospheric fractures as a result of Nayband fault, the presence of mantle xenoliths and alkaline nature of basalt all reveal a fast deep ascending of magmas. Based on geochemical analysis and occurrence of nepheline in the norm composition the Gandom-Berian basaltic lava flows belong to basanite-tephrite group. The investigation on Gandom-beriyan alkali basalts clearly shows their relationships to an intera-continental extensional environment. Low ratio of Ce/Nb, Th /Nb, U/Nb, Ba/Nb and High levels Zr with mean 234.81 indicate a none depleted asthenospheric mantle source the origin of Gandom-Berian basaltic lava flows. Enrichment and depletion of light and heavy rare earth elements respectively indicate the existence of garnet in the source rock.
Original Research Paper
A Bayat Gol; N Abbassi
Abstract
A detailed ichnological study on the Geirud Formation (Late Devonian-Early Carboniferous) from the Zaygon area, central Alborz shows a diverse trace fossils, which include 14 ichnogenera represented by 23 ichnospecies. These trace fossils contains various ethological patterns, such as domichnia, fodinichnia, ...
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A detailed ichnological study on the Geirud Formation (Late Devonian-Early Carboniferous) from the Zaygon area, central Alborz shows a diverse trace fossils, which include 14 ichnogenera represented by 23 ichnospecies. These trace fossils contains various ethological patterns, such as domichnia, fodinichnia, grazing, equilibrichnia, and fugichnia. These trace fossils are: Arenicolites, Asterosoma, Chondrites intricate, Chondrites targionii, Diplocraterion parallelum, Arenicolites isp., Asterosoma isp., Chondrites intricate, Chondrites targionii, Chondrites isp., Diplocraterion parallelum, Helminthoidichnites isp., Helminthopsis abeli, Helminthopsis isp., Palaeophycus heberti,Palaeophycus tubularis, Planolites beverleyensis, Planolites isp., Phycodes cf. palmatus, Rhizocorallium jenense, Rhizocorallium irregular, Rosselia soccialis, Taenidium serpentinum, Taenidium satanassi, Talassinoides horizntalis, Thalassinoides suevicus, Thalassinoides paradoxicus, Zoophycos isp. Studied beds consist by alternations of laminated mudstones and siltstones, and thick- to medium-bedded sandstones with wavy lamination. Hummocky, trough and low angle to planar cross-bedding are common in layers. It seems that these beds were deposited in the delta to open marine environments. Determined ichno-assemblage represents characteristic of a moderately shallow-marine environment, which effected occasionally by high-energy conditions. A trace fossil assemblage has been examined from the uppermost dark-colored shale layers of the Geirud Formation in the Devonian/Carboniferous (D-Ca) boundary. This assemblage include Chondrites targionii, Zoophycos isp., which involved by Hangenberg event.
Original Research Paper
R Arjmandzadeh; M.H Karimpour; S.A Mazaheri; J F.Santos; M Medina
Abstract
The dehsalm porphyritic granitoids belong to the Lut Block volcanic-plutonic belt in East - Central Iran. The intrusive rocks range in composition from gabbro - diorite to granite and can be classified as high-K calc alkaline to shoshonitic volcanic arc granites. Elevated contents of Mo, Cu, Au, Pb, ...
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The dehsalm porphyritic granitoids belong to the Lut Block volcanic-plutonic belt in East - Central Iran. The intrusive rocks range in composition from gabbro - diorite to granite and can be classified as high-K calc alkaline to shoshonitic volcanic arc granites. Elevated contents of Mo, Cu, Au, Pb, Zn occur in silica veins within Bt - Px - Quartz monzonite and Hbl - monzonite. The trend of major oxides on Harker diagrams point to the crystal fractionation of Ca - plagioclase and mafic minerals. Primitive mantle - normalized trace element spider diagram display strong enrichments in LILE such as Rb, Sr, Ba, Zr, Cs and depletions in some high field strength elements (HFSE) e.g. Nb, P and Y. On chondrite - normalized plots, display significant LREE enrichments, high La/Yb = 21.5-31 and the lack of Eu. On the basis of Sr/Y and La/Yb ratios, Dehsalm intrusives cover characteristic features of adakites and (87Sr/86Sr)i and εNdi isotope ratios range from 0.70469 to 0.70505 and from +1.5 to +2.5 respectively, and show that the source is related to the mantle melts contaminated slightly by the crustal materials. They are classified into the magnetite series granitoids and have high mineralization potential for Cu-Mo-Au porphyry type deposits. Two-sided asymmetric subduction explains all the tectonic and magmatic occurrences and the mineralization of porphyry type deposits within the Lut Block during the Tertiary.
