سخن سردبیر
text
article
2008
per
سخن سردبیر
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
1
1
http://www.gsjournal.ir/article_57833_b259e8815c563286f7d6070d21fadddb.pdf
Feasibility Study on Electrical Separator Efficiency Increment for Kahnooj Titanium Mineral Processing Pilot Plant
S. M. Javad
Koleini
Mineral Processing Dep., Faculty of Engineering, T.M.U. University, Tehran, Iran
author
M.
Abdollahy
Mineral Processing Dep., Faculty of Engineering, T.M.U. University, Tehran, Iran
author
M.
Nasrabadi
Mineral Processing Dep., Faculty of Engineering, T.M.U. University, Tehran, Iran
author
text
article
2008
per
In this paper, a study on efficiency increment (operation efficiency) of Kahnooj titanium pilot plant electrical roll separator with optimization of variable and effective parameters (crona voltage intensity, feed temperature and size distribution, rolls speed, crona electrodes position and splitter position) on operation efficiency is investigated and obtained results are presented. To achieve this aim, parameters were classified and then tests designed with Taguchi method. Feed size distribution tests in laboratory scale and the other tests in pilot plant scale were performed. Optimized values of crona intensity voltage, feed temperature, rolls speed was found to be 22 kv, 109, 154 rpm. However, the optimum position of crona electrodes, the first, second and third splitters were obtained to be 6, 8, 10 and 10 cm. In the position of optimum values, operation efficiency was increased from 35.9% to 46.1%. Moreover, operation efficiency in laboratory scale with d80 of 259 microns feed was maximized and operation efficiency of 46.0% obtained.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
2
14
http://www.gsjournal.ir/article_57834_e71c105053b41b186d994083830c5386.pdf
dx.doi.org/10.22071/gsj.2009.57834
Introducing of Calpionellid Zonation at the Jurassic-Cretaceous Boundary in the Shal Section (South-East of Khalkhal)
R.
Azimi
Mining Department, Faculty of Engineering, University of Tehran, Tehran, Iran
author
K.
Seyed-Emami
Dept. of Geology, Faculty of Earth Sciences, Shahid Behashti University, Tehran, Iran
author
A.
Sadeghi
Dept. of Geology, Faculty of Earth Sciences, Shahid Behashti University, Tehran, Iran
author
text
article
2008
per
The calpionellid biozonation within Shal and Kolur Formations in Shal region, SE Khalkhal are accomplished based on standard biozonation of Allemann et al. (1977). In this study, 5 biozones are introduced from Tithonian to Hauterivian:biozone. Biozone 1 belongs to Shal Formation and biozones 2 to 5 to Kolur Formation: 1- Crassicollaria intermedia Taxon Range Zone; Late Tithonian, 2- Calpionella alpina Acme Zone; Early Berriassian, 3- Calpionellopsis simplex - Calpionellites darderi Interval Zone; Late Berriassian to Early Valanginian, 4- Calpionellites darderi - Tintinopsella longa Interval Zone; Valanginian, 5- Tintinopsella longa - Tintinopsella carpathica Interval Zone; Late Valanginian- Hauterivian. Biozone 2 is also subdivided into the Calpionella alpina and Calpionella elliptica Subzones. Biozone 3 is subdivided into the Calpionellopsis simplex and Calpionellopsis oblonga Subzones. Based on this zonation, the Jurassic /Cretaceous boundary (Tithonian/ Berriassian) is defined at the Lower boundary of the Calpionella alpina zone which is equivalent to the Shal and Kolour Formations boundary.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
16
25
http://www.gsjournal.ir/article_57835_c12a9d91eb34326775ab4f75b3ac8e9a.pdf
dx.doi.org/10.22071/gsj.2009.57835
Petrology of Quaternary Basalts of Tabas (East of Iran)
S. M.
Hashemi
Islamic Azad University, Sciences and Researches Branch, Tehran, Iran
author
M.
Emami
Geological Survey of Iran, Tehran, Iran
author
M.
Vossoughi Abedini
Earth Science, Faculty, Shahid Beheshti University, Tehran, Iran
author
M.
Pourmoafi
Earth Science, Faculty, Shahid Beheshti University, Tehran, Iran
author
M.
