مجله بلور شناسی و کانی شناسی ایران
سال سی‌ام شماره 2 (پیاپی 88، تابستان 1401)

The Pirashkaft bauxite deposit is located in north of the Paskuhak anticline in the Fars Province. The bauxite deposit present between Sarvak and Gurpy Formations, and formed during the Late Turonian time as a consequent of the Laramid orogeny phase. According to the geological investigations, the Pirashkaft bauxite is  Karstic type. The residual ore studied in the Pirashkaft can be classified into three groups: 1) kaolinite bauxite, 2) bauxite and 3) ferrite bauxite. Petrographically, pisolithic–oolithic is the most important texture. Mineralogically, the main minerals include boehmite, hematite, diaspore and kaolinite and minor minerals comprised of: gibbsite and rutile. The major oxides in the bauxite horizons mainly included: Al2O3 (37.88- 55.45wt%), SiO2 (2.01- 30.49wt%), Fe2O3(10.14- 36.71wt%) and LOI ( 9.72- 15.32wt%). There is a strong positive correlation between Al2O3 and TiO2, and also an enrichment of LREE (136.49- 928.56 ppm) relative to HREE (16.48-59.5 ppm) is observed in the bauxitic horizons.  The Eu / Eu* anomaly of the bauxite samples ranges between 0.26 and 0.99. Positive anomaly of Ce / Ce* between 1.2 and 2.33, indicates the dominant oxidation during bauxitization.

Angouran zinc and lead deposit is located about 135 km west of Zanjan city, in the northwest of the Sanandaj-Sirjan structural zone The results of this study indicate that the dolomitic alteration occurred in the carbonate hanging-wall and the presence of ankerite in the schist footwall. The main host of ore deposit is metamorphic carbonate. The Angouran dolomite is secondary and hydrothermal. Formation of secondary porosity in dolomite provided the required space for the formation of sulfide ores including sphalerite, galena and pyrite, in the carbonate host rock. We found out that sphalerite of Angouran is rich in iron, cadmium and germanium, and the galena is rich in antimony and silver. The geothermometry of Angouran sphalerite indicates that the mineralization temperature ranges between 170-190º C. Comparing these characteristics with other lead and zinc deposits, it is concluded that Angouran deposit is most similar to Mississippi Valley Type (MVT) deposits, and mineral chemistry and formation temperature are fundamentally different from other types of mineralization.

The Ay Qalasi Pb-Zn (Ag) epithermal deposit is located in the south east of Takab, northwest of Iran and is formd at the Urmia-Dokhtar magmatic belt and the Sanandaj-Sirjan zone intersection. Based on microscopic and EPMA analysis, the composition of this series is tennantite-tetrahedrite. These minerals are mainly replaced in host minerals. The EPMA analysis data show that their chemical composition is a function of the mineralogical composition of the sulfide ores in which they have been replaced. Tertiary dacitic domes replacement adjacent to the deposit has led to the formation of hydrothermal solutions with high fugacity of sulfur and arsenic, and to a lesser extent antimony. Due to the fault's reactivation, the initial sulfide minerals to be brecciated and provides the conditions for the penetration of these fluids. The penetration and circulation of these fluids in the brecciated parts of the deposit, due to the high fugacity of sulfur and arsenic, impose new thermodynamic conditions on the system, which in turn leads to the instability of sulfide minerals. In the new condition, the clasts of sphalerite, chalcopyrite, and pyrite ores react with these fluids to form sulfosalt minerals of tennantite-tetrahedrite series.

