مجله بلور شناسی و کانی شناسی ایران
سال بیست و نهم شماره 1 (پیاپی 83، بهار 1400)

In this paper, the chlorite geothermometry method is used to estimate the low and medium temperature of metamorphism in Zavarijan area, northeast of Boroujerd. Structural formula recalculation for chlorite samples, based on 14 oxygen, show that Si cation numbers are less than 2.91(apfu), and the sum of octahedral cations is very close to 12(apfu), therefore both of them show an indication of trioctahedral chlorite. The mole fractions in interlayered phase(Xc) confirm the purity of chlorite and lack  of any smectite. All major elements in the chlorite are strongly corresponded with each other and chlorite samples composition are mainly ripidolite and pychnochlorite respectively. Chlorite geothermometry shows an average of 345ºC, so that corresponded with the average of temperature of chlorite crystallization that is resulted from biotite alteration. Also, this temperature indicates the mesothermal or orogenic fluids that have been importanat in generation of chlorite. Based on the present evidences, we can conclouded that formation of chlorite in the studied area is the result of regional metamorphism performance.

Sangan prospect area is located northeast of Torbat-e-Heydarieh in Khorasan Razavi Province and in relation to regional geology, it is situated in eastern section of Khaf-Kashmar-Bardaskan magmatic belt. Metamorphosed sediments of the Shemshak Formation (slate, schist, quartzite) is the oldest unit, which is intruded by Kafardoogh granitic intrusion. The dikes of quartz monzosyenitic and dioritic composition in the last magmatism stage have intruded into the fore mentioned units. Structurally-controlled mineralization has formed along subsidiary faults, branching from the Doruneh major fault, with general trends of NNW-SSE to WNW-ESE (dipping 60-90 degrees southerly and westerly) and NE-SE (dipping 50-70 degrees easterly). The major parts of mineral deposit has occurred in fault zones of metamorphosed Shemshak Formation due to deposition of mineralizing hydrothermal fluid in open spaces of faults as cement of fault breccia fragments. The hypogene mineralization is characterized by chalcopyrite as the main ore mineral and minor amount of pyrite together with quartz and barite as gangue minerals. Malachite, chrysocolla, chalcocite, neotocite and secondary iron oxides constitute the mineralization of oxidation and supergene zone. The occurrence of structures and textures as vein-breccia, open space filling, veinlets and secondary replacement are characteristics of mineralized veins in this area. Silicification is the principal alteration associated with mineralization. The geochemical survey of veins indicates not only high content of Cu (more than 5 percent), but also considerable anomaly of Au up to 0.4 ppm while other significant metallic elements are not anomalous. Cu, Pb, Zn, Ag and Mo have good positive geochemical correlation but Au does not show correlation with other elements (except Ag). Studying two phase liquid-rich primary fluid inclusions of quartz and barite along with mineralographic studies demonstrate two phase of hypogene mineralization. Accordingly, the main phase of primary mineralization has formed from a hypogene hydrothermal fluid at temperature of 274°C to 318°C and salinity of 7.3 to 12 wt% NaCl equivalent. The late phase, which is related to barite mineralization, has been derived from a fluid at temperatures between 200°C to 259°C and salinity of 10.2 to 11.4 wt% NaCl equivalent. The temperature and salinity data represents the role of fluid mixing and dilution by cool-dilute meteoric fluids as ore-forming processes. Based on mineralogy, structure, texture, alteration, vein geochemistry and fluid inclusion studies, the Sangan mineral occurrence most resembles vein-hydrothermal deposits of epithermal Cu±Au type.

The Takht-e-Gonbad copper mineralization is located about 63 km of northeast of Sirjan city. Hypogene mineralization occurred as stockwork vein-veinlets and thick quartz veins hosted by Oligo-Miocene micro-granodiorite body and Eocene pyroclastic materials (mainly tuff with intermediate composition). The stockwork vein-veinlets contain three generations of mineralization, (1) quartz + magnetite ± chalcopyrite, (2) quartz + chalcopyrite + pyrite + magnetite, and (3) quartz + pyrite + chalcopyrite. Phyllic alteration was mainly developed in the wall rocks around the stockwork quartz vein-veinlets. The supergene mineralization in this deposit is characterized by the replacement of ferrous sulfides by hematite and goethite. Also, formation of the malachite, azurite, and native copper during destruction of the hypogene iron and copper sulfides occurred under oxidizing conditions. The study of the fluids inclusion in quartz crystals of the stockwork vein-veinlets showed that they are chiefly of L+V+S, L+V and V+L types having temperature and salinity ranges of 140-450°C and 0.35-57.8 wt% NaCl eq., respectively. The solid phases are halite, sylvite, and opaque minerals. The studied fluids inclusion in the thick quartz veins are of L+V type having temperature and salinity within the range of  207-344°C and 0.35-3.39 wt% NaCl eq., respectively. Based on microthermometric data, the boiling of the magmatic fluids was the effective factor of the ore and gangue minerals deposition in the stockwork vein-veinlets. Also, cooling and mixing of the atmospheric fluids with magmatic ones account for the deposition of the minerals in the thick quartz veins.  In general, the obtained data in this research revealed that the development and evolution trend of the hydrothermal system in the Takht-e-Gonbad is mostly similar to that of the porphyry copper system.

