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2019
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Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
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http://www.gsjournal.ir/article_88513_d41d8cd98f00b204e9800998ecf8427e.pdf
reviewer
text
article
2019
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Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
2
2
http://www.gsjournal.ir/article_88514_d41d8cd98f00b204e9800998ecf8427e.pdf
Petrography, mineral chemistry and origin of lamprophyric dykes from Sareashk Village, South West of Ravar- Kerman
A.
Bahrampour
Phd. Student, Department of Geology, Faculty of Sciences, University of Hormozgan, Bandarabas, Iran
author
Gh.
Ghadami
Assistant Professor, Department of Geology, Faculty of Sciences, University of Hormozgan, Bandarabas, Iran
author
H.
Atapour
Assistant Professor, Department of Mining Engineering, University of Shahid Bahonar, Kerman, Iran
author
M.
Poosti
Assistant Professor, Department of Geology, Faculty of Sciences, University of Hormozgan, Bandarabas, Iran
author
H.
Ahmadipour
Associate Professor, Department of Geology, University of Shahid Bahonar, Kerman, Iran
author
text
article
2019
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At 60km north-east of Kerman city,near Sarashk village (Ravar, Kerman province) and along the Kuhbanan fault, several lamprophyric dikes have been intruded into Carboniferous to Cretaceous sedimentary formations. Petrographically these lamprophyres could be classified into two groups: comptonites and sanaite. Olivine, clinopyroxene, plagioclase and potassium feldspar are the main minerals in all two groups. Mineral chemistry shows that olivines, clinopyroxenes and amphiboles are of chrysolite (Fo = 72.35-79.85)), augite (Wo = 44.3-50.2, En= 37.06-44.4, Fs = 9.24-14.6), and kaersutite (Ca+Na = 2), (Na+K = 0.59-0.95), (Mg/(Mg+Fe2) = 0.63-0.76) composition, respecrively. Geobarometric and geothermometric estimations along with the tectonomagmatic diagrams for clinopyroxenes show that the parental magmas werealkaline in which the clinopyroxenes crystallized at pressure of 11-15 Kbar and temperature of 1150-1300 ◦C.Whole rock chemical analyses of these rocks show that the parental alkaline magma was originated from a metasomatized lithospheric garnet- spinel- lherzolite mantle source and emplaced in a post-collisional environment.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
3
16
http://www.gsjournal.ir/article_88131_b4802f3d65fb147ace8d1b83a1509c08.pdf
dx.doi.org/10.22071/gsj.2019.88131
Thermometry and Origin of Mineralizing Fluid at Barika Gold Deposit, East of Sardasht
H
Tajeddin
Assistant Professor, Department of Economic Geology, Faculty of Basic Science, Tarbiat Modares University, Tehran, Iran
author
Ebrahim
Rastad
Department of Economic Geology, Tarbiat Modares University, Tehran
author
Abdolmajid
Yaghoubpour
Department of Geology, Kharazmi University, Tehran
author
Mohammad
Mohajjel
Department of Economic Geology, Tarbiat Modares University, Tehran
author
Richard
Goldfarb
U.S. Geological Survey, Denver Federal Center, Denver, Colorado
author
text
article
2019
per
Barika gold (and silver)-rich volcanogenic massive sulfide deposit is located 18 km east of Sardasht city in the northwestern of Sanandaj–Sirjan metamorphic Zone. The rocks in the vicinity of the Barika deposit predominantly consist of Cretaceous volcanosedimentary sequences of phyllite, slate, andesite and tuffite, metamorphosed under greenschist facies grade. Barika deposit is composed of stratiform ore and stringer zone that both are hosted in an altered and sheared metaandesite unit. Fluid inclusion studies indicated that quartz (stringer zone) and barite (stratiform ore) samples homogenized between 132° and 283°C. Salinities of the fluids inclusions show a range from 1.4 to 9.6% wt NaCl equivalent that are close to that of normal seawater. The study indicates the colling occurred in the initial ore fluids, as a result of mixing with sea water, is an important process in the formation of Barika deposit. The δ34S values of sulfide minerals (pyrite, sphalerite and galena) from stockwork mineralization in the Barika deposit range from -0.8 to +5.6 per mil and fall within the range of values observed for volcanogenic massive sulfide deposits. The narrow range of measured δ34S values from the sulfide minerals suggests that similar to almost of Kuroko VMS deposits, the ore-forming sulfur derived from the leaching of igneous sulfur from the underlying andesitic rocks. Calculated sulfur isotope temperatures for twelve coexisting galena-sphalerite and galena-pyrite pairs range from 146-293 ْ C that is consistent with temperatures estimated from fluid inclusion studies.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
17
28
http://www.gsjournal.ir/article_88024_584a6729ee8228c0921fa57e6806a92e.pdf
dx.doi.org/10.22071/gsj.2017.77436.1029
Geometric analysis and folding mechanism
ahmad
lashgari
دانشجوی دکتری
author
magmodreza
Hayhat
- Associate Professor Department of Earth Sciences, Birjand University
author
mohammd mahdi
khatib
- Professor, Department of Earth Sciences, Birjand University, Birjand
author
Mahdi
Najafi
هیات علمی
author
Jaume
Verges
Institute of Earth Sciences Jaume Almera (ICTJA), CSIC
Barcelona, Spain
author
text
article
2019
per
Determining the geometry and folding mechanism in Dezful embayment in the southwest of Iran due to the inclusion of a large amount of Iran's hydrocarbon reserves, also its role in the process of structural evolution of Zagros fold- belt, is important. In present study, structural evolution of Jarik anticline in the northwest of Dezful embayment have been studied based on 3D seismic data, drilling data that has been provided National Iranian Oil Company remote sensing, and the field observations. According to the provided structural cross sections, geometric variations of Jarik anticline across and along the anticline axis, has been investigated. Gachsaran formation as an upper detachment horizon, causes geometric and structural changes along the anticline axis. It seems that, in the nose of anticline, occurred the detachment folding mechanism associated with concentric geometry. And in the middle section of the anticline,that folding process is more advanced, faulted detachment folding mechanism has acted.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
29
42
http://www.gsjournal.ir/article_88033_db602fe8eb5bfaf545976b658595287a.pdf
dx.doi.org/10.22071/gsj.2017.93015.1200
Crustal velocity structure and Moho discontinuity depth beneath center of Iran
Afsaneh
Nasrabadi
