مهرداد بهزادی

The occurrence of copper and gold mineralization in Sultan Anouch area in the southwest of Malayer is a part of Sanandaj-Sirjan zone. The most important rock units in the studied area are schist, limestone and acidic to medium intrusive stocks. The dominant alterations in the area are propylitic, sericite, argillic and hematite, which are locally connected to the formation of skarn. Quartz, epidote, hematite, magnetite, pyrite and malachite minerals are the main ore minerals. The mineralization of gold and copper can be seen as streaks and filling the empty space. In the samples, the highest amount of gold is 0.67 grams per ton and the highest amount of copper is 37200 grams per ton. In the immediate vicinity of the intrusive mass with carbonate rocks, extensive traces of chemical reactions of open system neighborhood transformation have been observed. The intrusive masses are located in the most parts of the volcanic arc granites and at the same time as the impact, so the magmatism of the area is related to the subduction environment.

Northern Hired mining area with an area of about 25 square kilometers is located in South Khorasan province and 140 kilometers south of Birjand city. In this area, intermediate to acidic intrusive masses with the composition of granodiorite to granite have infiltrated and affected the Tertiary volcanic-sedimentary sequence. In the studied area, mineralization is associated with siliceous, sericite, tourmaline, chlorite and carbonate alterations. The structure and texture of these deposits include planar veins and veins and rarely stockwork, scattered, sheared and massed.

The studied area is located in the southern part of South Khorasan province. This area is located 145 km south of Birjand city and north of Hired village. The way to access this mineral area is the paved road from Birjand to Khosf and then Hird or from Nehbandan to Hired. After reviewing the library studies, a field visit was made to the target area. According to the area, samples were taken from all existing lithological units, mineral mass and alteration around the mine. 57 samples were taken for ICP-MS and ICP-OES analysis. The characteristics of all collected samples and studied stations are carefully recorded. Then, the analysis results were analyzed in the relevant software.

In this range, intermediate to acidic intrusive masses with the composition of granodiorite to granite have infiltrated and affected the Tertiary volcanic-sedimentary sequence. According to the field observations, the most important changes that have been identified on the surface of the earth are: 1) quartz-tourmaline-sericite, 2) carbonate and 3) propylitic. In the samples, plagioclase crystals can be seen both in the background and as phenocrysts, which sometimes have zoning. A number of plagioclases have been dissolved and recrystallized. The mafic minerals in the rock are amphibole and pyroxene.Amphiboles and plagioclase have generally changed to chlorite and sericite, which indicates the effect of atmospheric waters on the rocks of the region. Mineralization in the studied area can be seen in the form of veins with different thicknesses along fractures and faultzones, and most of the mineralization has occurred in the basalts and basaltic andesite of the area. Amphibole and plagioclase have generally changed to chlorite and sericite, which indicates the effect of atmospheric waters on the rocks of the region. Pyroxenes are also seen in the composition of the background. In the analyzed samples, 29 samples have values higher than one percent of copper, of which 18 samples have values higher than five percent of copper. The maximum amount of molybdenum in the obtained samples was equal to 1.1%. 30 samples have values higher than 0.12% of lead and 12 samples have values higher than 1% of lead and the maximum amount of lead measured in the samples of this area was higher than 3%. 28 samples have values higher than 0.2% of sulfur and 3 samples have values higher than 1% of sulfur and the maximum amount of sulfur measured in samples of this area was higher than 3%. By drawing correlation diagrams. Cu element also has a good correlation with Mo element. (Al, Ti, Cr, Ni) Al with Ti and Also, Cr has a strong correlation with Ni. The gold element is also strongly correlated with iron and arsenic.

