سخن سردبیر
text
article
2011
per
سخن سردبیر
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
1
1
http://www.gsjournal.ir/article_54195_526d90df36bec9ab3d5d4e21b8ee129a.pdf
Geochemical and Sedimentology Characteristics of Dariyan Formation in Fars Area, Case Study: Kuh-e Siyah and Sabzpushan Well# 1
M. H.
Adabi
Department of Geology, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran.
author
R.
Abbasi
Department of Geology, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran.
author
H.
Ghalavand
Oil-rich southern areas of the company, Ahwaz, Iran.
author
text
article
2011
per
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.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
3
14
http://www.gsjournal.ir/article_54196_b455df84d421bf6a16d3585929a09870.pdf
dx.doi.org/10.22071/gsj.2011.54196
Comparing the Performance of MLP, RBF, PNN and GRNN Neural Networks for Determining Boreholes of Porphyry Copper in GIS
M.
forutan
GIS Group, Faculty of Geodesy and Geomatics, K. N. Toosi University of Technology, Tehran, Iran
author
A.
mansourian
GIS Group, Faculty of Geodesy and Geomatics, K. N. Toosi University of Technology, Tehran, Iran.
author
M.
Zareinejad
GIS Group, Geological Survey of Iran, Tehran, Iran.
author
M. R.
Sahebi
GIS Group, Faculty of Geodesy and Geomatics, K. N. Toosi University of Technology, Tehran, Iran.
author
text
article
2011
per
Drilling in mine deposits has proven to be complicated, costly and time consuming process, hence it has identified the determining of optimum boreholes as a crucial issue in detailed studies. Because of some complexity in formation of mineral deposits, decreasing in risk and expenses of drilling may be continued by considering the wrapped condition of mineral deposits formation, followed by the integration of effective mineralization factors. By considering that in traditional methods of combination of mineralization’s factors like overlay and index overlay, is based on expert’s knowledge and expert knowledge is related to data accuracy, therefore, the accuracy of these methods could be remarkably decreased by large amount of data and noise. In order to solve these problems, utilization of flexible methods and powerful tools in data processing is obviously needed, especially in case of noise presence. Artificial Neural Networks are appropriate tools in large amount of data management and pattern recognition of noisy data, because of nonlinear, parallel and flexible architecture. So ANNs has been used in determining of proper position of boreholes. Neural Networks have various structures regarding their activation function and number of hidden layer and neurons in each layer. Consequently it is necessary to examine the performance of all these structures in determining the optimum position of boreholes.This paper represents a study on utilization GIS and four different Neural Networks namely: Multilayer peceptrons, Radial Basis Function, Generalized Neural Network and Probability Neural Network, for determining the position of boreholes of porphyry copper exploration in Chahfirouzeh region using cross correlation method. First, the mineralization factors are explained based on conceptual model of porphyry copper and predictor maps are produced, then, the training vectors are derived. After that, the networks are trained by geology, geochemistry and geophysics data layers. At the end, performances of the networks are compared. Implementation of Artificial Neural Networks reveals that two Neural Networks, GRNN and RBF, have the highest accuracy (approximately 80 to 83 %). Eventually, a potential map is produced by the best method.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
15
22
http://www.gsjournal.ir/article_54198_fbfa08c4e6126e47974bf02c620c2ea5.pdf
dx.doi.org/10.22071/gsj.2011.54198
Seismic Assessment of Kerman, with Specific Regard to Preliminary Semi Detailed Micro Zoning Using GIS
R.
Hassanzadeh
Department of Environmental Sciences, Faculty of Environmental Sciences, International Center for Science, High Technology and Environmental Sciences, Kerman, Iran.
author
A.
Abbasnejad
Department of Geology, Faculty of Science, Shahid Bahonar University, Kerman, Iran.
author
A.
Alavi
Kerman Disaster Management Center, Kerman, Iran.
author
E.
Sharifi Teshnizi
Department of Geology, Faculty of Science, Tarbiat Modares University, Tehran, Iran.
author
text
article
2011
per
In this article we examine the siesmicity of Kerman city. This city is located in a compressional graben which is bordered by several active faults, some of them are able to trigger an earthquake even stronger than Ms=7.0. Numerous historical earthquakes had occurred around the city which caused minor damage to the building. For seismic evaluation of Kerman city both probabilistic and deterministic methods have been taken into consideration. Accordingly, peak ground acceleration due to 15 fault segments can exceed greater than 0.2g. The intensity scale resulting from earthquakes by Kerman – Zangiabad, North Kerman and Ekhteiarabad faults would be around IXMMI in the city. In order to assess the site effect, semi detailed micro zoning was carried out by combining micro tremor and sediment facies maps using GIS. The thick young sediments would amplify the intensity to X+ MMI. Based on the resulting map, the intensity scale would increase in central, western as well as some localities of the southern part of Kerman and many buildings would be damaged by such intensity scale.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
23
30
http://www.gsjournal.ir/article_54199_7a56b81983e3d9e52f21fafcce975f02.pdf
dx.doi.org/10.22071/gsj.2011.54199
Presentation a Method for Optimization of Neural Network for Ore Grade Estimation Based on the Porphyry Copper System of Sonajil-Ahar
P.
Tahmasbi
Department of Mining & Metallurgical Engineering, Amirkabir University of Technology, Tehran, Iran.
author
A.