Original Research Paper
M.H Emami; S Houshmand
Abstract
Mylonitic granite-granodiorites of Nowghan shear zone extend in NW-SE trend in the metamorphic rocks of the southwest Golpayegan. Different outcrops of mylonitic bodies have been studied in order to investigate the origin of granitoid rocks in Nowghan shear zone and determined their tectonic setting ...
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Mylonitic granite-granodiorites of Nowghan shear zone extend in NW-SE trend in the metamorphic rocks of the southwest Golpayegan. Different outcrops of mylonitic bodies have been studied in order to investigate the origin of granitoid rocks in Nowghan shear zone and determined their tectonic setting in Sanandaj-Sirjan zone. Field evidence, mineralogy and geochemical data suggest that the mylonitic rocks have S-type and strongly peraluminous characteristics. From the tectonic setting point of view, the granitoid bodies are of the collisional type and they formed as syn-tectonic to post-tectonic intrusions.
Original Research Paper
H Harati; A Khakzad; N Rashidnejad Omran; H Asadi Harouni; S.J Javad Moghaddassi
Abstract
The kahang Copper porphyry deposit on Urumieh-Dokhtar magmatic arc, is located in NE of Esfahan. Around of this deposit, Eocene volcanics and pyroclastic rocks ranging in composition from basaltic trachy-andesitic to dacitic are exposed. Granitoids subvolcanic and volcanoplutonic, the causes of alteration ...
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The kahang Copper porphyry deposit on Urumieh-Dokhtar magmatic arc, is located in NE of Esfahan. Around of this deposit, Eocene volcanics and pyroclastic rocks ranging in composition from basaltic trachy-andesitic to dacitic are exposed. Granitoids subvolcanic and volcanoplutonic, the causes of alteration and mineralizaton, replacement in Eocene rocks assemblage in afew puls from Oligocene to Miocene. This plutons ranging in composition from monzodiorite quartzdiorite granodiorite to granite with porphyroeidal texture. Alteration and mineralization is classically developed in this deposit. Samples from surface soil were collected in 50m profiles gridding which the distance samplings in along the profile are 25m. The total numbers of samples are 2564 which are analyzed by ICP-OES method for 43 elements. In geochemical anomaly maps, activating of faults with another tectonic factors, environmental conditions alteration and erosion in moving and concentration this anomaly are illustrated. Same as the litho geochemical anomalies the most amount distribution of Cu in the eastern and center of the region, Au in the west and center and Mo in all three region are depicted. In elemental correlation graphs suitable correlation is for Copper and Gold.
Original Research Paper
B Zamani Gharechamani
Abstract
In the present study, the state of stress in SiahCheshme-Khoy fault zone area in the North-West of Iran has been analyzed based on the systematic inversion of focal mechanisms of earthquakes, and fault slip data, to characterise the stress regime controlling of most faults and earthquakes in this area. ...
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In the present study, the state of stress in SiahCheshme-Khoy fault zone area in the North-West of Iran has been analyzed based on the systematic inversion of focal mechanisms of earthquakes, and fault slip data, to characterise the stress regime controlling of most faults and earthquakes in this area. The calculated average stress regime in this area indicates major NW-SE trending compression which dominates stress regime in strike slip mode with an intermediate stress axis, σ2, close to vertical. Reconstructed stress has shown that average seismotectonic stress and average stress obtained from fault slip data do not have consistency due to of the multi stress regimes in this fault zone. Nonetheless stress separation analysis results for fault slip data and earthquake data have good consistency and their first and second analyzed stress regimes have the same trend. Also comparison between the results of the stress separation analysis between fault slip data and earthquake data, has shown that the second and third stress regime of this analysis are neotectonic stresses that controlling this fault zone movements. The forth stress regime also is a neostress regime that has been shown in seismotectonic stress separation analysis also, but it seems related to the deep faults. The first stress regime that have resulted from stress separation analysis of both field and earthquake data, it seems a paleostress regime which is not shown in seismic data analysis. Also reconstructed stresses in this study, have good consistency with the latest studies in this area especially with geodetic studies.