The garnet calc-silicates at Baba-Nazar are located in the NE of Takab, Sanandaj- Sirjan zone. Anhedral to euhedral green colored garnets is a characteristic feature of these Calc-silicates. Mineral chemistry shows that garnets are Andradite- Grossular and contain more than 13% uvarovite. The high chromium content garnet, Cr-Spinel that have relatively Cr rich core than the rim, sulfide opaque minerals such as pyrite and chalcopyrite in this calc-silicate unit are regarded as evidence of the ultramafic protolith which can be considered the source of chromium for these garnets. The similarity in the geochemical composition of whole- rock between these garnet calc-silicates and ultramafic rocks is also consistent with ultramafic protolith. These rocks were affected by hydrothermal alteration that has caused high Ca and low Mg contents in these garnets and the host rocks compare to those from mantle source and ultramafic rocks. The introduction of CO2 rich fluids caused the carbonatization of ultramafic protolith and preferential removal of Mg. The faults, as channels for circulation of the hydrothermal fluids, play a key role during the process of hydrothermal alteration.

Sub-volcanic diorite and granodiorite intrusive bodies (Middle Eocene) and dome shaped rhyolite have intruded into Lower to Middle Eocene volcanic rocks in Torud-Chah Shirin magmatic segment. The granodiorite plutons and rhyolitic dome host turquoise and gold mineralization in Damghan mine. Intrusive bodies display characteristics of high potassium CA and meta-aluminous (diorite and some of granodiorite samples) to per-aluminous (rhyolite and some of granodiorite samples). Comparison of TiO2-La-Hf and Zr-Nb-Ce / P2O5 values, as well as Rb to Y + Nb ratios indicate that magmatism is related to post-collisional tensional regime after closure of Neotethys. On the other hand, the metasomatism of  mantle due to the fluids release from subducted oceanic slab has caused  high ratio of LILE / HFSE with negative anomalies of Ti, Nb and Ta in magma. Partial melting of the metasomatized mantle has led to the formation of primary magma, which eventually has generated diorite, granodiorite, and rhyolite magmas by fractional crystallization, crustal assimilation and magma mixing

East Salmas gneisses are located in the northernmost parts of the Sanandaj-Sirjan zone and are seen in banded and deformed with the 6 different groups of lithological diversity. Their protolith is of paragneiss type with arkosic sedimentary rock type.Texturally, they are immature. Based on this study, chemical maturation trend of protolith of the present investigated gneisses are in the arid to semi-arid boundary climatic conditions with average granite composition and chemical alteration index of about 55%. The linear trend in the diagrams of major oxides variations of the parent gneisses in the region confirms the partial melting and granitization of the genesis in these rocks. According to the pattern of normalized diagrams, these rocks show good agreement with typical paragneiss diagrams of the world. Investigating the various diagrams reveals that the tectonic setting of the gneisses is mainly of continental margin type with passive sedimentary trend.

The gold-bearing prospect area at Gharehchay is located in about 2 km south of Tikmehdash, East-Azarbaidjan, NW Iran. The host rocks of the gold-bearing quartz veins/veinlets are principally Eocene andesites and upper Eocene-Oligocene felsic intrusive body (granite to alkali granite). Wall rocks alteration haloes developed around the veins/veinlets are mainly of silicic, phyllic, phyllic-argillic, and propylitic types. The sulfide and gold mineralization in the study area occurred as vein/veinlet, stockwork, and open-space filling. The hypogene opaque minerals are chiefly pyrite, chalcopyrite, and gold which were overprinted by supergene mineral assemblages like Fe-oxides/hydroxides (goethite, jarosite, and hematite), copper carbonates (malachite and azurite), and secondary copper sulfides (covellite and chalcocite). The quartz crystals within the veins/veinlets show typically brecciated, crustification, comb, and vuggy textures. Based upon the microthermometric analyses, the Th and salinity values of the studied fluid inclusions vary from 200ºC to 340ºC and from 6.2 to 11.7 wt% NaCl eq., respectively. The fluid inclusion data along with the presence of hydrothermal breccias in the quartz veins/veinlets show that both boiling and simple cooling were the important factors in precipitation of sulfide and gold minerals at Gharehchay. Both sulfide and chloride complexing ligands played significant role in transporting of the ore metals. According to the data obtained from fluid inclusions, mineralogy, and textures of the ore and gangue minerals in the quartz veins/veinlets, the sulfide and gold mineralization at Gharehchay can be reckoned as low-sulfidation epithermal type.