Assistant professor /Graduate University of Advanced Technology
author
Fateme
Azimi
M.Sc. in Seismology/ Graduate University of Advanced Technology
author
MohammadReza
Sepahvand
Graduate University of Advanced Technology
author
text
article
2019
per
Crustal velocity structure and Moho discontinuity depth have investigated beneath 7 the broadband seismic stations, AFRZ, TKDS, TPRV, TNSJ, ANAR, KRSH of the Iranian Seismological Center (ISC) and YZKH of Iranian National Seismic Network (INSN) located in the center of Iran by joint inversion of receiver functions and Rayleigh waves group velocity dispersion. Three years (2012 to 2014) teleseismic waveforms (with epicentral distance 25o-90o) for computation receiver functions by iterative approach in time domain have been processed. The Rayleigh waves group velocity dispersion curves were incorporated into our joint inversion scheme from an independent surface wave tomography study. Receiver function is response of local structure of ground (located beneath the three–component broadband seismic station) to teleseismic P-wave, that is sensitive to seismic discontinuities. Since there is very little absolute-velocity information contained in the receiver function, its inversion for shear-wave velocity structure is non-unique (velocity-depth trade-off). On the other hand, dispersion curves are sensitive to the average velocity structure of the upper layers rather than to seismic discontinuities. So the non-uniqueness problem can be solved by combining receiver function inversion with surface-wave dispersion. Results from joint inversion in center of Iran indicates that Moho discontinuity depth depth beneath AFRZ, TKDS and TPRV stations is 40 Km, beneath TKDS 42 Km, beneath ANAR is 38 Km and beneath KRSH and YZKH stations are 44 Km. It was shown that the joint inversion method can cause ±2 kilometers of error. The average Moho depth is about 42±2 kilometers beneath center of Iran.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
43
52
http://www.gsjournal.ir/article_88030_f1f6b9c2bf895581626937e3b2229874.pdf
dx.doi.org/10.22071/gsj.2017.87615.1128
Paleostress Reconstruction of Mesozoic deposits In Interior Fars Area( E-SE of Shiraz)
Tahmoores
Yousefi
Department of Geology, Shiraz branch, Islamic Azad University, Shiraz, Iran
author
Kooros
Yazdjerdi
Department of Geology, Shiraz branch, Islamic Azad University, Shiraz, Iran
author
2Manouchehr
Ghorash
2Earth Sciences Research Institute, Geological Survey of Iran,Tehran, Iran
author
Alireza
Shahidi
3Geological Survey of Iran, Tehran, Iran
author
text
article
2019
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Abstract: The brittle tectonic history expresses different tectonic events in the Zagros Simply Folded Belt. Consequence of Mesozoic extension, rifting and the shortening derived from the Cenozoic Eurasia – Arabia collision. In order to reconstruction the ancient tensions in the Mesozoic deposits in the east and south-east of Shiraz, geometry and kinematics of the faults data simultaneously with sedimentation was investigated using the inversion method, to evaluated rifting time, the former of Neo-Tethys and its collisions in Cretaceous and Paleocene. In this regard 21 stations have been exposed in Khanekat to Pabdeh Formations. The resulted geometry and kinematics of the faults data were calculated situation main tension axes (σ1, σ2, σ3 ), tension ellipsoid figure or ratio of difference (ɸ). The results are as follows: from Triassic to upper Cretaceous (Mastrichtian) in Khanekat,Surmeh, Fahlian, Darian, Sarvak, Ilam, Gurpi, Tarbur Formations and Ghorban Member; extensional tectonic regime was dominant and having NE-SW direction (N052°) but in Pabdeh Formation with Paleocene age, tectonic regime has changed into compression with NE-SW compressional stress direction(N045°). So it was concluded that in simply folded Zagros of interior Fars, time of rifting and the forming of Neo-Tethyan basin was Triassic or older (Permian) with NE-SW extensional direction. The beginning of compressional tectonic regime with the same direction has been in Paleocene.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
53
64
http://www.gsjournal.ir/article_68652_f2daaa841abe134a283e41ac77c50087.pdf
dx.doi.org/10.22071/gsj.2017.97004.1245
Calcareous nannofossil biostratigraphy of Valanginian ‒ Hauterivian sediments at the lower part of the Garau Formation, Arkavaz section (Kabir-Kuh anticline, SE Ilam)
Katayoon
Barmakizadeh
Department of Geology, Faculty of Science, Shahid Bahonar University of Kerman, Kerman, Iran
author
A.
Mahanipour
Assistant Professor, Department of Geology, Faculty of Science, Shahid Bahonar University of Kerman, Kerman, Iran
author
text
article
2019
per
Abstract The lower part of the Garau Formation with a thickness of 212 m at the southwest of the Kabirkuh anticline is investigated with regard to the calcareous nannofossils. Lithology of the studied interval is mainly consists of marl, marly limestone, black shale and limestone. 67 species from 33 genus and 13 families are recognized. Nannofossil events that are recorded from base to top of the section are as follow: the first occurrence (FO) of Calcicalathina oblongata, the last occurrence (LO) of Rucinolithus wisei, the FO of Lithraphidites bollii, the LO of Cruciellipsis cuvillieri, the first occurrence of Assipetra terebrodentarius and the last occurrence of Lithraphidites bollii. According to these index calcareous nannofossils, the studied interval is ranging from the uppermost part of CC2/NK2 biozone to the middle part of CC5b/NC5C subzone Considering these zonations, the age of the studied interval is Valanginian ‒ Hauterivian. According to the calcareous nannofossil data, the Valanginian ‒ Hauterivian boundary can’t be determined. This boundary is located at the base of the Tethyan ammonite Acanthodiscus radiatus at the leading GSSP candidate in the La Charce section of southeastern France.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
65
74
http://www.gsjournal.ir/article_88035_9be64d7b0a43d1573846c0d538813cfc.pdf
dx.doi.org/10.22071/gsj.2018.96207.1239
Application of multifractal methods in stream sediment sampling to identifying Cu and Mo anomalies in Varzaghan 1:100,000 Sheet
Meysam
Nikfarjam
Exploration Of Mining Engineering, Mining and Metallurgy engineering faculty, AmirKabir University of Technology, Tehran, Iran
author
Ardeshir
Hezarkhani
Mining Exploration, Department of Mining and Metallurgy, Amirkabir University of Technology, Tehran, Iran.
author
Kaveh
Pazand
Young Researchers and elites Club, Science and Research branch, Islamic Azad University, Tehran, Iran.
