Iranian Journal of Crystallography and Mineralogy
Year:2020 | Volume:27 | Issue:4|Papers Count:17

The Kuh-Baba iron ore deposit is located about 70 km south of Hashtroud, East-Azarbaidjan Province, NW Iran. The deposit is genetically affiliated with intrusive bodies of gabbroic to dioritic composition. The principal host rocks for the Fe mineralization include units of gabbro-norite and pyroxene hornblende gabbro-norite. The widespread alteration zones which are accompanied with Fe-mineralization are actinolitization, chloritization and epidotization. The principal ore mineral is magnetite with subordinate apatite showing massive, vein/veinlet, replacement, brecciated, and disseminated textures. The results of electron probe micro-analysis (EPMA) on 28 points of magnetite crystals show relatively high amounts of elements such as Al, Mn, Ti, and V. The values of components such as TiO2, V2O3, NiO and MgO in massive magnetites are higher than those present in disseminated and veinlet-type magnetites. Studies of primary fluid inclusions in quartz crystals coexisting with magnetite mineralization show that they are mainly liquid-rich 2-phase (L+V) and occasionally monophase-vapor (V). The homogenization temperatures of liquid-rich 2-phase inclusions range from 436º C to 544º C (average of 505º C). Based on temperatures of the last melting point of ice (TM), the obtained average salinity is 15. 82 wt% NaCl equ. Considering the measured parameters such as homogenization temperature, salinity, density, and pressure of the fluid inclusion, the depths of magnetite mineralization were estimated to be within the range of 1. 3-2. 7 (average of 2. 3) km (based on the lithostatic pressure). According to the EPMA and fluid inclusion data, the Kuh-Baba iron ores deposit can be classified as a ‘ Kiruna-type’ and subtype Iron-Oxide apatite-poor deposits and the origin of magnetite can be conceived as both magmatic and high-temperature hydrothermal.

The Shalang vein-type polymetallic ore deposit is located about 10 km southwest of Kerman and 70 km northeast of Sirjan, and lies in the central part of the Dehaj-Sarduieh metallogenic belt. This deposit is hosted by dacitic and andesitic vitric and crystal tuffs along with andesitic-dacitic lava flows of Eocene age. The alteration zones related to this deposit are propylitic, intermediate argillic, silicic, and carbonatized. Mineralization occurred principally as veins/veinlets in two separate stages, the hypogene (Chalcopyrite, Pyrite, Magnetite) and the supergene (Bornite, Chalcocite, Malachite, Azurite, & Hematite). The hypogene mineralization also took place in two distinct episodes, (1) formation of quartz-sulfide veins/veinlets and (2) development of carbonate-sulfide veins/veinlets. The average concentration values of cu, Pb, Zn, Au, and Ag within the ore-bearing veins/veinlets are 2. 5%, 0. 26%, 0. 16%, 1. 3ppm, and 28ppm, respectively. The strong positive anomaly values of Eu (5. 03-10. 31) and Ce (1. 48-5. 06) indicate an alkaline pH and reduced nature, respectively for the ore-forming fluids in the depositional environment. The microthermometric studies on fluid inclusions within the cogenetic quartz crystals were carried out. The studied fluid inclusions were chiefly of liquid-rich two-phase type and all of them were homogenized into liquid state. The obtained homogenization temperatures (Th) of the analyzed fluid inclusions varied within the range of 226º-313º C. The salinities of the studied fluid inclusions range from 3. 4wt% to 9. 9 wt% NaCl equivalent. Based upon microthermometric results, the boiling concurrent with cooling were two essential mechanisms in development and evolution of this deposit. Presence of colloform, cockad, blabed, and replacement textures in the ores, development of intermediate argillic and carbonatized alteration zones, and the low salinities and temperatures of the studied fluid inclusions provide persuasive evidence that the Shalang vein-type polymetallic ores have the most similarity to the low-sulfidation epithermal deposits.

SahebDivan porphyry copper system is located in Alborz-Azarbaijan magmatic zone at northwest Iran. Based on geological surveys, petrographic and geochemical studies, indicated that mineralized stock in this system mainly cosists of granodiorite, diorite and monzonite rocks. These rocks are peraluminous and belong to high-K calc-alkaline and shoshonitic magma series and plotted in the field of I-type granites. In Harker diagrams, SiO2 has a negative correlation with the elements of Al2O3, CaO, K2O, MgO, P2O5, TiO2, FeOt, Co, V and positive correlation with Cr, La, Zr and Nb. Enrichment in large-ion lithophile elements (e. g., Cs, Th and U), depletion of high-field-strength elements (e. g., Nb, Ta and Ti) and enrichment in light rare earth elemements than heavy rare earth elements with negligible Eu anomaly is another geochemical features of SahebDivan granitoid rocks. Tectonic setting discrimination diagrams indicate that these stock formed in a post-collision volcanic arc environment in the active continental margin. Geochemical data, indicates that partial melting of the lower continental crust due to the penetration of mantle melts in equilibrium with the residual consisting of amphibole and pyroxene and pyroxene with next function of contamination and fractional crystallizatin processes played role in the formation and evolution of this rocks.

