Petrology
Ziba Khodaean Chegeni; Nematollah Rashidnejad Omran; Ali Akbar Baharifar; Reza Nozaem; Carmela Vaccaro; José Francisco Santos
Abstract
Takhte-Soleyman ortho-amphibolites as a part of Takab metamorphic complex are located in Northeast Takab. These rocks consist of amphibolite, Garnet-amphibolite, Kyanite-Garnet-amphibolite, Hornblendite and Epidote-amphibolite. Petrography and whole- rock geochemistry show that basalt, andesite and/or ...
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Takhte-Soleyman ortho-amphibolites as a part of Takab metamorphic complex are located in Northeast Takab. These rocks consist of amphibolite, Garnet-amphibolite, Kyanite-Garnet-amphibolite, Hornblendite and Epidote-amphibolite. Petrography and whole- rock geochemistry show that basalt, andesite and/or their intrusive equivalents with calc- alkaline to tholeiitic affinity and even a peridotite could be their protoliths. Trace element and Sr-Nd ratios imply that these rocks were from mantle melt sources. In chondrite normalized plots, these amphibolites can be classified into at least two groups. The first group is characterized by LREE depletion relative to HREEs and some with flat patterns. The second has an enrichment of LREEs relative to HREEs. These two different patterns and some other geochemical characters suggest MORB or MORB-like and arc affinities of the parental magmas. This can be related to the time progressive evolution of magmatism either from MORB or Back-arcto Arc or from Arc to Back-arc setting.
Economic Geology
Maryam Honarmand; Ghasem Nabatian; Mahtab Aflaki; Mohammad Ebrahimi
Abstract
Geology, geochronology and tectonic setting of the Moghanlou mylonite gneiss and granite bodies, west of Zanjan Abstract The Moghanlou mylonite gneiss and granite assemblage is located in the west of Zanjan forming a part of the magmatic-metamorphic association in the Takab area. The Moghanlou assemblage ...
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Geology, geochronology and tectonic setting of the Moghanlou mylonite gneiss and granite bodies, west of Zanjan Abstract The Moghanlou mylonite gneiss and granite assemblage is located in the west of Zanjan forming a part of the magmatic-metamorphic association in the Takab area. The Moghanlou assemblage comprises of leucogranite and biotite granite intrusions which have surrounded the gneiss body. The zircon U-Pb dating shows the ages of 563±6.5 Ma for the mylonite gneiss, 576±13 Ma for the biotite granite and 559±6 Ma for the leucogranite intrusions. Moreover, the samples from the Moghanlou assemblage display high-K calc-alkaline and slightly peraluminous affinities, except those from the leucogranite which are low potassium samples due to the sodic alteration and albitization of the K-feldspars. The trace element patterns suggest LILE and LREE enrichment and HFSE and HREE depletion as well negative anomaly of Nb, Ta and Ti. In general, the geochemical features of the Moghanlou intrusions are comparable with the melts formed from crustal partial melting in magmatic arc environment. The Moghanlou assemblage is analogues to other Late Neoproterozoic-Early Cambrian igneous and metamorphic associations in Iran and Turkey which are related to the igneous activity along the Cadomian magmatic arc, in north of Gondwana supercontinent.
Economic Geology
Ghodratollah Rostami Paydar
Abstract
The Zarshuran gold deposit in northwest Iran is located in historic gold and arsenic mining area in the Sanandaj-Sirjan geo-structural zone. This area is mainly composed of Precambrian rocks. The Oligo-Miocene granitoid intrusions in Pre-Cambrian formations which are the country rocks of gold mineralization ...