At the base of Shemshak Formation in the south Azadshahr area, some igneous mafic rocks are discovered recently  as olivine gabbro bodies and pegmatoid alkali-diorite dikes. Rock-forming minerals of olivine gabbro includes olivine, clinopyroxene and plagioclase, alkali-diorites are composed of large amphiboles and plagioclase. Major and trace elements characteristics of these rocks indicate they have alkaline nature and derived from OIB-like mantle source. Mineral chemistry of olivines and plagioclases in olivine gabbros determined as chrysolite and labradorite, respectively. Clinopyroxenes in olivine gabbros have diopsidic to augitic composition  and alkaline (Non-orogenic) affinity, and they formed in 2-11 Kbar, 1200-1250˚C and high oxygene fugasity conditions. Amphiboles in alkai-diorites are calcic and characterized with kaersutite to magnesiohastingsite in composition, igneous nature and derived from mantle sources. Their crystallization temperature and pressure are 950˚C and 600-750 MPa (equivalent 6-7/5 Kbar). Plagioclases in alkali-diorites are albite.

The mineralization index of Yeylaghe Gharachi, as part of Arasbaran metallogenic belt, is located about 25 km northwest of Ahar, East-Azarbaidjan Province, NW Iran. The host rocks of this index consist of composite intrusive rocks with lithologic compositions of granite, quartz monzonite, granodiorite and diorite of Oligocene and Oligo-Miocene age. The alteration zones in this area are mainly potassic, phyllic, argillic, propylitic, silicic and carbonate. Mineralization occurred principally as disseminations, cross-cutting veins-veinlets and replacement in two separate stages of hypogene and supergene. Pyrite is the major hypogene sulfide mineral accompanied by magnetite, chalcopyrite, molybdenite, sphalerite and galena. The main supergene minerals in this area include hematite, goethite, limonite, bornite, chalcocite, covellite and malachite that accompany the hypogene mineral assemblage. In investigation of the phase contents of fluid inclusions in the quartz- sulfide veins-veinlets along with the potassic, phyllic and argillic alterations, five types of fluid inclusions have been recognized: mono-phase liquid (L), mono-phase vapor (V), liquid-rich two-phase (L+V), vapor-rich two-phase (V+L), and multiphase (L+V+S). Homogenization temperatures of the studied fluid inclusions vary from 190 to 530 °C. Considering the last ice-melting temperature of aqueous two-phase inclusions and halite melting temperature in the aqueous multiphase inclusions, the salinity ranges between 0.4 to 59 wt.% NaCl equivalent. Based on the microthermometric results of fluid inclusions, it can be conceived that episodic boiling and dilution by underground water of meteoric origin were the main mechanisms in development and evolution of this index. The zonation pattern of the alteration, mineralization and fluid inclusion data indicate that the Yeylaghe Gharachi mineral index is the most similar to porphyry copper deposits and the associated metallic veins.

The Deh-Salm Metamorphic Complex (DMC) is composed of metapelite, metabasite, metaperidotite, and calc-silicate rocks and is one of the few outcrops of the Lut block’s basement which emerged near to the Sistan suture zone. In the eastern part of the Deh-Salm metamorphic complex, the calc-silicate and marble appeared in the form of elongated tectonic lenses that have been metamorphosed in similar temperature and pressure conditions of the confined rocks. Evidences from mineralogical and petrographic studies indicate the existence of different mineral assemblages in the calc-silicates but with similar metamorphism conditions. Scapolite + alkali feldspar + plagioclase + sphene, scapolite + pyroxene, garnet + amphibole + epidote and garnet + pyroxene + Wollastonite are most important paragenesis recognized. The results provided by this study, based on the EPMA method, classify the scapolite into the calcic group that can be called mizzonite (Me% 70 – 80), alkali feldspar with a composition close to orthoclase, and plagioclase as an andesine composition. Garnet in the studied rocks are rich grassular end-member. Pyroxene of the calc-silicate rocks are the clinopyroxene with the diopside composition. Based on the metamorphic paragenesis, geochemical analyses, and comparsion of the metamorphic grade between the calc-silicate and the adjacent metabasites, a progressive metamorphism up to the upper amphibolite-granulite facies from the west to the east of the complex has taken place. It may be considered that the Late Jurassic regional metamorphism event was synchronous with the Shah Kuh granitization at the eastern margin of the Lut Block due to the subduction of the Neotethys ocean.

