مجله بلور شناسی و کانی شناسی ایران
سال بیست و سوم شماره 3 (پیاپی 61، پاییز 1394)

The Teminan bentonite deposit is located in ~25 km southwest of Naeen, Isfehan Province. This deposit has layered and massive form and is an alteration product of tuff breccias of Oligo-Miocene age. Mineralogical data show that montmorillonite, heulandite, clinoptilolite, quartz, anorthite, orthoclase, calcite, beidellite, illite, and microcline are the principal rock-forming minerals in this deposit. Distribution pattern of REEs normalized to chondrite indicate an intense differentiation of LREEs from HREEs accompanied by occurrence of negative Eu anomaly during bentonitization. Geological data suggest that the alteration processes of tuff breccias to bentonite in this area occurred in an open system, and leaching and fixation processes were two principal regulating factors in concentration of most trace and rare earth elements. By considering the obtained results, it seems that acidic pH and its variation degree, adsorption, inhomogeneity of parent rock composition, incorporation in crystal lattice, difference in degree of complexation with sulfate, chloride, and fluoride ligands, diagenesis, ionic exchange, residual concentrations, and difference in degree of stability of minerals against alteration are the key controlling factors for distribution of elements during evolution of the Teminan bentonite deposit.

The sowthwest of Sorkh kuh prospecting area is located in 120 km SW of Birjand city, western Lut Block. Geology of this area comprising andesitic and basaltic volcanic rocks, which have intruded by intrusive rocks such as hornblende diorite, hornblende tonalite, and biotite monzonite caused extensively alteration and mineralization. Based on remote sensing, field survey, petrography, and XRD, mineralogy of alteration zones are chlorite, epidote, carbonate, sericite, quartz, kaolinite, and natroalunite, so the alteration had been divided into 5 zones: porphyritic, argillic, carbonatic, quartz-sericite-pyrite, and silicification. Disseminated, stockwork and vein type of mineralization have been observed. The vein type of mineralization has NW-SE trend and hosted by hornblende diorite porphyry. This type of mineralization includes quartz, Chalcopyrite, pyrite, and secondary Cu-Fe minerals. Disseminated and stockwork mineralization is consist of quartz, pyrite, magnetite, chalcopyrite, and secondary minerals that formed in altered biotite monzonite and hornblende diorite porphyry rocks. Chalcocite, covellite, malachite, azurite, hematite, and goethite are the secondary minerals in this area. Geochemical studies of stream sediments show anomalies in some elements such as 48-92 ppm Cu, 16-22 ppm Pb, and 27-123 ppm Zn. In lithogeochemical samples, 5% of Cu, 1.3% of As, 150 ppm of Mo, 362 ppm of Pb, 743 ppm of Zn, and 278 ppb of Au have meseaured. The highest anomalies was related to vein type mineralization in NW of area. Different factors such as petrology, alteration type and development, mineralization form and geochemical anomalies are the evidences for probably porphyry copper deposit in the area that need more exploration studies.

Based on field observations, tourmalines in Mashhad leucogranites are divided into nodules and dendritic. Fractal geometry is a tool for measuring of irregular shapes. Based on the square method, that is one of the tools of fractal geometry; between fractal dimension and irregular shapes is a direct relationship. Therefore, objects with further irregularities have larger fractal dimension. Tourmaline nodules (dravite) and dendrites (schorl) are the result of late stages of magmatic activity. The difference in the growth rate, surface tension and latent heat of crystallization that would eventually be irregularities are major factors the establishment of various shapes of tourmaline in the study area. Rapid cooling of tourmaline crystals in the late stages of magma crystallization causes a heterogeneous surface with different surface tension. Crystals in the areas with low surface tension are finer and more and this due to high latent heat of crystallization, disorder and fractal characteristics more such as dendritic forms. In the nodules form, accumulation of volatiles escape into the cavities causes the difference in pressure between inside and outside of the cavity. High pressure of outside of cavity than it's inside move nutrients from the margins to center of cavity. Crystallization in center of cavity causes to raise the latent heat of crystallization in center, temperature gradient difference, convection and crystallization of tourmaline nodulesd with greater disorder in the cavity.

