مجله بلور شناسی و کانی شناسی ایران
سال بیست و پنجم شماره 4 (پیاپی 70، زمستان 1396)

Alkaline volcanic rocks of the northwest of Marand with Plio-Quaternary age are located in the northern part of Urumieh-Dokhtar Magmatic Arc. These rocks have a distinct enrichment in LILE and LREE and depletion in HFSE (such as Ta and Nb) and high Ba/Ta and Ba/Nb ratios, which are among the characteristics of subduction zones. The majority of hornblenditic autholiths and hornblenditic xenoliths are placed inside the trachy andesite rocks and the trachy basaltic andesite rocks. These autholiths and xenoliths, which have a cumulate texture, are classified into two groups based on the amount of plagioclase mineral. In Group 1, the amount of plagioclase is less than 10% and contains amphibole and biotite as the main minerals. Considering, contents of Cr and Ni, REE trend shape and the chemical composition of minerals, it seems that the origin of magma for group 1(hornblenditic autholiths) is the same as magma of host volcanic rocks. In Group 2, the amount of plagioclase is more than 20% and contains amphibole, plagioclase and biotite as the main minerals. The combination of minerals of group 2 are not similar to group 1. Considering, combination of minerals, REE trend shape and contents of REE and contents of incompatible trace elements, it seems that the magma of group 2 (hornblenditic xenoliths) is derived from the mantle metasomatized with less enriched than group 1.

The studied mylonite granites are exposed as small bodies at the west of Qushchi in the West Azarbaijan Province. These rocks contain orthoclase, microcline, plagioclase, fish muscovite, tourmaline ± garnet as porphyroclast. The matrix is composed of recrystallized quartz, fine grained muscovite and low abundant epidote. According to petrographic and mineral chemistry studies and BSE images, tourmaline and garnet are chemically zoned. The mineral chemistry characteristics of core of tourmaline and garnet crystals indicate magmatic origin for them, while the composition of rim part for these minerals, especially for garnet, is consistent with metamorphic origin. Presence of tourmaline muscovite ± Mn-rich garnet in the West Qushchi mylonite granites and occurrence of these rocks as small bodies within metasedimentary rocks suggested that the west Qushchi mylonite granites are formed by low grade partial melting of the metamorphic rocks. On the basis of the mineral assemblage, it seems that the studied rocks belong to Mg-poor peraluminous leucogranite type rocks.

On the basis of field studies, mafic-intermediate bodies of Kashmar are subdivided into the old series (often stocks of gabbro, diorite, quartz diorite/monzodiorite) and the new series (quartz monzodiorite swarm dykes). In terms of crosscutting relationships, old series has the age between oldest volcanic units (57 Ma) and Eocene granitoids (40 Ma), but the swarm dykes are attributed to the post Eocene (Oligocene?) in age. Mafic-intermediate bodies with the high-K calc-alkaline to shoshonitic, metaluminous to low peraluminous, LILE/HFSE and LREE enrichment [(La/Yb)N=5.3-6.8] and depletion of HREE characteristics are reminiscent of the arcs in subduction zone. These features accompany with negative anomalies of Eu indicating magma generating at the depth of plagioclase stability and contaminiation of magma to continental crust, which remains during the melting of the garnet rock. Linear trend of the major oxides and trace elements in Harker diagrams indicate in importance of fractional crystallization of magma evolution. Average of initial isotope ratios of 87Sr /86Sr and 143Nd /144Nd (in age 50 Ma) for the old series samples are between 0.7054 /0.7062 and 51262-0.51264 respectively, and the εNdi has a range of 1.08 to 1.42. Average of initial isotope ratios of 87Sr /86Sr and 143Nd /144Nd (in age 30 Ma) for swarm dykes are 0.7056 and 512623 respectively, and the εNdi amount is .059. εNdi positive values and low ISr of all rocks with their TDM (0.6-0.8) implying that they form from partial melting of lithospheric mantle source, which modified to earlier subduction processes melts. Based on the Th/Ta versus Nb/Ta and Nb/Y versus Zr/Y charts, both subduction and rift forming processes were involved in the formation of Kashmar rocks. This feature is compatible with subduction of Sabzevar oceanic crust to the Lut block.

