مجله بلور شناسی و کانی شناسی ایران
سال بیست و سوم شماره 4 (پیاپی 62، زمستان 1394)

The Simorgh area is located about 113 km southwest of Nehbandan. Initial prospecting conducted by satellite data ASTER sensor with spectral angle mapper method, in order to identify probable alteration zones. The data, compared with field observations, have provided satisfactory results. This area consists of Eocene volcanic units in which various sub volcanic rocks have intruded in them. The major alteration includes propylitic, argillic, silicified and sericitic. Mineralzation at the surface is observed in the form of disseminated and hydrothermal breccias. The maximum distributed gold element is 93 ppb, Arsenic 35 ppm and molybdenum 33 ppm. Disseminated mineralization, associated with hydrothermal breccias, widespread alteration and their relationship with lithology and structural geology indicates the presence of a type of epithermal gold deposit hosted breccia.

The study area is located about 220 km southwest of Mashhad and 80 km south of Neyshabur, at 54° 42' 15" to 54° 43' 40" longitude. Initially, remote sensing is carried out based on the SAM method and it denotes propylitic, carbonitization, silicification and argillic alterations. This area comprises of outcrops of Paleocen-Eocene volcanics. Golcheshmeh area also shows copper mineralization at surface such as malachite, chrysocolla and chalcocite. The copper minerals are seen as filling voids and thin veinlets in association with volcanic rocks in the study area. In some parts of the district, the movement of copper solutions is controlled by linear structures and fault zones, and the amount of solutions’ penetration-which differs from a few centimeters to several meters - in the host rocks is dependent on the wall rock composition, texture and the volume of the solutions. Based on the analysis, 80% of the samples show more than 1% copper.

Temperature and pressure of pelitic metamorphic rocks (metapelites), from the Jandaq area in NE Isfahan, are studied using pseudosection approach. The data used in this research are from already published data by other researchers; however the applied method is reported for the first time. The metamorphism temperature is estimated to be about 400 to 670°C and pressure to be 2-6 kbar in the published study. Our study confirming these results, indicates the pressure and temperature more precisely. Also garnet and biotite chemical zoning is studied. Since garnet and biotite are the main ferromagnesian minerals in these rocks, the chemical zoning are determined for these two minerals, based on Fe and Mg content, and the P-T is estimated using Fe and Mg mole fraction in the minerals. Using the whole rock chemistry, the stability of the mineral phases is modeled considering metamorphic grade increase.

Noghan granitoid intrusion is located at the NW of Boin- Miandasht and lies in the Sanandaj-Sirjan structural zone (SSZ). Based on field evidence and petrographic studies, the pluton is considered as two-mica granite that has been strongly affected by deformation and shows a good mylonitic foliation study area. The main minerals in the pluton are quartz, alkali feldspar (microcline and perthite), plagioclase, biotite, muscovite and the accessory minerals are monazite, apatite, epidote, zoisite, clinozoisite, allanite and opaque minerals which form the rock groundmass. Petrographic and geochemical studies indicate that the Noghan bridge plutonic rocks are of MPG and PLGS types, having calc-alkaline to high potassium calc-alkaline and peraluminous nature. On chondrite and primitive mantle-normalized spider diagrams, the REE pattern has a negative slope and definite negative anomaly of Eu, and they display enrichment of LILE and LREE and depletion of HREE and HFSE, along with negative anomalies of Nb, Sr, P, Ti and positive anomalies of Cs, K, Pb which are typical of magmatism in subduction-zone environment especially leucogranites in the active continental-margin.The tectonic settings of the leucogranite is post orogenic environment. The geochemistry of accessory and trace minerals suggest derivation from partial melting of meta pelites in the upper part of thickened crust.

Ophiolitic belt of Northern Sabzevar is invaded by basic, intermediate and acidic post-ophiolitic magmtism as dome, dyke and cone. Microscopically, the texture of the studied samples is porphyric and trachytic. Phenocryst mostly consists of amphibole, feldspar and clinopyroxene. All researchers that have investigated basic to acidic post ophiolitic magmatism of northern Sabzevar have consensus about their subduction related genesis. According to geochemical characteristics, basic and intermediate samples are resemble to normal arc island magma whilst rhyolitic and dacitic samples display adakitic nature. According to the binary diagrams, adakitic characteristic of these samples are as a consequence of amphibole, titanite and zircon fractionation. The existence of amphibole phenocryst and titanite and zircon as accessory minerals confirming this process as well. According to the barometry results, amphibole fractionation from water-rich melt of subduction zone at depth of equivalent to the middle and lower continental crust led to creation of adakitic signatures in the ultimate dacitic and rhyolotic magma.