Gazu copper deposit is located in the boundary of Tabas and Lut block, 65km southeast of Tabas and 15km southwest of Deyhouk. The dominant lithology in the area consists of Shotori dolomite and limestone and Shemshak shale and sandstone. Intrusive rocks with intermediate composition are widespread and numerous in the area. They consist of diorite, monzonite, and quartz monzonite to granite. Mineralogy of this intrusive are quartz, plagioclase, K spar, hornblende and slightly biotite and pyroxene. Accessory minerals consist of apatite and zircon. Main alterations in the area consist of: QSP, silicified carbonate, propylitic and skarnification. Main secondary minerals consist of sericite, quartz, carbonate, chlorite, epidote and calcsilicate minerals such as garnet, wollastonite, idocrase ets. In a 70 km2 area, mineralized and alteration zones exists in at least four locations: GA.I-GA.II-GA.III-GA.IV. Mineralization is frequently in the form of disseminated, stockwork, and less in hydrothermal breccias. Primary minerals consist of pyrite, chalcopyrite, sphalerite and barite, and secondary minerals are chalcocite, covellite, cuprite, malachite, chrysocolla, atacamite and turquoise. Considering the, presence of various intermediate to acidic intrusive rocks, type and extension of alteration, type and form of mineralization and geochemical data, Gazu deposit is introduced as a first porphyry copper mineralization and related skarn in Tabas block.

Mahour 2 lead deposit is located in the east of Lut block and 145Km west of Nehbandan and about 2 km north west of Mahour copper deposit. Altered andesitic rocks are the main host of lead deposit. Plagioclase, quartz, hornblende and biotite are major minerals of andesitic rocks. Plagioclase, the most abundant mineral, had mostly replaceded by secondary minerals such as sericite, chlorite and carbonates, as the result of alteration process. Argilic, sericitic, silicic, chloritic and carbonatic are main alteration types in the region, which are also supported by XRD graphs. S/Se ratios of the Galena samples indicate their igneous origin. Rare earth element graphs indicate an almost uniform, parallel and decreasing pattern from LREE to HREE. Based on graphs of the relevant behavior of La-Nb and La-Ba elements in cross indicates, the host rock of this deposit is relevant to orogenic region andesite tectonomagmatic environment. Spider graphs indicate depleted elements in Galena bearing samples in comparison with samples of host rock.

In this study, cerium substituted yttrium iron garnet thin films with nominal formulaY3-xCexFe5O12 and different x value (x = 0,0.1,0.3,0.5,0.7) were fabricated on quartz substrates viasol-gel method and spin coating technique. Samples taken to check physical characteristics. The effect of Ce doping on the structural properties, surface morphology and magnetization of the films were studied respectively by X-ray diffraction analysis (XRD), atomic force microscopy (AFM), and vibrating sample magnetometer (VSM). (AFM) image of annealed samples showed that the thin films had a smooth and continous surface.

Delbar metamorphic complex is located in 130 Km south of Shahrood (Biarjmand area) in Northern margin of the central Iran zone. The varied metamorphic rocks including meta-psammite, meta-greywacke, meta-pelite, marble and amphibolite and mylonitized granites and leucogranites intrusions are exposed in this complex. The field and petrography evidences indicated the evolutions resulted of the increasing in temperature and pressure from phylites and mica-schists to garnet bearing gneisses in meta-pelitic sequence and from amphibole schist to ortho-amphibolite and garnet amphibolite in meta-basite sequence. The thermobarometry studies based on the garnet, amphibole and plagioclase minerals chemistry in the garnet bearing amphibolites demonstrate 529-693˚C temperature ranges and 9.6-12.9 Kbar pressure ranges indicating of amphibolite to upper amphibolite facies for meta-basites, which has reached to the partial melting initiation. The field and geochemical evidences indicate that the protolith of the studied amphibolites were diabase dykes and basic-moderate lavas. These rocks originated from the primary magmas which were depleted in Nb, Ti and Zr and enriched in Pb and LREE with the calc-alkaline nature. The primary magmas derived from sub-continental lithospheric mantle in the extensional back arc basin during late Neoperotrozoic- Early Cambrian in Central Iran.

The Zahri granitoid body has intruded into the Late Cretaceous ophiolitic rocks syn-tectonically. This granitoid with NW–SE general trend was emplaced along the terminations of Nehbandan shear system in the northern Sistan suture zone during the Early Eocene. Development of magmatic to low temperature solid-state fabrics have shown the progressive deformation with decreasing melt content during crystallization and cooling in this body. There are clear evidences of deformation in the presence of melt phase such as fractures of plagioclase filled by quartz as well as microstructures of high-T solid-state deformation such as chessboard patterns and beginning of grain boundary migration in quartz grains that suggest these fabrics have been developed during or just after complete crystallization of magma. The solid-state microstructures such as subgrain rotation and occasionally bulging recrystallization in quartz grains, myrmekite and decrease in grain size of recrystallized plagioclase and ribbon patterns in deformed biotites have suggested changes in crystal structure in the progressive deformation during cooling of the body. Foliations measured in the field have shown predominantly W-E to NW–SE strikes (mean foliation pole: 002o/57o) in the Zahri granitoid and at different stages of magma crystallization have demonstrated similar orientations. The presence of synmagmatic microstructures and the concordance of solid-state mesoscopic-scale planar fabrics with general trend of shear zones in the terminations of Nehbandan shear system imply that the role of these terminations and associated deformation in fabric development during the Early Eocene.

