مجله بلور شناسی و کانی شناسی ایران
سال بیست و هشتم شماره 3 (پیاپی 81، پاییز 1399)

The Cheshmeh Zagh area is located on Khorasan Razavi Province, the southern parts of the Sabzevar zone, which is one of the most important metallogeny zones of Iran. Lithologically, the area includes a variety of Late Cretaceous volcanic rocks (dacite to basalt), intrusions (gabbro to synogranite), Oligo-Miocene sedimentary rocks, and Quaternary sediments. Alteration zones of propylitic, chloritization, and epidotization well developed but the main mineralization zones can be seen in the form of two lens-shaped zones which are surrounded by argillic and silicification-sericitization alterations. Hypogene minerals include pyrite, chalcopyrite, and magnetite; while secondary minerals contain malachite, covellite, and iron oxides. The maximum content of the main elements in the main mineralization zones includes 1.5% Cu, 2230 ppb Au, 40 ppm Mo, 363 ppm Pb, and 738 ppm of Zn. Factors, such as the tectonic setting of the Sabzevar zone, the presence of a large number of Cu-Mn and deposits in relation to the submarine volcanic activities in the region, and the accompanying mineralization with dacitic volcanic rocks containing specific alterations in the Cheshmeh Zagh area, all indicate a probablity of the Bimodal Felsic-type (Kuroko) volcanic massive sulfide origin for these deposits. The Sabzevar structural zone has a great potential for exploration of this type of deposit, which should be taken into consideration.

Geysour area, east of Gonabad, is a part of the northern Lut block. The rocks in this area include granitoid and a series of metamorphic rocks. In metapelitic rocks, the presence of S1 schistosity and the mineral chloritoid are indicative of regional metamorphism. The presence of random textural evidence in minerals such as andalusite, staurolite, muscovite and post-tectonic garnet and silimanite growth within the andalusite margin is characteristic of contact metamorphic rocks. The mineral garnet has two stages of growth, and mainly contains the end-members of Almandine, Grossular and spessartine. Chloritoid and staurolite are ferrous. Muscovite has little paragonite replacement. Chloritization of biotite and garnet, sericitization of andalusite and the occurrence of radial micro-cracks in garnet all indicate a retrograde metamorphism and uplift. Based on conventional geothermobarometric methods, temperature and pressure were calculated in the range of 550-608 oC and 3.8-4.5 Kbar, respectively. The existence of radial micro-cracks around quartz inclusions in garnet is due to a large component of isothermal decompression.

The Aghbolagh area is located about 21 km north of Oshnavieh city, West-Azarbaidjan Province, NW Iran. This study showed that the Fe-Cu skarn deposit in this area can be separated into two zones, (1) Garnet skarn and (2) Garnet-pyroxene skarn. Based upon the results of electron probe micro-analysis, the garnets are chemically of andradite-grossularite type with dominant andraditic component. The pyroxenes are also chemically of diopside-hedenbergite type. The skarnification processes took place in two distinct stages, (1) prograde and (2) retrograde. The lack of wollastonite, intergrowth of garnet and clinopyroxene crystals, and the lack of replacement texture indicate that garnets and pyroxenes were formed  concurrently during prograde stage within the temperature range of 450-500ºC and ƒO2 = 10-23- 10-26. During retrograde stage at temperatures < 430ºC, the anhydrous calc-silicate minerals were altered to hydrous calc-silicates, sulfides (pyrite and chalcopyrite), oxides, chlorite, quartz, and carbonates. During this stage, at temperatures <430ºC, andradite at ƒS2 > 10-6 was altered to assemblages of quartz calcite + pyrite but at ƒS2 < 10-6 to quartz + calcite + magnetite.