Geochemical investigations of associated elements show that the source magma of the mineralization in the northern Hired area is the result of subduction and hence it is type I. These investigations show that the existing gold is placed within the pyrite structure and according to the paragenesis of copper and molybdenum and also the presence of copper in the form of chalcopyrite minerals, it can indicate that the mineralization of copper and molybdenum is near The thermal source is formed, while gold mineralization is of epithermal type. Based on the conducted studies and field observations, the North Hired gold-copper deposit is mainly in the form of veins, and due to the high anomaly of elements such as lead, zinc and molybdenum, the term multi-metallic can be used for the North Hired deposit. In this range, intermediate to acidic intrusive masses with the composition of granodiorite to granite have infiltrated and affected the Tertiary volcanic-sedimentary sequence. The outcrop of these intrusive masses can be seen in the south of the range. Generally, the host rock of the mineralization in the range is basic to moderate, but in some places rhyodacite outcrops have also been observed.

Chapdoni-Posht-e-Badam complex is located in the structural zone of Central Iran and in the northeast of Yazd province. The study area is one of the areas with high potential for mineralization of rare earth elements. In this research, to investigate the mineralogy and mineralization of rare earth elements, field studies, mineralogy with transmission-reflection light microscope, electron microscope and X-ray diffraction method (XRD), chemical analysis by ICP-MS method have been used. After the studies, the results of studies show the enrichment of rare earth elements in the area. In between, Ce elements with an average grade of 1353 ppm, La with an average grade of 745 ppm, and Y with an average grade of 252 ppm from 170 analyzed samples have high enrichment and Dy-Sm-Gd-Yb-Er elements show slight anomalies.Gneiss, granite, granite-gneiss, magmatite and schist are the most important host rocks for mineralization in the area. These rocks are mainly altered and metamorphosed. The Metasomatization of the host rock is one of the most obvious evidence of alteration for the enrichment of rare earth elements. Different types of minerals have been identified in the region, the main minerals of which are rare earth elements including Bastnasite, Monazite and Allanite. Minerals that can contain trace amounts of rare earth elements include Thorite, Zircon, Uranothorite, Apatite, Fluoroapatite, and Titanite. Tourite and Uranothorite minerals, which are parageneses with rare earth element mineralization, can be considered as tracer minerals of mineralization in the region, and gamma radiometric method can be used to trace and explore the mineralization zones of rare earth elements.

Jeirud Phosphorite Mine is located in the phosphate-rich horizon of the Jeirud Formation of the Lower Devonian sediments in central parts of Alborz geotectonic zone, North of Iran. The sediments of this formation are mostly composed of detrital rocks such as sandstone, sandy shales and sandy limestones. Phosphorite mineralization is mainly concentrated in the shales of middle parts of the Jeirud Formation. In this research, we have studied the concentration and the possibility of exploitation of rare earth and radioactive elements in these phosphorites. Lithogeochemical samples were randomly collected from phosphorite horizons. The samples were analysed by ICP-MS and ICP-OES not only for REE but also for major oxides and radioactive elements. The geochemical data show that the average of P2O5 is 29.60 %. The average of U and Th is 4.97 and 8.64 ppm respectively. Also, this data show that concentration of REEs in these samples are , 3times more than rare earth elements in North American shales (NASC) and 2.6 times more than Past Archaen shales (PAAS). REE concentration of these phosphorites were normalised to North American shales (NASC) and Past Archaen shales (PAAS). The spider diagram shows positive patterns to REE, especially in Ce and Eu. Also, this spider diagram represents the diffrentiation of LREE with respect to HREE. This diffrentiation occurred due to preferential absorption mechanism and during late diagenesis in these sediments. The average concentration of P and REE is realtively high and it seems to be economic for next minning activites. But the average concentration of U and Th is too low and not economic for exploration.

