Petrography and chemistry of minerals show that rocks of Upper Eocene in northeast of Tafresh are composed mostly of andesitic basalt, basaltic andesite and andesite volcanic rocks. Mineralogically these rocks are com...Petrography and chemistry of minerals show that rocks of Upper Eocene in northeast of Tafresh are composed mostly of andesitic basalt, basaltic andesite and andesite volcanic rocks. Mineralogically these rocks are composed of phenocrystals of olivine, clinopyroxene and plagioclase and main texture of them is porphyry with cryptocrystalline or microcrystalline matrix. In addition, aphyric and pitted textures (amygdala) are also observed. According to the results of EPMA, phenocrystals of plagioclase in mentioned rocks include a range of anorthite to albite minerals. Alkali feldspars also contain a range of sodic to potassic minerals. Pyroxene crystals include hedenbergite, augite and hypersthene. Olivine minerals are often of the ferrohornblendite type. Based on thermobarometry it is estimated that to form clinopyroxene crystals of basaltic andesite rocks, temperature between 750°C to 1000°C is needed. Andesitic basalt rocks at higher temperature (1100°C) and andesite rocks at lower temperature (below 750°C) are formed. According to the distribution of aluminum in clinopyroxenes, these minerals at pressures less than 5 kbar and water content between 5% to 10% are crystallized. The mineral composition indicates that these rocks are formed in a tensional environment.展开更多
The reason of this research is to identify the favorable areas for copper, zinc, and lead mineralization in the western part of the 1:100,000 Tafresh geological Sheet in the Urmia-Dokhtar structural zone of Iran. Effe...The reason of this research is to identify the favorable areas for copper, zinc, and lead mineralization in the western part of the 1:100,000 Tafresh geological Sheet in the Urmia-Dokhtar structural zone of Iran. Effective data layers for mineralization, such as geology, geochemistry, structures, and satellite images, were analyzed and then integrated using the AHP-OWA method to identify favorable areas. Geochemical stream samples were analyzed by univariate, multivariate, and classical statistical methods and revealed the first, second, and third class anomalies for copper, zinc, and lead in the study region. Detection of hydrothermal alteration zones by Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite imagery in various algorithms, such as Relative absorption Band Depth (RBD), Minimum Noise Fraction (MNF), and Least Square Fit (LS-Fit), shows that argillic, phyllic, propylitic, and iron oxide alterations develop around the faults in the area under study. The favorable areas for copper, zinc, and lead mineralization have been identified by a combination of evidence maps of lithology, faults, dikes, geochemistry, and alteration data layers. Field observations in the area under study have confirmed the results.展开更多
Our study area “Tafresh” is located in the sedimentary-volcanic belt. This work was carried out as systematic for surveying ore potentials at Tafresh base on the geology, geochemistry, laboratories studies, remote s...Our study area “Tafresh” is located in the sedimentary-volcanic belt. This work was carried out as systematic for surveying ore potentials at Tafresh base on the geology, geochemistry, laboratories studies, remote sensing, and tectonic. According to study of 109 samples, most of the area’s mineralization has been associated with Dacite, Diorite, Tonalite intrusive massive, Andesitic dykes which are related to operation of thrust and strike slip faults. Also, most of these ore deposits had been concentrated at sedimentary rocks of Cretaceous that involves Limestone and Shale in the Southwest and Andesite to Andesitic Basalt at the Northern of Tafresh area. Most of the alterations zones associated with mineralization are androgenic like Argillic, Propylitic, Sericitic, and siliceous alterations that have appropriate adaptation with area’s major faults as well. Eventually, based on the geochemical studies and incorporating all data by GIS software, Tafresh has remarkable concentration of Cu and Au ore deposits that are recognized as Skarn and Hydrothermal ore deposits which are related to fluids flowing from intrusive massive and dykes.展开更多
