Volume 28, Issue 110 , December 2018, , Pages 2-2
Volume 28, Issue 111 , May 2019, , Pages 2-2
Volume 28, Issue 112 , August 2019, , Pages 2-2
Volume 29, Issue 113 , November 2019, , Pages 2-2
Volume 24, Issue 94 , March 2015, , Pages 3-3
Ramin Samadi; M. V. Valizadeh; H. Mirnejad; H. Kawabata
Abstract
Metamorphic rocks of Dehnow area mainly consist of gray to black fine-grained schists. Garnet schists are closer to the tonalitic body than the garnet chloritoid schists. There is a thin layer of staurolite and andalusite bearing hornfels between these schists and the Dehnow tonalitic body. Garnet schists ...
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Metamorphic rocks of Dehnow area mainly consist of gray to black fine-grained schists. Garnet schists are closer to the tonalitic body than the garnet chloritoid schists. There is a thin layer of staurolite and andalusite bearing hornfels between these schists and the Dehnow tonalitic body. Garnet schists and garnet chloritoid schists of Dehnow area are mineralogically comprised of quartz, biotite, muscovite, garnet, chlorite, chloritoid, tourmaline and ilmenite. Geothermobarometry results indicate that hornfels (550oC, 4.3 kbar) and garnet chloritoid schist (486-497oC) have formed in lower equilibrium condition in comparison with garnet schist (569oC, 5.3 kbar).
M. H. Adabi; R. Abbasi; H. Ghalavand
Abstract
In this investigation Dariyan Formation with the age of Lower Cretaceous (Aptian- Albian) were studied for geochemical and sedimentology characteristics in the surface section at Kuh-e Siyah Anticline and subsurface section Sabzpushan well number 1. Based on petrographical studies 12 microfacies identified ...
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In this investigation Dariyan Formation with the age of Lower Cretaceous (Aptian- Albian) were studied for geochemical and sedimentology characteristics in the surface section at Kuh-e Siyah Anticline and subsurface section Sabzpushan well number 1. Based on petrographical studies 12 microfacies identified which are belonging to 5 facies belt, such as: intertidal, lagoon, shoal, shallow open marine and deep open marine. The observed facies patterns indicated a carbonate ramp depositional environment. Important diagenetic processes were observed in Dariyan Formation including cementation, physical and chemical compaction and replacement processes such as pyritization and silicification. Prosities in these sections are secondary, including vuggy, fracture and channel types. Major and minor elements and carbon and oxygen isotopes studies are indicated that aragonite was original carbonate mineralogy for this Formation. The plots of elemental values also are illustrated that mainly burial diagenetic processes have been affected this formation in semi- close to semi- open system. A temperature calculation based on the heaviest oxygen isotope value indicates that the very early, shallow burial temperature was around 28.5°C during Dariyan carbonate deposition.
Fereidoun Rezaei; A. Dadsetan
Abstract
Ground subsidence in eastern part of Eshtehard, built on the alluvial deposits, is linear and gradual. Preparing geological map and profiles; we studied the structural geology of the area. The sort and situation of aquifer, evolution of ground water levels and hydrochemistry were studied and the presence ...
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Ground subsidence in eastern part of Eshtehard, built on the alluvial deposits, is linear and gradual. Preparing geological map and profiles; we studied the structural geology of the area. The sort and situation of aquifer, evolution of ground water levels and hydrochemistry were studied and the presence of ancient channel was detected by geoelectric method. The geotechnical studies suggest that the soils in the area (USCS Classification) belong to Lean clay (CL), Fat Clay (CH) and Silty Sand (SM). The maximum soil settlement is more than allowable settlements and soils recognized to be dispersive to semi-dispersive soils. The possible entrance of waste water from Eshtehard Industrial town into Eshtehard Qanat, from septic wells and transfer water system seems to provide necessary moisture for dispersive soils and have caused the subsidence in the area. Hydrogeology of alluvial aquifer was evaluated and indicates a negative debit. Although the hydrographs of pizometric wells are not compensated but it display any role in linear subsidence. Soils prone to dispersion by infiltration of water from septic wells and urban water system and the presence of ancient Qantas hidden in the depth of 15 meters caused linear ground subsidence. The results of this study show the development of ancient Eshtehard city and the selection of new site was not carried out on the geotechnical basis. Therefore it is recommended that before constructing any projects, geotechnical studies are necessary.