Hezarkhani
Department of Mining & Metallurgical Engineering, Amirkabir University of Technology, Tehran, Iran.
author
text
article
2011
per
In the present research, comparative evaluation of various learning algorithms in neural network modeling was performed for ore grade estimation in Sonjail porphyry copper deposit. The main goal of the following investigation would be optimizing the network architecture and to present an architectural optimization trend to better performing the copper grade estimation within the region. Therefore, 12 algorithms were investigated back propagation learning algorithms. Based on this research it is merged that by applying the LM and BFG algorithms, there would be the best performance. The reasons why the other algorithms have the same performance would be presented within the paper as well. The input parameters are coordinates and the outputs are the copper grades for each specified point. To obtain the optimal structure, a network with different layers has been applied, which it has acquired 12 neurons within one layer. To investigate the data normal shapes, various normal shape has been acquired in the [0 1], which could merged the best results. Finally to get the best network optimizations several transfer functions have been applied, and the sigmoid transfer function illustrated least error when the transfer function is selected. Considering the optimal conditions, the R2 value has merged 0.946 for network which could be the result showing that the optimal network architecture causes estimation improvement.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
31
36
http://www.gsjournal.ir/article_54200_b5fee5d15528d0eb49efbcaafcc875d0.pdf
dx.doi.org/10.22071/gsj.2011.54200
Assessment of Pollution rate Caused by the Mining Industries and Processing of Lead and Zinc on the Water and Soil of Angouran-Dandy Region
S.
Shariati
Islamic Azad University, Science and Research Branch, Tehran, Iran.
author
S. A.
Aghanabati
Geological Survey of Iran & Research institute for earth sciences, Tehran, Iran
author
S. R.
Mousavi Harami
Faculty of sciences, Ferdowsi University of Mashhad, Mashhad, Iran.
author
S.
Modabberi
College of Science, Faculty of Geology, Tehran University, Tehran, Iran.
author
M. H.
Adabi
Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran
author
text
article
2011
per
Angouran Lead and Zinc Mining deposit is one of the biggest Lead and Zinc deposits of Middle East and one of five great mines of Iran according to the article of categorization of the mines of Iran. In addition to the diverse metal and non-metal mines, there are many industries and factories in this region which most of them were active and are as conversion industries of Zinc soil into the Concentrate or as factoring of Lead and Zinc Bar. The realized studies demonstrate that due to activation of existent industries in that region, the rate of some elements are in unusual level and show some fundamental environmental abnormalities. The environment of the region is mostly influenced by the accumulation of wastes and residues dispossessed as cake in the borders of the rivers and canals and open lands. These Cakes which as a matter of fact are the residues of proceeding of the flotation and melting the Lead and Zinc and the process of Concentrate factoring, may have lost the great amount of their Lead and Zinc in the industrial point of view, but as an environment view, those have a lot of Lead and Zinc many times more than allowed limits which are potentially toxic. At the other hand, by reduction of these elements, the densities of other elements are increasing. This means intensive effects which in this paper are going to be surveyed. The rates of these elements in some samples are reported exceeding to 10,000 ppm Lead and Zinc and Nickel and also 8,000 ppm Arsenic and 4,000 Cadmium. The studies also demonstrate that waste pool or the pools of residues are one of the most fundamental causes of dangers for the environment of the region. The rate of 200,000 ppm of Zinc and sometimes 2000 ppm of Lead and 20,000 ppm Nickel, also tha rate of some hundreds ppm of arsenic and even 200,000 ppm of Cadmium in the water and water deposits of the region are some of those dangers. The most of these abnormalities are seen in the sediments and water of the region, however the agricultural grounds are also influenced by these pollutions and are included some major abnormalities in term of the environment. This paper will exclusively review the allowed rate of the elements of Lead, Zinc, Cadmium, and Arsenic and survey the principal manners of access of these elements to the environment of region and also try to present some solution for the control and reduction of these rates.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
45
54
http://www.gsjournal.ir/article_54201_4ae95d31e6f173ae3d57e4d0950c6e09.pdf
dx.doi.org/10.22071/gsj.2011.54201
Influence of Structures on the Ghezel Ozan River
V.
Hosseini toudeshki
Department Geology, Science & Research Branch Islamic Azad University, Tehran, Iran.
author
M.
Pourkermani
Department Geology, North Tehran Branch, Islamic Azad University, Tehran, Iran.
author
M.
Arian
Department Geology, Science & Research Branch Islamic Azad University, Tehran, Iran.
author
Kh.
Khosrotehrani
Department Geology, Science & Research Branch Islamic Azad University, Tehran, Iran.