Temelieh area is located about 20 Km northwest of Selseleh (Lorestan Province). Geologically, the area is a small part of the Harsin radiolarite complex. Petrography consists of radiolarite, peridotite, gabbro, plate dikes, basalt and andesite, limestone, and marble. Manganese mineralization occurs as vein-veinlet and is mainly formed in faults, joints, and fractures that crosscut in radiolarites. Based on mineralogical studies, the manganese paragenesis is composed of pyrolusite, psilomelane, todorokite, cryptomelane, lepidocrocite, and manganese oxide-hydroxide (housmanite, hydrohousmanite, Manganite). The essential waste minerals are calcite and quartz. Based on geochemical data from major and trace elements, using different distinguishing charts and elemental ratios, there is a good relation between the manganese-rich region and the hydrothermal deposits. On the other hand, calculation of element designated ratios like Mn/Fe )mean 0.92), Ti/Al (mean 0.01), Co/Ni (mean 0.97), Co/Zn (mean 0.28), U/Th (mean 0.73), La/Ce (mean 0.32), LREE/HREE (mean 8.64) and ΣREE (mean 56.53) indicate Temelieh manganese ore is hydrothermal. Comparison of the REE normalized pattern of Temlieh manganese ore with other manganese deposits in the world indicates the hydrothermal origin of this deposit. REE distribution pattern indicates Ce positive anomaly with mean 24.5 and Eu negative anomaly with mean 0.54 that is compatible with hydrothermal manganese deposit. Accordingly, ore-forming fluids could be originated from meteoritic or magmatic water circulating through volcanic rocks, dissolve manganese and other metals and, while rising from suitable areas, deposits them in along the fault planes and fractures.

The Lapeh-Zanak copper deposit is located about 15 km east of Tehran, in the southern part of the Central Alborz Zone. The rock units exposed in this area include a sequence of volcanic and pyroclastic rocks (basalt, andesite, trachy-andesite and dacitic and vitric tuff) belonging to the Fajan Formation with the Paleocene-Lower Eocene age, which are cut by subvolcanic igneous masses with a composition of micromonzodiorite-gabbro. Copper mineralization in the Lepeh-Zanak deposit occurred in the form of quartz veins-veinlets (± carbonate and barite) along with silicic, argillic, carbonate and propylitic alterations in andesite-trachyandesite rocks. Vein-veinlet and breccia structures and textures are very common in the copper- bearing ore in this deposit. The mineralogy of ore is simple and includes primary minerals of pyrite, chalcopyrite, magnetite, hematite and rutile, which are accompanied by secondary minerals such as digenite, covellite, malachite, and iron hydroxide compounds. The fluid inclusion studies of quartz and barite minerals in copper-bearing ores and barite veins indicate that majority of primary inclusions are two-phase liquid-rich (L+V). Microthermometric studies show that the homogenization temperatures in quartz and barite vary in the range of 100 to 198 and 110 to 207 °C, respectively. Salinity in the primary inclusions of these two minerals shows the range from 0.88 to 8.55 and 4.96 to 7.86% wt% NaCl eq., respectively. Salinity in quartz and barite minerals is in the range of 0.88 to 8.55 and 4.96 to 7.86 wt% NaCl eq., respectively. Based on the results of microthermometric of fluid inclusions, cooling and dilution of hydrothermal fluids with atmospheric waters are the main reasons for the deposition of minerals in the studied deposit. The combination of the results obtained from geological, mineralogical, alteration and fluid inclusions reveals that the Lapeh-Zanak copper deposit has most similar to low-intermediate sulfidation epitermal-type deposits.

The study area is located in the south of Qushadagh mountain range, in the north of Asbkhan village, Heris township. In terms of structural geology of Iran, this area is located in the main zone of Central Iran and Alborz-Azerbaijan sub-zone. The geological units of the region are including Eocene igneous and pyroclastic rocks with combination of andesitic, trachyandesitic, basaltic, tuffic and ignembritic. The semi-deep intrusive mass with Oligocene age, with the combination of quartz diorite, diorite and quartz monzonite in the form of stock and dyke is exposed in the area. Under the influence of hydrothermal processes originating from this intrusive mass and infiltration of fluids through the sedimentary-volcanic units of the Middle Eocene, extensive alterations (sericitic, medium argillic, propylitic and siliceous) have been taken place in the region. Preliminary results of geochemical studies of stream in the region led to the identification of several areas with grade 1, 2 and 3 anomalies of heavy minerals. The most important heavy minerals identified, include hematite, goethite, magnetite, pyrite-oxide, pyrite and zircon, These minerals and have closely relation to the alteration zones and veins mineralization. The conformity of the geochemical halos map with the geostructure and alteration map of the region shows a very high correlation between these regions and possibly the important role of faults and joints in the occurrence of alteration zones and abnormal regions. Anomaly maps and geostatistical analyzes performed on the findings in stream sediments and heavy minerals show that the enrichment of Ag, Au, Mo, Cu, As, Pb, Sb and Zn elements is higher than the background and the Au, Ag, Cu, As and Pb elements can be used as trace elements for epithermal gold reserves.