N. Babazadeh; A. Mansourian; M. Zareinejad; M. Farnaghi
Abstract
The current process of issuing industrial and mineral licenses is complex and time consuming. More specific, industry establishment generally makes environmental pollution. Such negative impact on environment is due to not using proper information and mechanisms for site selection and license issuance. ...
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The current process of issuing industrial and mineral licenses is complex and time consuming. More specific, industry establishment generally makes environmental pollution. Such negative impact on environment is due to not using proper information and mechanisms for site selection and license issuance. This research suggests a new process/method based on WebGIS enable e-government to simplify the issuance of industrial licenses, with special consideration of environmental impacts. To study, issuance of license for cement factory establishment is chosen as a case study. Investigation of the current process of certificating a cement factory establishment shows necessity of complex official process and long time consumption; also environmental considerations are not regarded properly. Then using concepts and aims of e-government and the abilities of geographical information systems in analyzing and spatial decision making, a new method to issue the industrial license is suggested. To show and evaluate the proposed method, architecture of a web based distributed geographical information system is designed and implemented. The results of the research indicate that the issuance of license for cement factory establishment using recommended method is performed in less time and with regarding the environment issues. The suggested process/method can be regarded as a pattern for creating spatial enabled e-government in industrial and mineral activities of the country.
A. Keynezhad; M. Pourkermani; M. Arian; A. Saeedi; M. Lotfi
Abstract
Detailed geological and structural analysis of north of Torud-Moalleman area (Central Iran), between Anjilu fault in north and Torud fault in the south, led to tectonic elements of this limit such as fractures and relative of their mechanism with left lateral sheared zone of two main faults. This study ...
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Detailed geological and structural analysis of north of Torud-Moalleman area (Central Iran), between Anjilu fault in north and Torud fault in the south, led to tectonic elements of this limit such as fractures and relative of their mechanism with left lateral sheared zone of two main faults. This study provides a movement system of Chalu, Gandi and Hafez faults in this shear zone. On the basis of kinematics findings and using general methods of fault slip analysis (orientation of slip plane, slip vector, shape of stress ellipsoid and angle of internal friction) region stress field were calculated after determining the angle of internal friction for each one of fault limits. Then, the main stress orientation determinates for combination data that values of ،وwere 195/10, 339/78 and 104/07 respectively. The shape of stress ellipsoid was defined on the basis of shape factor, [R= (-) / (-)], (Angelier, 1975). The R-value for whole studied regions was about 0.5 and deformation type was mainly left lateral transpressional with reverse component. Such results are evident from N-NE (N195) trending in the region and northward movement of the lithosphere. These finding are in line with field research results of fractures, faults and mechanism in this general shear zone.
Ahmad Kazemi Mehrnia; I. Rasa; S. Alirezaei; H. Asadi Harooni; J. Karami
Abstract
The Saridoon porphyry system is located 3 km northeast of Sarcheshmeh copper mine. Alteration mapping of the area was carried out using PIMA (Portable Infrared Mineral Analyzer) analysis of 145 samples, ASTER satellite images, XRD analysis of 22 samples, field observations and petrographic studies. The ...
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The Saridoon porphyry system is located 3 km northeast of Sarcheshmeh copper mine. Alteration mapping of the area was carried out using PIMA (Portable Infrared Mineral Analyzer) analysis of 145 samples, ASTER satellite images, XRD analysis of 22 samples, field observations and petrographic studies. The lithocap is characterized by an advanced argillic alteration assemblage. The alteration occurs at high topographic levels and on the flanks of the topographic heights. Despite extensive exposures, the alteration varies in intensity and occurs as patches or partially exposed. Pyrophyllite spectral feature is used as a measure of alteration intensity (pyrophyllite abundance).