In this research, magnesium-zinc ferrite nanoparticles (Mg1-xZnxFe2O4) (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1) have been synthesized using sol-gel auto-combustion method. The X-ray diffraction analysis (XRD) revealed that the samples crystallized in a single-phase cubic spinel structure. Crystallites size of samples varies from 13nm to 29nm, also the lattice parameters and bonds length tetrahedral site (RA) and octahedral site (RB) of these samples have been estimated. Values of RA (RB) increase (decrease) with increasing zinc content(x). The Fourier Transmission Infrared (FT-IR) spectra shows one fundamental absorption bands ν1 in the range 1000–450 cm-1, corresponding tetrahedral complex, respectively. The scanning electron microscope (SEM) micrographs show the uniform distribution of the particles. The saturation magnetization (Ms) and coercivity are obtained from VSM data. The saturation magnetization is found to be increased up to x = 0.4 and then decreased. These variations are attributed to the increase of magnetic moment and spin canting in the B-site.

Namen pluton is located in the SW of Sabzevar Zone and is composed of three different phases include two granitoid units and a basic phase. Namen syeno-granites (SG unit) are high temperature magmas enriched in HFSE such as Ga, Nb, Ta and Zr; and classified as aluminous A-type granitoids. This magmatic phase has been generated by partial melting of felsic rocks. The main phase of Namen pluton (BG unit) contains assemblage of various granitoids (granodiorite, quartz monzodiorite, quartz diorite). This phase shows I-type granitoid characteristics and has been yielded by amphibolite melting in the lower crust. Mafic rocks consist of hornblende gabbros which have cumulative texture of amphibole and plagioclase. There are diffused and circular patches of magnetite ore in some sections of gabbroic occurrences. Magnetite-hosted hornblende gabbros (MHB) are enriched of V, Cr, Co, Cu, Zn and Ca and depleted from incompatible elements of LILE and HFSE relative to other gabbros (HB). The separation of volatile phases during the gabbroic magma evolution has led to the segregation of primary magma. Finally, the F- P and H2O-S enriched parts of this fractionated magma have formed HB and MHB rocks, respectively.

Gabbroic rocks of Sarkobeh region are exposed as several intrusive bodies with a post-cretaceous age in north of Khomein city, Northern Sanandaj-Sirjan Zone. These igneous rocks are intruded in shale and limestone units which belong to cretaceous age. Main minerals forming the rocks are clinopyroxene, plagioclase and opaque. Microprobe analyses on the clinopyroxenes of the gabbros show a diopside composition with no chemical zoning. On the basis of geothermometry, crystallization-temperature yielded minimum temperatures of 550–700 ºC and crystallization-pressure is less than 5 kbar for the diopsides. AlVI/AlIV ratio is lower than 0.25 indicating a low pressure condition for gabbroic magma in the studied area. The clinopyroxenes composition show that they have crystallized from an alkaline basic magma. They plot in the within-plate alkalic basalt filed tectonomagmaticlly.

The area that contains studied gemstones is located in 19 km South of Torud and 135 kilometer Southeast of Damghan. The quickest and most cost-effective processing method for gemstones in this area is using grind discs in the abrasion and forming stage with the 120 mesh and dry method in polishing stage. The concentration of iron oxide and the presence of calcite and clay minerals made the variation of colors in Turod jasperits. Also Based on ICP-OES analysis, the color of chrysoprases could be related to presence of Ni, pinkish orange agates is due to Fe, Co, Mn and V; and gray colors in agates are related to Cr and Ti. For coloring treatment of yellow agates, cream jasperits, blood stones and opals, heating is the best method. Gems with the texture of micro-spherulitic and micro-variolitic are the most susceptible ones for coloring with chemical method.