Maharlou Lake, as the largest water body neighboring to the metropolis of Shiraz, plays a significant role in adjusting the ecosystem of the region. The objective of this study was to evaluate mineralogy and heavy metals enrichment in the surface sediments of the Maharlou Lake. The result showed a decreasing trend of heavy metals concentrations in studied region surface sediments as follows: Sr>Ni>Cr>Zn>Cu>Co>Pb>As>Cd. The XRD analysis revealed that main mineral phases including aragonite, calcite, halite and quartz, with lesser amount of montmorillonite, dolomite and sepolite. The result of Canadian sediment quality guidelines showed a rather toxic situation for investigated heavy metals. In addition, in terms of toxicity unit, the highest measure of generating toxicity for Ni and Cr were calculated. Among all sample stations, the most collected toxic unit and potential ecological risk were related to Lake inlet which is adjacent to the Khoshk River. In order to identify the source of heavy metals concentrations as well as major oxides, the multivariate statistical analysis used method. The result indicated that elements such as Ni, Co and Cr with major mineral-bearing oxides show can have a surce from Razak Formation, while the significant relationship between Sr, S, and calcium, magnesium and sodium oxides revealed the source from evaporate and carbonate rocks, which is mainly related to Sachun Formation in the investigated area. Also, the elements Pb, Cu. Cd, Zn and As, in the surface sediments of the lake can be related to human activities around the lake.

In The northern part of Kerman Volcanic Belt, southwest of Rafsanjan (Deh-Zahir area), a series of diabasic intrusives have intruded into the Eocene andesitic lava flows and pyroclastic rocks. These plutons occur as irregular shaped bodies (up to 8 m in diameter) and dikes (up to 4 m in thicknesses). They show ophitic, sub-ophitic, and porphyritic textures and their major minerals include plagioclase (bytownite), and clinopyroxene (diopside), with titanomagnetite as secondary mineral. Based on The petrographic characteristics, presence of the enclaves and chemical variations from core to rims of the pyroxenes and plagioclases suggest that the parent magmas probably tolerated magma mixing processes. Geothermobarometric studies on the clinopyroxenes indicate a temperature range of 1050-1200oC and pressures of more than 2 kbar. Accordingly, beginning of the clinopyroxenes crystallization can be considered approximately at the depth of 20 Km, i. e. in the middle crust. Furthermore, these evidences show that the oxygen fugacity was low and water vapor pressure was less than 10 kb during the crystallization of clinopyroxenes in the diabase rocks. Based on the chemical compositions of the clinopyroxenes, the primary magmas for these rocks had been calc-alkaline in nature and formed in a volcanic arc setting.

The Rangraz area is located about 20 km north of Saveh, which is situated in the central part of Uromieh– Dokhtar magmatic arc. The exposed rocks in the study area consist of a volcanic and volcanoclastic subvolcanic dikes and quartz monzodiorite intrusions. Mineralization in this area is mostly related to the silicic, argillic and chloritization alteration assemblages. The Rangraz area consists of 6 mineralized zones and mineralization appears in veins-veinlets and dissemination. The main ore minerals are chalcopyrite, specularite, pyrite, magnetite, bornite, chalcocite, covellite, and the gangue minerals are quartz, barite, and calcite. Supergene processes in the upper part of the mineralized zones have led to the formation of malachite, azurite, hydrated Fe and Mn oxides, covellite, chalcocite, and digenite. Gold in the study area does not occur as a free mineral, but the SEM observations revealed that chalcopyrite and specularite have a high content of gold. According to geochemical data, igneous host rocks in this area are calc-alkaline in nature and are formed at a magmatic-volcanic arc zone. In comparison with primitive mantle, they are enriched in LILE elements (Ba-k) and depleted in HFSE elements (Nb-Ti) and such pattern is similar to subduction environments. In addition, enrichment of LREE relative to HREE in chondrite normalized diagram show that the igneous rocks are formed in a subduction zone.