Original Research Paper
A. R Shafeii; M. R. Ghassemi
Abstract
The present research is aimed at investigation of geometry and kinematics of joints, relationships and temporal and spatial distribution of the joints regarding the two deformational events within the Purkan-Vardij thrust sheet. We also studied the relationships between development of different joint ...
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The present research is aimed at investigation of geometry and kinematics of joints, relationships and temporal and spatial distribution of the joints regarding the two deformational events within the Purkan-Vardij thrust sheet. We also studied the relationships between development of different joint sets and the lithological characteristics of layers of the Karaj Formation. Considering outcrops of volcaniclastic and igneous rocks of variable lithology, we have divided them into five different rock units including thick-bedded to massive tuffs, thin- to medium-bedded tuffs, tuff-shale-sandstone sequence, shale, and igneous units. Joint study was carried out using selection method, and in part using listing method, which are useful for quick survey and statistical purposes. Joint classification was carried out using concentrations of pole to joint planes. We have used the fracture spacing index (FSI), which is an important parameter in controlling morphology and erodibility of the rock units; it is also useful for prediction of joint spacing in other layers and in surrounding areas. These characteristics are useful in road construction, tunneling and other engineering projects. A comparison of the FSI in different rock units indicates that the intrusive bodies and thick-bedded units develop a highly variable FSI with a wide range of spacings, which in most cases due to lower concentration of the joints show lower erodibility as compared to the other rock units, and therefore have more relief in their outcrops. Two major joint sets, J1 and J2, show the highest frequency within the classified joint sets. Both of these sets are of extension joint type, and their strikes indicate the s1 direction during their development. Our study in this research confirms that amount of the strain produced by the joints is very small.
Original Research Paper
Habib Alimohammadian; F Mahdipour Haskouei; J Sabouri
Abstract
The study area is situated at about 8 km away of Neka city, on the main road of Sari-Behshahr, in MazandaranProvince, north of Iran. It is bounded by Alborz fault in the south and Caspian Sea coast line in the north. We applied new environmental magnetism technique and methods including magnetic susceptibility, ...
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The study area is situated at about 8 km away of Neka city, on the main road of Sari-Behshahr, in MazandaranProvince, north of Iran. It is bounded by Alborz fault in the south and Caspian Sea coast line in the north. We applied new environmental magnetism technique and methods including magnetic susceptibility, magnetic mineralogy, IRM and S-IRM to reconstruct the past 50 ka climate conditions and also investigate relationship between climate change and magnetic variations. We also compared the geochemistry and magnetic analysis of the loess/palaeosol deposits and the results were used to correlate these variations with climate change in the study area. The pattern of variation of geochemical data shows similarity with those of magnetic one. The increase/decrease in magnetic susceptibility is coinciding with palaeosol/loess sequences. Plotting magnetic susceptibility variation versus lithological column of Kolet section enabled us to recognize short period of climatically cycles known as stadials/interstadials in loess/palaeosol sequences. We recognized 4 stadials for upper palaeosol, single stadial for lower palaeosol, 6 interstadials for upper loess and one interstadial for lower loess deposites.
Original Research Paper
mohammad parchekani; M Shahrabi; K Bazargani-Guilani
Abstract
The west Alborz area with a crustal thickness of 35-40 Km is a part of the Alborz ranges and is located in the western part of the Alpine-Himalaya belt. This area is folded by Alpine orogeny and the orogen is formed by collision between Iranian and Arabian blocks. A thick and widespread sequence of volcanic ...
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The west Alborz area with a crustal thickness of 35-40 Km is a part of the Alborz ranges and is located in the western part of the Alpine-Himalaya belt. This area is folded by Alpine orogeny and the orogen is formed by collision between Iranian and Arabian blocks. A thick and widespread sequence of volcanic and pyroclastic rocks with 3800m thickness, Eocene in age, outcropped in west Alborz (Karaj Formation, KF). These rocks are intruded by younger plutons with Tertiary age. There are numerous geological, petrological, stratigraphical, geochemical and tectonical similarities between Miocene volcanic rocks in Turkey and study area in Iran (Eocene). The only difference is in age of volcanism in Turkey and Iran.