Phyllic alteration occurs in the central part of the sampled area. This spectrally distinct alteration assemblage occurs at all elevations, and is partially overprinted by advanced argillic alteration. Intermediate argillic alteration occurs on the flanks of advanced argillic and phyllic alterations. The mineral assemblage might have been formed by supergene processes, or alternatively, by low temperature hydrothermal fluids. The PIMA and XRD samples were analyzed by ICP-MS for a number of metals and semi-metals. A comparison of data from Saridoon and those from three other porphyry systems in northwest Kerman belt (Darrehzar, Abdar, and Chah Firuzeh) shows lower contents of Cu and Mo, and higher contents of As, Sb, Pb in Saridoon. The extend alteration systems in Iranian magmatic arc with low frequency of Cu and Mo shall be checked for advanced argillic alteration mineral assemblage using modern spectrometry instrument (e. g. PIMA). This distribution pattern of elements, coupled with the widespread occurrence of advanced argillic alteration at surface, suggests that stripping of overlying rocks at Saridoon was not as deep and effective as in many other porphyry systems in the Kerman belt. These findings suggest that alteration systems with low Cu and Mo contents and mineral assemblages typical of advanced argillic alteration merit closer and deeper inspection.
A. R. Ashouri; M. R. Majidifard; M. Vahidinia; A. Raoufian
Abstract
A thick succession of Middle – Late Jurassic rocks in the western part of BinaludRange has been studied. This succession consists mainly of limestone, marly limestone and marl. The thickness of the succession in the study section (Baghi, north of Neyshabour) is 709 meters and is subdivided into ...
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A thick succession of Middle – Late Jurassic rocks in the western part of BinaludRange has been studied. This succession consists mainly of limestone, marly limestone and marl. The thickness of the succession in the study section (Baghi, north of Neyshabour) is 709 meters and is subdivided into 4 members. The lower boundary with the underlying dark shale and upper boundary with the overlying buff limestone are inconspicuous and transitional. Ammonites are the most important and abundant macrofossils in this section. 43 genera and 76 species have been identified among them 8 species are reported for the first time from Iran. Based on the ammonite fauna, Early Bathonian to Kimmeridjian ages are purposed for these rocks. The fauna show close relationship to Sub- Mediterranean province and there is a great similarity between ammonite fauna of the investigated area with Kope – Dagh and AlborzRange.
Kh. Tahmasbi poor; A. Fazeli
Abstract
VENARCH Manganese Mine is located about 30 Km from south –east of Qom city Volcano– clastic rocks of middle to upper Eocene age make up major outcrops of the region. Sedimentary rocks of Oligo-Miocene age overlie previous rocks, Red earth is found with manganese in the majority of manganese ...
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VENARCH Manganese Mine is located about 30 Km from south –east of Qom city Volcano– clastic rocks of middle to upper Eocene age make up major outcrops of the region. Sedimentary rocks of Oligo-Miocene age overlie previous rocks, Red earth is found with manganese in the majority of manganese mines of which the most important are Darband & Doctor mines.Their probable reserves are 5760 and 1920 thousand tons.We took Samples were taken from these mines and XRF, XRD studies and microscopic studies were carried out to identify their chemical and physical properties.
Dry and Wet sieve and scrubbing analysis were carried out on the samples and in order to decrease the cost and time of project the number of tests was done based onTaguchi method. The concentration of the raw material is increased about 20 percent and a pigment with 70% Fe2O3 was obtained.At least oil absorbtion, covering power and coloured tests carried out.The results show that the pigment has adequate quality.
