مجله بلور شناسی و کانی شناسی ایران
سال سی و یکم شماره 1 (پیاپی 91، بهار 1402)

Cheshmeh-Bid chromite deposit is located in Nayriz ophiolite, about 200 km northeast of Shiraz. The ophiolite sequences in this area include ultramafic rocks (dunite, harzburgite, and pyroxenite). In this deposit, chromites are present in the mantle-crust transition zone and are enclosed by dunite. Based on chemical studies of major elements, chromite is depleted from Al and Ti elements and enriched by Fe, Cr and Mg. The calculated values of TiO2, Al2O3 and FeO/MgO indicates that the parent magma is the Boninite magma type with composition equilibrium to the podiform chromites. These chromitites are the result of relatively high melting of the mantle and Boninite melt, which are formed as a result of rising and mixing of magma with mantle harzburgites in the upper environment of the subduction zone. Variations in the chromite mineral composition along with the textural changes in host ores indicate the injection of at least two mineralizing melts in the study area.

Khut Copper deposit, located in west of Yazd, is one of the most important skarn deposits in Taft mining area where it is locateds in the middle part of the Urumieh-Dokhtar magmatic belt. Intrusion of Khut granodioritic stock into carbonate component of the Nayband Formation has led to the formation of Cu skarn deposit and different skarn zones. Mass changes has led to mineralogical variations in the different skarn zones. In this paper, element mass changes and element mobility in the skarn zones relative to the unaltered carbonates rocks are calculated. Results of these calculations show the most mass increase in the major elements of Si, Fe and Mn in the skarn zones. REE and the other rare elements such as Rb, U, V, Nb,Cr, Y, Cu and Zn have also shown mass increase. Enrichment value in the light rare earth elements can be attributed to the abundance of garnets and its composition, so that the amounts of light rare earth elements in the Al bearing garnets are higher than andradite garnets. In this paper, the causes of these changes and their effects are discussed by using geochemical method of mass change calculations.

The alpine ultramafic-mafic Sargaz-Abshour complex in the SW of Baft, as a part of the ultramafic-mafic/ophiolitic intrusives of the Hajiabad-Esfandagheh region, comprises of tectonite units (foliated harzburgite and porphyroclastic dunite), layered ultramafic-mafics, large isotropic gabbro bodies and scattered microgabroic-diabase dykes. In this complex, olivines are the main mafic residual phase in porphyroclastic dunites and harzburgites, as well as magmatic cumulate phase in chromitites, ultramafic and layered mafics. In most cases, composition of olivine is chrysolite and in chromitite is forsterite. Their compositions are consistent with mantle peridotites, abyssal peridotites, alpine massives and magmatic cumulative series. Due to the refractory nature in porphyroclastic dunites and primitive crystal phases in chromite and layered cumulative dunites, percentage of forsterite content is high, and will reduced with the progress of differentiation in the mafic layered rocks. These changes may indicate the residual nature of olivine and evolution of Mg-rich mantle-derived magma. Different source and origin of magmas  have been compareable with other ultramafic-mafic complexes of Esfandagheh region and alpine ultramafic-mafic intrusions which distinct from ophiolites.

Makran amphibolites are exposed in different locations in the northern Makran ophiolitic belt. Based on lithological studies and mineral assemblages in these rocks, they are containing ordinary amphibolite (oriented and massive), garnet-pyroxene amphibolite, epidote-garnet amphibolite and marble. The minerals that made up ordinary amphibolites (oriented and massive) include amphibole, plagioclase, zircon apatite, quartz and sphene. In addition to these minerals, garnet and pyroxene are found in garnet-pyroxene amphibolites. In addition, epidote, garnet and pyroxene are found in epidote-garnet amphibolites. Also, marbles are containing calcite with a distinct cleavage, quartz and amphibole. Geochemistry of amphibolites shows that these amphibolites are of igneous origin with basaltic protolith that originate from an enriched mantle. Amphibolite samples of the region have relatively similar composition based on the diagrams of changes of normalized rare earth elements to chondrite and N-MORB and are also similar to mid-oceanic ridge basalts (MORB) as well as within plate volcanic zone (WPVZ) basalts in terms of geochemical properties.