The Tashtab bentonitic clay deposit is located about 25 km southwest of Khur and Biabanak, Isfehan Province. This deposit is a product of alteration of ignimbrites with the age of early Eocene. Mineralogical examinations demonstrated that montmorillonite, saponite, quartz, nontronite, beidellite, microcline, anorthite, illite, albite, and calcite are the major mineral phases which are accompanied by lesser amounts of minerals such as vermiculite, sanidine, chlorite, orthoclase, actinolite, and dolomite in this deposit. Further investigations revealed that the studied samples are classified as dioctahedral smectites group and their mineralogical composition lies within the range of beidellite-montmorillonite-nontronite. Based upon geochemical studies, the processes of conversion of ignimbrite into bentonitic clays have been accompanied by enrichment of Mg; leaching-fixation of Si, Ca, Mn, Cr, Ba, Co, Cs, Rb, Ta, U, Zn, Cu, and Ni; and depletion of Al, Fe, K, Ti, P, Na, Hf, Nb, Sr, Th, V, Zr, Y, and RREs. Considering the obtained results, it seems that the development of the bentonitic clay deposit at Tashtab was controlled by structural processes. Discrepancy in the rate of alteration intensity of the source materials, chemistry of altering solutions, adsorption, incorporation in crystal lattice, to complex-forming ligands, and difference in the stability scale of primary minerals against alteration are the six key factors controlling the mobilization, distribution, and concentration of elements in the bentonitic clay deposit of the Tashtab area.

Basic rocks appear as cumulative hornblende gabbros in the Namen pluton, West of Sabzevar. One outcrop of these rocks contains magnetite ore patches. Although magnetite- bearing hornblende gabbro (MHG) and other hornblende gabbros (HG) have similar mineralogy, their trace element compositions are completely different. Trace element analysis of magnetite minerals by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) method on the MHG, HG and ore (MG) indicate that all magnetites could be classified as Ti and V enriched magmatic magnetite. MG and MHG magnetites have similar composition but trace element composition of HG magnetites display distinct characteristics. The HG magnetites are enriched in Mg, Al, Ga, Y, Nb and REE; while the MG and MHG have relatively higher concentration of Ti, V, Cr, Mn and Zn. These two groups show different trends in the REE diagrams. The MG and MHG magnetites have tetrahedral REE pattern with depleted LREE [(La/Yb)N= 0.46]; while HG magnetites illustrate relative enrichment of LREE/HREE [(La/Yb)N= 2.67]. The incorporation of magnetite trace elements and whole rocks geochemical data confirm the role of volatile phase separation in the gabbroic magma evolution in the Namen pluton.

The Takht-e-Soleyman complex is formed from various rock types including metapelites, metabasites and marbles which are metamorphosed under green schist through amphibolite to granulite facies. The amphibolites have been melted partially under high temperatures and mafic migmatites are formed in this regard. The pick metamorphic minerals of garnet amphibolites have been completely replaced by the low temperature plagioclase-hornblende symplectite. So, the pick metamorphic P-T conditions of these rocks (M1) have not been recognized due to the lack of proper mineral assemblage and chemistry of phases. The retrograde P-T conditions (M2) have been determined on the basis of textural evidence, equilibrium mineral assemblage and mineral chemistry as two stages: (1) the retrograde metamorphism as strong decreasing of pressure (M2-a) and (2) cooling and decompression stage during exhumation of the rocks (M2-b). The temperature and pressure conditions during M2-a and M2-b have been obtained as 650°C-700°C at 7-8 kbar and 510°C-570°C at 5.5-6 kbar, respectively. Considering textural evidence, mineral assemblage, thermobarometry estimations and clockwise retrograde P-T paths of the investigated rocks it can be considered that the first section of P-T path with deep dP/dT sleep indicates strong decreasing of pressure most probably related to thrust faulting resulted from crustal thickening during continental collision, whereas the second part of P-T path has been formed by cooling of the rocks related to crustal thinning and exhumation processes. So the retrograde metamorphism and exhumation of the Takht-e-Soleyman garnet amphibolites is consistent with the crustal thickening and its subsequent thinning due to compressions and extensions related to the Laramid orogenic phase during closuring of Neotethys.