Ghorbani
Earth Science, Faculty, Shahid Beheshti University, Tehran, Iran
author
text
article
2008
per
In southeastern Tabas there is a 400 square kilometer area of Quaternary basalts, which is geologically located in Lut zone. According to petrographic studies and EMPA analysis, the textures of these rocks are generally porphyric and some times aphyric. The phenocrysts of these basalts are generally chrisolite, augite, and plagioclase (andesine to labradorite), which are embedded in a texture of plagioclase microlites and small blades of pyroxene. According to the diagrams of accumulative amount of alkaline against the amount of SiO2, the nature of the magma is alkaline to sub-alkaline. The reason for the sub-alkaline character of some of these rocks is that the alkaline magma has been contaminated with crust materials. One of the most important reasons for this is the reduction of niobium in rocks enriched with SiO2. The alkaline samples have normative nepheline and the sub-alkaline samples normative quartz. The studies of Nd and Sr isotopes have confirmed the crust contamination and also the source for early magma of basalts is the upper parts of mantle. Based on the field studies and tectono- magmatic diagrams, these basalts are of intercontinental type because of the activities of great fault of Nayband in Quaternary and separation in their cross point reaching the earth's surface.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
26
39
http://www.gsjournal.ir/article_57836_2a077d4d9c5600db97903abb84f788c3.pdf
dx.doi.org/10.22071/gsj.2009.57836
Structural Evolution of the Basement and Activity of Salt Structures in Firuzabad Area, Fars
M.
Pirouz
School of Geology, University College of Science, University of Tehran, Tehran, Iran
author
A.
Bahroudi
Mining Faculty,Tehran University, Tehran, Iran
author
M.R.
Ghasemi
Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran
author
A.
Saeidi
Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran
author
text
article
2008
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The study area is located in Zagros simply folded belt, south of Firuzabad city. We have considered sedimentary basin floor deformation, initial time of folding and salt structure upwelling by using isopach data. Moreover, these data can be used to indicate the expanding development. We have used NIOC isopach data for the Permian to Paleocene and Oligomiocene. If isopach data values are reversed and the 3D patterns calculated, they can show sedimentary basin floor shape. According to the 3D patterns, sedimentary basin evolution pattern, primary time of salt structures movements and basement faults movement in Firouzabad area were obtained. Mengharak basement fault with N-S trend activated with vertical displacement in the Permian and its movement changed left lateral strike slip after Triassic. In addition, extensional structures formed in the east of Mengharak fault continued to middle Cretaceous. At the same time, Neothetys was closed and the extension structures were converted to compression structures and also Mengharak fault movement changed to right lateral strike slip. Activity of salt structures (Jahani and Firuzabad) began in Permian and its activation increased during the Cretaceous in the Mengharak fault zone.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
40
55
http://www.gsjournal.ir/article_57837_328a579f805abe9b96233a4958eb855b.pdf
dx.doi.org/10.22071/gsj.2009.57837
SPT - Based Liquefaction Assessment of Alluvial Foundation atChapar-Abad Dam
G.
Barzegari
Department of Geology, Tarbiat Modarres University, Tehran, Iran.
author
A.
Uromeihy
Department of Geology, Tarbiat Modarres University, Tehran, Iran.
author
text
article
2008
per
Development of liquefaction in saturated cohesionless deposits is one of the most dramatic causes of damage in civil structures during earthquakes. The potential damage caused by liquefaction includes: 1) loss of bearing capacity, 2) excessive settlement, 3) lateral spreading, 4) flow failure, and 5) ground oscillation.
The liquefaction susceptibility of a specific deposit is affected by many factors for example, wave-induced liquefaction characteristics, soil type, geological history, confining pressure, permeability, relative density, water content, and properties of the soil grain size.
