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Search Results: 1 - 10 of 6509 matches for " Central Iran "
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A Review on Fossil Findings of Central Iran’s Permo-Triassic Deposits  [PDF]
Hamideh Noroozpour, Mostafa Yousefi Rad
Open Journal of Geology (OJG) , 2015, DOI: 10.4236/ojg.2015.56035
Abstract: In this research, a review was done on Permo-Triassic deposits in Central Iran including Abadeh, Hambast, and Elika formations. Following an overview about the circumstances of Central Iran Basin during Permotriassic time interval, the respective formations are introduced, and then, history of paleontology studies on these deposits will be depicted. Through analysis and comparison of previous studies, the following ages were estimated for the aforementioned formations: Early Dzhulfian for Abadeh Formation, Late Dzhulfian-Dorashamian for Hambast Formation, and Early Triassic (Scythian) for Elika Formation. Also, Permotriassic boundary in Central Iran is continuous, bearing the proposed sedimentation and fossil content. It is noteworthy that due to volcanic events at the boundary of these deposits in Central Iran, one might infer that occurrence of the aforementioned activities has been among the major causes of the respective extinction.
The Biggest Salt-Tongue Canopy of Central Iran  [PDF]
Mehran Arian, Hamideh Noroozpour
Open Journal of Geology (OJG) , 2015, DOI: 10.4236/ojg.2015.52005
Abstract: One of the most interesting salt structures is salt-tongue canopy. The Central Iran basin has a few salt provinces and in this paper, morphotectonic concept of the salt-tongue canopy on the west of Garmsar city has been investigated. In this study, field data coupling with the salt tectonic-related factors to provide a position for salt rocks in the west Garmsar. Firstly, various geological factors such as faults, folds and roads were extracted and compiled. This is because the factors mentioned above play important role in the instability of the region. The results of this study showed that the salt extrusion from the Lower Red formation is severe. Further, it is evident that the shortening of main structures has had a great impact on it whilst the salt movements have occurred within Garmsar Syncline. Finally, the paper concluded that the salt-tongue canopy in the region has increased the rates of salt extrusion.
Neotectonics of Tabas Area, Central Iran by Index of Active Tectonics (IAT)  [PDF]
Elahe Javadi Mosavi, Mehran Arian, Manochehr Ghorshi, Mohammad Nazemi
Open Journal of Geology (OJG) , 2015, DOI: 10.4236/ojg.2015.54019
Abstract: In this research, Tabas area, which is located in central Iran, was selected as the study area and three geomorphic indices were calculated for its structural fronts. Through averaging these three indices, we obtained index of active tectonics (IAT). The values of the index were divided into classes to define the degree of active tectonics. Therefore, relative tectonic activity was calculated and their values were classified and analyzed in two groups. Regions were identified as high and moderate levels. In analyzing data and combining them with tectonic setting, the results were often associated and justified with regional geology. Our results show that the highest value is located along Shoutori fault, which shows 2 class of relative tectonic activity (high level). Also, moderate values are located along Ereshk, Ezmeighan and Jamal faults (moderate level). According to these results, Shoutori fault is the most active fault in the study area and this situation is compatible with its position as a mountain front fault.
Dolomitization Mechanism Based on Petrography and Geochemistry in the Shotori Formation (Middle Triassic), Central Iran  [PDF]
A. Rahimi, M. H. Adabi, A. Aghanabati, M. R. Majidifard, A. M. Jamali
Open Journal of Geology (OJG) , 2016, DOI: 10.4236/ojg.2016.69085
Abstract: Middle Triassic carbonate sequences of Shotori Formation have a thickness of 70 m and are deposited Robat-e-Kalmard region of Tabas city in Central Iran basin. Gradationally and conformably overlying Sorkh shale Formation, Shotori Formation, mostly composed of medium to thick dolomites (50 m), interbeded with thin lime and sandstones, is disconformable by a laterite horizon at its upper boundary. This Formation mainly consists of fine-to-coarsely crystalline dolomites. According to petrographic (fabric and grain size) and geochemical (elemental analysis of Ca, Mg, Na, Sr, Fe, Mn) evidence, five various types of dolomites were recognized in Shotori Formation. This variety results from early and late diagenetic processes, triggering a change in dolomitizing fluids and thereby forming various dolomites. Geochemical studies have revealed that the dolomites of Shotori Formation have formed under meteoric diagenesis and reducing conditions. Various dolomitization mechanisms are proposed for various types of dolomites; that is to say, Sabkha model is considered for type 1 dolomite, mixing zone model for type 2 and 3 dolomites and burial model for type 4 and 5 dolomites.