In Reza-Abad area (E- Shahrood city), diabasic dikes swarm (gabbro / diorite) with trends east-west intruded into Pre-Cambrian igneous - metamorphic complex of Central Iran Zone. These rocks display intergranular, ophitic and subophitic textures. Clinopyroxen (augite to diopside), plagioclase (oligoclase-andesine and labradorite- bitonite) and amphibole (magnesia hornblende) are the main minerals. Apatite, sphene and magnetite are accessory minerals. Based on the combination of clinopyroxene, primary magma of basalts has alkaline nature and were formed within-plate setting. The Clinopyroxene thermobarometry determines a temperature of 1100-1200 °C and pressures 1 – 10 Kbar with a density in 4-8 Kbar. Based on these results, crystallization of clinopyroxenes begins in the magma chamber at depth of 25km, this depth is at equilibrium with middle crust.

Metamorphic area, which is a subject of this study, is located in S-Qorveh (Zarineh region), northwest of the Sanadaj-Sirjan zone. According to the recent dating, the S-Qorveh plutonic body consists of a complex of granitoids, granodiorites, quartz monzonites, and gabbros, have intruded into the host metamorphic rocks, about 149-152 Ma and have generated contact metamorphism. Intrusions of various masses and protolites, such as politic and basic layers, have made metamorphic rocks of this area to be different. Regional metamorphic rocks include slates, schists, and amphibolites which are metamorphosed in the range of middle green schists to the early amphibolites facies. Contact metamorphic rocks include spotted slates, mica hornfels, and cordierite hornfels which have been subject to metamorphism from albite-epidote hornfels to hornblende- hornfels facies. In cordierite hornfelses facis, by getting far from the intrusion, cordierite crystals become smaller in size and larger in number. According to the petrographic evidence, metamorphic rocks of this area have been subject to 3 phases of metamorphisms including probably high pressure regional metamorphism, regional metamorphism, and medium contact metamorphism. To estimate the metamorphism pressure-temperature state of this zone, TERMOCALC computer software and also linear calibrations have been used. Pressure-temperature calculations for regional metamorphic M1, have shown 3.9 Kbar pressure and 539°C temperature. For contact metamorphism M2, by using the software, average pressure of 4.3 Kbar and average temperature of 607°C have been calculated. Also, for the contact metamorphism M2, using the experimental calibration of biotite-muscovite equilibrium, the temperature estimated to be 581.3°C and using chlorite-muscovite equilibrium for this phase (stage) of metamorphism, pressure and temperature have been yielded 3.65Kbar and 620°C, respectively. In generally, results of temperatures for all metamorphic rocks are acceptable and satisfactory, but in contact metamorphic rocks, data of pressure may be higher due to emplacement of the granitoid intrusive body.