author
text
article
2011
per
Rivers are the most important landforms on the ground whose analysis is known as a useful tool in tectonic surveys in several thousands to two million years ago. The Ghezel Ozan River, the longest river system in the country, has responded to tectonic deformation thoroughly. Detection and characterization of geomorphic anomalies in the Ghezel Ozan River and correlation with structures can specify the role of structures in making active deformations. The intense and sudden deflection in the river course, the abnormal changes in the river sinuosity and knick points upon longitudinal profile of the river are the geomorphic anomalies connected to the structures. Deflection of the river course and abnormal changes in the river sinuosity are identified on the satellite images and approved through field observations. Knick points are specified upon longitudinal profiles of the river and the effects of lithology are surveyed in making of them٫ so that only knick points are considered which are produced by structures. Longitudinal profiles of the river have been obtained from digital elevation model. Above mentioned anomalies then have been correlated with structures extracted from geology maps and in this manner structures effective in making geomorphic anomalies have been identified. The study region is located in Sanandaj – Sirjan, Centeral Iran and Western Alborz zones. Around the Ghezel Ozan River, marl, sandstone, siltstone, limestone, tuff, agglomerate and volcanic rocks are extremely exposed. These rocks belong to Qom, Upper Red, Lower Red and karaj formations. Deflection of the Ghezel Ozan River is surveyed in the regions of Kuh-e-Palangi, Jelovdarlou, Cham and Yengejeh. Abnormal changes in river sinuosity is studied in regions of Jomaelou, Gol gheshlagh, Armoutlou, Kuh-e-Qaravol, Ghaflankuh and Kuh-e-Pajdar. In the regions of Sharif Abad, Iemir, Kuh-e-Qaravol and Kuh-e-Pajdar, knick points are specified upon longitudinal profile of the Ghezel Ozan River. The obtained results show that folds with trends of NW – SE and NE – SW have the highest influence on deflection of the course of the Ghezel Ozan River. The other geomorphic anomalies produced by faults with trends of NW–SE , NE – SW, N-S and E-W especially in instances that faults with trends of NW – SE and NE – SW have intersected. Thus, the most active structural trends in around of the Ghezel Ozan River are trends of NW–SE, NE – SW, N-S and E-W which correlate with trends of fractures in basement of Iran. In this way active folds and faults are identified in the area.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
55
60
http://www.gsjournal.ir/article_54203_2ea02e8ebafda9c3655a876b5b96f3a2.pdf
dx.doi.org/10.22071/gsj.2011.54203
Studies of Geomorphology and Sedimentology Changes on the South East Coasts of the Persian Gulf Due to UAE Manmade Islands
K. N.
Afzali
Marine Geology Department,Geological Survey of Iran,Tehran,Iran
author
R.
lak
Research Institute for Earth science, Geological Survey of Iran, Tehran, Iran
author
text
article
2011
per
United Arab Emirate has recently started to build some artificial islands in the southern part of the Persian Gulf. Constructing of these Islands, such as each marine structure, have special effects on the morphology of the sedimentary Basin. This investigation focused on the documentation of morphological and environmental effects of making artificial islands by the UAE in the Persian Gulf. This research is based on remote sensing studies and sedimentology investigation. Remote sensing studies carried out with comparing satellite data related to 1998, 2003, 2007 and 2008. Sedimentology investigation of the three sediment samples taken from the coastal part of the artificial islands was carried out. The deliberations indicate that construction of these islands have negative effects on geomorphological features in coastal part of the Persian Gulf in UAE region. The Sedimentation around the islands leads to the reduction of water depth. The kind of the sediment is usually carbonates and their origin in the western part of the islands is affected by marine longshore currents. However, there are two sources proposed for the sediments in the eastern part of islands; intrabasinal (direct precipitation) and detrical. The construction of linear barriers along the coast leads to the building of restricted lagoons between the coast and barriers. It is estimated the rate of progradation of the coast (sea ward migration of the shoreline) is 120 m from 2008 to 2009.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
61
68
http://www.gsjournal.ir/article_54207_32654503018b666138103fe0c1ddd0fd.pdf
dx.doi.org/10.22071/gsj.2011.54207
Introduction to Permian Microfossils in Aru and Bibi Shahrbanoo Area (Albourz)
R.
Shabanian
Payam-e Noor University of Tabriz, Tabriz, Iran.
author
text
article
2011
per
The Permian sequences of Aru and Bibishahrbanoo sections comprise the Dorud, Ruteh and Nesen formations respectively. A precise dating of the formations was provided based on the analysis of smaller foraminifers and fusulinid assemblages. The clastic Dorud Formation refered to Asselian and Sakmarian stages. The platform limestone of Ruteh Formation corresponds to Kubergandian – Murgabian stages. The Laterite and Bauxite horizon in the studied area attributed to Midian and finally, the uppermost beds of Permian in Bibisharbanoo corresponds to Early Dzhzulfian, based on the proposed of international subcommission on Permian stratigraphy concerning Tethyian stage bourdaries. Biolithic limestones of Ruteh Formation lying transgressively and disconformably on the underlying clastic and continental Dorud Formation with a great hiatus consists of Yachtashian and Bolorian stages. In both stratigraphical sections, thin vermiculate and oolithic limestone of Elika formation belonge to Early to Middle Triassic lying disconformably on the Permian sequence with hiatus. The hiatus between Permian and Triassic in Aru comprise Dzhulfian and Dorashamian stages and in Bibi Shahrbanoo stratigraphical section include Late Dzhulfian and Dorashamian stages. In this study 45 species belonging to 40 genus related to fusulinid families, smaller foraminifers and calcareous algae were recognized.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
37
44
http://www.gsjournal.ir/article_54208_cbadc92158010e15a7da439f83778c5b.pdf
dx.doi.org/10.22071/gsj.2011.54208
Relative Strain Pattern in Ali Abad Damagh Granitoid
R.
Samanizadegan
گروه تکتونیک، بخش زمین شناسی، دانشگاه تربیت مدرس، تهران، ایران
author
M.