author
text
article
2019
per
The study area (Varzaghan 1:100,000 Sheet) is located in eastern Azarbaijan province and Ahar-Arasbaran metallogenic zone. The magmatism in this area is happened widespreadly that leads to several important deposits like Sungun world class deposit. According to the importance of this region from Cu-Mo porphyry deposits, we used structural methods like multifractal method to determinate Cu and Mo geochemical anomalies as indicator minerals of Cu-Mo porphyry deposits. In this paper two multifractal method like C-A (Concentration-Area) and N-S (Number-Size) method were used in order to separation geochemical anomalies from background and select the optimum method. In this way, first of all, we draw catchment basins for every stream sedimentary samples by using DEM and PFS (Priority-First-Search) algorithm. After drawing the catchment basins for each sample, concentrations of samples were assigned to their upstreams. In C-A method with plotting cumulative area of each sample catchment basin versus concentration content, 4 number society of each Cu and Mo elements identified. Also in N-S method, cumulative frequency of concentrations versus concentrations plotted. In this method in comparison to C-A method, 5 number society of Mo and 4 number society detected. In both performed methods can see good conformity of anomalous locations with well known deposits like Sungun worldclass deposit but N-S method has better efficiency by using logratio matrix. Also we can see the effect of lithology in anomalous places. Finally some of theses places addition to indications detected. So they require detailed exploration in future.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
75
82
http://www.gsjournal.ir/article_88031_fa80b9d92e23c3c84d4d22a5755ffe16.pdf
dx.doi.org/10.22071/gsj.2018.88813.1143
Seismicity and earthquake hazard assessment in North of Kerman
[By Kijko & Sllevoll (1992) method]
Amir
Shafiei bafti
Geology department, Islamic azad university. Zarand. Iran
author
text
article
2019
per
. Kouhbanan fault system in south of central Iran is one of the most active and seismic faults, has length of nearly 200km and seismic history from B.C to the present. Epicenter of seismic activities for this fault situated often near fault zone or on the Kouhbanan fault zone branches and other attached faults. Identify of ruptured and non-ruptured segments can clear the way to finding the areas that have the potential for creating earthquake. Field observation and library data were used for this purpose. According to the spatiotemporal distribution of historical and instrumental earthquakes, may be concluded, the most earthquakes are located where the fault branches or in its bend locations. Earthquake occurred in studied region, often known with absence of high magnitude earthquakes (M≥ 6.5). Interesting point is that in the period of about 160 years ago (Earthquake record time span) along of active faults, especially Kouhbanan fault zone, an area that is less a re-ruptured or be consecutive or earthquake epicenters are few. For earthquake risk assessment, we use Kijko& Sllevoll (1992) method, which show that the earthquake risk and seismicity rate is higher from other regions and earthquake have higher magnitude and less recurrence time. According to the obtained results, for earthquakes (M≥ 7) results should be used with caution.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
83
94
http://www.gsjournal.ir/article_88028_b03981f77b85ec8d04f324a3be6c1cd3.pdf
dx.doi.org/10.22071/gsj.2018.84623.1103
Investigation on the physical and chemical conditions of the formation of hexagonal colored quartz crystals in Qohrud area based on petrographic evidence and fluid and solid inclusion studies
M. R.
Rezapour
M.Sc. of geochemistry, Department of Earth Sciences, University of Tabriz, Tabriz, Iran
author
V.
Simmonds
Associate Professor, Research Institute for Fundamental Sciences, University of Tabriz, Tabriz, Iran
author
M.
Moazzen
Professor, Department of Earth Sciences, University of Tabriz, Tabriz, Iran
author
R.
Hajialioghli
Associate Professor, Department of Earth Sciences, University of Tabriz, Tabriz, Iran
author
text
article
2019
per
The Qohrud granitoid body of Miocene age is located 40 km SW Kashan, ranging in composition from granite through granodiorite to tonalite. Hydrothermal activities following the magma intrusion have brought about formation of various coarse automorphic and colored quartz crystals within the fractures and cavities of different lithologies. The quartz crystal varieties include transparent, semi-transparent, pale green, yellow and black crystals, as well as those with smoky and reddish brown roots and also crystals containing tiny acicular rutile inclusions. Mineral chemistry, as well as fluid and solid inclusion studies on the colored and automorphic quartz crystals indicate that various physical and chemical factors, such as temperature, pressure, magma and host rock compositions, hydrothermal fluids and the associated alterations, as well as pH and Eh were involved in the formation of these automorphic colored crystals. The solid inclusions within these automorphic quartz crystals might have formed in two ways: 1) introduction of the necessary elements for the formation of quartz and the solid inclusions by the fluids and then, entrapment of these inclusions within the growth layers of quartz crystals; 2) direct introduction of very fine mineral particles within the growth layers of quartz, leading to occurrence of various colored crystals. Smoky crystals can be formed by the replacement of Si by Al and also by the presence of U and Th within them. The reddish color of quartz crystals was recognized as the result of the presence of fine rutile needles. Automorphic black-colored quartz crystals are formed at oxidant and almost high pH conditions by initial precipitation of magnetite and then, manganese oxides at the outermost growth layers. The green quartz crystals have been resulted from chloritic and epidotic alterations within the host and neighboring rocks.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
95
104
http://www.gsjournal.ir/article_88144_3d3d9043bcea5504a8012a08c6917e4f.pdf
dx.doi.org/10.22071/gsj.2019.88144
Provenance of Dorud Formation Sandstones Based on Petrography and Geochemical Data, Khur Section, Central Alborz
Leili
Bastami
Shahid Beheshti University - Faculty of Earth Sciences
author
Reza
Moussavi
Department of Geology, Faculty of Earth Sciences, Shahid Beheshti University
author
Mahboobeh
Hosseini-Barzi
Associate Professor/Department of Geology, Faculty of Earth Sciences, Shahid Beheshti University
author
Bahaedin Hamdi
Hamdi
سازمان زمین شناسی و اکتشافات معدنی- پژوهشکده علوم زمین
author
text
article
2019
per
The sandstones of the Dorud Formation (Early Permian) have been subjected to petrographic and geochemical studies in order to investigate provenance, tectonic setting, source rock and paleoclimate conditions in Khur section, Central Alborz. The Dorud Formation with a thickness of 360 m is mainly composed of fine to medium grained sandstones with lesser amounts of carbonate and mudstone. In order to achieve the above-mentioned goals, 125 thin sections were subjected to petrographic studies. Modal analysis was performed on 20 thin sections and 13 samples of sandstones were analysed for major and trace elements. Based on petrographic studies the sandstones of the Dorud Formation are classified as quartzarenite with high textural and mineralogical maturity. Plotting point counting data on (Qt99.6, F0.2, L0.2( and (Qm95.9, F0.2, Lt3.9) triangles implies craton interior provenance. Also, major and trace elements based geochemical diagrams indicate that these sandstones deposited in a passive continental margin tectonic setting. According to petrographic and geochemical evidence the sandstones of the Dorud Formation derived from erosion of middle- to high-grade metamorphic, felsic igneous and quartoze sedimentary rocks. High mineralogical maturity, high values of chemical index of weathering (CIW) and chemical index of alteration (CIA) as well as SiO2 (%) versus Al2O3 + K2O + Na2O (%) diagram imply moderate to intense weathering under warm and humid climatic conditions. Passive continental margin tectonic setting and warm and humid paleoclimatic conditions is consistent with paleogeographic position of Iran during the Early Permian.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
105
120
http://www.gsjournal.ir/article_79561_c42d60311b8d54356c0c15e9f13f6661.pdf
dx.doi.org/10.22071/gsj.2018.90614.1174
Geochemical- Heavy Mineral Exploration and Determination of Promissing Ore-bearing Areas in the Qare-Naz 1:50,000 Sheet, Zanjan Province
M.