The lamprophyric body of the Houway area at northeast of Hourand and northwest of Iran, is injected in the form of a laccolite within the core of a plunging anticline with WNW-ESE axial trend, which is composed of the Upper Cretaceous-Paleocene flysch deposits, and is cut by an alkaline gabbroic stock. The lithology composition of the lamprophyric body indicates camptonite to sanaite. Based on the TAS diagram. The parental magmas of olivine gabbro and lamprophyres was alkaline in nature. On the basis of spider diagrams, both of the rock types display enrichment of LREE compared to HREE. Thermo-barometry using a variety of methods indicates that the minerals of the lamprophyric body are crystallized at a pressure equal to 6 kb and a temperature equal to 877˚c and olivine in the olivine gabbros is crystallized at a temperature of 1013˚c, respectively. The parental magmas of the alkaline gabbro and alkaline lamprophyre crystallized by the partial melting of 5% and 1% of the spinel-garnet lherzolite, respectively. The alkaline gabbro resulted from the melting of the enriched lithospheric mantle, evolved to the parental magma of the alkaline lamprophyres by ascending towards the upper levels and stopping at the base of the continental crust due to the low-rate contamination with the crustal materials. It embedded within the axis of a plunging anticline in upper levels of the crust. Subsequently, due to the ascending of the alkaline basaltic magma diapirs and their injection into the lamprophyric body, the gabbro was formed. Based on the studies, both of the rock types are evolved in a post-collision magmatic arc setting.

Tourmaline nodules in the Mashhad granites (g2) formed of two parts: dark core and white halo which are scattered in the leucocratic granites. Petrographic studies of these parts (core, white halo and host granite) show tourmaline accumulation in core, quartz, muscovite, microcline and orthoclase accumulation in white halo and quartz, plagioclase, microcline, muscovite and biotite accumulation in host granite. Based on the microprobe and geochemical analysis, the combination of tourmaline nodules is schorl and close to dravite. Features such as oscillatory zoning, Ca, Mg increase in rim, medium Fe/Fe+Mg (56-63) and the REE distribution pattern compatible to metapelite melting that show these tourmalines have double origin. In first stage, tourmaline have schorl composition, then with upward movement of magma and mixing to enriched liquid and boron originated of reaction to host metapelites, open system formed and tourmaline composition changed to dravite.

The Bazman granitoid is located in the south margin of Lut block, and southeastern of Iran. It composed of granite, granodiorite, monzodiorite, quartz monzodiorite, diorite and gabbro. Plagioclase, feldspar, quartz, hornblende and biotite are the major minerals; sphen, apatite, zircon, magnetite and ilmenite are the main accessory minerals. Amphibole mineral chemistry is calcic in composition and is classified as actinolite and magnesio hornblende. These amphiboles are related to subduction and are consistent with proposed tectono-magmatic features for this granitoid (active continental margin related to subduction). Al-barometer accounts that pressure of amphibole crystallization is 1.06 to 4.13 Kbar. Hornblende-plagioclase thermometer shows 649 to 754 ºC for equilibrium of these two minerals. The estimated oxygen fugacity (-15.66 to -19.37) imply an oxidation magma and its formation convergent plate.

Jarou deposit, with age of Middle Eocene –Oligocene, is located in 60 km to the southwest of Karaj and lies within magmatic rocks with felsic to basic composition. Host rock geochemical results have implied a calc-alkaline nature, magmatism related to an extensional back arc regime and lack of economic potential for igneous rocks. Petrographic and geochemical evidences of Cu minerals have shown that mineralization occurred in forms of native copper, sulfide, carbonate and oxide-hydroxide dominantly in vein texture. In addition to copper, ore geochemical results have demonstrated that Jarou deposit possesses a relatively good potential of having silver and gold content. The results of the geochemical elements distribution have indicated that Au and Ag elements are concentrated in minerals such as chalcopyrite. Based on fluid inclusion study, the origin of mineral-bearing fluids is epithermal, and magmatic and atmospheric liquids blended near earth surface. However, considering a pure magmatic source is not conceivable. Mineralogical evidences and fluid inclusions study indicate to the role of sulfide complexes and HS- and SO4-2 anions in transformation of metals. The type of alteration and presence of minerals such as malachite and azurite confirm the reduction condition during the mineralization process.

The Shah Jahan Granodiorite and granite rocks are part of the Ordubad granitoid body that outcrop in 10 km south of Aras River. These rocks are located in the Alborz-Azerbaijan zone in NW of Iran. The Granodiorite Pluton has granular texture; containing minerals are plagioclase (andesine), alkali feldspar (orthoclase), amphibole (magnesio-hornblende) biotite, titanite and magnetite. Alkali feldspar minerals in granodiorite pluton are less than granite pluton. The Initial rate of 87Sr / 86Sr =0.704486 in granodiorite and 87Sr / 86Sr =0.704432 in granites rocks and positive εNd value indicate to mantle origin and subduction-related area. The emplacement age of these rocks is related to the Eocene based on Ar-Ar by biotite minerals. Base on mineral chemistry of biotite, amphibole and whole rock geochemistry: these plutons are meta-aluminous, I-type granites and related to calc-alkaline magma series. Negative Nb and Ti anomalies in normalized graphs can be shown subduction-related zones. P-T replacement of the granodiorite rocks are estimated of 1.08 to 1.91 Kbar and 753 to 777 °C.