The Rigmalak granitoid is located East of Taftan volcano, southeast of Zahedan, in Sistan Suture Zone. This pluton (Oligo-Miocene) has intruded into Eocene Flysch deposidt and cause low metamorphism in the borders. This pluton is composed of granite, synogranite, monzogranite, granodiorite, tonalite, pegmatitie and diorite in composition. The main minerals in this pluton are quartz, plagioclase, orthoclase, biotite and hornbelande and they are mainly granoular to pegmatitic in texlures. Presence of biotite and hornbelends minerals in this granitoides show that it is simillar to Zahedan granitoid and it is belonging to I type granite. Geochemical studies show that these rocks have calcalkaline to low alkaline magmatic series and metaluminous, I type, enrichment from LREE and LILE and depleted from HREE and HFSE. Major, rare and trace elements digramas of shows crystal defferintation is important role the formation pluton. Digrams normalized to chondorite and primitive mantle show that rocks formed this pluton are enriched in LREE to HREE and dominantly simillar and parall trends. Also, Zr and Th elements show positive anomalyes and Sr, Nb and Ti negative anomalyes, similar to subduction zones. Tectono magmatic diagrams show Rigmalak granitoid rocks related to syncollision to low post collision environments. Geochemical evidence of Rigmalak samples showed that crystal differentiation was not the only effective process in the formation of magma but may be several phases or melting of a phase with different degrees also may happened in the region. It seems that the formation of this granitoid in the Sistan suture zone is related to the collisions between Lut and Afghan blocks.

A sequence of Tertiary basic volcanic rocks is exposed in the east of Qazvin. The volcanic sequence is mainly composed of olivine-basalt to trachyandesite with porphyrictic, microlitic, and glassy textures. Clinopyroxene, plagioclase, amphibole, and iddingsitized olivine are the main phenocrysts. According to EPMA data plagioclase shows labradorite to bytownite composition and clinopyroxene is diopside. Geothermobarometry of clinopyroxene and amphibole represents the temperature of 1100 C to 1200 C and pressure of 1 to 5 kbar during crystallization of these minerals. According to the geochemical data, the sequence shows calc-alkaline affinity which is related to volcanic arc setting. In comparison to chondrite, they are enriched in LILEs and depleted in HFS elements. Also based on geotectonic diagrams, these rocks have been derived from a high potassium calc-alkaline to shoshonitic magma in an active continental margin setting. Ti and Nb negative anomalies and LILE enrichment support an enriched mantle in a supra-subduction zone as a source for magma. According to this study, the magma originated from a low grade 5 to 10 % partial melting from an enriched garnet-spinel lherzolitic mantle source at depth of 50-70 km and finally has risen to the surface via deep fractures and faults within an intra-arc extensional basin in Central Alborz zone during the Middle and Upper Eocene time.

Talkhabvand mine is located east of Bajestan, Khorasan Razavi Province, and northwest of Lut Block. Geology of the area includes Jurassic metamorphic rocks, Cretaceous limestone, intrusive rocks, and skarn unit and Eocene volcanic rocks. Barite mineralization as vein, with mainly NW-SE trening has cut all rock units. Minerals consist of barite, quartz and calcite associated with minor oxidized pyrite and galena and secondary minerals such as goethite, limonite, covellite, malachite and anglesite. Positive anomaly of La and Gd, high negative anomaly of Ce (-0. 5 to-1. 27), and Ce/La <1 (0. 05 to 0. 55) reveal that barites have formed in marine environment. Although, field evidences reject this issue. LREE/HREE enrichment of barites indicates that the ore-fluid was Cl-rich. Formation temperature of different minerals of Talkhabvand deposit ranges between 138 to 390º C and is occurred from NaCl-, and CaCl2-bearing fluid with 7. 5 to 15. 8 wt. % NaCl equivalent salinity. The results indicate that barium-and silica-rich solutions originate from magmatic water. Increasing the salinity of the ore fluid in the final stages is due to the addition of basinal saline waters to the environment. Based on geology, mineralization, geochemistry of major oxides and REE, and fluid inclusion studies, Talkhabvand deposit can be hydrothermal barite.

The Eocene suite of volcanic rocks in Parandak area is located about 30 km NE of Saveh and is the host of different species of zeolites filling vesicles, amygdales and fractures. The elements forming for the formation of zeolites derived from the alteration of volcanic glass matrix and primary magmatic minerals. Based on their frequency, these zeolites are: natrolite, mesolite, tetranatrolite, scolecite, thomsonite, chabazite, analcime, stilbite, and epi-stilbite. In addition, other secondary related minerals are: chlorite/smectite, calcite (I), calcite (II), quartz and chalcedony. Development of zeolites in the basalts of the study area starts with lower Si/Al, Na-bearing and gradually grade into higher Si/Al Ca-bearing. It seems that the formation of zeolites might have occurred in two hydrothermal fluid stages. first stage, natrolite, mesolite, tetranatrolite and second stage, scolecite, thomsonite, chabazite, stilbite and epi-stilbite. It is estimated that the temperature of zeolite crystallization was less than 150 0C.