In this work, Cobalt doped Nickel Ferrite nanostructures (Ni1-xCoxFe2O4; (x = 0.0, 0.05, 0.15, 0.2, 0.3) were synthesized by Microwave assisted combustion method and then the powder obtained was pressed to form disk shape sample with 2.5cm in diameter. The samples were annealed at 700°C for 4 h. Structure, surface morphology and gas sensing properties of the samples were studied using X- ray diffraction (XRD), Filed Emission Scanning Electron Microscope (FESEM) and Gas Sensing Reactor (GSR). The XRD spectra of the samples indicate the formation of spinal phase. Sensors response at different temperatures were investigated for acetone gas (2500ppm) and the results indicate that the optimum work`s temperature for samples is about 300°C. The results showed that the as grown samples have the higher response compared to the annealed samples. The maximum response achieved in sample with %5 Cobalt doping.

Chah-Shoor kaolin mine is located about 150 km southeast of Isfahan and also located in the central Iran structural zone, Urumieh-dokhtar volcanic belt. Eocene Igneous rocks consist of andesite, tuffs and quaternary deposits have covered the area. Based on petrographic studies, the main minerals in the volcanic rocks are K- feldspar, quartz and plagioclase. Hydrothermal alteration has produced industrial soil. The major phases in this reservoir are kaolinite, illite, muscovite and residual of quartz, albite, and orthoclase and minor phases are montmorillonite, chlorite and hematite. Geochemical studies and physical tests show the clay soils of the mine have the range of color after firing from cream to brown, medium absorption of the water and high drying resistance, high firing resistance. The samples of Chah-Shoor Varzaneh have compared with industries standard. Industrial soil in Chah-Shoor is suitable for tile and ceramic industries; while for other application need to procreation.

The most important geological units in East of Sarbisheh are Upper Cretaceous ophiolites assemblages that are predominantly serpentinized ultramafic in composition (dunite, harzburgite and pyroxenite). Chromite deposits in these rocks have generally various forms such as lenticular, layered and disseminated with varying dimensions. Textural studies on Golab Chromites show that they have primary textures such as massive and disseminated as well as secondary textures including cataclastic, mylonites, bereccia and extensional. Geochemistry of Golab Chromites points to average amounts of Cr2O3 (42.26%), MgO (17.23%), TiO2 (0.36%) and Al2O3 (10.5%). The ratio Cr/Cr + Al (0.79 to 0.93) indicates that these chromites are enriched in Cr and depleted in Al. The high Cr2O3 and MgO contents in the Golab Chromite suggest that they were crystallized from a magma having relatively high degree of partial melting. High MgO content and Cr#, Mg# in Golab Chromites are comparable with typical parental boninitic magma. Podiform Chromitite deposits in East of Sarbisheh were probably formed in the mantle sequence, the latter was generated in the supra- subduction zone (SSZ). Golab Chromite are formed similar to Lubasa Ophiolite South Tabat.

Shelgerd area is located south of Mashhad, N.E of Iran, within Binalud Structural Zone. This region is affected by regional metamorphism, slate and phylite are the main metamorphic rocks of the area. Teriassic slate, phyllite, sandstone and Jurassic conglomerates crop out parallel to Sang bast- Shandize fault. Mineralization occurred as vein type, with trend of N65E to N50W with 75 degrees to the south west. In superficial zones slags are common. primary ores are quartz, pyrrhotite, chalcopyrite, galen, orpiment, realgar and secondary minerals are malachite, azurite, covellite, goethite, hematite, limonite and covellite. Stream sediment geochemical sampling method shows anomalities of Ag, Cu, Pb, Zn, Fe elements. In The heavy mineral samples, some mineral such as orpiment, realgar, gold, pyrite and cassiterite are recognized. Also, geochemical analysis conducted on the small rock samples from surface of gold veins and old tunnel show the amount of gold is about 4.424 ppm, silver 8.42 ppm, copper %4.4964, iron %1.4349, laed %0.6939, and zinc %0.2825. Chemical analysis of galena shows high concentration of Ag, Sb, Bi. Depends on the ratio of Sb/Bi, mineralization temperature is low to medium and epigenetic type. According to mineral galena, crystals are the primary type.