B. Mehri; E. Rastad; F. Fayyazi
Abstract
The Khanjar Pb– Ag (Zn) deposit is one of the stratabound deposits of Cretaceous age in Central Iran. The ore bodies may be grouped into two main geometric types: 1) Lenses of ore bodies congruent with bedding, 2) Ores as open space filling or with brecciate fabric due to faulting. Both types occur ...
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The Khanjar Pb– Ag (Zn) deposit is one of the stratabound deposits of Cretaceous age in Central Iran. The ore bodies may be grouped into two main geometric types: 1) Lenses of ore bodies congruent with bedding, 2) Ores as open space filling or with brecciate fabric due to faulting. Both types occur in limestone unit (k2b).Three ore bearing facies have been distinguished in the Khanjar area: 1) Siliceous limestone facies; galena, sphalerite and pyrite are the main ore minerals. Minor amounts of chalcopyrite are also visible. 2) Mullusca, Echinoderm wackstone facies with galena and sphalerite. 3) Rudist limestone facies with large amount of galena. As with other stratabound and stratiform Pb- Zn deposits, the main ore minerals are simple and few in number. In addition, galena, sphalerite and pyrite, some tetrahedrite, barite and minor amounts of copper minerals are observed. Pyrite often with framboidal texture and sphalerite with spheroidal texture form always part of paragenesis. Fluid inclusion investigations on saddle dolomite located in fractures with galena and sphalerite demonstrated the homogenization temperature of 145-230 centigrade and salinity of 17.5-23% NaCl equivalent.Geometry of ore bodies, occurrence of ore horizons in certain sedimentary facies, ore textures and structures, depositional environment (Lagoonal), paragenetic sequence of minerals and fluid inclusion data, all suggest that Khanjar Pb- Ag(Zn) deposit is an MVT deposit.
A. Ghanbari
Abstract
The results of over 100 geotechnical site investigations in different zones of Tehran alluvium in the south part of Tehran city were analyzed to determine the correlation of modulus between elasticity and SPT number of soil in southern Tehran alluvium. The alluvial deposits in southern Tehran are composed ...
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The results of over 100 geotechnical site investigations in different zones of Tehran alluvium in the south part of Tehran city were analyzed to determine the correlation of modulus between elasticity and SPT number of soil in southern Tehran alluvium. The alluvial deposits in southern Tehran are composed mostly of fine-grained materials or coarse-grained soils with silt and clay particles. Based on the soil material properties, the study area is divided into three sections. In each section, the results of a large number of in situ and laboratory tests are classified and analyzed to determine the elastic modulus of soil.
The study shows that, for the first part of the area the modulus of elasticity from plate load test correlates well with SPT number and for the second and third parts, the direct shear and triaxial tests have an acceptable correlation with SPT number. Formulas relating elastic modulus to standard penetration test number are given and compared to those reported in the literature. Also, from the analysis of data it was seen that the elastic modulus of soil is increased with increase of maximum soil particles. Finally average results for unconfined strengths of fine grained soil in alluvium of the south of Tehran are presented.
A. Amiri; I. Rassa; A. Khakzad; M. H. Adabi
Abstract
Stabilization of potentially sliding terraces and natural slopes are of great importance from view point of resident security, environment protection, river engineering and water and soil conversation. Soil reinforcement using tree toots is one of the methods being studied by many researchers. Most of ...
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Stabilization of potentially sliding terraces and natural slopes are of great importance from view point of resident security, environment protection, river engineering and water and soil conversation. Soil reinforcement using tree toots is one of the methods being studied by many researchers. Most of them have worked on the effect of root density and few of them on the root diameter leading to contradicting results. In this paper the combined effect of root diameter and density on the shear resistance of soil is investigated by series of in-situ direct shear tests. Eighteen tests were carried out on soil possessing Willow roots and the results compared with those of non rooted soil as reference. To explain the observations, a new parameter referred to as root diameter-density index (RDDI) was defined. The results reveal that an increase in RDDI causes a significant increase in the apparent cohesion of rooted soil, but a little decrease in the internal friction angle. In both cases the rate of variation decreases with increasing RDDI and tends to a little value; however the extreme values of 212% and -15% are observed respectively. As general conclusion for rooted soils, the dominance of variation of apparent cohesion with respect to that of internal friction angle results the shear resistance ameliorates within a range of RDDI, and for further values it tends to a stabilized value. Moreover, for practical purposes, a relation was developed to be used by designer engineers.