Badfar
M.Sc. Student, Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran
author
M. R.
Jannessary
Ph.D., Exploration Department, Geological Survey of Iran, Tehran, Iran
author
R.
Hosseinzadeh
M.Sc., Regional Exploration Group, Geological Survey of Iran, Tehran, Iran
author
M.
Ghaderi
Associate Professor, Department of Economic Geology, Tarbiat Modares University, Tehran, Iran
author
text
article
2019
per
This study is an investigation on geochemical exploration and economic geology of Qare-Naz 1:50,000 sheet, western Zanjan province. The scope of the study is to presentation of mineral pomissing area in a regional scale. For this reason, geochemical sampling was initially performed. The samples were analyzed by emission spectrometry, polarography and ICP methods. Then the results were processed using statistical methods. Anomaly samples were separated by method. In the control phase, the geochemical anomalies were studied using heavy mineral and economic geology studies viewpoint (field observation, study of polish and thin sections prepared from the mineralized zone as well as the analytical results for samples obtained from these zones). Combination of these results with geochemical anomalies the mineral promissing areas were defined, As follows: A) North – Northeast area has elements anomalies Au, Pb, Zn, Cu. B) Northwest area has elements anomalies Cu, Au, Fe, Mo, Bi and W. C) South – Southwest area has elements anomalies Cu, Pb, Zn, Mo, Mn and S.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
121
132
http://www.gsjournal.ir/article_88157_ee2010ec039f7b075e5a923163cd435c.pdf
dx.doi.org/10.22071/gsj.2019.88157
An assessment of the relationship between the Darang fault and the Kazerun- Burazjan fault system and their fractures pattern
Marziyeh
Khalili
Department of Earth Sciences, College of Sciences, Shiraz University, Shiraz, Iran
author
Maryam
Ezadi
Department of Earth Sciences, College of Sciences, Shiraz University, Shiraz, Iran
author
text
article
2019
per
The Kazerun-Burazjan fault is an active strike slip fault with an N-S trending located in the Zagros belt whose performance causes bends and stretches in the folds axis. The obtained results from the seismic profiles of the southern parts of Fars province suggest that there is no evidence as to the continuation of Burazjan fault segment along the Mand Mountain to Persian Gulf as the end part of the Kazerun fault. Studies show that the performance of the faults such as the Mountain Front Fault (MFF) and the rotation of the blocks adjacent to the strike-slip faults caused the Burazjan fault to slip under the Khormuj and Khartang anticlines and the Bangestan Group located in the Khormuj and Siah anticlines to be placed beside the Aghajari formation in the Kaki anticline. The orientation of the long axis of the Khormuj and Namak (Jashak) salt domes with N-S trends can be considered as the activity of the segments of the Burazjan fault system. Surface and subsurface studies have introduced the Darang fault with an N-S trend and strike slip mechanism as the southern terminus of the Kazerun- Burazjan fault system which extends from the Khartng anticline to the Persian Gulf. The fractures result from the fault system performance consists of a series of transverse-shear fractures with NNE-SSW and NW-SE trends with a visible distribution around the folds axis.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
133
138
http://www.gsjournal.ir/article_88029_d7ab10a3e4140a8a893556b83e5bce47.pdf
dx.doi.org/10.22071/gsj.2017.87001.1157
assessment land susceptibility to gully erosion using ensemble data-mining
Techniques (Case study: Shahroud Basin)
alireza
arabameri
TMU
author
khalil
rezaei
geology department
author
mojtaba
yamani
geomorphology department, tehran university
author
text
article
2019
per
at first, a gully erosion inventory map was prepared using extensive field surveys and interpretation of aerial photographs, of which 172 gully erosion, 70% (121 gully) are used for modeling and 30% (51 gully) are used for validation purposes. In the next step, for the selection of parameters, after their initial identification, the multicollinearity analysis test was performed using coefficients of tolerance and variance inflation factor and the parameters with multicollinearity were deleted due to the reduced accuracy of the modeling, , Finally, 12 parameters were selected for modeling. The results of determining the significance of the criteria by entropy index method showed that elevation, lithology and NDVI parameters had the greatest effect on the occurrence of gully. In order to validate the model, the prediction rate and success rate as well as the SCAI index were used. The validation results showed that the combined model with a prediction rate of 956.0 (95.6%) and a success rate of 92.33 (92.3%) had excellent predictive accuracy and compared with the entropy index and evidential belief function with prediction rates of 0.932 and 0.917, and the success rates of 0.911 and 0.901, have higher accuracy. According to the results of the SCAI, class differentiation was appropriate in the combined model. According to the results, 28.95 percentage of the study area is located in high and very high susceptibility classes. The results of this research can be used by landuse planners to expansion development activities.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
139
150
http://www.gsjournal.ir/article_88037_57918e321a417d37f81b678a0e8378af.pdf
dx.doi.org/10.22071/gsj.2018.114756.1374
Applying fractal models to delineation of rock quality designation
in the Zarshuran gold deposit, Takab, Iran
Ghodratollah
Rostami Paydar
Department of Geology, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
author
Hani
Asadi Hoveizian
Department of Geology, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
author
text
article
2019
per
Determination of relationship between rock mass properties concerning to rock qualification design (RQD) has an important role in mine planning and designation. The aim of this study is separation of rock mass properties to designing the mine planning based on the 3267 RQD data analysis of 43 drill-core within Zarshuran gold deposit in Orumieh- Dukhtar assemblage zone applying RQD-Number and RQD-Volume fractal modeling. The results of log-log plots for RQD-N model revealed four rock populations that divided by RQD thresholds 20.41, 47.86, 69.18 and 81.28. The results of log-log plots for RQD-V model release four populations divided by RQD thresholds 21.37, 43.65, 63.09, 79.43 respectively which represent very poor, poor, fair and good rocks based on Deere and Miller rock classification. In other hand the lithological units modeled based on the drill-core data to obtain the spatial distribution of Zarshuran deposit. The results of RQD-N and RQD-V fractal modeling versus lithological units modeling results revealed that Chaldagh limestone unit and Jaspiroid unit shows fair and good quality with RQD fractal value 69.18 till 81.28 and located at the center and western part of Zarshuran deposit. Therefore, in mine slop designing and planning have excellent conditions. The results of the RQD-N fractal modeling in Zarshuran deposit can usage as a practical method in similar districts.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
