1 1726-3689 Iranian Socity of Crystallography and Mineralogy 645 Special HT-MP metamorphism at the Shahindezh Metamorphic Core (SMC) –NW Iran; Mineral chemistry and thermobarometry of metapelites 1 4 2008 16 1 3 12 03 06 2017 03 06 2017 On the basis of microstructural evidence it is clear that SMC metapelites have experienced at least two regional (RM1, RM2) and one contact metamorphism (CM). During RM2, several porphyroblasts including kyanite, andalusite, staurolite, cordierite, garnet and fibrous sillimanite have grown in the mica - schists. In order to estimate the PT condition of metamorphism of metapelites, we used cation exchange and multi-equilibrium methods. Temperature of RM2 estimated using, Grt - Bt and Grt - Chl thermometry 650 - 700 °C. Also PT conditions are calculated by THERMOCALC computer program which is based on multi-equilibrium reactions. Kyanite - staurolite - cordierite - bearing mica - schists are metamorphosed at pressure ~5 - 7 kbar and temperature ~650  ±50 °C. Thermal gradient at the SMC is considered to be ~ 40 °C/km. This thermal gradient is similar to those from continent-continent collision settings.
646 Special Study on the structural changes occurred during the acid activation of Gharenaz bentonite as bleaching earth 1 4 2008 16 1 13 20 03 06 2017 03 06 2017 Gharenaz bentonite contains montmorillonite as the major mineral constituent and Ca as the major exchangeable cation. In the present study, the structural changes occurred in the course of acid activation of this bentonite was investigated by chemical analysis using  ICP-AES and phase analysis using XRD methods. Chemical analysis showed that most of the exchangeable cations i.e. K+, Na+ and Ca2+, can be dissolved at low acid concentration whereas the dissolution of the octahedral layer cations, i.e. Mg2+, Fe2+ and Al3+, depends on the acid concentration. The acid treatment experiments on Gharenaz bentonite by sulfuric acid showed that removal of octahedral cations increases as the acid concentration raises up to 3 normal after which, it remains almost constant. However a further increase in the dissolution of these cations was observed at the acid concentrations more than 5 normal. XRD analysis of the activated samples indicated, i) the elimination of calcite mineral even at low acid concentration. ii) the formation of calcium sulfate (gypsum) and iii) decrease in the intensity of (001) peak of montmorillonite during the activation process, due to the partial destruction of the octahedral layers. In order to evaluate the optimum structural changes, the activated samples was used in bleaching of an edible oil. The results showed that the bentonite activated at 3 normal is most efficient in the bleaching process. 647 Special Mineralogical Investigations of Shahid Nilchian (Dopelan) Bauxite Deposit 1 4 2008 16 1 21 30 03 06 2017 03 06 2017 Shahid Nilchian (Dopelan) deposit, located in high mountains of Chahar-Mahal Bakhtiari Province within the Zagros Thrust structural unit, is one of the main bauxite and argillite deposits of Iran. Many highly folded and faulted sedimentary successions are cropped in the area. The bauxite of Shahid Nilchian deposit is of lateritic type and belongs to Permo-Triassic in age. Five bauxite types with different quality have been recognized in the area. Mineralogical investigations have carried out using thin and polished sections, XRD and XRF analysis. According to these studies, it is verified that the major minerals are diaspore and kaolinite. Anatase and boehmite has identified as minor minerals. Some other elements such as iron, zirconium and vanadium are also presented in different minerals. The main identified textures are brecciated and pisolitic. In its application as refractory material, minerals containing iron, silica and titanium are the important gangues of bauxite. The main objective of this mineralogical study is to identify the minerals of the above mentioned elements. It is concluded that kaolinite, anatase and different iron oxides are the main sources of these elements. 