Mohajjel
گروه تکتونیک، بخش زمین شناسی، دانشگاه تربیت مدرس، تهران، ایران
author
text
article
2011
per
The Ali Abad Damag granitoid is intruded in Triassic-Jurassic schists located 35km south of Hamadan, southeast of the Alvand batholith. Northeast-southwest oriented mylonitised Ali Abad Damag granitoid has been intruded into a strike-slip dextral ductile shear zone. Abundant deformed enclaves exist in this granitoid that all were strongly elongated along the main extension direction (X axis). The elongation of the enclaves is concordant with the strain rate and development of the mylonitic foliation and stretching lineation. Structural analysis of exposed rocks in this shear zone indicates that the mylonitic foliation is sub-vertical or steeply dipping to NW in the western half and shallowly to moderately dipping to the same direction in the eastern half, but the stretching lineation is sub-horizontal sub-parallel to the strike of the mylonitic foliation throughout the shear zone. Dextral strike-slip displacement is identified by the shear sense indicators. The change of foliation dip of the eastern half against the western part is interpreted by rotation along the NW-SE trending Darreh-Gar strike-slip fault.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
69
74
http://www.gsjournal.ir/article_54209_69f55ae37d680218dbcc28764f726e66.pdf
dx.doi.org/10.22071/gsj.2011.54209
Geochemistry, Alteration and Mineralization of Gold in Shanegh Area, Delijan, (Isfahan)
M.
Sakhdari
Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran
author
M.
Yazdi
Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran
author
M.
Behzadi
Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran
author
text
article
2011
per
The Shanegh area is located in central part of Sanandag-Sirjan zone, 28km southeast of Delijan. Rock units exposing in the area consists of sedimentary (carbonate, sandstone, siltstone) volcano- sedimentary (andesite to andesitic tuff, tuff) and intrusive host rocks. The volcano- sedimentary units thought to be of Eocene to Quaternary ages which have been intruded by plutonic units. The main host rocks are monzonite, quartz monzonite, andesite and diorite. The host rocks have been altered by pervasive hydrothermal fluids. The alterations are sericitization, kaolinitization, carbonatization and silicification. The host rocks are characterized by fault or shear zones, vein systems, stockwork and dyke mineralization. Ore mineral assemblages are pyrite, chalcopyrite, Fe-oxide and Fe-hydroxides. We did not find gold minerals in our microscopic studies but the gold has been found in the lithogeochemical exploration. The results show that maximum grade of gold in some veins is about 2760 ppb and the mean grade of gold about 80 ppb. Comparing shanegh area main characteristics with epithermal gold deposits, shanegh area has the most similarities with epithermal gold mineralization; therefore, it is considered to be of this type.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
75
80
http://www.gsjournal.ir/article_54211_0397fc03436a4dbb5716a8f8505863b0.pdf
dx.doi.org/10.22071/gsj.2011.54211
The Mineralogy, Structure, Texture and Genesis of The Redbed-Type Sedimentary-Diagenetic Markasheh Cu Occurrence in The Jurassic Garadu Red Formation, South Central Iran
A.
Mahdavi
Metalic Exploration Department, Geological Survey of Iran, Tehran, Iran
author
E.
Rastad
Metalic Exploration Department, Geological Survey of Iran, Tehran, Iran
author
M.
Hoseini Barzi
Metalic Exploration Department, Geological Survey of Iran, Tehran, Iran
author
text
article
2011
per
Markasheh occurrence, includes redbed sediments (Garadu Redbeds) of Jurassic-Cretaceous age that extend in a large area for over 400 km in an area. Garadu Redbeds include alternate of red oxidized sandstone, conglomerate and siltstone that is partly reduced. Mineralization occurred in reduced horizons and is related with paleochannels. In the Markasheh area two obvious main reduced horizons and four sub-horizons occur. Each of these horizons includes three zones: Red oxidized zone, Bleached zone and Reduced mineralized zone. Based on characteristics of Markasheh Cu occurrence such as lithology, lens like and layered shape (in geometry), regional extent, replacement and disseminated textures, simple mineralogy, presence of plant fossils and concentration of copper mineralization in relation to fossils, Markasheh Cu occurrence is considered as a Red bed sediment-hosted copper deposit type. The mineralization has been occured after early diagenesis before burial of the host roks.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
81
92
http://www.gsjournal.ir/article_54370_c92d5e12c6c490fa86e214b8b7e95f74.pdf
dx.doi.org/10.22071/gsj.2011.54370
Landslide Susceptibility Mapping in the Reservoir of Alborz Dam Using Analytical Hierarchy Process and Bivariate Statistics
H.
Gharahi
Department of Geology, Faculty of Science,University of Tehran, Tehran, Iran
author
B.
Bohlooli
Department of Geology, Faculty of Science,University of Tehran, Tehran, Iran
author
A.
Sayyar
Mahab Ghods Consulting Engineers. Tehran, Iran
author
M.
Shariat jafari
Soil Conservation and Watershed Management Research Institute, Tehran, Iran
author
text
article
2011
per
Landslides cause damage to property and pose a threat even to human lives. Suitable landslide susceptibility, hazard and risk models could help mitigate or even avoid the unwanted consequences resulted from such hill slope mass movements. For the purpose of landslide susceptibility assessment, a spatial database, which included 18 landslides prepared and analyzed using LISS-IV satellite imagery and geographical information system (GIS) technology. Analytical hierarchy process (AHP), the statistical index (Wi) and weighting factor (Wf) methods were applied to determine the significance of event-controlling parameters in triggering the landslides. The parameters included lithology, slope gradient, slope aspect, elevation, distance from faults, distance from stream and drainage density. These factors are different in geomorphic and geologic setting. The result showed that lithology, slope gradient and distance to stream play most important roles in landslide susceptibility. To confirm the practicality of the three susceptibility maps, there were compared with landslides activity map containing 12 active landslides. The results showed that the Wi method gave a more realistic picture of the actual distribution of landslide susceptibility, than the Wf method in the reservoir of Alborz dam.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
93
100
http://www.gsjournal.ir/article_54371_cc10b63f04269dbf14b25aef80a51f19.pdf
dx.doi.org/10.22071/gsj.2011.54371
Extensional Structures in a Transpressional Tectonic Regime: the Relationship with Hydrothermal Vein Deposits and Porphyry Copper Deposits in NE Shahr-e-Babak
L.