151
160
http://www.gsjournal.ir/article_88026_8c1c04d38a7be88025b81639408bebf2.pdf
dx.doi.org/10.22071/gsj.2018.78009.1056
Mianaj iron occurrence, southwest of Zanjan: Metamorphosed and deformed volcano-sedimentary type of mineralization in Sanandaj- Sirjan zone
Fattaneh
Pourmohammad
MSc. Student of Economic Geology, Department of Geology, University of Zanjan, Zanjan, Iran
author
Hossein
Kouhestani
Geology, Sciences, University of Zanjan
author
Amir Morteza
Azimzadeh
Geology, Sciences, University of Zanjan, Zanjan, Iran
author
Ghasem
Nabatian
department of geology, faculty of sciences, university of Zanjan, Zanjan, Iran
author
Mir Ali Asghar
Mokhtari
Geology, Sciences, University of Zanjan
author
text
article
2019
per
Mianaj Fe ore occurrence is located in the Takab-Angouran-Takht-e-Soleyman metallogenic zone, 100 km southwest of Zanjan. In this area, Fe mineralization occurs as lens-shaped bodies parallel to the foliation of schist and rhyolitic meta-tuff units (equal to Kahar Formation). Based on mineralography, ore mineral is magnetite, and quartz present as gangue mineral at Mianaj. The ore minerals show disseminated, laminated, banded, massive, vein-veinlet and replacement textures. Three stages of mineralization can be distinguished at Mianaj. The first stage is recognized as stratiform and stratabound lenses, laminated and disseminated crystals of magnetite parallet to the foliation of host rocks. Stage-2 mineralization is recognized by folding of ore bands, σ microfabric and boudinage of magnetite crystals, quartz pressure shadows and surrounding of foliation around magnetite crystals, and recrystallization of quartz and magnetite crystals. Stage-3 is recognized by quartz vein-veinlets that cut previous mineralization stages. Chondrite-nonmineralized REE pattern of host rocks and the mineralized samples indicate that mineralized samples are depleted in REE. This signature indicates mobility of REE by Cl and F-rich oxidized fluids during mineralization processes. Characteristics of Mianaj occurrence are comparable with metamorphosed and deformed volcano-sedimentary type of iron deposits.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
161
174
http://www.gsjournal.ir/article_50053_1e118424163dc4a508b0f4eee340acbd.pdf
dx.doi.org/10.22071/gsj.2017.84283.1099
Structural evolution and active tectonic of Mianrahan area, northeast of Kermanshah
H.
Javanbakht Jabarabadi
M.Sc. Student, Faculty of Earth Sciences, University of Shahid Beheshti, Tehran, Iran
author
S. A.
Alavi
Professor, Faculty of Earth Sciences, University of Shahid Beheshti, Tehran, Iran
author
text
article
2019
per
The studied area located at the main suture zone of Zagros in the northeastern of Kermanshah. To do structural analysis in this area, six structural sections have been drawn perpendicular to structures direction. Structures and faults with different mechanism show that the studied area has passed two tectonic phases from Cretaceous up to present. The first phase which is a Compression phase, started from Cretaceous and lasted until Miocene. The created faults in this phase are thrusts with vast displacements in which the Main Zagros Thrust is the most important one of them. The second tectonic phase which is very young and active acts as a Transpressional system. The main structures created in second phase are dextral faults of Mianrahan and Sahne. These tow faults are part of Main Recent Fault and created some secondary structures such as Dinevar pull apart and flower structure on Sahne fault. Finally structural evolution model of the area has been expressed in six steps according to the relation among the structures and layers with different ages. During these steps, faults with the same dirctions but different mechanism have been created which demonstrates the counterclockwise rotation of stress axis σ1 since Cretaceous.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
175
184
http://www.gsjournal.ir/article_88498_f67fdb8e9295e723789cc747c6b66fde.pdf
dx.doi.org/10.22071/gsj.2019.88498
Petrology and geochemistry of plutonic rocks in west and south west of Salafchegan.
mozhgan
Taheri
Head of Communication and Information of Geologycal survey of Iran (Kerman)
author
afshin
ashjaardalan
Assistant professor, department of geology, north Tehran branch, Islamic Azad University,Tehran,Iran
author
Mohammad hashem
Emami
Associate professor, department of geology, Islamshahr branch, Islamic Azad University,Tehran,Iran
author
Seyed Jamal
Shaikh Zakariay
Assistant professor, department of geology,science and research branch, Islamic Azad University,Tehran,Iran
author
text
article
2019
per
Abstract In the west and south-west part of Salafchegan near Zavarian village in Iran (In central Iranian volcano plotonic belt) there are some Plutonic rocks. Based on petrography and geochemistry findings these Plutonic rocks are Diorite, Monzonite and less Quartz monzonite. The main texture in Dioritic rocks is intergranular and in Monzonite is Porphyritic. Based on TAS diagram Samples located in Diorite, granodiorite and gabbrodiorite. Tectono-magmatic diagram Y Versus Zr shows the magmatic arc setting and Zr/TiO2 Versus Ce/P2O5 diagram contrasts postcolligenal magmatic arcs. Based on Chondrite and primitive mantle Spider diagrams, LREE have enriched to HREE in this area that makes the overal slope of these diagrams declined from left to right and this consident with the overal pattern of subduction zone. The results of petrography, geochemistry and tectonic setting studies in this area, indicate that neogene magmatism occurred in post colligenal tectonic setting - subduction of Neo-thetise ocean under central Iranian plate in neogen era.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
185
194
http://www.gsjournal.ir/article_79554_357680d9a602f3082e35e8656cd11ac5.pdf
dx.doi.org/10.22071/gsj.2018.87169.1114
Estimation of water seepage from Azad dam foundation using multivariated geostatistic and comparison with observed flow
Ali
Aalianvari
mining Dept , kashan university
author
Saeed
Soltani-Mohammadi
Department of mining engineering, University of Kashan
author
Maryam
Miri
دانشگاه کاشان
author
text
article
2019
per
The main objective of this paper is to estimate water seepage from the Azad dam foundation, based on the combined geotechnical investigations and multivariate geostatistical methods. Geological filed investigations and records at the 38 exploratory boreholes have been considered as the main source for seepage calculations. Due to expansion of reservoir and a few boreholes and limitation of geological investigations, distribution of permeability and permeability changes in the reservoir area is not an indicator for reservoir. In this research using geostatistical method (Kriging), Lugeon values have been estimated for abutments and foundation of the reservoir. Afterward, seepage was estimated for reservoir by using numerical method (FEM).results show that around 450 lit/min water was seepage from the dam. That is very close to the observed seepage from dam foundation. Based on the results, the total seepage estimated is around 450 lit/min that is relatively closed to the observed and measurements flow (350lit/min).