648 Special Geochemical study of garnet-vesuvianite-wollastonite-pyroxene mineral assemblage in Hosh Skarns, west of Taft (Yazd) 1 4 2008 16 1 31 48 03 06 2017 03 06 2017 The injection of I-type granitoid bodies (Hosh intrusion) with calc-alkaline affinity into Lower Cretaceous limestones (Taft Formation) has produced the various types of related skarns and marbles. Thereby, those skarns formed can be undoubtedly divided into four groups, clinopyroxene-plagioclase skarns, clinopyroxene skarns, clinopyroxene- vesuvianite skarns and moreover garnet skarns. Additionally, calc-silicate bearing marbles also show an especial mineral assemblage consisting of olivine, clinopyrocxene, garnet and vesuvianite. Based upon geochemical studies, two types of garnet can be distinguished in these skarns. The first, Type is the garnets with grossular composition in which they are found with calc-silicate assemblages in skarns and the second, Type is the garnets with andradite composition present in garnet skarns. Clinopyroxenes in those skarns feature a composition varying between Ca-rich diopsides, salite and fassaite. Based on the chemical composition of the intrusive body and the related skarns, one can conclude the close relationship of these skarns with Cu and Zn skarns. 649 Special Mineral chemistry and thermobarometry of Kuh e-Dom granitoid, NE Ardestan 1 4 2008 16 1 49 66 03 06 2017 03 06 2017 Kuh e-Dom intrusion, located at the northeast of Ardestan, consists of granodiorite and diorite. The granodiorites have been intruded by various basic dikes. Plutonic rocks are mainly composed of plagioclase, biotite, amphibole, pyroxene, alkali-feldspar and quartz. Based on microprobe analysis, the biotite is classified as magnesiobiotites which typically occur at calc-alkaline orogenic igneous rocks. The amphibole belongs to calcic-amphibole group but its composition varies from magnesiohornblende to actinolite in granodiorite and from hornblende-actinolite to actinolite both in diorite and basic dikes. The plagioclase also shows variable composition from oligoclase to andesine in the granodiorite and from andesine to labradorite both in diorite and basic dikes. Based on the mineral chemistry data, the equilibrium temperature of the mineral crystallization is estimated at about 700°C, the pressure equilibrium occurred at ~1.5 Kb, which is consistent with a depth of 5.5 Km . 650 Special Phase Evolutions and behavior of Kalibbar Nephelen Cyenite in comparison with Indian Feldspar in Composition of Monokotorata Tile Engob 1 4 2008 16 1 67 78 03 06 2017 03 06 2017 The Kalibbar Nephelincyanite comes from a region in East Azerbaijan. Its mineral and chemical composition is nearly similar to an Indian feldspar which is used in some of Iranian tile and ceramic industries. The procreation and behavior parameters of Kalibbar Nephlincyanite with the Indian feldspar in production of Monokotorata tile engob, has been studied comparatively. Nephelincyanite has shown lower thixotropic behavior, compare to feldspar, during preparation of raw materials. Consequently, loss water requires in processing of granulates with more suitable particle size distribution in tile production. Phase analysis of the formulated engob containing feldspar showed orthoclase, anorthit, mullite and zirconium silicate after sintering of, while in the formulated engob with nephelincyanite, orthoclase, anorthit, zirconium silicate, leucit and nephlin phases are detected. However, zirconium silicate is added to both formulas in order to create color properties. Absence mullite phase and the presence of Nephlin and Leucit phases made little hesitation on properties and behavior of Nephelincyanite engob at different temperatures in comparison with feldspar. But further investigation on thermal behavior, energy changes and weight and volume differences during sintering process of the engobs, showed that the thermal behavior of both engobs are nearly similar and there will be no concern in substituting the Indian Feldspar by Kalibar Nephelincyenite in the tile production technology. Economically there is a good reason to use Nephlincyanite in this substitution 651 Special An Investigation on the Physical, Chemical and Mineralogical Properties of Iranian Biglar Refractory Bauxite Mines for Refractories Application 1 4 2008 16 1 79 90 03 06 2017 03 06 2017 In this research, the properties and characteristics of Biglar refractories bauxite mines have compared with two types of industrial China's and Iranian (Doplan super) refractory