Chapar-Abad Dam is an inhomogeneous earth-fill dam with height and crest length of 44.5 and 427 meters, respectively. The reservoir capacity is 127 million cubic meters. The dam which is under construction is located about 75 km southeast of UromiehCity, in West-Azerbaijan province. The foundation materials include 60 meters of alluvium deposits overlying the bedrock layers of carbonate units. The abutments consist of carbonate and schistose layers of Precambrian age. In this paper the potential of liquefaction of the site is evaluated according to the SPT results form in-situ tests performed in boreholes driven into the depth of alluvial deposits. Furthermore, recently modified relations of correction factors such as stress reduction factor (rd), earthquake magnitude scaling factor for cyclic stress ratios (MSF), overburden correction factor for cyclic stress ratios (Ks), and the overburden normalization factor for penetration resistances (CN) are presented and used in liquefaction assessment of alluvial foundation at Chapar-Abad Dam. The results indicate the possibility of liquefaction and instability of granular soils during earthquake and any types of strong motions.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
56
67
http://www.gsjournal.ir/article_57838_8a9b75f1b58b2e50d25952086968fcdb.pdf
dx.doi.org/10.22071/gsj.2009.57838
Evaluation of Reservoir Parameters for Burgan Formation in One of the Iranian Southwest Oil Field
S.
Nezamvafa
School of Geology, University College of Science, Tehran University
author
M.
Rezaee
School of Geology, University College of Science, Tehran University
author
R.
Moussavi-Harami
Department of Geology, Ferdowsi University of Mashhad.
author
M.
Bargrizan
Iranian National Oil Company,Falat Ghare Company.
author
A.
Chehrazi
Iranian National Oil Company,Falat Ghare Company.
author
text
article
2008
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Investigation and detail recognition of hydrocarbon reservoirs can have a good help in management of production wells, and field development. Burgan formation is deltaic sandstone from lower-median Cretaceous that is divided into three zones, A, B, and C. This formation in its type section (Kuwait) makes the second biggest world reservoir, with up to 72 billion barrels of in situ oil. In this study, evaluation of reservoir parameters has been made for this formation. Volume of shale, porosity, permeability, saturation, determination of oil water contact (OWC), net/gross and hydrocarbon column thickness, are the main reservoir parameters, that have been calculated with deterministic and problistic method using different logs and core data of 36 wells.
All of these parameters in problistic method have been calculated by professional petrophysic software, Geolog. Results of calculations show that despite of B zone lower thickness; this zone has a very high reservoir quality than the other two zones. This high quality arises from clean sand and high porosity (intergranualr) and permeability of this zone. Higher thickness of Burgan formation and its reservoir zones in the west of study field, and reservoir high quality in these horizons, show that the original source of clastic sediments is form the Arabian Shield toward Iran.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
68
79
http://www.gsjournal.ir/article_57839_07fbf2d007224c5a1cc49969e4a9f3f0.pdf
dx.doi.org/10.22071/gsj.2009.57839
Determination of P-T Conditions of Metamorphism of Mahneshan Complex NW Iran
A.
Saki
Depatrmant of Geology, Shahid Chamran University, Ahvaz, Iran
Depatrmant of Geology, University of Tabriz, Tabriz, Iran
author
M.
Moazzen
Depatrmant of Geology, University of Tabriz, Tabriz, Iran
author
M.
Modjtahedi
Depatrmant of Geology, University of Tabriz, Tabriz, Iran
author
R.
Oberhänsli
Institut fur Geowissenschaften, Universität of Potsdam, Germany.
author
text
article
2008
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Mahneshan Complex in the northwest of Iran was affected by regional and contact metamorphism. Microstructural and petrographical features as well as field relations show that Mahneshan Metamorphic Complex has been affected by four episodes of metamorphism (M1 to M4) and at least two deformational phases (D1 and D2). The M2 metamorphic stage is characterized by a strong preferential orientation of minerals (S2) and development of a peak metamorphic assemblage. This metamorphismis temporally associated with D2 deformational phase. The M3 metamorphism was contact metamorphism and M4 metamorphism is retrograde. The mineral assemblages of peak metamorphism M2 are muscovite, biotite, garnet, staurolite, andalusite and sillimanite. Pressure and temperature of metamorphism in the Mahneshan Complex were estimated by multiple equilibria calculations, cation exchange reaction thermometry and net transfer reaction in order to determine the geothermal gradients and type of metamorphism. The temperature of M1 metamorphism is estimated 420-450ºC and pressure of 3-4 kbar. M2 (peak metamorphism) temperature is 600-620ºC and pressure of 5-7 kbar. The temperature of M3 metamorphism is 520-560 ºC and pressure of 2.-3.5 kbar. The Geothermal gradients for the peak of metamorphism show high value for the upper crust (33° C/ km) indicating a Barrovian type of metamorphism for the study area. Tectonic setting of metamorphism is related to continental crust and magmatic arc.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
80
93
http://www.gsjournal.ir/article_57848_c2bb5a4043f58837e4ef41399fe4e1a6.pdf
dx.doi.org/10.22071/gsj.2009.57848
Stratigraphy of the Cretaceous Deposits in Haftad Gholleh(East of Arak)
P.