The Zeytoon clay deposit is located 30 Km northeast of Abadeh at Fars province. In this study, investigated physical, chemical, mineralogical and firing characteristics to evaluate their potential suitability as raw materials in various ceramic applications. Physical properties were identified by consistency limits and cation exchange capcity (CEC). Chemical and mineralogical properties were carried out by XRF and XRD. To evaluate their ceramic behavior, the samples were fired at temperatures 1156°C. Firing characteristics were determined by flexural strength, linear firing shrinkage, and water absorption. A Malaysian clay (BBC), which is a common raw material in ceramic tiles manufacturing, was used as reference sample. Results show that the main oxides in the samples were SiO2, Al2O3 and Fe2O3, whereas the other oxides were present only in small quantities. The amount of Fe2O3 in Zeytoon clays ranged from 2 to 11 wt.%, whereas Fe2O3 in BBC clay is about 2 wt.%. Kaolinite, Pyrophillite, Illite and Quartz were present as dominant mineral phases and different minor minerals. From the results of the fired properties, and analyses of chemical and mineralogical composition along with the mechanical properties of Zeytoon clays demonstrated that they are most appropriate to be used as raw materials for the production of structural ceramics.

The Baba Ali deposit is located about 39 km to the north west of Hamadan city. The syenitic pluton intruded and metamorphosed the diorite host rock producing the skarn deposit. Geochemical considerations indicate that the concentration values of rare earth elements in the syenite and diorite range from 35.4 to 560 ppm. Rare earth elements variation in syenitic, skarn and diorite rock are similar indicating the similar source of the REE. Eu and Ce anomalies show varying values within the range 0.29 -1.24 and 0.8-1.09, respectively. Positive Ce anomalies occurred in the ores of low REE content and negative Ce anomalies occurred in the ores of high REE content. The concordance of the values of CaO with those of Eu revealed that the degree of plagioclase alteration. The Eu anomaly decreases with decreasing intensity of alteration. The La/Y values (suitable parameter for determination of pH in the environment of ore formation) range from 0.37 to 2.89. REE mobility depends on changes in pH. As a whole, epidote has been enriched in REE contents and actinolites, magnitite, are depleted in REE. These REE signatures indicate that hydrothermal fluids responsible for epidote were mostly magmatic origin and for actinolite and phlogopite were magmatic origin with low REE concentration or meteoric water involved in formation of these minerals.

The Astarghan copper-gold deposit is located about 50 km north of Tabriz, southeast of Kharvana, East-Azarbaidjan. The most important lithologic units in the area are a hypabyssal prophyritic granodioritic intrusive stock (Oligo-Miocene) and flysch-type sedimentry sequence consisting of limestone, limy sandstone and marl (Paleocene-Eocene). The plagioclases range in composition from oligoclase to andesine and K-feldspars are mainly orthoclase. Amphiboles are principally of calcic-type and vary in composition from magnesio-hastingsite to edenite. The stock is of I-type granites and meta-aluminous, belonging to high-k calc-alkaline to shoshonitic magma series, which are related to post-colission volcanic arcs. Intrusive body shows enrichment in elements such as La, Nd, Rb, U, Pb, Zr, Cs and P and depletion of Ce, Pr, Ta and Nb. LREEs relative to HREEs are also enriched. Electron probe micro-analyses of ore minerals proved the presence of native gold within sulfides (stibnite and tetrahedrite) and quartz veinlets. The highest gold content is within the structure of sulfosalts (tetrahedrite-tenantite) and low-temperature sulfides (stibnite). The presence of high values of gold-tracing elements such as Sb, Hg, Bi and As within the studied ores is in accordance with the studied geochemical halos of these elements in the area which, in turn, may indicate a low temperature for the formation of the ore minerals.