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The Zarshuran gold deposit in northwest Iran is located in historic gold and arsenic mining area in the Sanandaj-Sirjan geo-structural zone. This area is mainly composed of Precambrian rocks. The Oligo-Miocene granitoid intrusions in Pre-Cambrian formations which are the country rocks of gold mineralization have resulted from intensive alteration, milonitization and gold mineralization. The main aim of these study is the separation of gold mineralization zones by using concentration-number (C-N) and concentration- volume(C-V) fractal techniques, which is based on 44 drill hole data and 5800 analyzed samples. Firstly, the logarithmic graph of gold was plotted for each model. Five gold mineralization zones were identified by using concentration-number model and four zones with concentration- volume model, indicate that intense of gold mineralization in wall rock, weak, medium, high and highly enriched zone, respectively. 3D geologic and fractal models show that low mineralized zones occurred in most of the ore deposits, which are often related to the Iman-Khan rock unit. In addition, based on fractal model interpretations and calculation of the overall accuracy matrices, these regions with medium, high and enriched zone have good overlaps to the Jasperoid rock unit, Chaldagh limestone, and Zarshuran shale units, respectively.
A Mohammadi; B Nekouie Sadri; S.S Hashemi; A Bayatani
Abstract
In 21st century, geologists of the developed countries paid special attention to the usage of criteria for evaluation of geodiversity and introduction of the country’s geoheritage to conserve this valuable heritage and its usage in sustainable way. Conservation and utilization of geoheritage or ...
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In 21st century, geologists of the developed countries paid special attention to the usage of criteria for evaluation of geodiversity and introduction of the country’s geoheritage to conserve this valuable heritage and its usage in sustainable way. Conservation and utilization of geoheritage or mining heritage is carried out in the framework of introducing a national or global region as geopark. Geopark is an under protection area that in addition to the geosite richness contains historical, cultural, and natural (ecosites) places. Making use of efficient management and proper training of local people and emphasizing on recreational teaching of geological and environmental concepts, it can attract tourists to fill their time through interpretation of all attractions in a way that this measurements cause improvement in economic-social situation of the local people as well as all people in the country. The study area is located around the world heritage site, namely Takht-e-Soleiman in the northwest of Iran that is rich from geodiversity, biodiversity and historical-cultural diversity points of view. However, the study area is economically poor. Accordingly, establishment of a geopark in the region can increase job creation, prevent immigration of villagers to the cities and flourish economic life of the region. In this study, two methods used for evaluation of criteria each of them includes some parameters and sub-parameters. Based on calculated scores for each site and making use of interpolation methods in GIS environment, the geopark territory and the best geotrail were selected.
S Alipour; P Shirmohammadi; Y Rahimsouri; H Bagheri
Abstract
Baba-Nazar garnet occurrence is located in northwest part of Sanandaj-Sirjan geological zone. Rock units in the area, including hornfels, garnetite and extensively weathered host rocks in contact with granite indicate garnet may have formed by metamorphism of clay-argillite, sandstone and calcareous ...
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Baba-Nazar garnet occurrence is located in northwest part of Sanandaj-Sirjan geological zone. Rock units in the area, including hornfels, garnetite and extensively weathered host rocks in contact with granite indicate garnet may have formed by metamorphism of clay-argillite, sandstone and calcareous rocks. The mineralogical and petrographical studies revealed that the evolution of mineralization has occurred during several progressive, retrograde and supergene alteration, while garnet has formed during progressive alteration. The results of the petrographical study of fluid inclusions show that most of the fluid inclusions in the garnet crystals fall in two groups: (1) Primary inclusions distributed randomly on the crystal faces and (2) secondary inclusions oriented along fractures and cleavage surfaces. Based on the inclusion diversity, four groups of these inclusions were differentiated: (1) single-phase liquid, (2) two-phase liquid-vapor, (3) solid multi-phase and (4) two-phase liquid–liquid. Micro thermometry of fluid inclusions in the garnet and quartz crystals show homogenization temperatures and salinities from 318 to 438 °C and 18.63 to 22.71 weight percent NaCl equivalent for garnet, and from 209 to 219 °C and 239 to 254 C° with 4.18 to 10.61 weight percent NaCl equivalent for quartz crystals.
Soroush Modabberi; Y. Rahimsouri; A. Yaghubpur; S. Alipour
Abstract
Black shales of the abandoned antimony mine of Aq-Darreh Bala Village in northwest of Takab city, northwest Iran, contain high concentrations of toxic elements, especially As (4403–11883 ppm), Sb (405–1022 ppm) and Hg (30–58 ppm). Enrichment factor calculations revealed that some ...