Rezaei rouzbahani
Islamic Azad University, Khorram Abad Branch, Khorram Abad, Iran
author
B.
Hamdi
Research Institute of Earth Sciences,Tehran, Iran
author
text
article
2008
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Cretaceous deposits are outcropped in Haftad Gholleh area, 25 km in the east of Arak city. In this study three stratigraphic sections were measured in the northeast, southeast and center of the area. Based on detailed study of stratigraphy and paleontology, in contrast to some other geologists' opinion, it has been concluded that the Cretaceous deposits in this area can be divided into lower Cretaceous and upper units and distiguished well by their microfauna assemblages. The age of the Upper Cretaceous deposits is Early Cenomanian which conformably overlies the Early Cretaceous deposits. Also the Early Cretaceous succession is divided into basal part (detrial-carbonate) and upper part (carbonate with Urgonian facies). The age of basal part, a barren zone, overlies dark shale and sandstone of Shemshak group with angular unconformity is Early Cretaceous (Neocomian?-Barremian) based on stratigraphic position and microfauna assemblage of the lowermost part of the Cretaceous carbonate sediments.
The upper part of the Early Cretaceous succession based on identified fossil assemblages is devided into four biostratigraphic units and consists of 9 biozones. The age of this part is Albian-Barremian.
The beginning of transgrassive sea can be considered in Neocomian?-Barremian that lasted until Cenomanian. Tectonic occurrence of the Middle Cimmerian leads to considrable angular unconformity in the basal part of the Lower Cretaceous deposits.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
94
107
http://www.gsjournal.ir/article_57850_8cde703f4ff91311715d9f2e4c1427f2.pdf
dx.doi.org/10.22071/gsj.2009.57850
Gold Mineralization in Ductile – Brittle and Brittle Shear Zones, Zartorosht Deposits, Sanandaj-Sirjan Zone,
Southwest of Sabzevaran
Gh. R.
Rastgoo Moghaddam
Department of Geology, Tarbiat Modarres University, Tehran, Iran
author
E.
Rastad
Department of Geology, Tarbiat Modarres University, Tehran, Iran
author
N.
Rashid Nejad Omran
Department of Geology, Tarbiat Modarres University, Tehran, Iran
author
M.
Mohajel
Department of Geology, Tarbiat Modarres University, Tehran, Iran
author
text
article
2008
per
Zartorosht gold deposit is located in southeastern part of the Sanandaj-Sirjan zone. Rock units exposed in the area include mafic to intermediate volcanic series, metamorphosed volcano-sedimentary rocks and meta-basites intruded by basic to felsic dikes. These late Paleozoic units have been metamorphosed under lower to medium green-schist facies. Due to several phases of intense deformation, rock sequence indicates new fabrics. The intensity and types of deformation are not the same in the area, so that rock units illustrate ductile-brittle to brittle shear zones.
Gold mineralization occurs in ductile-brittle and brittle shear zones. In ductile-brittle shear zones, gold mineralization occurs parallel to the foliation with lenticular geometry along the strike and dip of the foliation. Analysis of samples from silicified parts of this zone indicates 0.5 to 7.95 ppm Au. In these zones, deformation fabrics can be observed as primary mylonitization in marginal and middle parts, and brittle fabrics in central parts. Gold mineralization in brittle type shear zones has occurred mainly along N70W to E-W and southern dipping normal faults. This type of mineralization includes gold-bearing veins and siliceous-sulfidic bands and can be followed in a 1.5 km long zone. Au grade in samples from siliceous-sulfidic zone is 17.2 ppm and sometimes it reaches up to 35.7 ppm. Mineralized rock units in shear zones indicate different types of alteration including chloritization, epidotization, sericitization, carbonatization, argilization, silicification and sulfidization. Siliceous-sulfidic alteration corresponds to ore-bearing zones within the shear zones.