grade bauxite in order to use in refractory industries. At first, physical, chemical and thermal properties, phase and microstructural characteristics have been measured and sintered samples of Biglar Bauxite at different temperatures were analyzed and then were compared with China's and Doplan calcined bauxite properties. The results showed that the refractory bauxite minerals obtained from Iranian Biglar mines contains the proper amounts of alumina and other oxides. So it could be concluded that these properties are comparable to the China's and Doplan bauxite and this refractory grade bauxite is suitable for refractory industries for using in the production of many kinds of shaped and monolithic refractory product. 652 Special Investigation of physical properties of conductive, transparent RF sputtered ITO thin films as a function of thickness and post annealing Temperature 1 4 2008 16 1 91 98 03 06 2017 03 06 2017 Thin films Indium tin oxide (ITO) with various thicknesses, from 130-620nm, have been deposited on the thin glass substrates by RF sputtering using ITO ceramic (90% wt. In2O3 and 10% wt. SnO2) target, and subsequently annealed in vacuum at various temperatures. Electrical and optical characteristics of ITO samples, before and after annealing at different temperatures, were investigated by four point probe and UV/VIS/IR spectrophotometer. Structural properties of layers deposited at optimum temperature of 400˚C were analyzed by XRD. SEM analysis was used to investigate the morphology of the optimal surface layer. Results show that by increasing the thickness, crystalline structure varies, so that sheet resistance, resistivity and transparency of films vary. Layer deposited with 130nm (lower thickness) has 83.71% transmittance and 2.34×10-4Ωcm resistivity. In contrast, 620nm thickness film with 79.07% transparency has the lowest electrical resistivity about 1×10-4Ωcm at 400˚C. This layer can be used as an optimal film with 1.6 Ω/□ sheet resistance for many applications.     653 Special Mineral chemistry of volcanic rocks from the West of Arousan-e- Kaboudan (NE of Isfahan) 1 4 2008 16 1 99 112 03 06 2017 03 06 2017 Arousan -e- Kaboudan area, located about 115 km northeast of Nain (south of Choupanan), is part of Central Iran (Yazad block). The Eocene volcanic rocks of the area are composed of lavas and pyroclastic rocks. The lavas can be divided into acidic (rhyodacite) and relatively basic-basic (trachyandesite, mugearite and hawaiite) rocks. The textures of these rocks are trachytic, hyaloporphyritic and poikilitic. Plagioclase (albite to andesine), alkali feldspars (sanidine-Or: 65-86%), clinopyroxene (diopside to augite), mica (biotite to phlogopite), amphibole (magnesian hastingsitic hornblende to magnesian hastingsite) and chlorite (brunsvigite) from thaerochs were analyzed by electron microprobe. Geochemical evidence and mineralogical characteristics indicate that the acidic rocks are calc-alkaline and basic rocks have shoshonitic nature. The tectonic environment, in which these rocks were formed, is probably a volcanic arc related to subduction (in the continental margin of central Iranian micro – continental). 654 Special Crystal chemistry and comparison of mineralogical composition of Eocene volcanic rocks and their basic enclaves in north of Anarak (NE of Isfahan province) 1 4 2008 16 1 113 124 03 06 2017 03 06 2017 Eocene volcanic rocks of north Anarak area are as scattered as masses. These rocks cross the Anarak schists and Ashin-Zavar ophiolites but had not metamorphosed them. Their outcrops follow the direction of within the area faults. Mineralogicaly, these rocks are limited in composition from Andesi-Basalt and Andesite to Dacite. These rocks have phenocrysts of amphibole and plagioclase in microcrystalline and microlitic matrix. The andesitic and andesibasaltic rocks in the study area have a lot of enclaves that contain many amphiboles.  