M. Shirkhani; Majid Ghaderi; N. Rashidnejad-Omran; R. Mohammadi-Niaei
Abstract
AyQalesi polymetal deposit is located 30 km southeast of Takab in Orumieh-Dokhtar structural zone. For Enzyme LeachSM analysis at the deposit, 723 samples were collected from B-horizon soils. Based on the analytical results and data interpretation, six oxidation anomalies, A through F, have been defined. ...
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AyQalesi polymetal deposit is located 30 km southeast of Takab in Orumieh-Dokhtar structural zone. For Enzyme LeachSM analysis at the deposit, 723 samples were collected from B-horizon soils. Based on the analytical results and data interpretation, six oxidation anomalies, A through F, have been defined. Five of these are recommended as drill targets while one, anomaly C, is not recommended for drilling because it appears to represent a buried intrusion without significant Zn enrichment. Anomalies B, D and E have very high Zn values. For anomaly D, this is because of outcropping Zn mineralization and the presence of mine waste at surface. Anomalies B and E may occur above shallowly buried mineralized zones. Anomalies A, C and F contain much less Zn. Anomaly A may overlie a concealed zone of Zn mineralization that could be buried to a substantial depth. Anomaly F is not recommended for drilling because it appears to be a quite narrow mineralized zone.
Gh. Hosseinzadeh; A.A. Calagari; M. Moayyed; B. Hadj-Alilu; M. Moazzen
Abstract
The Sonajil area is located in ~17 km east of Heris, East-Azarbaidjan. The major lithological units in the area include bodies of volcanic and volcanoclastic rocks (lower to middle Eocene), Sonajil porphyry stock (upper Eocene-lower Oligocene), Incheh granitoid stock (diorite, syeno-diorite, gabbro) ...
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The Sonajil area is located in ~17 km east of Heris, East-Azarbaidjan. The major lithological units in the area include bodies of volcanic and volcanoclastic rocks (lower to middle Eocene), Sonajil porphyry stock (upper Eocene-lower Oligocene), Incheh granitoid stock (diorite, syeno-diorite, gabbro) (middle-upper Oligocene), and Okuzdaghi volcanic rocks (Plio-Quaternary). The Sonajil porphyry stock hosts a porphyry copper-type mineralization and varies in composition from micro-syenodiorite through micro-gabbro-diorite to micro-gabbro and micro-granodiorite, featuring principally porphyritic to microlithic porphyry textures. The parental magma of these igneous bodies had shoshonitic character (to high-K calc-alkaline), and tectonically belongs to post-collisional volcanic arc. Various generations of banded quartz, quartz-sulfides, quartz-oxides, and sulfides veinlets and micro-veinlets were developed within the porphyry body featuring typical stockwork texture. Veins of sulfide mineralization are also present in peripheral parts of the porphyry body. Alteration and mineralization occurred principally within the Sonaljil porphyry stock. Three types of pervasive hypogene alterations are developed in Sonajil stock: (1) potassic; (2) phyllic; and (3) propylitic. The principal hypogene opaque minerals include pyrite, chalcopyrite, bornite, tetrahedrite, enargite, molybdenite, hematite and magnetite occurring as dissemination and stockwork (veinlets and micro-veinlets). The chief supergene minerals in this body are hematite, goethite, malachite, azurite, chalcocite, covellite, and clay minerals.
Behnaz Barghi; Ali Asghar Calagari; Mohammad Hossein Zarrinkoub; Vartan Simmonds
Abstract
Mn-bearing veins of Jonub -ESehchangi are located 200 km southwest of Birjand, Southern Khorasan province (east of Iran). These veins are hosted by andesitic rocks of Eocene to Oligocene ages. Ore minerals identified by XRD method and mineralographic studies and are Pyrolusite, cryptomelane, psilomelane, ...