Geochronology and isotope geology of the Late Neoproterozoic granitic and gneissic rocks of the Neybaz complex (West of Saghand)Neybaz igneous and metamorphic complex (west of Saghand, North Yazd) is one of the Late Neoproterozoic Iranian basement terrains which include a wide variety of igneous and metamorphic rocks. Some parts of metapelitic outcrops of this complex can be considered typical evidence of partial melting, migmatitization and mylonitization. The obtained ages of the complex and the adjacent complexes (such as Chapedony, Tashk and Zaman Abad), based on K-Ar, Rb – Sr, Sm-Nd and U-Pb methods, show several ages ranging from Late Neoproterozoic to Miocene. But the presence granitic and gneissic pebbles bearing conglomerate which originated from basement of the Lower Cretaceous sedimentary sequence of the southwest of Saghand indicate that age younger than Cretaceous which attributed to Neybaz complex are not correct. Some of the reported ages are only reflected the tectonomagmatic or tectonometamorphism events which affected these crystalline basement complexes during different times, such as Middle Jurasic metamorphism and Eocene to Miocene magmatism activities. Based on the regional evidence and field relationships, the range of 570 to 530 Ma is more consistency with actual regional geology. The events happened during this time, most likely related to Cadomian orogenic evolutions. Hafni isotopic investigations on granitic rocks of this complex indicate that the eHf of the studied rocks show negative values and varies from-1. 02 to-18. 87. The negative eHf values correspound with originating of granitic melt from crustal rocks or the same gneissic rocks of Neybaz complex (west of Saghand).

Champeh salt dome is located in the north of Bandar Lengeh (Hormozgan Province). This dome has penetrated into the Champeh anticline with sequences from the formations in as ending order of Pabdeh, Jahrom, Asmari, Gachsaran, Mishan and Aghajari. The compositions of volcanic rocks inside this dome are different ranging from rhyolite to basalt and are accompanied by granodiorite rocks. The study of mineral chemistry in granodiorite rocks shows that the amphiboles are located in the calicic group and subgroup of ferrohornblende. The plagioclase of these rocks is albite and alkali feldspar is an orthoclase. Barometric measurement, based on the amount of Al in Amphiboles, shows the amphibole crystallization pressure as 1. 54 kbar. Thermometry, shows based on the coexistence of hornblende and plagioclase minerals in granodiorite rocks, the crystallization temperature ranging between 684 ° C to 811 ° C. The amount of calculated oxygen fugacity for these amphiboles is about-17. 08, which shows the conditions of the oxidant environment at crystallization. Based on the whole rock geochemistry, the composition of igneous rocks changes from mafic to acidic, corresponding to that the nature of their magma as calc-alkaline. In the normalized multi-elemental of chondrite and primary mantle diagrams, in most samples LREE enrichment is observed in comparison to HREE and depletion of Ti, P, Ta and Nb, which is characteristic of volcanic arc of the subduction region and in different tectonic diagrams, they represent the active continental margin environment. The result of U-Pb zircon dating of granodiorite is 549. 2± 4. 8 Ma (Late Neoprotrozoic time).

Bahramtaj Pb-Zn deposit is located about 90 km NW of Yazd, central Iran. The area has been located in Central Iran geotectonic zone and hosted in dolomitic limestone of Paleozoic age. The purpose of this research is to investigate Zincian-dolomite as one of the important effects of the alteration process. Zincian-dolomite as a non-sulfide zinc mineral is characterized by a different amount of Zn, as well as lower amounts of Pb, Cu, and rarely Cd. Characterization of Zn-bearing dolomite, using differential thermal analysis, shows a drop in temperature of the first endothermic reaction of dolomite decomposition with increasing Zn contents in dolomite. The substitution of dolomite by zincian-dolomite supergene is known as a part of a multi-stage mineralization process in Bahramtaj, which begins with the development of the zincian-dolomite process and continues with the dolomitization of the previous dolomites, and finally results formation of zinc non-sulfide minerals such as smithsonite and hemomorphite.