Kishan lead-zinc deposit is one of the Malayer-Esfahan metallogenic belt deposits, located NW Arak, Markazi Province. The fluid inclusion microthermometry of the primary liquid-vapor bearing fluid inclusions trapped in the cogenetic quartz veins exhibited a homogenization temperature ranges from 140 and 272 °C (average 208.47 °C from 68 fluid inclusions), corresponding with the salinity of 10 to 22 wt.% NaCl equivalent (average 17.78 wt. % NaCl equivalent from 68 fluid inclusions) and density of 0.9 to 1.1 gr/cm3, illustrating the Irish-type characteristic in the Th versus salinity diagram. Additionally, following the mineralogical study and identifying three main mineralization stages of the Kishan deposit, including pre-, main- and late-stages, the sulfur isotope (δ34S) of six galena samples from the main mineralization stage were measured. The δ34S data varies between -3.76 and -5.36‰, which after temperature corrections by fluid inclusion microthermometeric data with average of 200 °C gave a narrow range of -0.98 to -1.76‰, consistent with the sulfide precipitation from the bacteriogenic sulfur-reduction. Consequently, the Irish-type metallogeny of Kishan deposit mostly involves with the intermittent mixing of the relatively cool and dense brines modified from the contemporaneous seawater with the circulating principal ore fluids containing leached metals from the beneath basement, i.e. metamorphosed shale and sandstone of Shemshak Formation. However, considering the extent of granitoieds in the area, recognizing of the plausible magmatic origin of sulfur and metal of the deposit also requires accurate dating of the igneous bodies and further studies.

The Anjir Khajeh area is located in the southern part of Sanandaj-Sirjan metamorphic belt in northwest of Golgohar iron mine. The rock units of the region include metabasites, metasediments, igneous and sedimentary rocks. Metasedimentary rocks containing mica-schist, garnet schist, and garnet staurolite schist, having metamorphosed into greenschist facies and amphibolite facies. Garnet mineral is the most abundant porphyroblasts in metasedimentary rocks which is present in the form of  amorphous to semi-amorphous with the large to medium sizes. Electron Microprobe results show the solid dissolution evidences of garnets with the highest frequency in almandine type. Based on petro-fabric analysis, three generations of garnets are identified that have different chemical and Raman spectral characteristics too. These three generations include Almandine rich, Grossular rich and Pyrope rich  garnets that have been analyzed and classified based on petrography, mineral chemistry and Raman spectroscopy. Almandine rich type with higher Iron content and lowest peak wavenumber under 320 cm-1, Grossular rich type with relatively lower Fe and higher Ca content and highest peak wavenumber between moderate frequencies of 400 to 650 cm-1 and Pyrope rich type with higher Mg and lower Fe content and highest peak wavenumber more than 800 cm-1 can be seen. The petrogenetic investigations of the Anjir Khajeh garnetschists classifies their protholites as shale and sandstone that geodynamicaly formed in a continental island arc setting.

The Daraloo ore deposit area, structurally located in the Central Iran and Urumieh Dokhtar magmatic belt, is situated in the south of Kerman Province. In this region, Eocene andesitic flows and pyroclastic rocks have been invaded by Oligo-Miocene hypabyssal intrusive bodies. Most of the intrusive samples are granodiorite porphyry to monzogranite porphyry with a microgranular groundmass and affected by severe phyllic alteration. Mineralogical and geochemical evidence show that Daraloo granitic rocks are calc-alkaline, metaluminous to slightly peraluminous and I-type in nature. Clear negative Nb-Ti anomalies in most samples can be explained by the fractionation of titanium-containing phases such as titanite and titanomagnetite. Also, obvious enrichment in the large ion lithophile elements (LILEs such as K, Rb, Ba and Cs) and light rare earth elements (LREEs) compared to high field strength elements (HFSEs such as Ta, Nb, Ti and Zr) and heavy rare earth elements (HREEs), all clearly show a geochemical feature of magmas generated in subduction environments. So, it can be concluded that Daraloo granitic rocks must be formed in an active continental margin environment as a result of subduction of the Neotethys oceanic crust beneath the Central Iranian microcontinent during the Tertiary time.