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Black shales of the abandoned antimony mine of Aq-Darreh Bala Village in northwest of Takab city, northwest Iran, contain high concentrations of toxic elements, especially As (4403–11883 ppm), Sb (405–1022 ppm) and Hg (30–58 ppm). Enrichment factor calculations revealed that some trace elements including As, Sb, Hg, Zn, U, Sr, Ni, V, Co, Cu, Mo, Ni, and Zr have been depleted, while, Pb, Th, Ga, Rb, and Ta are enriched during weathering. Mass balance calculation results show the highest release percents (% loss) belongs to Cd, Zn, U, Sr, Ni, V, Cu, As, Mo, Tl, Zr, Hg and Sb respectively. The highest weight amount of released elements belongs to As, Sb, Sr, Zn, Ni, V, Zr, Cu, U, and Hg respectively. As a result, it can be concluded that the black shale outcrops in the Aq-Darreh Bala abandoned antimony mine area have a main role as a geogenic source in environmental contamination of downstream environments.
Y. Rahimsouri; A. Yaghubpur; S. Modabberi
Abstract
The results of physicochemical parameters (pH, Eh, EC, TDS, TH, TA, T, and Salinity) and chemical analyses of the springs and drinking water samples of the study area indicate obvious variation compared to each other. Based on these results, the minimum pH and maximum of TDS, EC, salinity, total hardness(TH), ...
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The results of physicochemical parameters (pH, Eh, EC, TDS, TH, TA, T, and Salinity) and chemical analyses of the springs and drinking water samples of the study area indicate obvious variation compared to each other. Based on these results, the minimum pH and maximum of TDS, EC, salinity, total hardness(TH), total alkalinity(TA) parameters and cations and anions, major and trace elements (especially As and Sb) concentrations in spring water samples belong to spring Aq.D1-1(located downstream of Aq-Darreh Bala abandoned antimony mine) and spring Sp.5 (downstream of tailing dams of Aq-Darreh Au mineral processing unit) samples, and the drinking water samples of the Aq-Darreh Paeen village ( spring D.W.P). The Aq-Darreh Paeen drinking water, supplied from the spring near the village, outpoured from the mineralized travertine. Compare to the international standards, main cations and anions concentrations and physicochemical parameters values (exception total hardness) of the springs and drinking water samples are located in permissible ranges. While, Aq-D1-1, Sp.5 and W.D.P springs water samples are polluted regarding to total hardness value and As concentration. Based on the geological map of the study area and location of the all spring water samples (except spring Sp.5), it can be concluded that the chemical composition of the bed rocks around the springs had the main role in controlling the water quality, and the main cause of Sp.5 water spring contamination is polluted waters leaked from the tailing dams of Aq-Darreh Au mineral processing unit.
M. Shirkhani; Majid Ghaderi; N. Rashidnejad-Omran; R. Mohammadi-Niaei
Abstract
AyQalesi polymetal deposit is located 30 km southeast of Takab in Orumieh-Dokhtar structural zone. For Enzyme LeachSM analysis at the deposit, 723 samples were collected from B-horizon soils. Based on the analytical results and data interpretation, six oxidation anomalies, A through F, have been defined. ...
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AyQalesi polymetal deposit is located 30 km southeast of Takab in Orumieh-Dokhtar structural zone. For Enzyme LeachSM analysis at the deposit, 723 samples were collected from B-horizon soils. Based on the analytical results and data interpretation, six oxidation anomalies, A through F, have been defined. Five of these are recommended as drill targets while one, anomaly C, is not recommended for drilling because it appears to represent a buried intrusion without significant Zn enrichment. Anomalies B, D and E have very high Zn values. For anomaly D, this is because of outcropping Zn mineralization and the presence of mine waste at surface. Anomalies B and E may occur above shallowly buried mineralized zones. Anomalies A, C and F contain much less Zn. Anomaly A may overlie a concealed zone of Zn mineralization that could be buried to a substantial depth. Anomaly F is not recommended for drilling because it appears to be a quite narrow mineralized zone.