Original Research Paper
M Ramazani; M. R. Ghassemi; A Zanchi; M. R Sheikholeslami
Abstract
Theerosional window of Aghdarband , located in NE Iran to the SE of Mashhad is a unique place for study of the Eo-Cimmerian event. This event (Late Triassic-Middle Jurassic) resulted from clousureof thePaleothetys ocean and collision between the Iran and Turan plates. These two plates were separated ...
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Theerosional window of Aghdarband , located in NE Iran to the SE of Mashhad is a unique place for study of the Eo-Cimmerian event. This event (Late Triassic-Middle Jurassic) resulted from clousureof thePaleothetys ocean and collision between the Iran and Turan plates. These two plates were separated from each other before Late Triassic, and therefore they had different tectonic and sedimentary histories. At this time the Aghdarband area was located on active margin of Eurasia, and therefore the units that are exposed in the erosional wiondow of Aghdarband have basic differences with their counterparts in other places of Iran. During the Eo-Cimmerian event, the Aghdarband area was affected by a sinistraltranspression. Strain in this transpressional zone was intensively partitioned, and three major structural domains with different structural characteristics were formed in it. A sinistral strike-slip fault zone and an imbricate thrust fault zone were formed respectively in northern and southern part of the Aghdarband area. Development of this transpressional zone may be attributed to the oblique convergence between Iran and Turan plates during above mentioned time interval.
Original Research Paper
M Asadpour; S Heuss; S. M Pourmoafi
Abstract
The Gharebagh intrusive complex which includes mafic, diorite and acidic rocks is a part of the Sanandaj-Sirjan zone in northwestern of Iran and a part of the Zagros orogenic belt. This complex has intruded into Precambrian metamorphic rocks. U-Pb daiting of zircons of a Lueicogranite has been identified ...
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The Gharebagh intrusive complex which includes mafic, diorite and acidic rocks is a part of the Sanandaj-Sirjan zone in northwestern of Iran and a part of the Zagros orogenic belt. This complex has intruded into Precambrian metamorphic rocks. U-Pb daiting of zircons of a Lueicogranite has been identified 558.6 ± 3.8 Ma. The cores of some zircon grains are aged too old to 2400 Ma in this sample. These are the parts of remained original rocks. It can be inferred that the basement area is older than Precambrian intrusive, and maybe indicate the presence of Panafrican basement similar to which has been found mainly in the central Iran. Ages obtained in five Gabbro samples are 300.0 ± 1.3 Ma to 301.5 ± 1.3 Ma, in two Diorite samples 300.7 ± 1.5 Ma and in a Monzogranite sample 300.7 ± 1.7 Ma. Age obtained in Alkaligranite pach within the Gabbros is 303.4 ± 1.5 Ma. These rocks have the same ages and that can be inferred that all of them have been affected by one geology event in late Paleozoic. Based on chemical analysis data, a mantle source for mafic rocks is understanded. This Mafic magma has a very high temperature so that its heat causes melting of the lower crust and formation the Alkaligranitic magma simultaneously with it intrusion. These datings, shows polotonism of upper Paleozoic in the northwestern part of Sanandaj–Sirjan zone. It can be inferred that this is the beginning of Neotethys opening in Iran.
Original Research Paper
M Khalatbari Jafari; M Mirzaie; M. R Jannessary
Abstract
The plutonic crustal sequence of Garagoli-Bagjar, located in NE Sabzevar, is a part of ophiolitic association in the outer part of Central Iran microcontinent. This sequence comprises cumulative olivine gabbro, pyroxene gabbro, isotropic gabbro, foliated gabbro and diabasic sheeted dike complex, cross ...