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
195
202
http://www.gsjournal.ir/article_88038_6103bdae3c28f3fc13fc92728447f253.pdf
dx.doi.org/10.22071/gsj.2018.112706.1363
Vein-type copper mineralization in the Zarandieh area based on mineralogy, geochemistry and fluid inclusions studies, Saveh, Markazi province
seyran
yousefi
M.Sc. Student, Faculty of Earth Sciences, Shahrood University of Technology, Shahrood, Iran
author
masoud
alipourasl
Assistant Professor, Faculty of Earth Sciences, Shahrood University of Technology, Shahrood, Iran
author
text
article
2019
per
The Zarandieh district is situated approximately 42 km northeast Saveh (Markazi province) and in the northwestern part of the Urumieh-Dokhtar magmatic belt. In this area, mineralization is hosted by Eocene andesitic lava and Oligo-Miocene diorite and gabbroic rocks. According to the geochemical evidence, parental magma of igneous rocks is calc-alkaline, metaluminous and related to continental margin volcanic arcs. Mineralization has been observed as veins, veinlets and brecciated forms in diorite and gabbroic rocks. The main ore mineral is chalcopyrite and associated with pyrite, bornite, oligist, chalcocite, covellite, neotosit, native copper, malachite, azurite, chrysocolla, goethite and limonite. Cu grade in the ore samples are varied from 0.04 to 1.7 % (0.40 % in average). Statistical analyses of geochemical data from mineralized samples by Pearson method displayed that Cu has maximum correlation with Ag, As, Zn, Cd and Pb, respectively. Microthermometry studies of fluid inclusions show that the average homogenization temperature is 195° C and the average salinity of 23 wt% NaCl. The Zarandieh Copper mineralization is closely related to hydrothermal vein copper deposit types.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
203
214
http://www.gsjournal.ir/article_88027_3e527bfb80bcba448d9e53c78a8bf3af.pdf
dx.doi.org/10.22071/gsj.2018.82635.1090
Determination of main reservoir controlling factors of Asmari Formation in Naft-Sefied oil field, Northern Dezful Embayment
ayeshah
salmani
1Department of Geology, Science and Research Branch, Islamic Azad University, Tehran, Iran
author
Hossain
Rahimpour-Bonab
Department of Geology, Faculty of Science, University of Tehran, Tehran, Iran
author
Mohsen
Ranjbaran
Department of Geology, Faculty of Science, University of Tehran, Tehran, Iran
author
Seyed Mohsen
Aleali
ِepartment of Geology, Science and Research Branch, Islamic Azad University, Tehran, Iran
author
text
article
2019
per
Asmari Formation (Oligocene - Miocene) is the first fractured proliferous carbonate reservoir that ever known in the world and is the most important hydrocarbon reservoir in Iran. The large quantity of the produced oil in Dezful Embayment is from this formation. Thin section studies in this formation lead to identification of eight microfacies related to the homoclinal ramp with three subdivisions (inner ramp, middle ramp and outer ramp). Many diagenetic processes such as; micritization, neomorphism, bioturbation, dolomitization, dissolution, cementation, mechanical and chemical compaction, fracturing have affected the Asmari carbonates in studied oil field during eogenesis, mesogenesis and telogenesis processes. Three sequences (third order) have been identified based on sequence stratigraphy studies. Based on all results from this study it could be pointed out that; dolomitization, dissolution and cementation are the most important factors that controlled the reservoir quality in this field. Cementation (calcite and anhydrite cements with different fabrics) reduced reservoir quality in different facies. Seemingly, fabric destructive dolomitization increased reservoir quality with creating intercrystaline porosity in mudstone facies and connecting isolated pores (via dissolution) in most of facies. Dissulotion has prime importance where occurred and increased reservoir quality. Contrasting to the other Asmari hydrocarbon fields in Zagros which fracturing is the most important factor in increasing reservoir quality, in Naft-Safid oil field, most of fractures have been filled by calcite cement. Thus, diagenetic imprints (such as dissolution and dolomitization) have more effects on increasing reservoir quality than fracturing.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
215
226
http://www.gsjournal.ir/article_88023_22978fbba6f10bc2ae3937aee95bf16b.pdf
dx.doi.org/10.22071/gsj.2017.77997.1041
Investigation of active tectonics and identification of active faults by geophysical methods case study: Gohartapeh- Behshahr
F.
Alahverdi Maygooni
M.Sc., Department of Geology, Islamic Azad University, Karaj Branch, Karaj, Iran
author
M.
Mohamadi Vizheh
M.Sc., Geological Survey of Iran; Institute of Geophysics, University of Tehran, Tehran, Iran
author
A.R.
Farrokhnia
Assistant Professor, Department of Geology, Islamic Azad University, Karaj Branch, Karaj, Iran
author
E.
Boostan
Assistant Professor, Department of Geology, Islamic Azad University, Karaj Branch, Karaj, Iran
author
H.
Nazari
Associate Professor, Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran
author
text
article
2019
per
Undoubtedly, one of the evidence of tectonic activity in each region is earthquake, which has a major role in casualties and financial losses. The earthquake is usually caused by faults that sometimes extend to the depths of the earth's crust. In cases where no signs or complications of these faults are observed on the surface of the earth, it is necessary to get a better understanding of these faults and its sub branches by combining geological knowledge as well as remote sensing and geophysical instruments. The Kazar fault in the study area is a fundamental fault that has been attributed to at least six historical earthquake events. Due to quaternary activities, recognition of this fault is very important in the region. Therefore, geological and geophysical studies were carried out on the historical site of Gohartepeh in Behshahr city to reveal its hidden parts. Specific resistive methods with bipolar bipolar arrangement at 10 and 20 meters intervals are used to provide sections and maps. By examining them and considering the position and depth of the anomalies obtained in the next stages, new profiles and networks were designed. In order to obtain more accurate results, the cesium magneto metric scanning was performed on 4 profiles. Data obtained from field operations and data acquisition as well as final processing of data in specialized software have been incorporated and clearly interpreted from sub-surface structures, especially faults and discontinuities in the study area, which indicate an impressive anomalous adaptation obtained with field evidence.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
227
236
http://www.gsjournal.ir/article_88499_f9481589dd2a7c6efa0848be66590699.pdf
dx.doi.org/10.22071/gsj.2019.88499
Biostratigraphy, depositional environment and sequence stratigraphy of the Kalat Formation in the Sheikh Syncline (north east of Bojnurd)
M. H.
Kazemzadeh
Ph.D. Student, Faculty of Earth Sciences, University of Shahid Beheshti, Tehran, Iran
author
A.
