Eocene to Oligocene volcano-plutonic rocks arewidespread throughout NW Iran. The Tarom-Hashtjinme... more Eocene to Oligocene volcano-plutonic rocks arewidespread throughout NW Iran. The Tarom-Hashtjinmetallogenic province is one of the most promisingepithermal-porphyry ore mineralized districts in NW Iran.The Glojeh gold deposit, located in the center of thisprovince, is a typical high to intermediate sulfidation epithermalsystem, spatially and temporally associated witha granite intrusion and associated high-K calc-alkalineto shoshonitic volcano-plutonic rocks. The intrusive complexesof the Glojeh district are characterized by: SiO2contents of 60.9 to 70.7 wt.%, K2O+Na2O of 7.60 to 8.92wt.%, and K2O/Na2O ratios of 0.9 to 1.8. They are enrichedin light rare earth elements (LREEs), and large ionlithophile elements (LILEs), depleted in high field strengthelements (HFSEs), and have weak negative Eu anomalies(Eu/Eu*= 0.5 to 0.9). 40Ar/39Ar geochronology appliedto biotite and feldspar, separated from two intrusives(Goljin and Varmarziar), and two feldspar aliquotsseparated from hydrothermal...
The granitic intrusives in southwest Saqqez are located in the northern Sanandaj Sirjan zone. The... more The granitic intrusives in southwest Saqqez are located in the northern Sanandaj Sirjan zone. These granites can be divided into mesocratic and leucocratic granites. The external morphology and internal structures of zircon from these granites have been investigated employing the classic Pupin method supplemented by electron microscope analysis. The zircon crystallization is a function of temperature, chemical composition, water content of magma, velocity of crystallization and Zr saturation of magma. So, we have focused on the study of zircon to evaluate the chemical characteristic of these bodies. The minimum temperature of crystallization in mesocratic granite based on morphology of zircon crystal ranges from 784 to 847°C and for leucocratic granite ranges from 704 to 785°C, which show good correlation with calculation of saturation temperature of zircon (755 to 866°C for mesocratic granite; 755 to 832°C for leucocratic granite). Crystal growth {101} in most of zircon crystals in...
Abstract The Qolqoleh gold deposit is located in the northern part of the Sanandaj-Sirjan Zone (S... more Abstract The Qolqoleh gold deposit is located in the northern part of the Sanandaj-Sirjan Zone (SaSZ), northwest Iran. The main host rocks include mylonitic granite and chlorite schist. Four generations of Au-bearing sulfides have been identified and are referred to as Py1 to Py4. LA-ICP-MS elemental maps and spot analyses of gold and other trace elements in Py1 to Py4 were performed to provide robust information about the ore-forming fluid and conditions of saturation. Element compositions in all generations of pyrite show heterogeneity in fluid compositions and reflect the role of a multistage hydrothermal system in their formation. The earliest hydrothermal event is related to magmatic fluids synchronous with magmatic fluids from a granitic pluton emplacement in Carboniferous time. Multistage magmatism and related heating caused reaction, replacement, and recrystallization (RRR) of original Py1, generating overgrowths of Py2 to Py4. The variation in the Au-As rim compositions shows that fluctuating temperatures occurred during overgrowths of pyrite. The ratios of Co/Ni for most Py1 to Py4 are higher than 1. This along with the high Te contents infer that the ore-forming fluids came from mainly a magmatic source with low redox conditions. The increase in Au and other elements in Py2 and Py4 shows enrichment through the coupled dissolution-reprecipitation reaction (CDRR) mechanism in response to greater non-metamorphic fluids. The bulk δ34S values range from 3.1 to 6.9‰. Two samples range from 13.8 to 14.3‰, which are compatible with a main magmatic source and to a minor metamorphic source for the ore-forming fluids. Subsequently, dextral movements caused brittle-ductile deformation and dislocation of mineralization and mylonitization. However, this study determines that the Qolqoleh deposit is a magmatic-related gold deposit.
Magnetiteapatite deposits in the Alborz volcanoplutonic belt, southeast Zanjan, in Iran, have b... more Magnetiteapatite deposits in the Alborz volcanoplutonic belt, southeast Zanjan, in Iran, have blade, lenzoid, and vein forms, which extend in an EW direction. There are many magnetiteapatite veins and veinlets in this region, and some of them are economically ...