Analyzing Typical Characteristics of Central Zagros Potteries during the Chalcolithic Period  [PDF]
Behzad Balmaki, Kamal Aldin Niknami, Mohammad Reza Saeedi Harsini
Archaeological Discovery (AD) , 2013, DOI: 10.4236/ad.2013.12002
Abstract: Some 152 Chalcolithic sites were identified by the means of an archaeological surface survey in the Central Zagros mountainous region. As a whole, the analysis of data shows that the majority volume of finding pottery groups is classified as Red-Slipped Wares belonging to the Late Chalcolithic period. Beside this, the Black on Buff Wares and also the Impress Dalma Wares (Middle Chalcolithic) are the two types dominating the samples. The altitude of the settlements has risen by transition from the Early to the Late Chalcolithic periods. By Middle Chalcolithic we confronted different kinds of potteries indicating an improvement in the pottery making techniques or communicating with the neighboring regions. The Late Chalcolithic societies have witnessed a decline in the pottery types produced, but dramatic increases in the production rates. All factors show that in the Late Chalcolithic, population has been increased and a category of settlement systems have been propagated in the region which includes agricultural village-based pastoralism and nomadism.
Biozonation and Paleobathymetry on Foraminifera Upper Cretaceous Deposites of Central Iran Basins (Isfahan, Baharestan Section)  [PDF]
Bita Ghasem Shirazi, Lida Bakhshandeh, Abdollah Yazdi
Open Journal of Geology (OJG) , 2014, DOI: 10.4236/ojg.2014.48026
Abstract:

In this study Late Cretaceous stratum in central Iran, Baharestan section in Isfahan area, was evaluated by biozonation and paleobathymetry. These sediments have 89 meters thick, and strata have been formed of marl and marl limestone. In order to indicate the ancient depth of Upper Cretaceous at this time, planktonic and benthic foraminifera were studied. The percentage of the total planktonic foraminifera to the whole sample of foraminifera after the removal of indwell benthic foraminifera (%P*) using the formula D = e(3.58718 + (0.03534 × %P*)) was identified and depth of 200 - 450 meters was achieved for them. In the present investigation, 30 planktonic species of 11 genus have been identified. The Upper Cretaceous deposit was divided to 6 biozones on the basis of planktonic foraminifera which

Tectonics and Mineralisation of Copper in the Ardestan-Kahang Area, Central Iran by Remote Sensing  [PDF]
Nazanin Jamalian Daryani, Mehran Arian, Nematllah Rashidnezhad Omran
Open Journal of Geology (OJG) , 2015, DOI: 10.4236/ojg.2015.54017
Abstract: The Ardestan-Kahang area is located in Urmieh-Dokhtar Magmatic Arc. This area is situated in Ardestan, Kouhpayeh, Kajan and Zefreh in 1:100,000 geological maps. In order to extract mineralization zones related to copper mineralization and accessories elements, and also identify Argillic, Prophylitic, Sericitic and Siliceous alteration with major and minor lineaments, various kinds of algorithms, band ratio and personal interpolation have been utilized. The applied methods for extracting alteration consist of LS-Fit (Least Square Fit), Matched Filtering (MF), Spectral Angle Mapper (SAM) and Spectral Feature Fitting (SFF), band ratio and visual interpretation. Comparing different outputs of utilized algorithms illustrates that the best algorithm for argillc alteration extraction are Matched Filtering (MF) and Spectral Feature Fitting (SFF), with visual interpretation, and for argillic alterations the visual interpretation with RGB: 468 that has seen pink-red color. For prophylitic alterations the utilized algorithms are Matched Filtering (MF). Lineaments have extracted with visual interpretation on satellite images and it is revealed that in areas where the fracture density is greater, conditions are more suitable for copper mineralization.