Studies suggested temporal and spatial relation between alteration and deformation. Spatial relation is explained by overlapping alteration and deformation zones. Foliation parallel open spaces (generated during ductile deformation and mineralization processes) and also micro-fractures in porphyroclasts (generated during grain cataclastic flow) have been filled with hydrothermal - stage quartz and pyrite indicating temporal correlation of alteration and deformation. Au grade changes have close relation with deformation and alteration intensity. This relation has been distinguished by analysis of samples taken from trenches and tunnels perpendicular or parallel to general foliation of rock units. High gold content is related to intensely deformed (mylonitic and ultracataclasite) siliceous and sulfidic parts and Au-bearing siliceous-sulfidic parts coinciding with the inner parts of alteration zones.
Ore-mineral assemblages in the area are relatively simple including pyrite, arsenian-pyrite, rarely galena and sphalerite. Based on microscopic studies, Au occurs as free grains and electrum. Also electron-microprobe and electron-microscope analysis indicate that at least some of Au grains are in sulfide minerals lattice. According to these studies, gold has been observed with both pyrite and arsenian-pyrite phases. Ag has also been detected in sulfide minerals lattice and siliceous gangue.
Controlling parameters for mineral concentration in Zartorosht deposit are shear zones (ductile-brittle and brittle) and alteration (silicification and sulfidization). Based on the comparison of Zartorosht main characteristics with orogenic gold deposits, Zartorosht has the most similarities with orogenic gold mineralization; therefore, it is considered to be of this type.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
108
129
http://www.gsjournal.ir/article_57851_5f1634ad15f949b6a3e2b3bb2a74a098.pdf
dx.doi.org/10.22071/gsj.2009.57851
Petrography, Geochemistry, and Petrogenesis of Lava Flows and Dykes in Abaregh Area (Kerman Province)
A.
Zahedi
Shahid Bahonar university of Kerman, Kerman, Iran
author
H.
Ahmadipour
Shahid Bahonar university of Kerman, Kerman, Iran
author
text
article
2008
per
The Abaregh area is located in 40 km northwest of Bam city in Kerman province. Rock units of the region consist of lava flows and dikes that crop out along a fault system trending NS. Mineralogically, the rocks contain plagioclase, augite, hypresthen, and minor olivine. Heterogenous mineralogy, field and textural evidences such as sieve texture in plagioclase, resorption rims in crystals, oscillatory zoning in plagioclase, high normative quartz and rounded enclaves suggest that the primary magma undergone magmatic evolution including fractionation, contamination, and magma mixing during ascending. The Y/Rb ratio and AFC (assimilation and fractionational crystalization) petrogenetic models confirm the occurrence of evolution in primary magma. Concentration of elements such as K, Pb, P, Zr, Sr, Ba, Rb shows that these rocks belong to the calcalkaline series. Similarity between the andesitic lava and dykes shows a considerable similarity with the calcakaline andesite from Turkey and from this point of view; these rocks belong to the post - collisional arcs. In this tectonic setting, magma ascent is controlled by strike - slip faulting and associated pull- apart extensional tectonics. This post - collisional magmatism may have been occurred due to the Arabian- Iranian collision events.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
130
139
http://www.gsjournal.ir/article_57852_1da126bdf75691974ad2b5b78410d76b.pdf
dx.doi.org/10.22071/gsj.2009.57852
Source and Tectonic Setting of Zarjebostan (NE of Qazvin) Paleogene Volcanic Rocks using REE and HFSE Elements
K.
Kalantari
School of Geology, College of Sciences, University of Tehran, Tehran, Iran
author
A.
Kananian
School of Geology, College of Sciences, University of Tehran, Tehran, Iran
author
A.
Asiabanha
Department of Geology, Faculty of Sciences, Imam Khomeini International University, Qazvin, Iran
author
M.