Many mafic dykes, with the Early Paleozoic age, have intruded into Zarigan granitoid pluton and its host sedimentary units in the northeast of Bafq city. Petrographycal studies show these dykes are alkaline gabbro to monzogabbro with medium to fine grain intergranular to granular textures. Major minerals include clinopyroxene, amphibole and plagioclase and minor minerals are a few amounts of biotite, olivine, alkali feldspar, and nepheline. Amphiboles are calcic and belong to kaersutite-potasic kaersutite type. Geothermo-barometry calculations, based on amphibole mineral, show the prevailing pressure and temperature of kaersutites crystallization at 6.3-8.2 Kbar and 1040-1140 °C. According to geochemical composition, kaersutites are in the range of alkaline amphiboles, so that they are derived from mantle and are related to intercontinental extensional tectonic environment. Based on these evidences, minerals have been crystallized from the magmas originated from asthenospheric upwelling during Paleo-Tethys early rifting and associated with Posht-e-Badam block basement tension faults function.

In the Bisheh area, intrusion of hornblende porphyry diorite in limestone and tuffs rocks caused skarn formation. Garnet and pyroxene are the most abundant minerals in prograde exoskarn, respectively. In retrograde processes, epidote, tremolite-actinolite, quartz, calcite and opaque minerals such as magnetite were formed. Electron microprobe analysis shows that the studied garnets are andradite-grossular solid solution. Studied garnets show variations in Fe3+/Al ratio that is related to changing conditions during growth. Studied pyroxenes are very close to diopside end member and lowest diopside content is 64.97%. Based on garnet and pyroxene composition, the average  logarithm of oxygen fugacity is calculated -20.18 megapascal. The presence of magnetite, pyrite and pyrrhotite along with calcite and quartz show that metasomatism fluids probably had ƒS2~10-7 and temperature < 430°C.

The magmatic-metamorphic Tutak Complex, as a part of the Bavanat belt, is located in the high pressure-low temperature metamorphic belt of the Sanandaj-Sirjan Zone. The complex contains schists, marbles, granite gneiss, meta-granitoid, meta-aplite granite, amphibolites, and meta-dolerite with different ages and degrees of metamorphism. Based on field evidence, the rocks are not uniformly distributed throughout the complex, thus, the Tutek Complex can be divided into central and marginal sub-zones. In the central sub-zone, most of the metasediments are calcschist, micaschist, garnet-muscovite-schist, and quartz-feldspathic-schist, and types of metabasites include amphibolite and garnet-amphibolite. In the marginal sub-zone, most metasediments are biotite-epidote-schist and meta-basites including of schist-amphibolite and amphibolite. Combining field evidence and microstructures in the metasediments and the metabasites from both sub-zones suggests that the rocks have mainly undergone metamorphism and deformation under the amphibolite to green-schist facies conditions in the central sub-zone and green-schist facies conditions in the marginal sub-zone.

The Sartip Abad metamorphic complex in Qorveh (Kurdistan Province) is located in the Sanandaj-Sirjan zone. The complex is composed of regional metamorphic rocks including contact metamorphic rocks (hornfels), variety of schists (amphibole schist, actinolite schist, mica schist, and garnet schist), marble, metadiorite, metagabbro, and paragneiss. In schists and paragneiss, biotite is siderophilite and in hornfels and metadiorite is anite to phlogopite in composition, respectively. Paragneiss and metadiorites include hornblende and actinolite. The garnets, in the garnet-mica schist, are almandine type, and plagioclase crystals in the metadiorites and metagabbros are labradorite type in composition, as well as their paragneiss have andesine- type plagioclase. Petrography and thermobarometric studies indicate that the different types of regional metamorphic rocks are formed in green schist to epidote-amphibolite facies and in the interval between biotite and staurolite zones. But for contact metamorphic rocks, the maximum facies is assumed albite-epidote hornfels in isograd of zoisite to amphibole. Thermometry calculations, using biotite single and garnet-biotite exchange, show that the average temperature for the metamorphic rocks of this region is about 567°C and for the contact metamorphic rocks is about 647 °C. Also, we used thermo-barometer methods for M1 and M2 metamorphic stages. Data are yielded, M1 stage temperature and pressure are about 578°C and 5.16 kb and for M2 stage ~565 °C and 4.6 kbar. Based on field relationships, petrographic evidence and geochemical data, protoliths are sedimentary rocks including greywackes/arkoses and shales for paragneiss, hornfels and schists, respectively.