Sadeghi
Professor, Faculty of Earth Sciences, University of Shahid Beheshti, Tehran, Iran
author
M. H.
Adabi
Professor, Faculty of Earth Sciences, University of Shahid Beheshti, Tehran, Iran
author
H.
Ghalavand
Ph.D., National Iranian Oil Company, Tehran, Iran
author
text
article
2019
per
In order to determine biostratigraphy, depositional environment and sequence stratigraphy of the Kalat Formation in the Sheikh Syncline (north east of Bojnurd), Four stratigraphic sections including South Sheikh, North Sheikh, Qaleh Zu and Ziarat were selected and sampled. The thickness of the Kalat Formation in the South Sheikh, North Sheikh, Qaleh Zu and Ziarat sections were 25, 16, 25 and 5m respectively, and its lithology consists mainly of brown to yellow limestones. The reason of changes in thickness in studied sections is tectonic factors, subsidence and different rates of sedimentation. The layer of conglomerate in the base part of the Kalat Formation at South Sheikh and Qaleh Zu sections and the layer of sandstone in the base part of the Kalat Formation at Ziarat section were recognized. In the biostratigraphic studies, 15 species belonging 23 genera of foraminifera were recognized and one biozone including Siderolites calcitrapoides-Sirtina orbitoidiformis assemblagezone was identified. The age of the Kalat Formation in all of studied sections based on the above biozone and fossil contents Maastrichtian were determined. Petrographic analysis led to recognition two silliciclastic and eight carbonate facies belonging to four depositional environments including tidal flat, restricted and semi-restricted lagoon, shoal and open marine. Based on the recognized facies and its gradual trend, abundance of shoal facies, absence of reefs and sediment of turbidite flows such as Falling and sliding sediments, the sedimentation of the Kalat Formation was occurred on the homoclinal ramp setting. Based on the vertical changes of facies and recognized depositional environments, one third-order depositional sequences was represented. This depositional sequence consists mainly of shoal facies rich in bioclast, intraclast, benthic foraminifera, echinoid, rudist (Hyporite) and bivalve. MFS of this sequence is represented by open marine facies rich in echinoid.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
237
246
http://www.gsjournal.ir/article_88501_3ac169d5f40c2c5f634e646038056876.pdf
dx.doi.org/10.22071/gsj.2019.88501
Investigations on Bagher Abad and Darreh Badam fluorite deposits based on REE data, Southeast Mahallat, Markazi Province
mohammad
maanijou
Member of faculty, Dept. of Geology, Bu-Ali Sina University, Hamedan
author
Azadeh
Mirzai
Student of economic geology, University of Bu-Ali Sina, Hamedan, Iran
author
text
article
2019
per
Bagher Abad and Darreh Badam fluorite mineralizations are located in southeast Mahallat city (Markazi province) and occured as veins with common trend of East-West within slate and phyllite of Shemshak Formation (Lower Jurassic). The fluorite is the main mineral of the veins and quartz, barite, calcite, dolomite, pyrite, chalcopyrite, goethite and covellite are the sub-ordinary minerals of deposits. The distribution of rare earth elements (REE) indicates that the violet, colorless and gray fluorites in primary mineralization stage have been enriched in LREE (result of digestion and wall rock replacement) and and the blue types of fluorites enriched in MREE and HREE, formed in post mineralization stage. Tb/La vs Tb/Ca and Y/Ho ratios diagrams are used for determination of genesis and differentiation of fluorite mineralization. These data show all samples can have a hydrothermal source for Bagher Abad and Darreh Badam deposits. Negative anomaly of Eu in all samples of fluorite can be caused by the formation of fluorite at above 200°C temperatures. In addition to, depletion of Ce in fluorites of studied areas indicated a reduced fluid and presence of pyrite and chalcopyrite sulphide minerals confirming this.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
247
256
http://www.gsjournal.ir/article_88032_1480ff445856ab234ed8768428f2c8c2.pdf
dx.doi.org/10.22071/gsj.2018.88934.1146
Evaluation of neotectonic activities in East-Yazd
M.
Mirjalili
M.Sc. Student, Department of Geology, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
author
F.
Ghaemi
Associate Professor, Department of Geology, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
author
B.
Rahimi
Professor, Department of Geology, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
author
M.
Moshrefifar
Assistant Professor, Department of Geology, Faculty of Sciences, Yazd University, Yazd, Iran
author
M.
Gholamzadeh
M.Sc., Department of Geology, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
author
text
article
2019
per
The study area is located in the east of Yazd and is part of Yazd block (western block of central Iran). There are two major fault systems, Anar and Kharanagh with lengths of 100 and 62 km and numerous minor faults represents an important tectonic phenomenon in the region. The aim of this study is to investigate neotectonics in this area by using geomorphic indicators. To achieve this goal, have been used of seven geomorphic indicators: Hypsometric integral (HI), Drainage basin asymmetry factor (AF), Stream length- gradient index (SL), Mountain Front sinuosity (Smf) and the ratio of valley floor width to depth Valley (Vf), River sinuosity index (S), Basin shape factor (Bs). Based on Active tectonics indices (Iat), the study area is divided in Four terms of tectonic activity rates, category 1 (very high tectonic activity, 7.4% of the region), category 2 (up 74%), category 3 (average 11%) and category 4 (less 7.4%). Morphotectonical and morphological evidences indicate that the rate of tectonic activity in this region is moderate to high. According these evidences, the northern part of Kharanagh fault and southwestern part of Anar fault are more active than other parts.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
257
270
http://www.gsjournal.ir/article_88502_ae24e7099520c58f00ec0d7c669bdcc6.pdf
dx.doi.org/10.22071/gsj.2019.88502
Mineral chemistry and thermo-barometry of Ziyaran intrusion (West Taleghan)
E.
Keshtkar
Ph.D., Faculty of Geosciences, Shahid Beheshti University, Tehran, Iran
author
M.
Ghorbani
Associate Professor, Faculty of Geosciences, Shahid Beheshti University, Tehran, Iran
author
J.