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Mn-bearing veins of Jonub -ESehchangi are located 200 km southwest of Birjand, Southern Khorasan province (east of Iran). These veins are hosted by andesitic rocks of Eocene to Oligocene ages. Ore minerals identified by XRD method and mineralographic studies and are Pyrolusite, cryptomelane, psilomelane, hollandite, hematite and goethite, displaying colloform and open-space filling textures. Gypsum, halite, barite, carbonate and silica are the gangue minerals. Alteration zones, specifically argillic alteration zone, are developed along the vein within the andesitic wall rocks. Based on the mineralogical and geochemical data, the primary manganese minerals were Mn oxides and hydroxides, which have gradually been converted to psilomelane and hollandite, and finally pyrolusite. The average grade of Mn within the veins is 38.61%. Considering the average Mn/Fe ratio (about 48.55) in the Mn-bearing veins, as well as the positive correlation of Sr, U and Ba with Mn mineralization in this area show hydrothermal origin.
Economic Geology
Majid Hafez Darbani; Ali Abedini; Farhang Aliyari; Ali Asghar Calagari
Abstract
The Kuh-Baba iron ore deposit is located in ~70 km south of Hashtroud, East-Azarbaidjan province, NW Iran. The lithologic units cropped out around this deposit include Oligo-Miocene volcanic-sedimentary rocks, Pliocene intrusive rocks, and Pliocene dacitic domes. The principal host rocks for the Fe mineralization ...
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The Kuh-Baba iron ore deposit is located in ~70 km south of Hashtroud, East-Azarbaidjan province, NW Iran. The lithologic units cropped out around this deposit include Oligo-Miocene volcanic-sedimentary rocks, Pliocene intrusive rocks, and Pliocene dacitic domes. The principal host rocks for the Fe mineralization include units of gabbro-norite, pyroxene hornblende gabbro-norite, and monzo-diorite. Remote sensing investigations (using Sentinel satellite images) display the presence of lineaments, NE-SW trending fault structures, and various alteration zones. The dominant hydrothermal alteration in inner parts of the deposit is mainly propylitic (epidote, chlorite, sericite) which gradually changes to argillic outward toward the peripheral parts. Based upon field relations and microscopic examinations, the ores show massive, vein/veinlet, brecciated, and disseminated textures. In the propylitic zone, magnetite is accompanied by epidote and actinolite. The geochemical studies revealed that the FeT content in the diamond drill core samples varies from 3.85 wt% to 63.2 wt%. Ground magnetic survey was conducted in the area and also, the maps of total magnetic field, reduced to pole magnetic, analytic signal, first vertical derivative, and upward continuation were prepared in an attempt to identify the potential deep and shallow subsurface mineralized zones. The obtained results show that two anomalies, one in the north and the other in the central parts of the study area, were recognized which almost correspond with the location of the intrusive bodies.
R. Deevsalar; M.V. Valizadeh
Abstract
The results of field studies (i.e. shape, dimensions, spatial distribution, condition of enclaves and xenoliths in the host rocks at available outcrops) experimental observations (i.e. petrographical and microstructural study of enclaves and xenoliths and whole rock geochemistry of magmatic encalves) ...