Eliassi
School of Geology, College of Sciences, University of Tehran, Tehran, Iran
author
text
article
2008
per
Paleogene basic to intermediate lava flows of Central Alborz, in the northeast of Qazvin city (Zarjebostan), include trachy-andesite, basaltic trachy-andesite and basaltic andesite. These volcanic rocks are high-K calc-alkaline rocks. Based on the 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 has little effect on the concentration of Zr, Ta, Hf, Sm, Tb, Nd, Eu and Y elements, while it has strong influence on concentration of Th, U and La elements. Due to high Ba/La, Ba/Ta and La/Ta ratios and low TiO2 content of lavas, they could be attributed to magmatic arc setting. Th/Yb vs. Ta/Yb diagrams and association of study suite with extensive volume of acidic tuffs, indicate that these rocks have been formed in an active continental margin.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
140
149
http://www.gsjournal.ir/article_57853_551fb603379e9a4d2c6ab62d1046f289.pdf
dx.doi.org/10.22071/gsj.2009.57853
History of Tsunami Occurrences and Assessment of Tsunami Generation Potential of Makran Subduction Zone
M.
Heidarzadeh
Civil Engineering, College of Engineering, University of Tehran
author
M.
Dolatshahi Pirooz
Civil Engineering, College of Engineering, University of Tehran
author
N.
Zaker
Environmental Engineering, University of Tehran
author
M.
Mokhtari
International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, Iran
author
text
article
2008
per
This research attempts to assess the history of tsunami occurrences and potential for tsunami generation at the southern coasts of Iran bordering the Indian Ocean by providing a list of historical tsunamis in this region and also, modeling of phases of tsunami generation and propagation. After the December 2004 mega-tsunami in the Indian Ocean, wide efforts were devoted to assess hazard of tsunami, and to develop tsunami warning and mitigation systems in the region. To assess the hazard of tsunami in any particular region, the compilation of historical records of tsunami is always the first primary task. Such a list may lead to useful information about the return period of tsunami events, and most vulnerable coastlines to the impact of possible tsunami. Regarding this fact, in the framework of this study, the first list of Makran historical tsunamis is provided. The Makran zone is located offshore Iran and Pakistan and any tsunami in this region would affect coastlines of Iran, Pakistan, Oman, and India. The last major tsunami in this region was produced following the occurrence of an 8.1 magnitude earthquake which took the lives of at least 4000 people all over the Makran coasts. Also, in this research, the potential for tsunami generation in the Makran subduction zone is quantitatively estimated through modeling of tsunami generation phase. In this regard, based on Mansinha and Smylie (1971) formulas a computer program has been developed to predict the ocean floor deformation due to the occurrence of underwater earthquakes in subduction zones. After the verification of model results, it has been employed to predict possible ocean floor deformation after the occurrence of underwater earthquake in the Makran subduction zone. Tsunami generation analysis shows that the risk of tsunami generation from Makran subduction zone can be classified into three main categories, as follows: (1) very little risk for tsunami generation in the case of occurrence of an earthquake having magnitude up to 7; (2) little to medium risk (Magnitude ranging 7 to 7.5); and (3) high risk (Magnitude greater than 7.5). In the next section of the paper, the tsunami propagation in the Makran zone was modeled. The results of tsunami propagation indicate that in the case of tsunami production in this region, the first tsunami waves will hit the nearest shoreline within 15 to 20 minutes. Finally, considering tsunami hazard assessment performed in this paper, the necessity for the development of a tsunami warning system in southern coasts of Iran was emphasized and its components and orderly sequences of tasks are proposed.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
150
169
http://www.gsjournal.ir/article_57854_19de746296f33244ee80ecf5e6eef1b3.pdf
dx.doi.org/10.22071/gsj.2009.57854
Mineral Potential Mapping of Copper Minerals Using Geographical Information System (GIS)
M.
Karimi
Faculty of Geodesy & Geomatics Engineering, K. N. Toosi University of Technology (KNTU), Tehran, Iran.
author
M.J.
Valadan Zoej
Faculty of Geodesy & Geomatics Engineering, K. N. Toosi University of Technology (KNTU), Tehran, Iran.
author
H.
Ebadi
Faculty of Geodesy & Geomatics Engineering, K. N. Toosi University of Technology (KNTU), Tehran, Iran.
author
N.