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The plutonic crustal sequence of Garagoli-Bagjar, located in NE Sabzevar, is a part of ophiolitic association in the outer part of Central Iran microcontinent. This sequence comprises cumulative olivine gabbro, pyroxene gabbro, isotropic gabbro, foliated gabbro and diabasic sheeted dike complex, cross cut by the wherlitic intrusion, pegmatite gabbro and plagiogranite as small bodies, dikes and veins. This sequence is comparable to upper gabbroic part of the well known ophiolite complex. These rocks construct a large tectonic slics thrusted over the serpentinized peridotites and tectonically located under serpentinites. The cumulative gabbros change gradually to isotropic gabbro upwards and at the same time isotropic gabbro change generally to diabasic sheeted dike complex. The structural measurements of magmatic layering and strike of sheeted dikes, wherlitic intrusions, pegmatite gabbro and plagiogranite revealing E-W direction in the north of Qaragoli and N-S direction in SW Solymanieh might be comparable to the formation of plutoinc oceanic crust in fractures zone. The microscopic studies exhibit that mesocumulate to heteradcumulate textures are abundant which indicate the open magmatic chamber of the supra-subduction zones. The crystallization trends show diversity from olivine-plagioclase-clinopyroxene-orthopyroxene-amphibole trend (MORB like) to olivine-clinopyroxene-orthopyroxene-plagioclase-amphibole trend (as arc type). The study of the chemical analyses indicates diverse compositions and primitive mantle normalized spider diagrams show depletion of Nb with different enrichement of LREE. The low-Ti character, locations in arc related cumulate and non cumulate fields, island arc to MORB tectonomagmatic setting remark their supra-subduction origin which formed in Late Cretaceous.
Original Research Paper
Seyed Mohsen Mortazavi
Abstract
Damavand is a stratovolcano and has power full explosive eruptions during its activity. Pyroclastic products in Damavand volcano has been mostly deposited as pyroclastic fall and flow deposits. Pyroclastic fall deposits in some locality extending up to 20 km from the summit. Damavand pyroclastic deposits ...
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Damavand is a stratovolcano and has power full explosive eruptions during its activity. Pyroclastic products in Damavand volcano has been mostly deposited as pyroclastic fall and flow deposits. Pyroclastic fall deposits in some locality extending up to 20 km from the summit. Damavand pyroclastic deposits cover much of the eastern and southern flanks of the volcano suggested that during the eruption, tephra dispersal axes was toward to the east. There are a major young pumice deposits, named as Karam Poshteh pumices, are identified and consists of a coarse-grained pumice fall deposit with proximal welded facies dispersed to the west, but lacks pyroclastic flow deposits with provisional ages in the interval >7.3 ka and < 25 ka.This young pumice fall deposit is distributed over much of the western and south-western flanks and is located at the foot of the steep Damavand cone at the mouth of a ravine where the proximal welded facies is well exposed on the ravine walls. The deposit can be divided into thin more distal unconsolidated pumice fall deposits and think proximal welded pumice fall deposits. Karam poshteh deposits also consist of welded beds of pale pink pumice with minor cross-layered ash beds. Atmospheric information, in particular wind data, is crucial in order to perform tephra dispersal simulations. Tephra transport and sedimentation is controlled by wind in the atmosphere and is a function of wind velocity and provenance for tropospheric and stratospheric levels. Mehrabad meteorological station is supplied wind data at different altitudes. We apply and intemperate wind data between 1995 to 2010 at Damavand volcano to understand regional distribution of tephra fall. Westerly winds are persistent during winter and summer time at troposphere. The most prominent features in the stratospheric circulation are a westerly jet in the winter hemisphere and low velocity easterly jet in the summer hemisphere. Easterly jet in the summer implies that Westward transport of tephra in Karam poshteh.
Original Research Paper
A Mahdavian
Abstract
The study area includes Golestan Province and is located in the North and North-East of Iran. This area contains Gonbad, Koh-e-Kurkhod and a part of Gorgan quadrangle maps. The aims of this research are as follows: detailed seismicity and Seismotectonic studies, recognition of active faults and preparing ...
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The study area includes Golestan Province and is located in the North and North-East of Iran. This area contains Gonbad, Koh-e-Kurkhod and a part of Gorgan quadrangle maps. The aims of this research are as follows: detailed seismicity and Seismotectonic studies, recognition of active faults and preparing seismic hazard zoning map based on peak ground accelerations (PGA) for difference return periods. These studies performed in order to seismic resistance of important buildings, reducing of human and economy disaster against earthquake hazards and future planning for Golestan province. This area is located in the Central Iran and Kopeh-dagh seismotectonic provinces. There are many active faults within this area and many destructive earthquakes occurred along them. For example the Atrak-Nesa earthquake of August 943 with Ms 7.4 occurred due to activity of Ashkhaneh fault (eastern segment of Takal Kuh). Many other active faults such as Khazar, Ali-Abad, Gomishan, Maraveh-Tappeh etc distinguished in this area so that this Province can be affected of reactivation of them.