The Godar Sorkh area is located in the central part of the Sanandaj-Sirjan zone, 20 km southwest of the Muteh region. Gold mineralization at Godar Sorkh occurs in quartz-sulfide veins that hosted in metasedimentary rocks. Veins of mineralization typically formed along normal faults.  Rock sequences are affected by several deformation phase, gold mineralization occurs in ductile to ductile-brittle shear zones and had been under poly-phase metamorphism.  The main alterations are Sulfidation, carbonization, silicification, chloritization, and sericitization. Ore-mineral assemblages include pyrite and chalcopyrite, arsenopyrite, sphalerite, galena, and Fe-oxide.  Mean homogenization temperature in gold-bearing quartz range between 275oC and 300oC. Fluid inclusions in quartz veins are dominated by CO2-H2O-NaCl fluid. Salinity ranges from 9 to 17 wt. % NaCl equivalent. Corresponding to a depth of <2 km, Godar Sorkh deposit is formed in epizonal environment.  Measured δ18O values for the gold-bearing quartz range between 12.7 to 14.3 permil, estimated δ18Ofluid values range from +6.4 to +7.3 permil, δ34S values range from –16 to +5 permil, and estimated δ34Sfluid values range from +4.2 to -17.3 permil.  Fluid inclusion and stable isotope studies on ore-bearing quartz-sulfide veins indicating the major role of metamorphic fluids. Gold derived from metasedimentary rocks. Gold mineralization in the Godar sorkh deposit classified as an orogenic gold deposit.

The Chapdoni-Posht-e-Badam complex is located in the Central Iranian structural zone and the northeast of Yazd province. This complex is one of the areas with high potential for thorium-rare earth elements mineralization in Central Iran. In this research, the network modeling method has been used to determine the type and potential of Th-REE mineralization in the study area. Different methods such as geochemistry, geophysics, remote sensing, field observations, and laboratory works have been used, and different criteria have been considered for scoring. After applying the mentioned methods, creating a database, and combining multiple layers, the mineralization model or possible deposit types have been determined. This research uses a network method to integrate different data layers and model them to produce a mineralization potential map. The results obtained for different types of mineralization models were combined in the form of final modeling, and a comprehensive map of mineralization potential was prepared. Finally, mineralization types related to granite, metasomatism, and metamorphism were determined for thorium and rare earth elements in the Chapdoni-Posht-e-Badam complex. The mineralization potential of thorium-rare earth elements in the center and south of the study area is more than in other places.

The Oshvand Skarn deposit is located about 10 km east of Nahavand city in the Sanandaj-Sirjan structural zone. In this area, garnet (grossular-andradite) is the most abundant mineral in the skarn zone and their compositions are in the range of Adr(67.2 - 45.9%) Gro(50.1 - 31.8%) Sps(1.8 - 0.3%) and Prp(2.5 - 0.6%). EPMA data indicate a decrease in andradite and increase in the amounts of grossular and pyralspite group from the core to the margin of the garnet minerals. Increasing the substitution of Al by Fe+ 3 from the core to the rim of the garnet crystals indicates an increaseing FO2 during the growth of the garnet crystals. Pyroxene is the second most abundant mineral in the skarn zone and has a more homogeneous composition than garnet. The main pyroxenes of this deposit are in the range of hedenbergite to diopside with the combination of Fs(41.2 - 30.6%) En(26.6 - 9.5%) and Wo(49.3 - 42.8%) which has an average ratio of Fe/(Fe + Mg) in the range of 0.81 to 0.53. Thermobarometry studies indicate the formation of the progressive stage of skarnification at a pressure of 1 to 2 kbar and a temperature less than 600°C, depth of formation is about 5 km and  FO2 is about -16 to -27. The EPMA results of garnets and pyroxenes of skarn zones indicate that their composition is located at the range of Fe-Cu-Au type skarns.

Ramand area is located about 80 km south of Qazvin Province, northwest of Central Iran. The study area is a part of the magmatic belt of Orumieh-Dokhtar of the structural zones of Iran. The area consists of rhyodacitic igneous rocks, rhyolite, rhyodacitic tuff, crystalline tuffs and rhyodacitic flow lavas. The pyroclastic and volcanic units are interrupted by major faults such as Korcheshmeh and Hassanabad faults as well as sub-faults with a northwest-southeast trending. The most important alterations in the area includes sericitization, argilitization and hematization. The main ore minerals include pyrite, oxides and iron hydroxides. The most associated gangue minerals are quartz, potassium feldspar, albite and rock fragments in tuffs. In order to determine the properties of mineralizing fluids, fluid inclusions within quartz were analyzed, which are closely associated with gold mineralization in the area. The results of these analyzes show that the salinity of the fluids involved in the quartz minerals varies between 2 and 11.7 wt% NaCl equivalent. Also homogenization temperature of fluid inclusions for quartz varies between 141 and 230 0C. Most of the fluid inclusions in these veins are liquid double phase (L+V) and have sizes smaller than 20 micron. The analytical results of the analyzed samples show low temperature and salinity range which is consistence with metamorphism and basin brine sources. The fluid inclusions, mineralogical and geochemical data show that the gold mineralization in the Ramand area is similar to Epithermal type.