Altered quartz feldspathic rocks and associated soils with the felsic source rock crops out in different areas of the Yazd Province, and are used as ceramic, porcelain and glass raw materials. Alteration products in the igneous rocks of the Cambrian Rizo series (Zarrin and Tut), Precambrian metagranites (Saghand), post-Jurassic leucogranites (Khezrabad) and Neogene Dacites (Abdolah) were investigated and compared to each others for the intensity of alteration, textural variations, and mineralogy in the units. The major mineralogy of their alteration products includes quartz, feldspar, illite, kaolinite, and montmorillonite. Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), Index of compositional variety (ICV), and Plagioclase Index of Alteration (PIA) were determined for the alteration products. The indices values show a weak to moderate degree of alteration for Saghand metagranites, Khezrabad leucogranites, and Abdolah Dacites, and a moderate to strong degree of alteration for Rizo series. The observed differences have resulted from the lithologic type of the source rocks, age, climatic conditions as well as structural characteristics of the areas.

The Balazard prospecting area is located about 120 km southwest of Nehbandan city, Khorasan Jonoobi Province, in the central parts of Lut block volcano-plutonic belt.  The intrusion of a granitoid pluton into rhyolitic and andesitic rocks has led to alteration and mineralization. Hydrothermal alteration zones consist of argillic, sericite-argillic, silicic-argillic, propylitic, and advanced argillic. Sulfide and oxide mineralization occur as disseminated grains, veinlet, hydrothermal breccia and carbonate-silicic veins. The geochemical and radioisotope data are consistent with subduction related magmas that formed in an active continental margin, and these data suggesting a major interaction with upper crust during magma ascent. Microthermometric measurements of fluid inclusions yielded homogenization temperatures (Th) of 385–550 °C and moderate salinities of 7.1–21 wt% NaCl equivalent in Au bearing quartz vein, indicating the mixing of ore-forming fluids. Geology, mineralogy, alteration, fluid inclusions and geochemical studies all indicate that mineralization at Balazard area occur as both porphyry and high sulfidation epithermal systems.

Considering the importance of plagioclase in reconstructing magma cooling processes, the size and shape distribution of this mineral is investigated for Chah - Musa sub-volcanic intrusion (NW Toroud- Semnan Province). The slopes of CSD diagrams, the natural logarithm of the density of the crystalline density (n) against the length of the crystal (L), show plagioclase phenocrysts available in this intrusion have been grown with rates of 1.4×10-8 to 9.27×10-9 mms-1, in time limited 118.62 to 630.7 years. The calculated residence time of magma in Chah-Musa intrusion coincides with sub-volcanic nature of the studied samples. Crystal size distribution diagrams suggest presence of two populations of crystals that formed during the anneal period as well as during decompression, associated with separate nucleation regimes.

Rasht Abad Cu±Au deposit is a part of the Tarom-Hashtjin metallogenic belt in the western Alborz-Azerbaijan zone. The exposed units in the area include volcanic, sub-volcanic calc-alkaline to shoshonitic rocks with Upper Eocene age and belongs to magmatic arcs setting. The most important alterations related to mineralization include low temperature silicification and sericitic alterations. Mineralization with quartz-sulfide veins in the area consist of a series of oxide (hematite), sulfide (chalcopyrite, galena, bornite, covelite), sulfate (barite) and carbonate (malachite, azurite). Fluid inclusions measurements on primary two-phase L+V inclusions determined homogenization temperatures between 138 to 320°C (229°C) and salinity between 2.49 to 9.41wt% (9.41) NaCl eq, evidence of isothermal mixing and dilution. The δ13C (-9.21to -6.81‰) and δ18O (-14 to -15‰) also show the influence of meteoric waters in late carbonate veins. The results of this study show that the high similarity between Rasht Abad and intermediate sulfidation epithermal deposits.