Omrani
Ph.D., Geological Survey of Iran, Tehran, Iran
author
text
article
2019
per
In the north of Ziaran village, a Sill olivine gabbro to monzodiorite composition is injected into the Karaj tuffs. The dominate minerals composition of plutonic rock are Plagioclase, Alkali feldspar, Pyroxene, Olivine and Biotite. Plagioclase composition is varies, and it’s changed from Labradorite to Bytownite. Alkali feldspar is in the Orthoclase range and Pyroxene is part of Diopside. Olivine composition change from Chrysolite to Hortonolite and most of the indicators are in the Hyalosiderite range. Biotite is one of the most prominent ferromagnesian mineral in the studied bodies. Compositionally, it is plotted between the field of annite and siderophylite. Most of these biotites are primary magmatic and some are plotted in the reequilibrated area. Based on the FeO*, MgO and Al2O3 binary and ternary diagrams, the studied biotites plot in the calc-alkaline orogenic field or crystallization temperature the have been calculated between 690º to 780 ºC. The chemical composition of the pyroxenes shows that these rocks have been crystallized in a subduction geological setting. The average crystallization temperature of clinopyroxenes is about 1215 °C. Furthermore, the calculated pressure for clinopyroxenes is less than 9 Kbars.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
271
280
http://www.gsjournal.ir/article_88503_248fa97db59c03feb99fe3f8ba678f2e.pdf
dx.doi.org/10.22071/gsj.2019.88503
The investigation of paleo-stress based on the study of fractures in Zagros collision zone Kermanshah region
Sepideh
Rezabeyk
Ph.D. Student, Islamic Azad University, Science and Research Branch, Tehran, Iran
author
Abdollah
Saidi
Earth Sciences Research Institute, Geological Survey of Iran, Tehran, Iran
author
Mehran
Arian
Department of Geology, Islamic Azad University, Science and Research Branch, iran
author
Ali
Sorbi
Department of Geology, Islamic Azad University, Karaj Branch, iran
author
text
article
2019
per
In the Northern part of Suture Zone (Kermanshah) the deep sea sediments, oceanic crust remnants, platform carbonates, igneous and metamorphosed rock of active margin and carbonate sequence of passive margin are assembled in this studied area. This convergent area has provided a very complicated structural zone. The main purpose of this study is stress characteristic analysis. A great data has gathered from the faults which are appeared within the rocks specially the radiolaritic rocks. The data includes characteristics of fault surface geometry, fault slip and lineation slip related. By using the method Right Dihedral, the position of main stress was obtained. The great number of reverse faults have a NW- SW trend, while the strike- slip faults, show a NE- SW direction. The Normal faults with a different displacements appeared younger than the other faults. The result of this study that we obtained the situation of main stress σ1, σ2 and σ3 respectively is 059, 305 and 195.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
281
288
http://www.gsjournal.ir/article_88034_2b09a2540f1e87a43f66b0dfdb540fee.pdf
dx.doi.org/10.22071/gsj.2017.95512.1228
Facies analysis, depositional environments and palaecological conditions of the Lower Carboniferous carbonate ramp in the Sanandaj- Sirjan zone, Iran
F.
Shirezade Esfahani
Ph.D., Department of Geology, Islamic Azad University, North Tehran Branch, Tehran, Iran
author
A.
Bayet-Goll
Assistant Professor, Department of Earth Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran
author
N.
Kohansal Ghadimvand
Assistant Professor, Department of Geology, Islamic Azad University, North Tehran Branch, Tehran, Iran
author
A.
Kangazian
Assistant Professor, Departmentof Geology, Islamic Azad University, Esfahan (Khorasgan) Branch, Esfahan, Iran
author
A.
Akbari Mohammadi
M.Sc., Departmentof Geology, Islamic Azad University, Esfahan (Khorasgan) Branch, Esfahan, Iran
author
M.
Sadri
M.Sc., Departmentof Geology, Islamic Azad University, Esfahan (Khorasgan) Branch, Esfahan, Iran
author
text
article
2019
per
The carbonate successions (Tournaisian-Visean) exposed in the Tang-e-Darchaleh and Banarizeh sections from Sanandaj-Sirjan Zone (SSZ), Iran, have been used to generate a facies model. From the analysis of facies and their associations, four depositional zones are recognized on the Tournaisian-Visean ramp: basinal environments, outer ramp (FA1 and FA2; deep subtidal associations), mid ramp (FA3, FA4 and FA6; shallow subtidal to lower intetidal associations), and inner ramp (FA5; shoal). The gradual transitions between facies and facies associations, as well as the depositional profile of the shelf transect indicate a low gradient ramp. The observed sedimentary features in the facies associations portray a transgressive, proximal-to-distal, wave-dominated combined flow marine ramp sequence, as recorded in stratigraphic changes in character of storm bed sequences and the spatial arrangement of types of storm bed along the depth related environmental gradients. This study suggests that during the Lower Carboniferous, a broad shelfal platform covered the southern margin of the Palaeotethys, which was characterized by dominantly shallow carbonate ramp.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
289
300
http://www.gsjournal.ir/article_88505_9782d442ac642cd35487eaa3035645d6.pdf
dx.doi.org/10.22071/gsj.2019.88505
The structural analysis of Boshruyeh Kooh-e-Ahan area, South Khorasan
M.
Jamali
Ph.D. Student, Department of Geology, Islamic Azad University, Science and Research Branch, Tehran, Iran
author
M. R.
Ghassemi
Associate Professor, Research Institute for Earth Science, GSI, Tehran, Iran
author
M.
Lotfi
Associate Professor, Research Institute for Earth Science, GSI, Tehran, Iran
author
A.
Solgi
Associate Professor, Department of Geology, Islamic Azad University, Science and Research Branch, Tehran, Iran
author
text
article
2019
per
Kuh-e-Ahan is a high-standing single relief within a rather flat plain, which is located in the north of the Tabas block, near the intersection of the Nayband and Kalmard faults and there are great outcrops of fe-oxide, along with eastern-western faults and fractures in Kooh-e-Ahan area.. The present study uses structural and remote sensing methods to discover the mechanism for evolution of the Kuh-e-Ahan, and to understand style of mineralization in the mountain, emphasizing on the role of fractures and major faults. In our remote sensing approach, we used DEM data and Aster satellite images and their filtering in main directions to detect displacements and sudden offsets of lithologic units and changes in drainage patterns. In our field studies, we studied mechanism of the faults, emphasizing on the faults within the Kuh-e-Ahan mining district. The results show N-S faults (Nayband fault trend) and NE-SW faults (Kalmard trend) have a general right-lateral mechanism, and the E-W faults are left-lateral with a reverse component. Structural model developed in this study suggest that strike-slip displacement on conjugate fault provided the space required for ascend and development of hydrothermal mineral deposits within the mine district.
Scientific Quarterly Journal of Geosciences
Geological Survey of Iran
1023-7429
28
v.
111
no.
2019
301
310
http://www.gsjournal.ir/article_88510_2df71bf6257dd332dde0416a09a9502e.pdf
dx.doi.org/10.22071/gsj.2019.88510