Ebadi
Department of Geology, Faculty of Earth Sciences, University of Shahid Beheshti, Tehran, Iran
author
S.A.
Alavi
Department of Geology, Faculty of Earth Sciences, University of Shahid Beheshti, Tehran, Iran.
author
Sh.
Shafiei
Department of Minning, Facult of Engineeting, University of Shahid Bahonar, kerman, Iran.
author
text
article
2011
per
Hydrothermal vein and porphyry copper deposits are notable within Eocene volcanic rocks of Shahr-e-Babak area. In this paper, the structural patterns within Shahr-e-Babak area as well as the relationship between structural elements and the emplacement of dikes and hydrothermal vein and porphyry copper deposits have been discussed. Three fault trends of WNW-ESE and N-S are recognized in northeastern Shahr-e-Babak according to satellite images and field observations. The WNW-ESE and N-S trending faults are normal faults, while the NE-SW trending faults are sinistral faults with normal component. Two trends are recognized for the dikes in Shahr-e-Babak area namely, WNW-ESE(T2) and N-S (T1) following the trends of preexisting fractures in the area. The existence of an extensional system is recognized by the pattern of tension gashes and Pennant and the presence of extensional joints in the area. The shift in s1 direction from NE-SW to N-S, confirm the presence of some rotation in the area. The rotation in a transpressional regime caused the development of extensional structures in the Shahr-e-Babak area; the extensional structures provided the space for the passage of ore fluids and the emplacement of polymetallic vein and porphyry copper deposits in northeastern Shahr-e-Babak
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
101
114
http://www.gsjournal.ir/article_54372_766fca0515855339bfc65354e048ff96.pdf
dx.doi.org/10.22071/gsj.2011.54372
Investigation of 2-D Electrically Anisotropic Structures Employing Magnetotelluric Data
M.
Montahaei
Institute of Geophysics, University of Tehran, Tehran, Iran.
author
B.
Oskooi
Institute of Geophysics, University of Tehran, Tehran, Iran.
author
H.
Brasse
Dept. of Earth Sciences, Free University of Berlin, Berlin, German .
author
G.
Kapinos
Dept. of Earth Sciences, Free University of Berlin, Berlin, German
author
text
article
2011
per
Investigations made in current study illustrate that an application of 2-D isotropic inversion algorithm for magnetotelluric data affected by anisotropy could recover macro-anisotropy reasonably well. First anisotropy effects on common MT interpretation steps, dimensionality analysis and 2-D inversion modeling, are investigated. Two kinds of azimuthally anisotropic features (anisotropic block and anisotropic layer) which generally form a part of 2-D models are considered. The influence of different anisotropy strikes and resistivity contrasts on dimensionality analysis and on the behavior of induction arrows is studied. These investigations evince that, a strike direction close to the anisotropy strike can be chosen by the dimensionality analysis of the data. Then if the data are rotated to this angle, 2-D inversion would recover the anisotropy sensibly by means of macro-anisotropy. This procedure is tested successfully on a field data set where anisotropy had been previously recognized. The results show that the proposed approach reproduces the anisotropy acceptably via macro-anisotropy in the final inversion model.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
115
120
http://www.gsjournal.ir/article_54374_9a001588283d9d4ffeb6dabf0d37c999.pdf
dx.doi.org/10.22071/gsj.2011.54374
Introducing of Copper Porphyry Type and Gold Mineralization in Siliceous Veins at Mirkuh Ali Mirza Area, Sarab,by Geochemical
Exploration
A.
Maghsoudi
Faculty of Earth Science, Shahid Behshti University, Tehran, Iran.
author
M.
Yazdi
Faculty of Earth Science, Shahid Behshti University, Tehran, Iran.
author
M.
Mehrpartou
Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran.
author
M.
Vosoghi Abedini
Faculty of Earth Science, Shahid Behshti University, Tehran, Iran.
author
text
article
2011
per
The Mirkuh Ali Mirza area is situated at north of Sarab, NW of Iran. The study area is located in in Meshkin Shahr 1:100000 geological sheets at western Alborz–Azerbaijan structural zone. The major exposed rocks in the area are the Eocene and Neogene volcanic and subvolcanic rocks which include rhyolitic and dacitic tuff with intermediate to basic rocks. Recent geochemical stream sediment (1:25000 scale) and litogeochemical surveys showed base and precious metals in the form of veins at the periphery of a porphyry copper deposit model. Occurrence of this mineralization can be a small part of a big hydrothermal fluids circulation that its effects were developed in large scale up to 10km2 to porphyry copper mineralization. The mineralization model follow as; porphyry copper in center, gold and other base metals in periphery, anomalous concentration of Ag, As, Sb, Pb and Zn in more distal relative to central body and Mn, Ba and Hg can be found at the outer part of the system
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
121
128
http://www.gsjournal.ir/article_54375_68ba6069156114ebe621e4d5530acfa4.pdf
dx.doi.org/10.22071/gsj.2011.54375
Geochemical Evaluation of Surmeh Formation as a Candidate Source Rock in South Pars Field
M.
Memariani
Research Institute of Petroleum Industry, Tehran, Iran
author
H.