The Malek Siah Kuh igneous complex of is located about 35 km north of Zahedan and among the villages of Lar down, Qarqoruk and Horamak. According to the results of rock naming diagrams, the volcanic rocks of Malek Siah Kuh complex have a combination of basaltic andesitic and trachyandesitic and its plutonic rocks show a combination of granodiorite and diorite. Using field studies and lithological studies, it was possible to prepare a lithological map of the area. The most important minerals in the igneous rocks of the region are plagioclase, amphibole, clinopyroxene, quartz and alkaline feldspar. In terms of magmatic series, the igneous rocks of the region show the characteristics of sub-alkaline from calc-alkaline to shoshonitic. Most of the rocks in the area are enriched with LILE and LREE and depleted of HFSE and HREE. These properties of depletion and enrichment in the above elements in the rocks of the region are compatible with the geodynamic environment including subduction zone magmatism. The intrusive masses show the characteristics of type I, metaaluminous and magnesian granites and Cordillera type granites. Determining the characteristics of the origin of the mother magma based on the rare and rare earth elements of the samples of the region shows that these rocks are obtained from partial melting of a mantle of origin with the composition of lherzolite spinel. The studied masses are located in the tectonic environment diagrams in the arc range of the continental active margin type with normal arc characteristics.

Basalts in the Gasht-Masuleh area crop out in the SW Fuman, Gilan Province, and are exposed in the Jurassic and Late Cretaceous units in this area. Whole rock chemistry shows that the rock samples have Mg numbers between 30 and 31.7. Rare earth element patterns (REE) indicate light REE (LREE) enrichment and heavy REE (HREE) depletion (LaN/YbN= 7.7-9.8). Nb, Ta and Ti negative anomalies in primitive mantle normalized multi-element diagrams indicate the formation of parent melt in an arc-related tectonic setting. Clinopyroxene phenocrysts have diopside compositions, crystallized from a calc-alkaline basic parent melt in an extensional tectonic setting. These geochemical features indicate that the basalts of the Gasht-Masuleh area probably formed in an extensional related tectonic setting and inherited their arc signatures from a previous subduction event, possibly of the Paleo-Tethys Ocean crust subduction.

The studied bodies are located in the west of Urumieyeh Lake and northeast of Oshnavieyeh, in the Sanandaj-Sirjan structural zone. Compositionaly, these bodies are formed from gabbro-diorite (Dourbeh) and granite (Nari). Gabbrodiorite rocks are composed of plagioclase (andesine to bytownite), amphibole (calcic group and magnesio-hornblende-tschermakite-hornblende type) and pyroxene (augite) as the essential minerals. The essential minerals in granitic rocks are quartz, plagioclase (albite-oligoclase), alkali-feldspar (orthoclase) and mafic minerals are amphibole (actinolite) and biotite (annite). These rocks are metaluminous and have calc-alkaline nature and belong to I-type granitoids. Geothermobarometry of amphibole and biotite suggest that crystallization equilibrium temperatures at 700-860°C, at 2.21-7.10 Kbar for gabbrodiorite and 740-760°C for granitic rocks respectively. These conditions are in agreement with their formation and indicating crystallization crustal depths of about 8-26 Km.

The Avin kaolin deposit is located about 35km of northeast of the Mianeh town, East-Azarbaidjan Province, NW Iran. Field evidence and petrographic studies indicate that development and formation of this deposit is genetically related to alteration of dacite rocks of Eocene- Oligocene age. In attention to mineralogical data, this deposit consists of minerals such as kaolinite, quartz, muscovite-illite, cristobalite, rutile, orthoclase, and goethite. Investigation of some geochemical parameters such as values of TiO2, Ba+Sr, and Ce+Y+La show that development of this deposit is related to function of two processes of  hypogene and supergene. Incorporation of the obtained results from mineralogical studies, mass changes geochemistry, and variations trend of elemental ratios indicate that chemistry of altering fluids (pH and Eh), surface adsorption, scavenging by metallic oxides, fixation in neomorphic mineralogical phases, ratio of fluid to rock, and amount of availibility to complexing ions are six effetive parameters in mobilization, distribution, and enrichment of trace and rare earth elements in this deposit. Geochemical analysis indicates that decrease of  Eu anomalies in kaolinized samples was related to destruction of plagioclase minerals of the dacitic rocks by high temperature hydrothermal fluids and decrease of negative Ce anomalies is due to development of kaolinization process by fluids with acidic-oxidizing nature.