The Oshvad skarn type deposit was formed during the intrusion of a felsic mass into the Permian and Triassic carbonate rocks and ion exchange occurred between the intrusion mass and these units. In order to determine the properties of the mineralizing fluid in this skarn, several fluid inclusions in quartz and calcite minerals of the mineralization zone were analyzed. The results show that these minerals have two types of fluids inclusion. The first group includes L+V type, low to medium salinity, and with homogenization temperature of 194 to 480°C. The second group includes V+L type, low to moderate salinity, and homogenization temperature of 338 to 448°C. The origin of L+V type fluid inclusions are magmatic-meteoric and metamorphic type and V+L fluid inclusions are metamorphic type. Mixing and dilution of fluids occurred during the mixing of meteoric waters with magmatic-metamorphic fluids. These processes are the main factors of mineralization in this deposit. Fluid inclusions data show that fluid pressure has been 50 to 150 bars during the ore-forming minerals. Also, the fluid temperature has been between 200 to 360°C. The data suggest that the ore minerals have been formed in depth of 650 meters lower than the old water table.

The phosphorites horizon related to the Jeirud area is located in the central part of the Jeirud Formation, in the northern Tehran. The Late Devonian sediments of this formation is composed mainly of detrital rocks such as sandstone, sandy shale and sandy limestones. Phosphorite mineralization is mainly concentrated in the sandy shale horizon. Optical microscopy and X-ray diffraction (XRD) results showed that fluoroapatite is the main phosphate mineral and other gangues minerals composed of quartz, calcite, pyrite, iron oxides (mostly goethite) and clay minerals. The X-Ray Probe Micro Analysis (XPMA) results showed that fluoroapatite is the main host mineral for REEs. Other REE-bearing minerals include monazite and very rarely zircon. The Ce concentration (as representative of REEs) is highly variable in the decomposed apatite grains and the amount of Ce and other REEs in sedimentary apatite originating from primary rare earth elements. The concentration of REE in this phosphorites are related to the deposition environment, duration of seawater interaction during and after apatite formation, chemical composition of pore-water, organic source, apatite crystal network and the effect of the allogenic events.

Gold deposits formed during mountain-building processes in Phanerozoic terranes that formed in metamorphic environment have a great dispensation in the world (Goldfarb et al., 2001). They constitute an economically important type of gold mineralization called orogenic gold deposits (Groves et al., 2003). The Sanandaj-Sirjan zone is one of the most important areas for orogenic gold exploration and it hosts several orogenic gold deposits (Aliyari et al., 2012).  This zone is characterized by regionally metamorphosed and deformed Paleozoic and Mesozoic sedimentary, volcanic and volcanoclastic rocks under green schist and amphibolite facies conditions. (Rashidnejad-Omran, 2001; Abdollahi et al., 2009; Kouhestani et al., 2014(. The Godar Sorkh area is locatedin the central part of the Sanandaj-Sirjan zone, 20km southwest of the Muteh region. The rocks sequence of the Godar Sorkh area comprise of the volcano-sedimentary rocks of the greenschist complex with Paleozoic age rock units intruded by basic and felsic dikes. These country rocks are affected by a NW-SE-trending shear zone and are highly deformed. Rock units illustrate ductile-brittle to brittle shear zones and had been under poly-phase metamorphism. In other words, Godar Sorkh has the most similarity with orogenic gold.