Type of the amphiboles is Magnesiohastingsite. Similarity of composition of amphiboles and biotites in the volcanic rocks and their enclaves indicate that these volcanic rocks and their enclaves are possibly cogenesis. There are three types of feldspar in these rocks that are andesine-oligoclase, alkali feldspar and bytownite. Bytownite is found only in certain enclaves. Geothermometry studies on phenocrysts of plagioclase and amphibole, that are in equilibrium, indicate that crystallization temperature of these phenocrysts is 835°c to 925°c. 655 Special The Phase Investigation of Mo + 2(1 - x)Si + 2xAl Compounds 1 4 2008 16 1 125 130 03 06 2017 03 06 2017 X-ray powder diffraction data for Mo2.85Al1.91Si4.81 are presented here. The new Mo2.85Al1.91Si4.81 compound was successfully prepared, using the self-propagating high-temperature synthesis (SHS) technique. The starting atomic mixture of reactant powders was Mo + 2(1 - x)Si + 2xAl with 0.2 ≤ x ≤ 0.5. The final powder compound obtained by the SHS technique was determined to be in x = 0.2; Mo(Si, Al)2 and in 0.3 ≤ x ≤ 0.5; Mo2.85Al1.91Si4.81. respectively X-ray powder diffraction pattern of Mo2.85Al1.91Si4.81 was recorded using an X-ray powder diffractometer and CuKa radiation that have been analyzed by automatic indexing programs. Mo2.85Al1.91Si4.81 was found to be hexagonal. 656 Special Influence of thermal processing and 10 Mev electron beam on the crystallinity of polyethylene 1 4 2008 16 1 131 140 03 06 2017 03 06 2017 Samples from two type of polyethylene, with low and high density, had been subjected to three different initial processing. The samples were heated to 170 oC and then cooled by different cooling rating in air, in mold (10 oC/min cooling rate) and in 0.0 oC water. Following this step, each sample irradiated by 10 MeV electron beam. The gel content of the samples, which is a measure of interchain cross links formed on the amorphous area of the polymer, is a created due to electron impaction and was extracted into the xylene. Change in crystallinity of the samples was monitored by differential scanning calorimetry (DSC) technique. It has been shown that increase of the radiation dose up to 200 KGy, increases to the gel content of the polymer samples, but in higher doses remains without considerable change. Crystallinity of the polymer samples depends on the heat treatment and also radiation dose. Cooling rate has significant effect on crystallinity, so the more cooling rate the crystalline content of the polymer more reduces. However, Cystallinity of the polymer samples due to the absorption of  radiation up to 200 KGy increases and then with increase of radiation dose decreases. Our study showed that change in crystallinity of the LDPE due to the absorption of the radiation is more than that of HDPE. 657 Special Zoning and chemistry of garnets in eclogites and blueschists in ophiolitic complex of eastern Birjand: An evidence for subduction process in eastern Iran 1 4 2008 16 1 141 158 03 06 2017 03 06 2017 The ophiolitic complex of eastern Birjand consists of various rocks of a complete ophiolitic complex. Except for basaltic pillow lavas which are changed to metabasites such as eclogites and blueschists under metamorphic conditions, all other rock types of an ophiolitic complex could be seen in this sequence. Chemistry of garnets and their zoning patterns indicates the occurrence of subduction in the study area. The presence of the low-temperature and medium-temperature eclogites in the study area also may show the collision process between Lut and Afghan Blocks which has occurred after the subduction process. This collision process has lead to the occurrence of medium-temperature eclogites in response to the increase of temperature in the study area and then uplifting of the eclogitic rocks during the emplacement of area ophiolite in the suture zone between Lut and Afghan Blocks. 644 Special The mechanism of fibrolite formation in the contact aureole of Mashhad granite 1 4 2008 16 1 159 168 03 06 2017 03 06 2017 The mechanism of fibrolite formation in metapelitic rocks of the contact aureole of Mashhad granite is examined in this study. According to textural features, fibrolite considered to be disharmonious. Textural evidence strongly suggests that most of the fibrolite in this aureole are formed by decomposition of biotite. Fibrolite produced late in the thermal history of the aureole through a reaction involving acidic volatiles emanating from the adjacent intrusion. Textural evidence suggest that the fibrolite formed at temperatures within the andalusite stability field in the aureole investigated in this study.