Kermanshahi
Research Institute of Petroleum Industry, Tehran, Iran.
author
M. R.
Kamali
Research Institute of Petroleum Industry, Tehran, Iran.
author
text
article
2011
per
With respect to distribution of Surmeh Formation in Persian Gulf region, this formation may act as candidate source rock for hydrocarbon accumulation in this region. A comprehensive geochemical analysis including Rock-eval Pyrolysis, Gas Chromatography (GC), Gas Chromatography – Mass Spectrometry (GC-MS), were carried out on cuttings, in order to determine its hydrocarbon potentiality. Based on Rock-Eval data, the organic matter of the Surmeh formation is type II and III kerogen, with low maturity being at the end of diagensis stage. It exhibits a poor source rock characterization with low content of TOC. A close similarity can be seen, between organic matter extracted from Surmeh sample with that of oil sample collected from Upper Dariyan, Lower Dariyan and Maudud reservoir in the field. Biomarker results indicate that an open marine and few terrestrial input source rocks deposited in an anoxic condition with carbonate origin. Based on geochemical investigations Surmeh Formation isn't suitable source rock in the study area locally. Biomarker derived from rock extracts and trapped oils indicated that they share the same origin and were stained by laterally migrating oils from distant area.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
129
134
http://www.gsjournal.ir/article_54376_efcb6b0fdfbcbabedd20893ecd3df46a.pdf
dx.doi.org/10.22071/gsj.2011.54376
Designing of Exploration Algorithm to Generate Optimum Mineral Potential Models and Management of Exploration Operation: A Special Emphasis on Preliminary Exploration of Gold Deposits
Mahyar
Yousefi
Faculty of Mining, Petroleum and Geophysics, Shahrood University of Technology, Shahrood, Iran.
author
R.
Gholami
Faculty of Mining, Petroleum and Geophysics, Shahrood University of Technology, Shahrood, Iran.
author
A.
Kamkarr-Ruhani
Faculty of Mining, Petroleum and Geophysics, Shahrood University of Technology, Shahrood, Iran.
author
A.
Moradzade
Faculty of Mining, Petroleum and Geophysics, Shahrood University of Technology, Shahrood, Iran.
author
text
article
2011
per
In the systematic exploration plan for prospecting the mineral deposit, we can design an exploration algorithm using the modeling of known mineral occurrences. Such an algorithm is a key to recognize the area where is high probability of mineralization, reduce the risk of exploration and increases the probability of exploration success. In this paper, we introduce an algorithm for optimizing mineral potential model and target generation in the exploration operation with focus on the gold exploration. In this way, after descriptive and conceptual modeling of gold deposit, all of the characteristics that can be used as an exploration criterion have been identified and assembled as a target model. Then, various data layers have been used to generate significant evidential maps. Then all of the evidential maps should be combined to generate mineral potential model (map) of the mineralization type sought. Recent map shows the probability location of gold mineralization as target area. Finally an algorithm has been introduced in which all of the exploration stage and methods have been identified base on priority.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
135
142
http://www.gsjournal.ir/article_54377_8bd2a9692d8ff487e33c3cee98d36768.pdf
dx.doi.org/10.22071/gsj.2011.54377
Characterization of Geochemical Pattern Using Principal Component Analysis (PCA) and Fuzzy C-mean Clustering (FCMC) For Enhancement of Weak Anomalies (Gulan area, E-Azerbaijan, Iran)
M. J.
Mohammadzadeh
Faculty of Mining Engineering, Sahand University of Technology, Tabriz, Iran.
author
H.
Shahinfar
Department of Geology, Islamic Azad University-Tabriz Branch, Tabriz, Iran.
author
A.
Nasseri
Department of Mining Engineering, Islamic Azad University –Ahar Branch, Ahar, Iran .
author
text
article
2011
per
Optimization of geochemical anomalies needs an orientation survey in which one of its important aspects is selecting an advanced data processing method. The main objective of this study is to recognize the blind and mineralization zones by employment of new processing techniques in order to establish an optimized exploration tool and reliable geochemical pattern for potentially promising areas in Gulan. In this respect 233 stream sediment samples were collected and analyzed for Cu, Pb, Zn, Mo, Co, Ni, Cr, As, and Y. The anomalous zones were detected by using PCA&FCMC methods. The FCMC results revealed Cu, Mo anomalous zones in Garachilar area. It shows secondary halos separation of Cu and Mo probably due to transportation of Mo in the form of molybdates by acidic solution around outcrops, and consequently their adjoined redeposition. Application of Fuzzy logic Based FCMC shows the emplacement of Cu and Mo in the same cluster and overlapping of their anomalies which indicate their paragenetic relation in the ore bearing solution. Comparative study of the methods (FCMC&PCA) revealed some how similar results in detecting Garachilar anomalies. But the PCA results not only indicate Garachilar as promising zones but also could detect western part of Lutkeh and blind anomalies of Namnig in the same trend of NW-SE. This study indicates that geochemical pattern detected by PCA is more effective in enhancement of halos and blind anomalies than FCMC. Moreover, the characterization of geochemical pattern by PCA can be optimized more precisely in eliminating lithological effect and its results can be used successfully as prospecting tool in the area.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
143
150
http://www.gsjournal.ir/article_54378_5e087044fbd3cd31d02648a52442b809.pdf
dx.doi.org/10.22071/gsj.2011.54378
Late Devonian Conodonts from Baghin Section, West of Kerman
H.