In this study after field observations, rock samples were collected from mineralized and altered zones that included 26 thin sections, 47 polished sections and 10 polished thin sections which were prepared for petrography, mineralization and alteration studies, 10 samples were prepared for XRD analyses, 21 samples were analyzed for Au  content by the Fire Assay method and 21 samples were analyzed by the ICP-MS method for REE and trace element amounts in the Iran Minerals Research and Processing Center, and 9 samples  were selected  for XRF analyses  in the Kansaran Binaloud laboratory.  According to the petrographic studies and the results of chemical analysis 7 polished double sections were selected to determine the amount of gold and other elements by electron-microprobe analysis.

The rocks sequence of the Godar Sorkh area comprise of greenschists complexes including limestone, dolomitic, marbles, micaschists, black schist, greenschist, intercalations of quartzite, calc schist, phyllites and slate, metamorphosed under greenschist facies grade. These units are considered to belong to the Paleozoic age. Rock unites have been intruded by basic and felsic dikes. Rock assemblages are characterized by several phases of deformation and generation of various fabrics and structures. Gold mineralization occurs in ductile and brittle shear zones, along N45W trending and controlled by structures. The main alterations are sericitization, carbonization, chloritization, silicification and sulphidization. Ore-mineralogical paragenesis mainly includes pyrite and locally chalcopyrite, arsenopyrite, covellite, sphalerite, galena and Fe Oxide-Hydroxide secondary minerals such as goethite, hematite and limonite. The results show that the maximum grade of gold in the mineralization zone has been reported to be 9.9 ppm and the average value of gold in the area is about 0.3 ppm. The microscopic studies show native gold minerals in the range of 15 to 30 micrometers.  Also, electron-microprobe analysis indicates Au in the lattice of sulfide minerals. Based on geochemical studies, rocks have characteristics peraluminous range and the granodiorite intrusion belongs to S type granitoids. LREE are enriched. Controlling parameters for mineral concentration in Godar Sorkh area are shear zone. Therefore, regarding the development of Paleozoic metavolcanic-sedimentary sequences and the formation of multistage extensional structures including the normal faults, and fractures, texture and structure investigation, mineral paragenesis, alteration and geochemistry, gold mineralization in the Godar Sorkh area can be classified as orogenic gold mineralization.

The Ti- Fe mineralization in Bafq 15 anomaly located 35 Km NW of Bafq city, and is a part of Poshte Badam Block in the Central Iran. Mineralization including magnetite, titanomagnetite, ilmenite, and minor pyrite which hosted by gabbro and pyroxenite intrusions syngeneticly. Based on the whole rock chemistry, FeOt, TiO2, CaO, Ni, Cr and V show a positive correlation with MgO, whereas Al2O3, Na2O+K2O, and SiO2 display a negative correlation. These correlations are in agreement with the crystallization of clinopyroxene, amphibole, plagioclase, and oxide minerals in the intrusion. The positive correlation of V, Cr, and Ni with Fe indicates the concentration of these elements in Fe minerals. The chemical composition of ore minerals mostly plots in the solid solution of magnetite- ulvospinel (titanomagnetite) and magnetite- ilmenite fields. In QFM+1> conditions, the high Fe-Ti contents along high H2O content (>2 Wt. %) of parental magma are the most prominent factors controlling Fe- Ti mineralization. According to the proposed model for mineralization, as a new pulse of magma enters the chamber, the high H2O content sufficiently depressed the crystallization temperature of silicates in analogy to oxides, giving rise to early crystallization of Fe-Ti minerals. Increasing of H2O content and magmatic volatiles during magma fractionation consequently may induce immiscibility and separation of oxides from residual melt in late magmatic stage whereas this dense oxides melt flow through pre-crystalized silicates and solidified as intercumulus phase.