Saheb Zamani
National Iranian Copper Industries Company
author
text
article
2008
per
Considering the vast area of Iran and extent of her potential mineral reserves (existence of volcanic belt of Urumieh-Dokhtar), a systematic view for mineral deposit exploration and mineral potential mapping is essential. Lack of a systematic view and appropriate models for collecting, managing and integrating various geo-spatial data from different sources based on various formats make it difficult to identify, evaluate and proioritize mineral potentials.
Since most of the data related to mineral deposit exploration activities are geo-spatial, Geographical Information System (GIS) can describe and analyze interactions, make predictions with models, and provide support for decision-makers. Mineral potential mappig composes of different steps including: identifying mineralization recognition criteria, data perparation and structuring, producing factor maps and integrating factor maps in the appropriate inference networks. In this research conventional models for integrating factor maps have been investigated. Index overlay and fuzzy logic models are selected to be appropriate models for mineral deposit exploration in semi-detailed (regional study) and detailed stages. An integrated model was also proposed based on Boolean, index overlay and fuzzy logic models . For experimental test, the mineral potential map of Rigan Bam copper deposit with appropriate methods in different inference networks have been produced and 3 appropriate inference networks (one network by Fuzzy Logic model and two networks by integrated models) were selected. Results of three selected networks are in a good accordance with drilling results (%75). Proposed model in Rigan Bam copper deposit capability with required variation can be used for other mineral potential areas and site selection of drilling wells.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
170
181
http://www.gsjournal.ir/article_57891_054d147ac7dfded3a0f27673a0c0e685.pdf
dx.doi.org/10.22071/gsj.2009.57891
Active Faulting and Segmentation along Qom-Zefreh Fault System between Zerfreh and The North of Kashan, Central Iran
F.
Jamali
International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, Iran
author
K.
Hessami Azar
International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, Iran
author
M.
Ghorashi
Geological Survey of Iran (GSI) & Islamic Azad University- North Tehran
author
text
article
2008
per
The N-NW trending Qom-Zefreh fault system has long been recognized as one of the major faults in Central Iran. We have used observations of faulting, recognized on satellite images and aerial photos, in conjunction with field investigations, to infer fault activity along this structure in an area between Zefreh and the north of Kashan. Right-lateral strike-slip motion along this fault can be inferred from the associated lateral offset of stream beds and alluvial fan observed on aerial photographs and on the field. Morphological features and observations of fault exposure in several places also indicate that the western block is up-thrown relative to the eastern block across reverse component of the Qom-Zefreh fault system. Using changes in fault geomorphology and fault trace orientation we have defined two segment boundaries and structurally divided the Qom-Zefreh fault system into three segments in the region, namely Zefreh, Kashan and Ravand segments. The recognition of these segments is important because it may have implication in assessment of seismic hazard for the Kashan region.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
182
189
http://www.gsjournal.ir/article_57892_38783b29aeed37455046afe5fc1e4b8a.pdf
dx.doi.org/10.22071/gsj.2009.57892
Biostratigraphic Study of Mila Formation in Shahmirzad Section, North of Semnan with Special Reference to Conodonts
L.
Fazli
Islamic Azad University, Damavand Branch, Tehran, Iran
author
B.
Hamdi
Islamic Azad University of North Tehran, Tehran. Iran
author
text
article
2008
per
The Mila formation from late Early Cambrain to Early Ordovician age is well exposed in the Shahmirzad section consists of 5 lithological members. Several biozones of conodonts have been identified in this section, several taxa of body and trace fossils have been collected from members 2 – 5 of this section.
Member 1, consisting of stromotolitic dolomite, indicates at least one paleosol in the middle part. The second lithological member which includes several beds of salt peseudomorphs does not indicate any condont, while trilobites as well as trace fossils such as Rusophycus sp. and Cruziana sp. have been found frequently. These trace fossils, characteristic of cruziana ichnofacies, occur only in shallow marine environments. Eocrinoids debris and epirelief of the root of this fossil strongly supports this fact. In addition, presence of storm beds and oriented deposition of Hyolithids indicate high degree of water agitation in environment of deposition. Biozones of Conodont have been identified from members 3-5.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
17
v.
68
no.
2008
190
195
http://www.gsjournal.ir/article_57894_5250346e8300bb13197996be87cc57b2.pdf
dx.doi.org/10.22071/gsj.2009.57894