Residual layers and lenses of the Borhan area (SE Mahabad, NW Iran) contain considerable volume of ferrite ores, which are surrounded by carbonate rocks of the Ruteh Formation of Permian age. Petrographic examinations show that these ores have polycyclic nature and allogenic origin and their evolution is largely affected by the diagenetic and epigenetic processes. Mineralogical studies reveal that hematite and goethite are the major mineralogical phases, accompanied by minor phases such as kaolinite, illite, boehmite, rutile, calcite, pyrolusite and crandalite. Based on semi-quantitative values of minerals, the studied ferrites have iron ore and Si-rich iron ore. Geochemical investigations suggest that distribution of most trace elements in the ores was controlled by the Fe-Al differentiation degree. REEs values vary from 10.80 to 145.07 ppm in the ores. La/Y, Eu/Eu* and Ce/Ce* values in the ores are within the ranges of 1.00-10.4, 22.29-5.65 and 3.63-5.22, respectively. The combination of the obtained mieralogic and geochemical results reveal that environmental conditions (oxidant-basic) and mineralogical control have played the important role in fixation of trace elements in the ferrite ores. Correlation coefficients among elements indicate that minor mineralogical phases such as clays, boehmite, pyrolusite, rutile and crandalite are the potential hosts for REEs in the ores.

The Qohrud granitoid is a part of the Urmia-Dokhtar magmatic assemblage. The main rock types are Miocene granite and tonalite. The hydrothermal activities were effective due to intrusion. Hydrothermal activities were more intense in the southern part of the pluton. This has produced relatively large automorph quartz crystals. The alteration of the granitoid wall rocks was accompanied with alteration of K-feldspar, plagioclase and biotite, which has released Sr, K, Rb and to the lesser amounts Al from the mineral structures into the hydrothermal fluid. ICP-MS analysis of quartz samples reveals increase in concentration of some elements including Li (10.33 ppm), Al (6900 ppm), K 9600 ppm) and considerably two elements Rb (1.2 ppm) and Sr (3.35 ppm), along with positive anomaly of HREE in comparison to LREE that all indicate an hydrothermal origin for the studied quartz crystals. Using Ti content of quartz or TitaniQ thermometer gives temperatures of 307 to 547°C with an average of 371°C for crystallization of the quartz crystals. This temperature is in good agreement with temperatures calculated by fluid inclusions (306 to 550° C).

The Ghikhlar area is located at the NW Marand town, East Azarbaidjan. The wide range of Plio-Quaternary volcanic activites with volcanic and associated volcano-clastic rocks having compositions mainly as andesite to silica-undersaturated rocks (leucite basanite, leucite-tephrite and tephrite) have been covered mostly the rock units prior to the Cenozoic. The phenocrysts in andesites are amphibole, plagioclase and clinopyroxene which occurred in microcrystalline and microlithic matrix. The main characteristic of these rocks is bearing various enclaves as autholiths and xenoliths. The clinopyroxenes in the host andesite and cumulative enclaves are diopside to augite. The autholithic andesitic and dioritic enclaves indicates compositions as augite and dipside, respectively. Investigation of mineral chemistry and magmatic features for the host andesitic rocks and their enclaves are the main goal of this research. Variety of magmatic enclaves are including homogenic, cumulative and gabbroic ones. They all show similar mineralogy with host andesitic rocks whereas they are different texturally. Homogenic and gabbroic enclaves are more fine and coarse grained than host andesite, respectively. Cumulative enclave has been formed as aggregation of coarse grained ferromagnesian crystals similar with phenocrysts of andesite. On the basis of mineral chemistry data, composition of the host andesite as well as homogenic and cumulative enclaves are subalkaline with arc magmatic tectonic setting feature. However gabbroic enclave with alkaline characteristic corresponds to interior plate tectonic setting. Considering mineralogy, textural evidence and mineral chemistry data from the host andesite and their magmatic enclaves it can be concluded that the homogenic and cumulative enclaves are autoliths. The homogenic enclave corresponds to chilled margin of magma reservoir which disjoined during upward ascending of andesitic magma and their falling into magma chamber. Cumulative enclave resulted from aggregation of magmatic minerals in the magma chamber. About genesis of the gabbroic enclave it seems that gabbroic enclave has exotic genesis. Gabbroic rocks fall into andesitic magma during magma passing upward.