Seismic zoning maps prepared base on peak ground acceleration for return periods of 475 and 2475 years. The results show the Golestan province is divided to four seismic zones as follows:The area with PGA more than 0.35g that named Very High Seismic Zone includes parts of south of province; The area with PGA between 0.3 g to 0.35g that named High Seismic Zone includes southern, eastern and north-eastern parts of province; The area with PGA between 0.25g to 0.3g that named Moderate Seismic Zone; The area with PGA less than 0.25g that named Low Seismic Zone mainly includes western and north-western parts of province.
Original Research Paper
S Soleymani; M.H Mahmudy Gharaie2; F Ghasemzadeh; A Sayyareh
Abstract
Water quality assessment is very important in the area where water resources are used as drinking water. Monitoring of polluted waters and its distribution are applied in water management planning. It requires information on the location, the amount and distribution of chemical parameters on the samples ...
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Water quality assessment is very important in the area where water resources are used as drinking water. Monitoring of polluted waters and its distribution are applied in water management planning. It requires information on the location, the amount and distribution of chemical parameters on the samples from studied area. Identification of contaminant type, the sites, and also optimum use of water for different purposes are helpful. Thus, for these purpose six chemical parameters of TDS، SO42-، Cl-، Na+، Mg2+، Ca2+, which are referred by WHO standard were examined to apply for GQI method by GIS. The GQI method of groundwater quality evaluated and prepared a groundwater quality map in west region of kooh-sorkh. Values of GQI index vary between 82.9% to 94.8%, which indicate the groundwater quality placed in suitable to acceptable class of quality. Groundwater quality map indicate that GQI index values reduced from lateral sides to the center of studied region. It may be affected by geological factors such as lithology, current direction and also hydrothermal system in the area.
Original Research Paper
G. R Hosseinyar; R Moussavi-Harami; R Behbahani
Abstract
Using high-resolution shallow seismic data, we have investigated the seismic facies in northern Qeshm Island waterways in East of Persian Gulf. Seismic data obtained with Sub-bottom profiler and then interpreted by ISE software. Studies lead to recognizing 7 types seismic facies on seismic data. These ...
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Using high-resolution shallow seismic data, we have investigated the seismic facies in northern Qeshm Island waterways in East of Persian Gulf. Seismic data obtained with Sub-bottom profiler and then interpreted by ISE software. Studies lead to recognizing 7 types seismic facies on seismic data. These facies are detectable by amplitude, continuity, geometry, internal pattern and staking pattern from each other. Results show that seismic facies formed in two various environments condition. Lower part facies have low amplitude with high lateral continuity and sustainability; but upper seismic facies have various amplitude with low lateral continuity. These facies have deposited in five periods that separate with erosional surfaces. Changes of depositional environments and province region of sediment supply can be realize from seismic facies. So, through deposition of LAP-C and MAC facies sediments have supplied from Qeshm Island; but, at the time of deposition of LAC and HAC sediments interred from the North.
Original Research Paper
Mohammad Parandavar; A Mahanipur; S. A Aghanabati; S. A. Hoseini
Abstract
In this study the upper part of Gurpi Formation and the lower part of Pabdeh Formation have been investigated with regard to the calcareous nannofossils. The thinkness of the studied section is about 127 meter and it consists of Marls, gray-green shales and purple shales. 50 genus and 101 species ...
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In this study the upper part of Gurpi Formation and the lower part of Pabdeh Formation have been investigated with regard to the calcareous nannofossils. The thinkness of the studied section is about 127 meter and it consists of Marls, gray-green shales and purple shales. 50 genus and 101 species of calcareous nannofossils have been recognised in the studied section. According to the index genus and species in the studied interval, calcareous nannofossil biozones CC25-CC26 have been recognized at the cretaceous sediments and NP1-NP5 and NTp1-NTp9 biozones have been determined at the Paleocene sediments that NP1-Np4 and NTp1-NTp7A biozones are reported for the first time from the upper part of Gurpi Formation at the studied section. With regard to these biozones, the age of the upper part of Gurpi Formation in the studied section is late Maastrichtian- late Danian (late early Paleocene) and the age of Pabdeh Formation is started from early late Paleocene. According to the nannofossil data, the K/Pg boundary is continuous and is located at the upper part of Gurpi Formation. The K/Pg boundary is marked by a decrease in abundance of Cretaceous species, increase in the abundance of Thoracosphaera operculata and the appearance of the new-Paleocene taxa. In the Danian sediments the Cretaceous species are present along with Paleocene species continuously and with a good preservation that can be considered as surviving species that may have passed the boundary and are present at the Danian sediments.