Migmatites have formed an important part of high-grade metamorphism in the Boroujerd area aureole. Leucosome of migmatites are mainly composed of plagioclase, quartz, potassium feldspar and biotite. Migmatites mesosome are mainly composed of plagioclase, quartz, potassium feldspar, biotite, garnet, andalusite, sillimanite, spinel, corundum and cordierite. Geochemical studies of migmatites show that composition of old meta-sedimentary rocks (source of migmatites) are shale and pelitic. Discrimination diagrams indicate an active continental margin tectonic setting for the source of Boroujerd migmatites. Sources of Boroujerd migmatites are intermediate and felsic igneous rocks (andesite – dasite and ryodacite) based on geochemistry of immobile elements. Field observations, microscope and geochemical data show that the migmatites are composed of the metaplites partial melting. Decreasing and increasing trace and rare earth elements in the metaelites and migmatites were resulted of stability or instability in the metamorphic minerals during peak of the metamorphism, which caused migmatization. Based on the partition coefficients of elements in different minerals, light rare earth elements and high rare earth elements (LREE, HREE) were mostly controlled by garnet and apatite (but not a lot) during the partial melting of the metaelites. Related to the LREE, heavy rare earth elements (HREE) and Y were controlled by garnet. Elements with high field strength (HFSE), such as Zr, Nb, Ta and Th were controlled and distributed by biotite and ilmenite. Large ionic lithophile elements (LILE) such as Sr, Ba and Rb showed that plagioclase and biotite are the main minerals that control and distribution the elements. Based on the P– T pseudosection, Crd+Kfs+Spl+Crn minerals paragenesis, the maximum temperature and pressure for metamorphism estimated approximately 750 ° C and 2. 7 kbar respectively. Therefore, the intrusion of mafic intrusions in the metapelite caused the formation of pelitic hornfels and partial melting derived migmatites.

1-Phenyl-1, 2-ethanediol was synthesized from the hydrolysis of epoxy styrene in water medium. The compound was characterized by FT-IR and NMR spectroscopic methods and structure was characterized by single crystal X-ray diffraction method. The crystallographic information was collected at 293 K. This compound is crystallized in the triclinic space group with unit cell parameters of a = 6. 0274(10) Å , b = 16. 204(2) Å , c = 17. 345(2) Å ; α = 117. 584(14)° , β = 99. 322(13)° , γ = 90. 047 (14)° , V = 1476. 1 (4) Å 3 and Z = 8. The asymmetric unit of the crystal structure consists of four molecules of 1-phenyl-1, 2-ethanediol which are connected to each other by strong hydrogen bond and C-H∙ ∙ ∙ π interactions. A supramolecular network is generated by intermolecular O-H∙ ∙ ∙ O and C-H∙ ∙ ∙ O hydrogen bond interactions.

Yttrium calcium borate Y2CaB10O19 (YCB) compound is a new member of Rare Earth Borate compounds with nonlinear optical application. In the present research, the synthesis of YCB compound was investigated by using solid-state reaction method. Instead of usual preliminary and secondary thermal treatments, a single stage thermal process was developed. This new method is particularly important in terms of reducing the time and cost of synthesis. The structure of produced powder was analyzed by X-Ray diffraction and the powder x-ray data were also investigated by FullProf program. This Rietveld analysis confirmed the Hexagonal structure and P63/m space group, The bond angles were also reported. The anionic group and bond formation were studied using Raman spectroscopy. The results confirm both BO3 and BO4 formation. The Field emission scanning electron microscopy was carried out to study the morphology of the optimum sample.

In this research, semiconductor nanoparticles of Aluminum doped zinc oxide (AZO) were synthesized using zinc nitride as a precursor and ethylene-glicol as complexing agent with Aluminum molar ratio of 0, 2, 4, 6, 8 and 10% by solvo-thermal method. Crystal structure and surface morphology of the samples were studied by X-ray diffraction analysis (XRD), Field Effect Scanning Electron Microscopy (FESEM) and Tunneling Electron Microscopy (TEM). XRD Results describes the Hexagonal wurtzite structure of zinc oxide with preferred peaks corresponding to (100), (001), (101), (102), (110) and (103) planes. Also by increasing of Aluminum concentration, the preferred peaks shift to higher angles, hence lattice constants have a decreasing trend. While, nano-crystallite sizes have an increasing trend and the sizes were found between 17. 5 to 25. 2 nm. FESEM and TEM images show that increase of Aluminum concentration causes increase of the nanoparticles size. The optical band gap of the samples was found between 2. 03 to 2. 66 eV. By increasing Aluminum content from 0 to 4%, band gap decreases and then increases for higher concentrations from 4 to 10%. Investigation of the Acetone gas sensor properties for the sample of 4% impurity shows that maximum response time is for 2300 ppm density which is 60 s and the minimum is 42 s for 3600 ppm.