The Mazraeh Shadi is located about 130 km northeast of Tabriz (NW Iran) in the Arasbaran metallogenic belt. The deposit occurs as a series of veins within the Eocene andesites. Mineralization shows epithermal system that controlled by fault distribution. Epithermal textures within the veins include comb, vaggy quartz, cockade, boxworke, plate calcite and breccia. Pyrite is the main ore mineral associated with chalcopyrite, chalcocite, covellite, sphalerite, galena and gold. The result of geochemistry on the small rock samples from silica veins shows values of gold (max17100 ppb), Pb(max 21100 ppm), Ag(max 9.43ppm), Cu(max 611ppm) and Zn (max 333 ppm). Microthermometric studies were conducted on quartz samples from silicified and mineralized zones and provides substantial micro-thermometric data for a new interpretation. Fluid inclusions generally occur in range from 5 to 90 μm in size. Three types of fluid inclusions are typically observed at Mazraeh Shadi:(1) liquid-rich two-phase, (2) vapour-rich two-phase (3) vapour-rich mono-phase. The homogenization temperatures of all inclusions from 160 to 324 °C and the average of homogenization temperature is 228°C .The salinities are 0.17–5.1 wt.% NaCl equiv. The last ice-melting temperature is between –2.2 and -3.2°C. All fluid inclusions are plotted into the epithermal box and into the region between the primary magmatic water box and the meteoric water. Mineralization of Au is the result of pyrite precipitation, dilution- mixing of an oxidized meteoric water decreasing of pH, boiling and fluid mixing and there are two fluids participated in the formation of Mazraeh Shadi deposit. Fluid inclusion data shows the depth of mineralization at Mazraeh Shadi deposit probably ranged from 230 m to 380 m below the paleosurface and three-dimensional graphs confirm the deposition of lead and zinc in with high temperature-low salinity fluid and deposition of gold with low temperature-high salinity fluid. The zoning pattern shows clearly base metals such as Cu, Pb, Zn and Mo occur at the deepest levels, whereas precious metals occur at higher elevations with respect to base metals due to boiling of hydrothermal fluids in epithermal system.

Roudgaz granitoid is located in south of Bajestan. In this granitoid body, tourmaline occurred in two forms, as luxullianite and as veins of quartz-tourmaline with a 30 cm width. Based on petrography and electron microprobe analyses data, these tourmalines are schorl-dravite- foitite in composition, with a tendency toward schorl end member, and belongs to alkali and vacancies groups. In comparison with the ideal composition of schorl- dravite, many of tourmaline samples have high Al contents and alkali – site vacancies. The increase of the amount of octahedral aluminum reflects a combination of substitutions in tourmaline involving deprotonation (O-OH exchange) and vacancies in the alkali-site and therefore they have originated from magmatic source. In contrast, the presence of zoning, its occurrence as vein form, having a high Mg compared to samples with high Fe and tendency away from alkali- deficient and proton-deficient tourmaline vectors, shows that tourmaline in the luxullianite as well as the vein tourmalines are hydrothermal in origin. So, based on the evidence described above, tourmaline veins have formed by interaction of boron on-rich magmatic-hydrothermal fluids of the origin of mass granitoid rocks along with various quartz-tourmaline and metapelitic-metapesamitic host rocks.

The Rahmatabad Kaolin deposit is located about 25 km southwest of Nain. This deposit is formed by alteration process from Eocene volcanic rocks and pyroclastic units. Mineralogical studies display that the kaolinite, jarosite, hematite, quartz, calcite, anortite, alunite, diaspore, chlorite, montmorillonite, illite, albite, orthoclase, halite, sanidine, goethite, malachite, azurite and sericite are the rock-forming minerals in this deposit. Based on geothrmometry data on the chlorite which produced by alteration process, the temperature of hydrothermal fluid formed this deposit has been between 98.25 oc to 321.04oc. According to geochemical studies, the alteration process of volcanic and pyroclastic rocks to Kaolin have been accompanied by enrichment of Rb, Cs, Ba, Sr, Nb, Hf, Zr, Y, Th, Al and U; leaching-fixation of Si, Ca, Ti, Na and P; and depletion of Fe, Mn, Mg, K Cr, Ni and RREs. Furthermore, the geochemical data can be refer to high (La/Lu)N, and high Sr, Ba values than to La, Ce and Y. Also Ce and Eu anomalies in the studied area were controlled by degree of feldspar alteration as well as changing the in degree of oxidation of environment respectively. It seems that the development of the Rahmatabad Kaolin deposit was supported by mixing of two hypogene and supergene processes. The discrepancy in the rate of alteration intensity of the source materials, chemistry of altering solutions, adsorption, incorporation in crystal lattice, difference in degree of complexation with sulfate, chloride, and fluoride ligands and difference in the stability scale of primary minerals against the alteration are considered as six important factors for controlling the mobilization, distribution, and concentration of elements in the Rahmatabad Kaolin deposit.