The vein-type mineralization of the base (Zn, Pb, and Cu) and precious metals (Au) in the Qarah Changel area (northwest of Qazvin) is located in the southern part of the Tarom-Hashtjin metallogenic belt. Volcanic (trachy-andesite, rhyolite and dacite) and pyroclastic (tuff, tuffite and tuffaceous shale) (Eocene) rocks are the hosts of this mineralization. Distinctive alterations around mineralized veins include argillic, sericitic, propylitic and silicic. Ore mineralization has occurred in two forms, hypogene and supergene. Hypogene ore minerals include sphalerite, galena, chalcopyrite, pyrite, magnetite, gold, digenite, and bornite, which are associated with supergene mineralogical assemblages such as calcocite, covellite, cerussite, malachite, azurite, hematite, and goethite. Calcite and quartz are the associated gaugues of this mineralization. The texture of the ore consists of vein-veinlet, replacement, breccia, disseminated, bladed and open space filling. According to geochemical studies, volcanic host rocks are peralumine and have the nature of high- potassium clac-alkaline to shoshonitic. The enrichment of K, Ba and Cs in comparision to Ti, Nb and Zr, the LREEs enrichment relative to HREEs, and the occurrence of negative Nb anomaly indicate the formation of a magma generating volcanic rocks in the subduction zone. Studies of fluid inclusions in quartz mineral co-genetic with sulfide ore minerals showed that they are chiefly of L+V and having homogenization temperature in the range of 202 to 247 C°. The salinity of fluid iinclusions also ranges from 10 to 22 wt% NaCl eq. According to microthermometric data, boiling and cooling are the most important mechanisms in the development of mineralized veins. Evidence such as the coexistence of liquid and vapor-rich fluid inclusions, hydrothermal breccias, microcrystalline quartz and bladed calcite confirm the occurrence of the boiling phenomenon during the formation of mineralized veins. Combining the results of mineralogical studies, texture and associated alterations, geochemistry and tectonic setting of volcanic rocks, and   microthermometry of fluid inclusions indicate that  mineralization in the Qarah Changel area is most similar to low sulfidation-type epitermal ore deposits.

Garagheh granitoid is located in the northwest Zahedan batholite and is exposed in Zahedan-Saravan granitoid belt and Sistan suture zone. This granitoid is composed of granite (synogranite, monzogranite) and granodiorite. These rocks have mainly consist of plagioclase, orthoclase, microcline, quartz, biotite and hornbelend with granoular texture. This pluton cut by microdioritic dykes. Garagheh granitoid have metapellitic enclaves with enrich from quartz and mica minerals with granoular texture. This granitoid is calc-alkaline, metalluminous, with (I) and slightly to S typs, enrichment from in LREE and LILE and depleted from in HREE and HFSE. Tectono magmatic diagrams show Garagheh granitoid is related to active continental environments. Positive anomalies in K and Cs elements and negative anomalies in Zr, Sr, and Ti elements show patterns similar to the subduction environment. Based on the Sr/Y versus Y and FeOt+MgO+TiO2+ Al2O3 versus Al2O3/FeOt+MgO+TiO2 digrams, it is thought that the constituent magma of this pluton is similar to the Zahedan granite due to the melting of amphibolite source, that resulted during closure of the Neothytean ocean east of Iran, located between the Lut and Helmand plates, during the Eocene-Oligocene to Miocene times.

KTiOPO4(KTP) nanoparticles were synthesized by co-precipitation method using L-Alanine as capping agent. Different mole ratios of L-Alanine used to study on the effect of capping agent concentration on size, structural quality and morphology of KTP nanoparticles. XRD analysis confirmed the formation of orthorhombic phase of obtained KTP nanoparticles. Using L-Alanine as capping agent results in crystal lattice rotation. Largest and smallest grain size were obtained 46.2nm and 39.5nm by 1:1 and 3:1 mole ratios of capping agent respectively. Lowest lattice strain (0.0012) was observed at 3:1 mole ratio of L-Alanine. Structural quality and morphology of synthesized nanoparticles were studied with FT-IR and FE-SEM analyses.

In this research, Zn0.97Cu0.03O nanoparticles are prepared by sol-gel method using various stabilizers (Mono, Di, and Tri-ethanolamine). The effect of stabilizers on the structural, morphological and optical properties of the nanoparticles were investigated. Study of X-ray diffraction pattern shows the hexagonal wurtzite structure of samples. The crystallite size, strain, stress, and deformation energy of the lattice were determined by modified Williamson-Hall relations. The results showed the sample prepared with monoethanolamine has the lowest crystallite size, lattice parameter and strain. FESEM images revealed a decrease in nanoparticle accumulation with increasing amine group. By the change of mono to tri-ethanolamine in the primary sol, the red shift was observed at the near band edge emission of Pl spectra which consistent with decrease of optical band gap from 3.16 eV to 3.11 eV deduced from strain enhancement.