Malmir area is located in the east of Doroud city, in the Sanandaj-Sirjan metamorphic zone. The earliest deposits contain a relatively uniform sequence of slates and phyllites with silisic veins and veinlet. Various granitoid units, with Middle Jurassic age, are the most important geological event that occurred in the area. Microprobe analyses of tourmalines in pegmatites and and quartz-tourmaline veins show that these tourmalines are schorl-foitite type with dominance of schorl type. Different tourmaline occurrences in the granite units, euhedral forms and absence of chemical zoning, high Fe/Fe+Mg, deficiency in X sites and high Al contents are recognizable in most tourmalines and display their magmatic origin. Therefore, the tourmalines in Malmir area are depended on granite environment and were formed by hydrothermal source of magma. This study shows that the relative amount of Fe# is high and the tourmaline formation area is close to the fluid feed source and the low distance to the intrusive mass.

The sedimentary copper mineralization of the Sorkheh area is located about 20 km northwest of Marand, East-Azarbaidjan Province, northwest Iran. The most important lithologic units in this area include sandstones and red-color shales, with the Late Miocene age, that are intruded by lamprophyric dike. The copper mineralization in the study area occurred as stratiform laminations and disseminations hosted by sandstones and shales and as open-space filling textures within lamprophyric dike. The ore mineralization in the sandstones consists of chalcopyrite, bornite, chalcocite, tetrahedrite, covellite, native copper, and cuprite. This study showed that mineralization is associated with weathering and leaching of the lamprophyric dike. Also, deposition of copper in sandstone units can be related to trapping of organic matters. Activity of the hydrothermal fluids,  presence of abundant organic matters, function of diagenetic processes, existance of the geochemical barriers (organic matter and silicification), and the active tectonic in the area played crucial roles in this ore mineralization.

Sepiolite is an Mg-rich fibrous clay mineral which occurs in agricultural soils of arid regions. Although many investigations have been carried out on the formation and stability of this clay mineral, no information is yet available on the mineralogical changes of this mineral by earthworms. Therefore, this study was conducted to examine the effect of Eisenia foetida earthworms on sepiolite weathering using two factors including the presence or absence of earthworm and also various time periods (90, 135 and 180 days). Upon the completion of the experiment, the amount of available Mg، was measured and the mineralogical changes were studied using an X-ray diffractometer and a field emission scanning electron microscope (FESEM). The results indicated that sepiolite was partially weathered to kaolinite in the treatments with earthworm. The results also indicated that the amount of Mg in all samples decreased with time. Since the amount of dolomite increases with time, it could be concluded that dissolved Mg, released as a result of sepiolite weathering, may combine with dissolved Ca ion to produce dolomite.

The study area is located about 105 kilometers east of Sarbisheh in Southern Khorasan and in the Sistan suture zone. The magmatic rocks of this area are exposed as intrusive and sub volcanice including diorite, quartz diorite, porphyry quartz diorite and porphyry diorite with Oligocene- Miocene age. These rocks have granular, porphyry with fine- grained matrix, ophitic, intergranular and glomerular porphyry textures. The minerals that form the investigated rocks include plagioclase, hornblende, quartz, biotite, clinopyroxene, apatite, zircon and sphene. The magmas that form these rocks are of low calc-alkaline and meta-alumina nature. The samples show relative enrichment of light Rare Earth Elements (LREE) and Heavy Rare Earth Elements (HREE). The negative anomaly of P, Nb and Ti elements and the positive anomaly of K and Cs in these samples indicate their similarity with the volcanic arc magmatism. The enrichment of LILE elements relative to HFSE indicates subduction- related magmas.

The Mehdiabad zinc-lead deposit, which is located at the East of Mehriz city, is a carbonate-hosted ore deposit lying in the dolomitic rocks of Taft Formation. This deposit is composed of oxide-carbonate and sulfide ores. Different spectral processing techniques were applied to ASTER and Landsat 8-OLI multispectral images to detect different mineralization zones and associated alterations. In OLI image, Principal Component Analysis, Independent Component Analysis, and Band Combinations consisting of Band Ratios were successful for detecting mineralization zones and associated alterations. In ASTER image, the best results were obtained from Principal Component Analysis and Linear Spectral Unmixing methods. Based on the results of this study, zinc-lead mineralization occurred in the areas where gossan and siderite alteration zones overlap. The results of the spectral techniques were confirmed by field studies and X-Ray Diffraction analysis of the obtained samples.