Sarchah Cu-Au mineralization area is located in South Khorasan Province, about 180 km southwest of Birjand city, and in Lut Block Tertiary magmatism assemblages. Geology of the area consists of Eocene to Holocene volcanic lavas with basalt – andesite composition and crystal tuff. Landsat and ASTER data detected alunite, jarosite, sericite, epidote, and kaolinite alteration minerals using"standard and selective principal component analysis" and "spectral angle mapping"methods. Then the detected argillic (illite, Kaolinite and montmorillonite), jasproid and silicification alteration zones in the study area were proved by the following field, petrography and X-ray diffraction studies. The range of elements variation in the stream sediments is: Au <5 to138 ppb, Zn 48 to144 ppm, Pb 7 to 40 ppm, Cu 20 to 51 ppm and Ag 0.18 to 0.31 ppm. The high values are related to argillic zones and silicified veins. The result of chip composite geochemistry shows values of Au (max 75 ppb), Zn (max665 ppm), Pb (max 404 ppm), Cu (max <5%), Ag (max 5.3 ppm) and Mo (max 10.7 ppm). The high contents related to argilic alteration zone and silicified veins in center to south of the study area. Evidence of geology, alteration, mineralization, and geochemistry indicate a high sulphide epithermal mineralization associated with the upper parts of a copper porphyry system in the area that could be considered for the detailed exploration.

The study area is located in Khorasan Razavi Province, NW Gonabad and based on tectonic setting, it is situated in the north of Lut Block zone. Subvolcanic bodies intruded the andesitic lava flows and the pyroclastics rocks. These intrusive bodies consist of small stocks and dykes with composition from quartz diorite, monzodiorite to granite. Widespread alteration identified in southern region that is mainly argillic. Mineralogical composition of this alteration to the abundance is quartz, kaolin, dickite, montmorillonite, hematite and alunite. According to geochemical studies, the granitoids and volcanic rocks are high-K calc-alkaline per-aluminous rocks. REE patterns in all of intrusions rocks show enrichment in LREE (3.5-6.5; ave., 4.75) rather than HREE. Volcanic rocks show high value of LREE/HREE, with LaN/YbN = 3.53 to15.47 and negative Eu anomaly (mean EuN/Eu*= 0.54).

Lalezar Granitoid Complex is located in the south-east of Urumieh-Dokhtar volcanic belt and Dehaj-Sarduieh belt (Kerman Province). It contains plutonic rocks with granitoid composition and has been intruded into the Eocene volcano-sedimentary rocks. The plutonic rocks have granite to gabbrodiorite composition with dominance of tonalite and diorite rocks. The main mineral phases are sodic plagioclase, k-feldspar, quartz, biotite and amphibole in granite to tonalite, and calcic plagioclase, amphibole, biotite, clinopyroxe and orthopyroxene (hypersthene) minerals in diorite to gabbrodioritic rocks. Tourmalinization is a common feature in the granitoides and related aplites. The tourmalines are seen as medium to coarse-grained prismatic crystals, veinlets, radial assemblages, euhedral to anhedral, nodular and needles. The tourmalinization in granitoids of this area is occurred in hydrothermal and pneumatolitic stages due to infiltration of boron rich fluids in rock fractures. In the aplites, probably, tourmalinization occurred as tourmaline rich nodules due to gas (pneumatolitic) differentiation in silicic- boron rich fluids at the late stage of crystallization. Sometimes the tourmaline emplacement has begun from margins, fractures and weak planes of feldspars lattices (such as cleavage and twining) and extended to other parts of crystals. The geochemical data reveal that the granitoids belong to I-type and Calc-alkaline series. They have emplaced in continental arc and REE studies show that the source rocks could have been garnet or spinel bearing mantle peridotites.

Sarvian intrusion is located in northeast of Delijan in the Orumieh-Dokhtar magmatic belt. Sarvian pluton consists of acidic and intermediate units and is composed of granite, granodiorite, tonalite and quartz-diorite. Main minerals of the intrusion are plagioclase, amphibole, biotite, quartz and K-feldspar. In this research, based on the EPMA analyses, thermobarometry of the rocks investigated. Based on microprobe analysis, the amphibole is in calcic amphibole group and its composition varies from magnesiohornblende to actinolitehornblende. The plagioclase composition is also in the range of andesine to labradorite. The average crystallization pressure of amphibole inclusions, quartz-diorite and tonalite are estimated 2.6, 1.56 and 1.4 Kbar respectively, using aluminum in hornblende barometer. The average equilibrium temperatures are 875.2, 795 and 759.7 ºC respectively. The intrusion is formed in high oxygen fugacity condition and Log ƒO2 is estimated to be about -11.06 to -15.76.