Original Research Paper
D Mokhtari
Abstract
The fluvial systems and landscape of the semiarid environments of northwestern Iran have preserved evidence of Quaternary environmental and tectonic changes. Djolfa-Hadishahr tectonic depression is a plain along Aras River in this territory. Data on the fluvial systems have been synthesized to evaluate ...
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The fluvial systems and landscape of the semiarid environments of northwestern Iran have preserved evidence of Quaternary environmental and tectonic changes. Djolfa-Hadishahr tectonic depression is a plain along Aras River in this territory. Data on the fluvial systems have been synthesized to evaluate the roles of tectonic, base-level and environmental factors in plain landscape. The satellite images were used to determining of morphometric characteristics and limiting the boundaries of studied drainage basin and alluvial fans limitation. Structural features analyzed via geological and geoelecteric sections and field studies included: thickness, orientation, fault effectuality and stratification. The results showed that geomorphologic and morphometric characteristics of fluvial systems specially on alluvial fans, influenced severely by Quaternary tectonic, base-level and other environmental changes. Because nowadays Djolfa-Hadishahr plain evolution is controlled by human constructive activities, this research emphasize on geomorphological considerations before every landscape changes in study area. This considerations could explain the human impact on plain nowadays and at the future via analyzing of main morphodynamic features.
Original Research Paper
N. Fatehi Gelab; H Mirnejad; R Mathur
Abstract
The Darrehzar and Parkam deposits in Kerman province are two examples of porphyry type copper deposits in the Cenozoic Urumieh- Dokhtar magmatic arc. Volcanic rocks in the study areas are dominantly composed of andesite, trachyandesite and basalt. The Darrehzar quartzmonzonite stock consists of phenocrysts ...
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The Darrehzar and Parkam deposits in Kerman province are two examples of porphyry type copper deposits in the Cenozoic Urumieh- Dokhtar magmatic arc. Volcanic rocks in the study areas are dominantly composed of andesite, trachyandesite and basalt. The Darrehzar quartzmonzonite stock consists of phenocrysts of plagioclase, hornblend, quartz and biotite, andconstituent minerals of diorite-microdiorite porphyry in Parkam include plagioclase, alkali-feldspar, amphibol, biotite and quartz. The thickness of oxide zone in Darrehzar deposit is few meters and in many well cores it cannot be obsereved at all, while the the thickness of leached zone varies between 2 and 80 m. Supergene zone in the center of this deposit has the greatest thickness (120 m). The depth of hypogene zone from Darrehzar is 400 m. The thickness of leached zone from Parkam is around 20 m. The average thickness of supergene zone in this deposit is 15 m and its maximu depth is 64 m. The depth of hypogene zone in some cores is around 500 m. Evalutating the Cu isotope ratios from leached, supergene and hypogene zones in these two deposits show that the magnitude of Cu isotopic fractionation and Cu concentrations are mainly controlled by the weathering processes. The average δ65Cu values of copper in the leached, supergene and hypogene zones in Darrehzar deposit are, respectively, -6.16‰, +2.52‰ and +0.79‰, and those in the Parkam are -4.33‰, +4.82‰ and +0.34‰. Therefore, weathering of Cu sulfide minerals generated isotopically lighter residual minerals and dispersed the heavy isotope to the percolating groundwaters. It is thus expected that the copper isotope ratios of the leached zones in various porphyry copper deposits to be linked with the extent of leaching and the supergene enrichment processes. Microscopic studies and mineralogical studies shows that hematite in the Darrehzar’s leached zone in more abundant than that in the Parkam, while Parkam’s leached zone contain higher goethite content relative to that of the Darrehzar. The amount of chalcosite, and pyrite–chalcopyrite in the supergene and hypogene zones, respetively, from Darrehzar, are more abundant compared to those in the equivalent zones in Parkam.