The mafic- ultramafic intrusion in the Bafq anomaly Iron located 35 Km northwest of Bafq city, Central Iran. The 15th anomaly intrusion intruded the Rizu sequence series, stratigraphically attributed to early Cambrian magmatism in the west of Posht-e- Badam block. The Rizu sequence series is composed of carbonate rocks of upper Neo-Proterozoic-early Cambrian. The mafic-ultramafic intrusion is dominated by amphibole-gabbro, apatite- gabbro, anorthosite- gabbro, amphibole- pyroxenite, apatite-pyroxenite with predominant granular texture and cumulate characteristics. The associated main mineral assemblage composed of cumulate predominantly clino-pyroxene, Fe-Ti oxides, calcic plagioclase, amphibole, apatite, as well as minor olivine. The intrusion formed from mafic magma and differentiated from tholeiitic to weakly calc-alkaline affinity. Spider diagrams of the analyzed samples were normalized to the standard values of chondrite and primitive mantle. REE– normalized diagrams are characterized by LILEs enrichment and HFSEs depletion and mild negative REEs trend. Different tectonic setting discriminative diagrams and elemental ratios are indication of a subduction related affinity. The parental magma could be generated by melting of mantle peridotites (lithospheric mantle) which previously affected by subduction related fluids. The results of this research is consistent with the previous models which considered the Early Cambrian magmatism in Post-e-Badam block related to the subduction of Proto- Tethys oceanic crust beneath the Central Iran in the north of Gondwana land.

Mineralogical examination of the gangue and ore parts of the Se-Chahun magnetite-apatite ore deposit revealed the existence of Th and REE bearing minerals with paragenetic relationships with amphiboles, magnetite and calcite. Trace and REE host minerals are found in both of the gangue and the magnetite-apatite ore showing remarkable concentration in a phase referred to as the brecciated phase. This zone (phase) is characterized by high amounts of trace (Th) and light rare earth elements including La, Ce, Pr and Nd that were revealed in geochemical analysis. Mineralization of these elements is related to fluids appeared after magnetite mineralization in the region and resulted in metasomatism of the host rocks and a part of the ore and also concentration of the REE and trace elements as phosphates and silicates, respectively. There is not a clear key concerning the origin of these fluids but based on the geochemical evidence, the probable provenance is thought to be related to the magmas derived from the arc related subvolcanic bodies injected in subduction zones. Based on the paragenetic and geochemical evidence, a part of these elements is transported by carbonate complexes and accumulated in the brecciated rocks.

Examination of geochemical distribution pattern of trace and rare earth elements in the rocks affected by metasomatic processes revealed a magmatic origin for Th-REE mineralization at the Se-Chahun ore deposit. Chondrite and primitive mantle-normalized patterns of REE and trace elements for the rhyolitic host rocks (which formed in a subduction setting) compared with the patterns of the Th-REE mineralization zone also provides evidence that the origin of the Th-REE mineralization zone is similar with rhyolitic magma or a magmatic chamber from which the rhyolitic magma was originated. This is also supported by oxygen and hydrogen isotopic data in actinolite paragenetically associated with Th-REE bearing minerals. Thorium minerals at the Se Chahun ore deposit include huttonite and thorite. O and H isotopic data for actinolite paragenetically associated with Th-silicates revealed a magmatic source for Th-REE mineralizing fluids in the ore deposit δD and δ18O for actinolite paragenetically associated with Th silicates are calculated between -73.29 to -42.04 and 6.65 to 7.71, respectively, which lie within the field of magmatic fluids.