The study area is located about 45 km southeast of Hamedan, northeast of Azandarian city and east of Alvand batholith. Graphite is seen in two forms in the region: 1) in the form of graphite veins with 5 to 10 cm thickness, in contact with smoky quartzite veins, 2) Scattered in spotted graphite schist, containing large crystals of muscovite, quartz, garnet, andalusite, kyanite and biotite. In this region, the most important impurities associated with graphite are ​​sersite and muscovite. In the X-ray diffraction pattern (XRD), graphite peaks with hexagonal crystallization system were observed in the samples. Thermometric studies show that there are 4 types of fluid inclusions in quartz veins:1) LCO2 + VCO2 + LH2O 2) LCO2 + VCO2, 3) VH2O + LH2O and 4) LCO2 + VH2O. Homogenization temperature for the fluids inclusions in all two-phase samples (range between 240-150) is 180 ° C in average, and calculated salinity is between 3 to 16.4% by weight equivalent of NaCl according to H2O-CO2-NaCl system. In addition, presence of CO2 in the fluids inclusions indicates the hydrothermal origin of available quartzite veins. The results of petrographic and physical properties studies of graphite mineral indicate, the formation of this mineral from the metamorphic transformation of organic matter from initial sediments to amphibolite facies. The mineralization of graphite in this deposit is directly related to formation of quartz hydrothermal vein of origin.

The Guydash Fe deposit is located in the south of East Azarbaijan Province, about 27 km southwest of Qara Aghaj city at the northwestern parts of the Sanandaj-Sirjan zone. This research was conducted to study the mineralogy of the ore and the geochemistry of the intrusive bodies producing skarn mineralization. A set of granitoids with porphyry diorite-monzodiorite and porphyry granodiorite-monzogranite compositions have intruded  into the Jurassic carbonate rocks and caused iron skarn mineralization. The ore is composed dominantly of magnetite with subordinate minerals including hematite, pyrite, chalcopyrite, tetrahedrite, tennantite and goethite. The skarn zone includes various minerals of garnet (grossular and andradite), pyroxene, chlorite, epidote, actinolite, calcite and quartz. This mineral assemblage indicates that the skarn is calcic. In the geochemical diagrams, skarn-producing igneous rocks locate in granite and monzodiorite fields. All of these rocks are calc-alkaline, diorite rocks are meta-aluminous, and granodiorite rocks are per-aluminous in nature. Granodioritic rocks are adakite-type with high silica, and dioritic rocks are ordinary calc-alkaline type. The enrichment of Rb, Th, Ba and U, and the depletion of Nb and Ti elements in these rocks relative to the primitive mantle is comparable to the rocks derived from subduction zones. The chondrite-normalized REE patterns are almost similar for the studied rocks, indicating their richness in light rare earth elements (LREE) compared to heavy rare earth elements (HREE). The LaN/YbN ratio in these rocks indicates the absence of garnet at the source site and the shallow depth of magma formation. Granodiorite-producing magma is obtained by melting of the thinned lower crust. The Nb/Zr and Sr/Ce ratios in these rocks reveal that magma was formed by melting of the subducted crust and the sediments on it. The studied rocks fall in the category of igneous intrusions relating to magmatic activity in the active continental margin, in a continental arc.