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The results of field studies (i.e. shape, dimensions, spatial distribution, condition of enclaves and xenoliths in the host rocks at available outcrops) experimental observations (i.e. petrographical and microstructural study of enclaves and xenoliths and whole rock geochemistry of magmatic encalves) show that magmatic enclaves are mafic and felsic types, while xenoliths are hornfelsic. Elongation of magmatic enclaves and hornfelsic xenoliths along their apparent longitude axis in the margin of intrusive body are attributed to influence of stress on enclaves in melt or semi-solid phases and xenoliths in plastic form. In addition, this is related to impact of high force of magmatic flow in contact with metamorphic wall rocks. This indicates that the origin of xenoliths is the metamorphic rocks which lie at the periphery of the intrusive body. Existing of aligned mafic enclaves in the host, in addition to, presence of signs of plastic deformations (in microscopic scale) in micro-scale fluid features can be attributed to superimposition of solid-state deformation on magmatic flow. Due to lack of solid-state plastic deformation evidences, applicability of magmatic flow criteria and distinguishable interface of magmatic enclaves with host rocks in microscopic and macroscopic scales, spherical, globular, ellipsoidal and spindle shapes of mafic magmatic enclaves attributed to presence of theirs as mafic globule and packets in the host felsic magma, and also their similarity in superficial appearance, textural, mineralogy and geochemistry with the host rock, attributed to their different origin and magma mixing event. The formation of irregular shaped magmatic felsic enclaves with recognizable mineralogical and geochemical similarity to the host rocks, which are observed at the periphery or ceiling of the plutons, related to peripheral interruption in the primary phase of magmatic injection caused by the high pressure of consecutive injection pulse and replacement of new magmatic charge.
Tectonics
Rojan Hemati; Manouchehr Ghorashi; Ali Solgi; Abdollah Saidi
Abstract
The Zagros suture zone is one of Key regions. Continent - Continent collision between Arabian plate and Iranian Block. This region is coincided by High Zagros and Zagros Simply Fold Zones in Western side and in other side is the Sanandaj- Sirjan Zone. The region of this research in situated in Northern ...
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The Zagros suture zone is one of Key regions. Continent - Continent collision between Arabian plate and Iranian Block. This region is coincided by High Zagros and Zagros Simply Fold Zones in Western side and in other side is the Sanandaj- Sirjan Zone. The region of this research in situated in Northern part of suture zone. The Zagros suture is oriented parallel to the other collision Structures as passive and active margins of Neo- Tethys Basin and also to Magmatic Arc (Urmiyeh - Dokhtar Arc).The main Faults in this region which we can mention by name are Zagros Main Thrust Fault and Zagros Main Recent Fault, Which they are also parallel to others structures. This region of suture zone in highly deformed and structures as folds, faults and nappes are the evident of a long compression Tectonics. The aim of this research firstly is analysing of folds and secondly is calculation of shortening rate of crust in this part of collision Zone. Three structural section (Eslam Abad- e- Gharb - Mahidasht, Kamyaran and Gazorkhani) have been balanced and the rate of shortening which is obtained respectively is 6252m , 6530m and 2040m.
M Khademi; F Ghaemi; S.K Hosseini; F Ghaemi
Abstract
In this paper, the feedback or interaction between tectonic and surface processes in the Binaloud Mountains and Neyshabour plain has been investigated. To achieve this, we have used topographic data, recorded earthquake data provided by the Geophysical Institute of Tehran University (Mashhad center) ...
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In this paper, the feedback or interaction between tectonic and surface processes in the Binaloud Mountains and Neyshabour plain has been investigated. To achieve this, we have used topographic data, recorded earthquake data provided by the Geophysical Institute of Tehran University (Mashhad center) and field surveying results. Surface processes affect the propagation of tectonic thrust wedges in orogenic belts. In regions where tectonic processes have led to an increase in the surface slopes due to development of mountain highs, surface processes will justify the uplifted areas by smoothing the slopes, eventually shedding off a massive load of clastic sediments into the foreland basin. Because of their huge weight and volume, these sediments prevent the forward propagation of the wedge and therefore increase the accumulation rate of stress in the orogenic wedge. Also the increase of fault-plane dips in the orogenic wedge will make the slip along the fault planes hard or even impossible. Formation of out-of-sequence faults and back-rotation of preexisting thrust faults may be considered as results of these accumulated stresses. North Neyshaboor thrust fault is a later or secondary structure and can be considered as an out-of-sequence thrust because it cuts other thrust sheets and limbs of folds. Our research shows that the high volume of Paleogene/Neogen sediments in the Neyshabour foreland basin has prevented the forwards (southwestward) propagation of the Binaloud mountain range as the orogenic wedge. Releasing of the accumulated forces has therefore led to the development of the North Neyshaboor out-of-sequence fault and back-rotation of former thrust faults.