Gholamalian
Department of Geology, Faculty of Sciences, Hormozgan University, Bandar Abbas, Iran.
author
S. M.
Hosseini-Nezhad
Faculty of Geosciences, Damghan University, Damghan, Iran.
author
Z.
Khosravi
Faculty of Geosciences, Damghan University, Damghan, Iran.
author
I.
Turkzadeh Mahani
ِِDepartment of Geology, Kerman High Education Institute, Kerman, Iran.
author
text
article
2011
per
Bahram Formation equivalent sequence in the Baghin area spans late Givetian to late Frasnian age. Thirty-two species and subspecies are identified. Ancyrodella alata, An. pristina, Polygnathus aspelundi, P. aequalis, P. subincompletus,P. politus, Icriodus alternatus alternatus, I. iowaensis iowaensis are of important species. The presence of An. pristina and An. alata in the lower part of Bahram Formation in this section shows the late Givetian marine transgression. Five conodont biozones are recognized on the basis of stratigraphic ranges of species: Lower to Upper falsiovalis zones; transitans to punctata zones; Lower hassi to jamieae zones; Lower rhenana Zone; and Upper rhenana to ?linguiformis zones.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
151
158
http://www.gsjournal.ir/article_54379_cac2eb5c397600d60c35b195fcf76cd1.pdf
dx.doi.org/10.22071/gsj.2011.54379
Geotechnical Properties of Central Part of Karaj Alluvium
A.
Ghanbari
Faculty of Technology and Engineering, Tarbiat Moallem University, Tehran, Iran
author
S. S.
Zerangzadeh
Science & Research Branch, Islamic Azad University, Tehran, Iran
author
F.
Rezaee
Research institute for Earth Sciences, Geological survey of Iran, Tehran, Iran
author
S. J.
Zakariaee
Science & Research Branch, Islamic Azad University, Tehran, Iran
author
text
article
2011
per
In this study, the geologic formations of central part of Karaj alluvium are studied and a new division for layers is presented. The results of hundreds geotechnical in-situ and laboratory tests in Karaj alluvium were carried out and analyzed. Based on soil material properties, the study area is divided to six individual layers. In each layer, the results of a large number of in situ and laboratory test to determine geotechnical properties of soil are classified and analyzed. Finally, average geotechnical parameters for different layers of soil in study area are presented. To determine the range of modulus of elasticity and relation between bearing capacity and SPT number in Karaj alluvium, results of laboratory and in-situ tests were assessed and compared with instrumentation data.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
159
168
http://www.gsjournal.ir/article_54380_2ebd5b176fde2889d46d1aac0d523a04.pdf
dx.doi.org/10.22071/gsj.2011.54380
First Records of 1384 AD Shahr-e-Rey’s Historical Earthquake on Pishva Fault based on Paleoseismology Researches, South East of Tehran
T.
Majidi Niri
Islamic Azad University, Research and Science Branch, Tehran, Iran
author
H.
Nazari
Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran.
author
M.
Ghorashi
Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran.
author
M.
Talebian
Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran.
author
A.
Kaveh Firooz
Islamic Azad University, Research and Science Branch, Tehran, Iran
author
text
article
2011
per
Pishva fault with about 35km length is located between Alborz and Central Iran structural zones in southeast of Varamin. General trend of the fault is NW-SE (N38W, 33NE) which has reverse mechanism accompanied by sinistral component. Achieved Morphotectonic studies along the Pishva fault reveal its activity. 3-5 seismic events with recurrence time of 3265 years are identified by studying on two Paleoseismic trenchs T1 and T2, The youngest and oldest events are 0.87 Ka and 29 Ka respectively. According to Wells and Coppersmith equations (1994), the biggest and smallest computed earthquake magnitudes are respectively 7.08 and 5.9. It would be possible to assign Shahr-e-Rey 1384 AD earthquake to this fault, since Event 1 is 870 years old.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
169
178
http://www.gsjournal.ir/article_54381_5c72c8ec5cfbfc24ece85d7c598cc568.pdf
dx.doi.org/10.22071/gsj.2011.54381
Source and Tectonic Setting East of Sahand (Southeast of Tabriz) Volcanic Rocks Using Geochemical Evidences
F.
Pirmohammadi
Departmant of Geology, Islamic Azad University, Shabestar Branch,Shabestar,Iran.
author
A.
Ameri
Departmant of Geology, Tabriz University, Tabriz, Iran.
author
A.
Jahangiri
Departmant of Geology, Tabriz University, Tabriz, Iran.
author
Ch.
Chen
Institute of Earth Sciences, Academia Sinica, Taiwan
author
M.
Keskin
Departmant of Geology, Istanbul University, Istanbul,Turkey
author
text
article
2011
per
In southeast Tabriz, as a part of Western Albourz-Azarbaijan magmatic belt the vocanic and pyroclastic rocks of Sahand cover vast areas. The volcanic rocks include andesite, dacite, rhyodacite and rhyolite and pyroclastic rocks largely occur as vast ignimbritic outcrops. Based on high LILE/HFSE and LREE/HREE ratios and their similar composition to subduction volcanic rock suites; it seems that they have formed in a subduction zone. The subduction process had low effect on the concentration of Zr, Ta, Hf, Sm, Tb, Nd, Eu and Y, while it had strong influence on concentration of Th , U and La. Concentration of elements such as Ba , K , Rb , Cs , Sr , Pb shows that these rocks belong to calc-alkaline series. The studied rocks show considerable similarity with calc-alkaline rocks from Turkey and from this point of view; these rocks belong to post-collisional arcs. In this tectonic setting, magma ascent is controlled by strik-slip faulting and associated pull-apart extensional tectonics. This post-collisional magmatism may have occurred due to Arabian-Iranian plates collision.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
http://www.gsjournal.ir/article_54382_d41d8cd98f00b204e9800998ecf8427e.pdf
dx.doi.org/10.22071/gsj.2017.54382
Effective Processes in Evolution of Kuh-e Dom Plutonism, NE Ardestan, the using of Geochemical and Isotopic Evidence
A.