The Jizvan region with an area of ​​45 km2 is located about 70 km northwest of Zanjan town in the Tarom-Hashtjin metallogenic zone. The major rock units in the Jizvan area consist of a regular sequence of thin-layered tuff and breccia tuff with intermediate to basic compositions, interlayered with andesites and basalts. In addition, volcanic trachytic and porphyry andesitic rock units are also scattered in the region. Parts of the tuff and breccia tuff sequence are intruded by hypabyssal quartz monzonite, monzodiorite and syenite intrusions in the east of the region. As a result of this event, due to the presence of linear structures and the invasion of hydrothermal fluids, the above-mentioned rocks are affected by advanced argillic alteration. Carbonatic (malachite) and sulfidic (chalcopyrite, bornite, tetrahedrite-tennantite and chalcocite-covellite) copper mineralizations, along with pyrite, galena, sphalerite, arsenopyrite, quartz, calcite and goethite minerals are developed with a vein-veinlet texture in the above-mentioned units. Using the study of primary biphase fluid inclusions containing liquid and gas phases, homogenization temperatures from 95.6 °C to 268.9 °C with the highest frequency at 185 °C are recorded. The salinity of mineralizing fluids is between 4.65 and 23.8 wt% NaCl equivalent, while their density falls in the range from 0.77 to 1.08 g/cm3. Based on the fluid inclusion data, the mixing between magmatic and meteoric waters is the main cause for precipitation of metallic elements and the occurrence of mineralization in Jizvan area. These data overlap with the representative data of epithermal deposits.

Nickel oxide thin films were successfully percipitated at different substrate temperatures (440, 460, 480, and 500 oC), spray rates (1, 2.5, 5, and 7.5 ml/min), solution volumes (50, 100, 150, and 200 ml), and nickel concentration (5, 10, 15, and 20 at.%) glass substrates using NiCl2.6H2O as precursor and the spray pyrolysis technique. The structural and  optical properties of the thin films were characterized. They show a polycrystalline nature with a cubic structure of single-phase NiO and peaks related to (111), (200), and (220) with a preferential orientation along (111). The morphology of the NiO thin films resembles that spherical grains on the entire surface, with an average roughness ranging from 28.71 to 105.63 nm, depending on the deposition conditions. The range of the optical gap and Urbach energy were measured to be 2.55 to 3.49 eV and 0.41 to 0.55 eV, respectively.

In this study, ZnS/MoS2 nanocomposites were synthesized by hydrothermal and ZnS/MoS2/Fe3O4 nanocomposite by chemical co-precipitation methods. ZnS nanoparticles were synthesized initially and then loaded with MoS2 nanostructure. After that ZnS/MoS2 product was mixed by Fe3O4 nanoparticles and the final product that obtained, was ZnS/MoS2/Fe3O4 nanocomposite. XRD, FTIR, TEM, BET and Raman Analyses were used to identify and characterize the samples. Photoluminescence spectroscopy was employed to investigate the optical properties of both composites. The infrared Fourier transform spectra showed a well developed Zn-S, Fe-O and Mo-S bonds. X-ray diffraction pattern confirmed the presence of cubic structure for ZnS and Fe3O4 and hexagonal structure for MoS2. Electron microscopy images well confirmed the formation of nanostructures. Based on PL spectroscopy, the intensity of the luminescence peak decreased, which could be due to a decreases in the electron-holes recombination percentage of the triplet sample compared to the binary sample. Photocatalytic activity of ZnS/MoS2/Fe3O4 on degradation of methyl orange (MO) and acid brown (AB) dye degradation was investigated using UV radiation. The sample showed good photocatalytic activity and can be easily recycled due to its magnetic properties, which can be used as photocatalyst in other reactions.

Microstructural, optical, and photocatalytic properties of (x = 0, 0.05, 0.10, 0.15) LaMn1-xZnxO3 nanoparticles have been investigated by X-ray diffraction, Raman and Fourier transform infrared spectroscopy, field emission scanning electron microscope, Energy-dispersive X-ray spectroscopy, and UV-Vis spectroscopy. Our study indicates that there is a structural phase transition from the rhombohedral (space group R3c) to the orthorhombic (space group Pbnm I) structure. Lanthanum manganese (LM) is one of the most promising and efficient photocatalysts for the degradation of organic pollutants. To determine the photocatalytic performance of LaMn1-xZnxO3 nanoparticles, the effects of three operational parameters including irradiation time, pH, and the catalyst amount on the degradation of aqueous solution of methyl orange (MO) and methyl blue (MB) were investigated. The results showed that LaMn0.9Zn0.1O3 has higher photocatalytic activity than the LM for degradation of MO and MB under sunlight. A possible mechanism for better photocatalytic performance of the samples was discussed. The LaMn0.9Zn0.1O3 did not exhibit any significant loss after six cycles of the degradation of MO and MB under the same conditions.