Mashkan barite prospect area is located in the northeastern Sabzevar, Khorasan Razavi Province. Geology of the area includes sedimentary rocks of conglomerate, sandstone, limestone with interbeds of shale and shale with interbeds of sandstone and Eocene volcanic units of andesite and trachyandesite. Barite with open space filling, massive, radial, and planar textures occurs as vein-type with mostly northwest-southeast trend. Mineralogy of deposit includes barite, quartz, and calcite and secondary minerals are malachite, azurite, goethite and hematite. The vein mineralization was formed in two stages, including: 1. main stage (barite+quartz) and 2. late stage (calcite). Fluid inclusions in the quartz and barite samples are anhedral to subhedral forms (conical and rod) with a size of about 4 to 12 microns. Maximum  geochemical anomalies in veins are 394 ppm Zn, 52 ppm Sb, and 90 Pb ppm. Based on fluid inclusion studies of quartz and barite samples of the main stage, minimum formation temperature of mineralization is about 181 to 370ºC and with salinity of 6.5 to 13.6 NaCl wt. % equivalent. Based on evidence such as structural control (fault) of mineralization, geology, mineralogy, geochemistry, and fluid inclusion, veins are hydrothermal type. Temperature decreasing and mixing with high salinity fluid during the evolution of hydrothermal fluids are effective during the formation of vein.

The study area known as ‘Chahar-Dahaneh’ is part of the Iranian southeast ophiolites related to Alpian-Himalayan Mesozoic orogeny belt, and is located in the western margin of the Makran subduction zone. Chahar Dahaneh peridotite section consists of three major lithologies including: 1.dunite lenses 2. harzburgites and 3. Lherzolite. Based on electron microprobe analysis ,we estimated pressure of 5kb with 10%wt H2O for magma with temperature of about 1150-1200C for the origin of clinopyroxene crystallization and chrome spinels are ferrian palenaste in composition. Enrichment of Al3+ ratio to Fe3+ in spinels from lehrzolites suggest that they formed in lower oxygen fugacity and higher pressure than those spinels in dunites and olivines are forsterite in type with  88-91 Mg#. Based on microprobe datas, Chahar Dahaneh peridotites are related to back arc metasomatised mantle in SSZ tectonic setting.

The process of migmatitization in the Ghareh Naz has resulted in the formation of various rate of partial melting and eventually the formation of a large spectrum of metatexite and diatexite migmatites. Mineral chemistry studies by EPMA method shows that amphibole composition is magnesio-hastingsite and has a metamorphic origin and feldspar composition is andesine to oligoclase. Effective reactions in the formation of the melt and Leucosome part of migmatites are include fluid-present reactions and fluid-absent reactions. High grade mineral assemblages are probably formed by the decomposition of lower-grade minerals by fluid absent reactions. The mineralogical composition of the leucosome is similar to that of tonalite to granodiorite resulting from partial melting and corresponds to the crystallization origin of the melt. Based on the thermobarometry of these rocks. the temperature is about 767 to 868 °C and the pressure is about 5.7 to 7.7 Kbar.

Palang Dar gabbrodioritic intrusion cropped out in about 30 Km NE of Damghan in the eastern part of the Alborz structural unit. In this area a few small-scale gabbrodioritic intrusions and diabasic dikes with Middle Jurassic age intruded into shale, sandstones and limestones of Shemshak Formation. Emplacement of this intrusion into host rocks are associated with contact metamorphism and formation of marble. Field observation and petrography indicate evidences of fractional crystallization from olivine-gabbro to gabbro, pegmatoid gabbro and diorite. Olivine, clinopyroxene (augite), plagioclase, hornblende and biotite (essential minerals), rutile, sphene, apatite, magnetite and zircon (accessory minerals), chlorite, calcite, epidote, secondary sphene and iron oxides (secondary minerals) found in these gabbrodiorites and fractionated members. These rocks have alkaline to calc-alkaline nature and based on discrimination tectonic setting diagrams, they plotted in the domain of basalt in relation to intracontinental extensional setting (back arc basins). Evaluations of REE diagrams and spider diagrams which normalized to chondrite and primary mantle (in respectively) indicate that the studied rocks enriched in light rare earth elements (LREEs) and large ion lithophile elements (LILEs), and depleted in heavy rare earth elements (HREEs) and high field strength elements (HFSEs). Based on geochemical and petrogenetical studies, alkaline-calc-alkaline magma formed the Palang Dar gabbrodiorites from low rate partial melting (about 10 percent) of a metasomatized subcontinental lithospheric mantle with original garnet peridotitic nature in nearly 100 to 110 Km depth and in intracontinental extensional setting (back arc basin). Geochemical evidences indicated magma forming of Palang Dar gabbrodiorite contaminated with upper crustal during it’s ascend and emplacement. These magmatic activities had been a part of magmatic activities in relation to synchronous with extension and extent of Jurassic back arc basin of Alborz.