E Ghadiri-Sufi; M Yousefi
Abstract
Integration of different kinds of data is a useful method which can be used in exploration studies to determine the location of undiscovered hidden or outcropping mineral deposits in an area under prospecting. The results obtained by considering all data sources and their relations have better reliability. ...
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Integration of different kinds of data is a useful method which can be used in exploration studies to determine the location of undiscovered hidden or outcropping mineral deposits in an area under prospecting. The results obtained by considering all data sources and their relations have better reliability. In this regard, modeling the mineral potential is commonly used to combine the results achieved by different exploration methods in order to generate target areas. In this research, surface exploration data over the 1:100000 geological map of the Manheshan quadrangle (Zanjan Province) were integrated by a new data-driven and knowledge-driven fuzzy approach to determine areas of high mineralization potential. Various dataset used in this study include geological map, geochemical stream sediment data, and fault distribution map. In this new approach, evidential geochemical and fault density maps were weighted ad produced without the use of any analyst’s subjective judgment and location of known indices. In contrast, the evidential weighted geological map was produced considering the analyst’s subjective judgment. The weighted data layers produced by fuzzy logic were then integrated using OR and Gamma fuzzy logic operators. Finally, known mineral occurrences (Zn-Pb) in the Mahneshan area were used to evaluate the generated models. Results show that the generated target areas have a good spatial coincidence with the position of known mineral occurrences.
L Fazli
Abstract
For biostratigraphy of the Gurpi Formation, three sections of Halegan well, Kuh-e-Harm and Kuh-e- Nareh were selected and sampled in south Qir, Fars province. The formation is 152m thick in Kuh-e- Harm section, 124m in Kuh-e Nareh section and 128 m in well Halegan and is mainly containing argillaceous ...
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For biostratigraphy of the Gurpi Formation, three sections of Halegan well, Kuh-e-Harm and Kuh-e- Nareh were selected and sampled in south Qir, Fars province. The formation is 152m thick in Kuh-e- Harm section, 124m in Kuh-e Nareh section and 128 m in well Halegan and is mainly containing argillaceous limestone with interbeds of limestone. In Kuh-e-Harm section and Halegan well the Gurpi Formation unconformably overlies the Ilam formation and underlies the Pabdeh Formation. In Kuh-e- Nareh, the Gurpi Formation conformably overlies Ilam Formation and unconformably underlies the Pabdeh Formation. A total of 108 samples were collected and studied from the three sections mentioned and 25 Species of planktonic foraminifera belonging to 10 genera and 3 species of benthic foraminifera were identified.
On the basis of the planktonic foraminifera the age of the Gurpi Formation was determined as Campanian to Maastrichtian in Kuh-e- Harm and Halegan well and Santonian to Maastrichtian in Kuh-e-Nareh. A few biozones differentiated here are comparable with global biozones of Caron 1985 and Wynd 1963. Based on the distribution of planktonic foraminifera 6 biozones are identified as follow:
Globotruncanita elevate Partial Range Zone .
Globotruncana ventricosa Interval Range Zone .
Radotruncana calcarata Total Range Zone .
Globotruncanella havanensis Partial Range Zone .
Globotruncana aegyptica Interval Range Zone .
Gansserina gansseri Interval Range Zone .
In Halegan well Globotruncana falsostuarti zone instead of Globotruncanella havanensis Zone and Globotruncana aegyptiaca biozone was erected by the author. This zonation can be correlated with Globotruncanita elevate Total Range Zone and Globotruncanita stuarti- pseudotextullaria varians Assemblage Zone of Wynd, 1963.