波斯语和阿拉伯-波斯语文本,经常将新罗作为一个重要的地名。而且很明显,波斯文本中对新罗的描述不能与其他地名相提并论。《阿杰布-马赫鲁格特》是一件手稿的名称,它记载了波斯文学中有关土地、岛屿、海洋、动物、鸟类、人及习俗等奇...波斯语和阿拉伯-波斯语文本,经常将新罗作为一个重要的地名。而且很明显,波斯文本中对新罗的描述不能与其他地名相提并论。《阿杰布-马赫鲁格特》是一件手稿的名称,它记载了波斯文学中有关土地、岛屿、海洋、动物、鸟类、人及习俗等奇妙的内容。卡兹维尼的版本中没有关于地名的设计和绘画。哈吉-穆罕默德-纳西尔-汉萨里(Haji Mohammad Nasir Khansari)于回历1283年(公元1904年),在德黑兰首次出版了该手稿的印本。他在印本中描述了南亚和东南亚(印度到新罗)的土地和岛屿,并附有插图。作为一个例外,新罗被描述得非常积极、文明,充满吸引力和魅力。本文根据画作,重点讨论了新罗与其他国家的显著区别。展开更多
文摘Petrography and chemistry of minerals show that rocks of Upper Eocene in northeast of Tafresh are composed mostly of andesitic basalt, basaltic andesite and andesite volcanic rocks. Mineralogically these rocks are composed of phenocrystals of olivine, clinopyroxene and plagioclase and main texture of them is porphyry with cryptocrystalline or microcrystalline matrix. In addition, aphyric and pitted textures (amygdala) are also observed. According to the results of EPMA, phenocrystals of plagioclase in mentioned rocks include a range of anorthite to albite minerals. Alkali feldspars also contain a range of sodic to potassic minerals. Pyroxene crystals include hedenbergite, augite and hypersthene. Olivine minerals are often of the ferrohornblendite type. Based on thermobarometry it is estimated that to form clinopyroxene crystals of basaltic andesite rocks, temperature between 750°C to 1000°C is needed. Andesitic basalt rocks at higher temperature (1100°C) and andesite rocks at lower temperature (below 750°C) are formed. According to the distribution of aluminum in clinopyroxenes, these minerals at pressures less than 5 kbar and water content between 5% to 10% are crystallized. The mineral composition indicates that these rocks are formed in a tensional environment.
文摘The reason of this research is to identify the favorable areas for copper, zinc, and lead mineralization in the western part of the 1:100,000 Tafresh geological Sheet in the Urmia-Dokhtar structural zone of Iran. Effective data layers for mineralization, such as geology, geochemistry, structures, and satellite images, were analyzed and then integrated using the AHP-OWA method to identify favorable areas. Geochemical stream samples were analyzed by univariate, multivariate, and classical statistical methods and revealed the first, second, and third class anomalies for copper, zinc, and lead in the study region. Detection of hydrothermal alteration zones by Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite imagery in various algorithms, such as Relative absorption Band Depth (RBD), Minimum Noise Fraction (MNF), and Least Square Fit (LS-Fit), shows that argillic, phyllic, propylitic, and iron oxide alterations develop around the faults in the area under study. The favorable areas for copper, zinc, and lead mineralization have been identified by a combination of evidence maps of lithology, faults, dikes, geochemistry, and alteration data layers. Field observations in the area under study have confirmed the results.
文摘Our study area “Tafresh” is located in the sedimentary-volcanic belt. This work was carried out as systematic for surveying ore potentials at Tafresh base on the geology, geochemistry, laboratories studies, remote sensing, and tectonic. According to study of 109 samples, most of the area’s mineralization has been associated with Dacite, Diorite, Tonalite intrusive massive, Andesitic dykes which are related to operation of thrust and strike slip faults. Also, most of these ore deposits had been concentrated at sedimentary rocks of Cretaceous that involves Limestone and Shale in the Southwest and Andesite to Andesitic Basalt at the Northern of Tafresh area. Most of the alterations zones associated with mineralization are androgenic like Argillic, Propylitic, Sericitic, and siliceous alterations that have appropriate adaptation with area’s major faults as well. Eventually, based on the geochemical studies and incorporating all data by GIS software, Tafresh has remarkable concentration of Cu and Au ore deposits that are recognized as Skarn and Hydrothermal ore deposits which are related to fluids flowing from intrusive massive and dykes.
文摘波斯语和阿拉伯-波斯语文本,经常将新罗作为一个重要的地名。而且很明显,波斯文本中对新罗的描述不能与其他地名相提并论。《阿杰布-马赫鲁格特》是一件手稿的名称,它记载了波斯文学中有关土地、岛屿、海洋、动物、鸟类、人及习俗等奇妙的内容。卡兹维尼的版本中没有关于地名的设计和绘画。哈吉-穆罕默德-纳西尔-汉萨里(Haji Mohammad Nasir Khansari)于回历1283年(公元1904年),在德黑兰首次出版了该手稿的印本。他在印本中描述了南亚和东南亚(印度到新罗)的土地和岛屿,并附有插图。作为一个例外,新罗被描述得非常积极、文明,充满吸引力和魅力。本文根据画作,重点讨论了新罗与其他国家的显著区别。