Oxide materials such as Al2O corundum has a great influence on the mechanical and oxidation properties of refractory or refractory materials. In this paper, the effect of Al2O3 powder density, apparent porosity, linear shrinkage, and oxidation resistance of SiC composite refractory materials is investigated. Meanwhile, the compressive and flexural strengths were investigated before and after heat treatment. The mechanisms of oxidation resistance of SiC composite refractory materials have been investigated by using atmospheric heating at temperatures above 1400°C. The microstructures and phases, that formed in this research, have been investigated by corundum enhancement, using (SEM) scanning electron microscopy. Increasing the amount of Al2O3 reduces the linear shrinkage and consequently increases the density and mechanical strength. Moreover, with the maximum values ​​obtained by adding Al2O3 at 8 wt%, the flexural strength was initially increased and then decreased.

The Goushe granitoid Pluton is located southeast of Boroujerd. The study area is composed of granite, granodiorite and the microgranular enclaves located in it with the granodiorite to quartzmonzodiorite combination. The microgranular enclaves presence along with evidence of the presence of the non-equilibrium textures such as dissolved margin and plagioclase zoning, sieve textures, mafic clots, blade biotite, feldspar Poikilitic texture indicate the unstable conditions and imbalance in the crystallization environment that probably has been created due to rapid ascent of magma or magma mixing process. Alkaline feldspar and plagioclase crystals in the Goushe intrusive rocks show zoning structure in terms of composition and texture. Feldspar crystals were analyzed in different units such as granodiorite, monzogranite and microgranular enclaves, which are relatively abundant throughout the granitoid intrusion. The plagioclase chemical composition in granitoid rocks changes in the compositional range of albite (An: 2) at the edge to Andzin (An: 33) in the center and the enclavesn plagioclase composition of in a wider range fluctuates from early oligoclase (An: 11) to mid-andesine (An: 36). The alkaline feldspar composition is determined in granitoid rocks with Or = 94-97 and in the enclave with Or = 69-96. The abundance of trace elements Fe, Sr, Ba and Mg in feldspars show an oscillating and variable pattern. The trace and rare elements oscillation pattern from the center to the margin in the feldspar crystal indicates the effective role of the magmatic mixing phenomenon in the formation of the Goushe Pluton.

A new azo-Schiff base"Ethyl 2-((E)-(4-((E)-(4-ethylphenyl)diazenyl)-2-hydroxybenzylidene)amino)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate" was prepared by the reaction of "Ethyl 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate" and "(E)-5-((4-ethylphenyl)diazenyl)-2-hydroxybenz aldehyde" (1:1 molar ratio) in MeOH under reflux condition. The structure of compound was studied by elemental analysis, including IR and 1HNMR spectroscopy and single crystal X-ray diffraction method. The synthesized compound has been crystallized in triclinic system with Pī space group and a = 9.752 (2)Å, b = 10.349(2)Å, c = 13.263(3)Å, α = 87.72(3)˚, β = 75.80(3)˚, γ = 62.21(3)˚ cell parameters. The final R value is 0.098 for 4038 independent reflections. X-ray diffraction results confirm the planar geometric structure with a slight deviation and intermolecular hydrogen bond for the compound.

In this paper, the bismuth vanadate (BiVO4) nanoparticles were synthesized at 600 °C calcination temperature by co-precipitation method. To study the crystal structure, morphology, optical and photocatalytic properties of the samples, the X-ray diffraction analysis, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy and ultraviolet– visible spectroscopy were used. The X-ray diffraction patterns were indicated that the BiVO4 samples have a monoclinic structure. The ultraviolet-visible analysis was revealed the BiVO4 samples have an optical band gap in the visible light range. The photocatalytic activities of the synthesized BiVO4 were evaluated by photodegradation of Congo red under visible light irradiation. According to the results of the analysis, the synthesized nanoparticles is a good choice for the degradation of organic matter into the sunlight.