Gabbroic intrusions are located about 40 Km southeast of Fariman in Central Iran zone along the Fariman- Torbatjam road that could be seen at the end of Bardoo river and in Chahak village. Previous studies have emphasis on the age and genesis relationship between granites and gabbroic rocks. So in order to investigate this matter, granites and gabbroes dated by using U-Pb method in Oslo University. Granites show the age of 548.3 Ma that is concarrent with the formation of schists during high temperature metamorphism in Fariman area. Dating of gabbroic rocks suggest an age of 471.14 ±0.85 mainly Early Paleozoic age that is younger than magmatism formed granites. Introducing Ordovician plotunism in this area is very important for reconstruction of Caledonian event. It seems that the formation of Gobbroic rocks is as a result of a short orogeny event due to opening of paleotethys during ordovician and Silurian.

In this work, samarium ion (Sm3) substituted yttrium iron garnet nanoparticles Y3-xSmxFe5O12 (x=0.0, 0.2, 0.3) were fabricated by the sol-gel method. X-ray diffraction (XRD) patterns confirmed the pure garnet structure for all samples. The garnet phase were studied, using, Far-FTIR. The results of vibrating sample magnetometer (VSM) represents that saturation magnetization decrease with increasing samarium ion concentration. These changes assigned to the destrucive role of Sm ionic size on magnetization of substituted garnet

In this research, ZnO nanorods were grown via hydrothermal method on the glass substrate. The effect of precursor and the thickness of the seed layer on the structural and optical properties of grown ZnO nanorods were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and UV-vis spectroscopy. The XRD patterns indicated that the nanorods had wrutzite hexagonal crystalline structure with orientation of [002]. FESEM images clearly revealed that the ZnO nanorods with different solution concentration on different seed layers and precursor solution concentration were grown on substrate glass. The ZnO nanorods with solution concentration of 50 mM and 10 times the seed layer deposition are the better morphology and more optical transmittance in the range of visible. So this sample could be a suitable candidate for electron transport layer on inverted polymer solar cells.

In this paper, Y-type strontium hxaferrite (Sr2Co2Fe12O22) nanostructure with molar ratio of citric acid to metal nitrats of 1:0.5, 1:1, 1:1.5 and 1:2 prepared using a sol-gel of auto-combustion method and then prepared powders were sintering at 1000 ˚C for 3 h. In order to investigate structural, magnetic and dielectric properties of the Sr2Co2Fe12O22 nanostructure, samples have been analyzed by X-ray diffraction analysis (XRD), Fourier transforms infrared spectroscopy (FT-IR), scanning electron microscopy field emission (FESEM) , vibrating sample magnetometer (VSM) and LCR meter methodes. The results of measurements of structur show that Y-type hexaferrite structural in the samples with molar ratios of 1.5 and 2 was completely formed, so that in the sample with molar ratio of 1.5 peaks and its intensity is closer to the standard card. Also, the results of dielectric reveal that by increasing frequency, dielectric constant and dielectric loss decreases which indicates that samples could be suitable for use in devices. The results show that the best papered sample is at temperature and time of 1000- 3h, respectively, with citric acid mole ratio of 1.5.