Sedimentary Environments Can Be Changed by Geotechnology (Case Study: A Morphotectonic Idea for Design of Extensive Artificial Bay on the Iranian Plateau)  [PDF]
Mehran Arian, Azar Khodabakhshnezhad
International Journal of Geosciences (IJG) , 2015, DOI: 10.4236/ijg.2015.65039
Abstract: Iranian Plateau between the Lesser Caucasus-Alborz Mountains on the north and Zagros-Makran Ranges on the south has several inter-mountainous depressions which were filled by Quaternary deposits. Geologic evidence implied that, the last marine conditions in some depressions such as the Dasht-e Kavir, Dasht-e Lut and Jazmourian basins, had been changed to land conditions in middle Miocene. Based on shape and elevation of the Dasht-e Kavir, Dasht-e Lut and Jazmourian plains related to sea level and geomorphology of Iranian plateau, three semi-connective artificial lakes can be constructed upon the mentioned plains by consideration of many geologic and geotechnical parameters. These artificial lakes can feed by pumping of water from Oman Sea and form a triple artificial bay which they must be connected together by two gated straits. Therefore, a possible morphotectonic idea with many advantages has suggested that it can be present as an international geotechnologic design. This design has the important environmental impacts which can be changed desert to lake sedimentary basins.
Application of Self-Organizing Map for Exploration of REEs’ Deposition  [PDF]
Mohammadali Sarparandeh, Ardeshir Hezarkhani
Open Journal of Geology (OJG) , 2016, DOI: 10.4236/ojg.2016.67045
Abstract: Varieties of approaches and algorithms have been presented to identify the distribution of elements. Previous researches based on the type of problem, categorized their data in proper clusters or classes. This means that the process of solution could be supervised or unsupervised. In cases, where there is no idea about dependency of samples to specific groups, clustering methods (unsupervised) are applied. About geochemistry data, since various elements are involved, in addition to the complex nature of geochemical data, clustering algorithms would be useful for recognition of elements distribution. In this paper, Self-Organizing Map (SOM) algorithm, as an unsupervised method, is applied for clustering samples based on REEs contents. For this reason the Choghart Fe-REE deposit (Bafq district, central Iran), was selected as study area and dataset was a collection of 112 lithology samples that were assayed with laboratory tests such as ICP-MS and XRF analysis. In this study, input vectors include 19 features which are coordinates x, y, z and concentrations of REEs as well as the concentration of Phosphate (P2O5) since the apatite is the main source of REEs in this particular research. Four clusters were determined as an optimal number of clusters using silhouette criterion as well as k-means clustering method and SOM. Therefore, using self-organizing map, study area was subdivided in four zones. These four zones can be described as phosphate type, albitofyre type, metasomatic and phosphorus iron ore, and Iron Ore type. Phosphate type is the most prone to rare earth elements. Eventually, results were validated with laboratory analysis.
Non-Diapiric Salt Domes in the West Zanjan, Central Iran  [PDF]
Sina Alizadeh
Open Journal of Geology (OJG) , 2017, DOI: 10.4236/ojg.2017.72009
Abstract: The salt domes of the west Zanjan (Central Iran) are the most important structures in the study area. They have been formed by the uplifting and erosion together under low humidity and dry and warm climate condition. The salt rocks with near to 200 meters thickness are related to lower member of the Upper Red Formation (Early Miocene) that deposited in the inverted back arc basin. They have been formed in the Central Iran basin after the Arabian-Eurasian convergence. Based on filed works and preparation of geologic map, salt domes have been cropped out during regional uplifting and erosion along hinge zone of a longitudinal anticline. Also, there is no evidence for salt diapirism and so, they are different from some salt diapirs in the southwestern margin of Zanjan that is investigated by other researchers.
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