Kananian
Department of Geology, School of Science, Tehran University, Tehran, Iran
author
F.
Sarjoughian
Department of Geology, School of Science, Tehran University, Tehran, Iran
author
J.
Ahmadian
Department of Geology, Payam-e Noor University, Tehran, Iran
author
text
article
2011
per
The Kuh-e Dom intrusion is a small section of Upper Eocene Urumieh- Dokhtar magmatic belt in the Central Iran tectonic zone. This intrusion is composed of two separate phases which include an acidic and intermediate- mafic units. The acidic rocks consist of monzogranite, granodiorite, quartz monzonite and quartz monzodiorite whereas the intermediate-mafic rocks comprise gabbro, diorite, quartz diorite, monzodiorite and monzonite. Mafic microgranular enclaves of dioritic, quartz dioritic, monzodioritic and quartz monzodioritic composition are common in the acidic rocks. Based on geochemical data, magma mixing along with fractional crystallization has important role in evolution of the plutonic rocks. Also, Kuh-e Dom intrusive rocks have low TiO2, P2O5 and Nb/Zr ratio which are characteristics of active continental margin. The isotopic signature of plutonic rocks is not exactly like those of mantle- or crustal-derived magma, but these rocks have some features commonly found both in the crustal and mantlic sources so that the enclaves tend to illustrate mantlic composition and the acidic rocks tend to show crustal composition, but the intermediate- mafic rocks are in the range from acidic rocks to enclaves. This result along with field and petrographical studies indicate that magma mixing/magma or mingling processes may play an important role in evolution of the intrusion. The upper mantle magma forming the microgranular enclaves, after emplacement in the crust may lead to partial melting of lower crust and because of magma mixing between crustal and mantlic melts, the mafic to intermediate rocks may form.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
191
200
http://www.gsjournal.ir/article_54383_c197ac75899998d69bb10e7e54593276.pdf
dx.doi.org/10.22071/gsj.2011.54383
Tectonic Evolution of the Alborz in Mesozoic and Cenozoic
Alireza
Shahidi
Geological Survey of Iran, Tehran, Iran.
author
E.
Barrier
Tectonic Laboratory, Paris 6 University, Paris, France.
author
M.-F.
Brunet
Tectonic Laboratory, Paris 6 University, Paris, France.
author
A.
Saidi
Geological Survey of Iran, Tehran, Iran
author
text
article
2011
per
In northern Iran the Eo-Cimmerian orogeny resulting from this collision is associated with a regional unconformity and a major change in sedimentation. From Norian to middle Bajocian (Shemshak group), 030° trending extension is indicated by syndepositional normal faults. We assign this extensional tectonics to the rifting phase preceding the oceanic opening of the South Caspian Basin. Dalichai and Lar formations, late-Bajocian to Neocomian in age, conformably cover the Shemshak in central Alborz. They are contemporaneous with the opening of the South Caspian marginal basin. In Alborz, the lower part of the Cretaceous sequence is associated with E-W to WNW-ESE trending normal fault systems associated with magmatism related to an N-S to NNE-SSW trending extension during this period. The Cretaceous-Palaeogene boundary is marked by a major regional unconformity. This unconformity is related to a major inversion of the southern margin of the South Caspian basins. During the early-middle Eocene, southern Alborz is characterized by a rapid subsidence of the Karaj basin. Syndepositional E-W to WNW-ESE trending normal faults are common in the Karaj Formation. They are associated with a well-determined N-S to NNE-SSW extension. We assign the Karaj basin to a back-arc basin related to the NE subduction of the neo-tethyan oceanic lithosphere beneath the southern margin of Eurasia.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
201
216
http://www.gsjournal.ir/article_54384_2d8d060991e84f290328292a624e5c9d.pdf
dx.doi.org/10.22071/gsj.2011.54384
Geotourism: A Royally Sustainable Path toward the Excellence in Beauty
A.
Mehrpooya
Department of English Language, Hamedan Branch, Islamic Azad University, Hamedan, Iran
author
A. A.
Morovat
Payame Noor University of Tuyserkan, Tuyserkan, Iran.
author
text
article
2011
per
Basing its foundation on the common sense and relying on the human rationality as a collective tool, this study brings to light the fact that touring in nature by providing the due opportunity of gaining underived data through the rationalistic exploration of nature in its rich variety of geomorphologic and geological phenomena can afford a clearer definition of ‘beauty’, hence the term ‘aesthetic geotourism’. In other words, the geotourist in his own endeavor by taking the natural paths leading to a closer look at the delicate strands of the rich fabric of nature is involved in a rationalistic attempt which will culminate in coming up with an illuminated mental concept of beauty. In the last analysis, touring in the nature and its geological phenomena is among the effective factors helping to illuminate and clarify man's mental concept of beauty, which in itself can open a more reliable horizon toward developing a sustainable geotourism based on rationalistic geological aesthetics.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
21
v.
81
no.
2011
217
221
http://www.gsjournal.ir/article_54385_520744d18fe40b39108fad0de436cdef.pdf
dx.doi.org/10.22071/gsj.2011.54385