ABSTRACT Garnets show wide ranges of chemical compositions and are key minerals for reconstructin... more ABSTRACT Garnets show wide ranges of chemical compositions and are key minerals for reconstructing the thermodynamic evolution of metamorphic terranes. The properties of garnets – including Mohs hardness ~7, lack of cleavage, vitreous luster and multiple colors – also makes them useful as semi-gemstones. Garnets are widespread accessory minerals in igneous and metamorphic rocks of western and southern Iran and are especially abundant in skarns and regional metamorphic rocks. 45 garnet deposits of western and southern Iran show six associations: (1) skarn (35 locations); (2) peraluminous granitoid and rhyolite (4 locations); (3) alkaline granite (1 location); (4) metamorphic rocks (3 locations); and (5) ophiolites (2 locations). Distinct garnet compositions are found in each association: mostly grossular-andradite in skarn, Ti-andradite in alkaline granite, almandine in peraluminous granite and volcanic rocks, almandine-grossular in metamorphic rocks and andradite- uvarovite associated with ophiolites. Western and southern Iran garnets are mostly related to skarns around Cenozoic granitoid intrusions. Ti-rich garnet formed at the expense of clinopyroxenites in alkaline igneous complexes due to alkaline metasomatism. These associations are useful for understanding garnet semi-gemstone deposits in western and southern Iran.
Abstract Late Neoproterozoic basement of the Soursat complex to the southeast of Shahin-Dej, NW I... more Abstract Late Neoproterozoic basement of the Soursat complex to the southeast of Shahin-Dej, NW Iran, spans an area wider than 100 km2 and is cut by Paleogene monzonite and granodiorite bodies. Zircon U-Pb dating yields monzonite and granodiorite crystallization ages of 54.7 ± 3.8 Ma and 57.7 ± 2.9 Ma, respectively. The monzonite group has relatively high MgO (2.40–7.01 wt%), Cr (37.5–233 ppm) and Ni (30.6–177 ppm), and high Sr/Y (103−132) and La/Yb (68.0–102) similar to low silica-adakites (LSA). The granodiorite group has low MgO (
Eocene to Oligocene volcano-plutonic rocks arewidespread throughout NW Iran. The Tarom-Hashtjinme... more Eocene to Oligocene volcano-plutonic rocks arewidespread throughout NW Iran. The Tarom-Hashtjinmetallogenic province is one of the most promisingepithermal-porphyry ore mineralized districts in NW Iran.The Glojeh gold deposit, located in the center of thisprovince, is a typical high to intermediate sulfidation epithermalsystem, spatially and temporally associated witha granite intrusion and associated high-K calc-alkalineto shoshonitic volcano-plutonic rocks. The intrusive complexesof the Glojeh district are characterized by: SiO2contents of 60.9 to 70.7 wt.%, K2O+Na2O of 7.60 to 8.92wt.%, and K2O/Na2O ratios of 0.9 to 1.8. They are enrichedin light rare earth elements (LREEs), and large ionlithophile elements (LILEs), depleted in high field strengthelements (HFSEs), and have weak negative Eu anomalies(Eu/Eu*= 0.5 to 0.9). 40Ar/39Ar geochronology appliedto biotite and feldspar, separated from two intrusives(Goljin and Varmarziar), and two feldspar aliquotsseparated from hydrothermal...
The granitic intrusives in southwest Saqqez are located in the northern Sanandaj Sirjan zone. The... more The granitic intrusives in southwest Saqqez are located in the northern Sanandaj Sirjan zone. These granites can be divided into mesocratic and leucocratic granites. The external morphology and internal structures of zircon from these granites have been investigated employing the classic Pupin method supplemented by electron microscope analysis. The zircon crystallization is a function of temperature, chemical composition, water content of magma, velocity of crystallization and Zr saturation of magma. So, we have focused on the study of zircon to evaluate the chemical characteristic of these bodies. The minimum temperature of crystallization in mesocratic granite based on morphology of zircon crystal ranges from 784 to 847°C and for leucocratic granite ranges from 704 to 785°C, which show good correlation with calculation of saturation temperature of zircon (755 to 866°C for mesocratic granite; 755 to 832°C for leucocratic granite). Crystal growth {101} in most of zircon crystals in...