In this study, nano-sized cobalt oxide samples were prepared by changing the NaOH concentration by co-precipitation using N-octyl pyridinium bromide [OPy][Br] ionic liquid in an aqueous medium. Properties of prepared nanostructures were investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), vibration sample magnetometer (VSM), and ultraviolet-visible (UV-Visible) spectroscopy. XRD diffraction results show that with increasing NaOH concentration, the average size of crystals decreased. In this paper, the smallest particles in the range of 19 to 23 nm were obtained using 3 mmol NaOH. Using FE-SEM images, it can be seen that the particles have a spherical and plate-like shape. The value of Eg for the sample with the smallest crystal size of 17 nm has the highest bandgap energy of 3.01 electron volts. VSM analysis of the samples showed that all samples were ferromagnetic in nature and the saturation magnetization of the samples decreased with decreasing particle size.

The reaction of magnesium chloride and cadmium nitrate with benzene-1,2,4,5-tetracarboxylic acid in the presence of NaOH and in aqueous solution led to formation of 3-dimensional coordination polymer formulated as, [Cd(bta)Na(H2O)4Mg0.5].2H2O}n(1) (btaH4 = benzene-1,2,4,5-tetracarboxylic acid),. The crystal structure of 1 was determined by X-ray diffraction. The Single-crystal X-ray structure shows that the asymmetric unit of 1 consists of cadmium, sodium and magnesium in (1:1:0.5) ratio. Three metals cations are linked with oxygen atoms of benzene-1,2,4,5-tetracarboxylate.  Benzene-1,2,4,5-tetracarboxylate acts as bidentate and monodentate bridging ligand and causes to making trimetallic 3-dimentinal coordination polymer.

In this research, Graphene/ Bismuth aerogel nanocomposite was fabricated by hydrothermal method and it’s structural, magnetic and photocatalytic properties were investigated. For this purpose, aerogel of nanocomposites were prepared with a concentration of 4 for graphene oxide and concentrations of 0.2, 0.5 and 1 mg/ml for Bismuth ferrite. Phase and structural studies with XRD and FT-IR analyzes confirm the formation of bismuth ferrite with a rhombohedral structure of perovskite type and reduction of graphene oxide. The SEM images show the porous structure of graphene aerogel well. TEM analysis confirms the composite of bismuth ferrite nanoparticles in the structure of graphene aerogel. The energy gap of the samples was calculated from the results of UV-Visible spectroscopy. Based on the parameter measured by the vibrating sample magnetometer (VSM), it shows a decrease in the magnetization saturation of bismuth ferrite nanoparticles after composite with graphene aerogel. Methyl blue decomposition was evaluated by bismuth ferrite nanoparticles and graphene/ferrite bismuth nanocomposites using UV-Vis apparatus. The best photocatalytic performance of graphene/bismuth ferrite aerogel is in the sample with 0.5 mg/ml concentration.

Muddy volcanoes are one of the most fascinating and significant features of the earth's crust. The purpose of this research is to get a better knowledge of the physical qualities of clay muddy volcanoes, such as magnetic properties and structural characteristics, and to conduct quantitative analysis to determine the substances contained therein. Particle sizes ranging from 0.07 to 12.00 microns were determined using scanning electron microscope images. Infrared spectroscopy has shown adsorption peaks associated with many substances. The sharp and significant peaks of the samples were identified as quartz and calcite during the study of the X-ray diffraction data. Magnetometer demonstrated paramagnetic characteristics at relatively high applied magnetic fields, and modest ferromagnetism at low applied magnetic fields.

The effect of Ba ion substitution on structural, optical, and magnetic properties of Mn0.3-xBaxCu0.2Zn0.5Fe2O4 ferrites was investigated. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, UV-Vis spectroscopy, and vibrating sample magnetometer at room temperature. Structural results show that the structure of the samples with x up to 0.20 is completely indexed to a single-phase cubic structure (space group Fd m), while the impurity phase of BaO is observed in the samples with x = 0.25, 0.30. As the substitution content increases, the presence of non-magnetic Ba2+ ions in the octahedral site decreases the saturation magnetization of the samples. Comparison of the bandgap energy of the samples shows an increasing trend with Ba substitution for x up to 0.10 and then decreases, which can be interpreted in terms of changes in the electronic structure of the samples.