Abstract The Qolqoleh gold deposit is located in the northern part of the Sanandaj-Sirjan Zone (S... more Abstract The Qolqoleh gold deposit is located in the northern part of the Sanandaj-Sirjan Zone (SaSZ), northwest Iran. The main host rocks include mylonitic granite and chlorite schist. Four generations of Au-bearing sulfides have been identified and are referred to as Py1 to Py4. LA-ICP-MS elemental maps and spot analyses of gold and other trace elements in Py1 to Py4 were performed to provide robust information about the ore-forming fluid and conditions of saturation. Element compositions in all generations of pyrite show heterogeneity in fluid compositions and reflect the role of a multistage hydrothermal system in their formation. The earliest hydrothermal event is related to magmatic fluids synchronous with magmatic fluids from a granitic pluton emplacement in Carboniferous time. Multistage magmatism and related heating caused reaction, replacement, and recrystallization (RRR) of original Py1, generating overgrowths of Py2 to Py4. The variation in the Au-As rim compositions shows that fluctuating temperatures occurred during overgrowths of pyrite. The ratios of Co/Ni for most Py1 to Py4 are higher than 1. This along with the high Te contents infer that the ore-forming fluids came from mainly a magmatic source with low redox conditions. The increase in Au and other elements in Py2 and Py4 shows enrichment through the coupled dissolution-reprecipitation reaction (CDRR) mechanism in response to greater non-metamorphic fluids. The bulk δ34S values range from 3.1 to 6.9‰. Two samples range from 13.8 to 14.3‰, which are compatible with a main magmatic source and to a minor metamorphic source for the ore-forming fluids. Subsequently, dextral movements caused brittle-ductile deformation and dislocation of mineralization and mylonitization. However, this study determines that the Qolqoleh deposit is a magmatic-related gold deposit.
Magnetiteapatite deposits in the Alborz volcanoplutonic belt, southeast Zanjan, in Iran, have b... more Magnetiteapatite deposits in the Alborz volcanoplutonic belt, southeast Zanjan, in Iran, have blade, lenzoid, and vein forms, which extend in an EW direction. There are many magnetiteapatite veins and veinlets in this region, and some of them are economically ...
ABSTRACT Garnets show wide ranges of chemical compositions and are key minerals for reconstructin... more ABSTRACT Garnets show wide ranges of chemical compositions and are key minerals for reconstructing the thermodynamic evolution of metamorphic terranes. The properties of garnets – including Mohs hardness ~7, lack of cleavage, vitreous luster and multiple colors – also makes them useful as semi-gemstones. Garnets are widespread accessory minerals in igneous and metamorphic rocks of western and southern Iran and are especially abundant in skarns and regional metamorphic rocks. 45 garnet deposits of western and southern Iran show six associations: (1) skarn (35 locations); (2) peraluminous granitoid and rhyolite (4 locations); (3) alkaline granite (1 location); (4) metamorphic rocks (3 locations); and (5) ophiolites (2 locations). Distinct garnet compositions are found in each association: mostly grossular-andradite in skarn, Ti-andradite in alkaline granite, almandine in peraluminous granite and volcanic rocks, almandine-grossular in metamorphic rocks and andradite- uvarovite associated with ophiolites. Western and southern Iran garnets are mostly related to skarns around Cenozoic granitoid intrusions. Ti-rich garnet formed at the expense of clinopyroxenites in alkaline igneous complexes due to alkaline metasomatism. These associations are useful for understanding garnet semi-gemstone deposits in western and southern Iran.
Abstract Late Neoproterozoic basement of the Soursat complex to the southeast of Shahin-Dej, NW I... more Abstract Late Neoproterozoic basement of the Soursat complex to the southeast of Shahin-Dej, NW Iran, spans an area wider than 100 km2 and is cut by Paleogene monzonite and granodiorite bodies. Zircon U-Pb dating yields monzonite and granodiorite crystallization ages of 54.7 ± 3.8 Ma and 57.7 ± 2.9 Ma, respectively. The monzonite group has relatively high MgO (2.40–7.01 wt%), Cr (37.5–233 ppm) and Ni (30.6–177 ppm), and high Sr/Y (103−132) and La/Yb (68.0–102) similar to low silica-adakites (LSA). The granodiorite group has low MgO (
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