The Bafq region hosts the most important magnetite-apatite deposits of Iran. The geology of this region has been studied by many researchers (e.g., Haghipour, 1977). The ore deposits are mainly hosted by a volcano-sedimentary unit. The presence of a brecciated unit at the margin of the magnetite -apatite ore deposits is discussed by several authors. This unit contains remarkable concentration of Th and REE minerals paragenetically associated with magnetite, actinolite, calcite and albite. Mineralogical properties of the brecciated unit as one of the most important geological events in the magnetite-apatite ore deposits of the Bafq region, and Th-REE mineralization hosted by this zone at the Se-Chahun ore deposit is discussed. The present study has been carried out in four stages including: field work, microscopic studies, ICP-MS and ICP-OEA analysis as well as EPMA analysis. The field work included observations, investigations, radiometry, spectrometry and sampling from different lithologies in both open pits and drilled cores. The microscopic studies were carried out in order to identify the minerals and examine the textural properties of these minerals found in the brecciated unit. The ICP-MS and ICP-OEA analysis were carried out on the samples taken from the ore bodies and the radioactive parts of the mine. The EPMA analysis was also carried out to achieve a more precise hint at the occurrences of the Th and REE minrals and also to investigate the paragenetic relationships between the minerals probed. The brecciated unit is generally formed at the margin of or within the ore deposits mentioned. The matrix of the brecciated unit at the Se-Chahun ore deposit is composed of different minerals including magnetite, titanomagnetite, actinolite, albite, apatite, titanite, calcite, epidote, chlorite and Th silicates. The coarse rock fragments are mainly of the rhyolitic rocks and metasomatic fragments. Based on the mineralogical studies, the brecciated unit is the host of Th-REE minerals. The Th-silicates are formed in two crystallized forms including monoclinic (huttonite) and tetragonal (thorite). Thorium occurrence is found in three types: granular, massive and veinlet. The geological investigations indicate the role of solutions derived from magmatic arc originated in calc-alkaline magmas as a source for Th(-REE) in the brecciated unit. Based on the field, mineralogical and geochemical evidence, a remarkable part of Th has been transported by carbonate complexes in basic and reduced solutions. Apatite and monazite show a notable concentration within the brecciated unit. Monazites are found mostly as single crystals not always hosted by apatite crystals. Two types of actinolite are recognized, 1. Older than Th mineralization within the magnetite ore and 2. A younger generation paragenetically associated with Th silicate. Two types of albites are recognized: an early (white) albite found within the magnetite ore; a late (red) albite also found within the brecciated zone in association with Th occurrences.
Metals such as Th and REE, at the Se-Chahun magnetite-apatite ore deposit are thought to be predominantly derived from the associated magmas, via magmatic–hydrothermal fluids exsolved upon emplacement into the crust. Two main sources exist for the origin of the metals (Th and REE): 1: sediments on the downgoing slab subducted into the mantle wedge (located between the downgoing slab and the overriding plate); 2: assimilation of crustal rocks within the magma chamber and also during ascending of the magmas. Th-REE have been transported mainly by carbonate complexes in alkaline and reduced environments. The presence of a reduced environment during Th-REE mineralization is evidenced by paragenetic association of magnetite and pyrite (and minor chalcopyrite) supported by negative Eu anomaly. Presence of an alkaline environment is also supported by the presence of calcite crystals, veins and veinlets paragenetically associated with Th-REE minerals. A limited number of models have been suggested to explain the provenance of the brecciated unit. Mohseni and Aftabi (2012), among others, suggested that this zone is a proximal zone of magnetite-bearing keratophyres formed in submarine environments. By contrast, no clear source for thorium silicate is suggested. Recently, Khoshnoodi (2016) discussed the subject in one of the largest iron-apatite ore deposits in the region, the Choghart. According to his suggestions, the solutions derived from the calc-alkaline magmas are the source of thorium.
According to our suggestions, the lower continental crust and also the continental derived sediments on the sea floor adjacent to the subduction zones can be proposed as one of the most important sources for limited amounts of thorium found within the magmatic arc magmas. It is proposed that these magmas and associated mineralization are not limited to the margin of the magnetite-apatite ore deposits. Until now, the importance of the Bafq mining district has been due to its discovered magnetite-apatite resources. Further exploration programs supported by mineralogical and geochemical studies may lead to opening new ways in exploration of uncovered ore deposits in the Bafq district containing more economical resources.

Nodushan Zn-Pb deposit at the western margin of Urumieh-Dokhtar volcano-plutonic belt resulted from granitoid intrusion into Eocene dacitic to andesitic rocks. Pyrite, sphalerite, galena and chalcopyrite are the main sulfide minerals. The chemical composition of sphalerites and pyrites indicates two different type of sphalerite (high Fe types demonstrating chalcopyrite disease and low Fe type) and two different types of pyrite (high As and low As), but weaker chemical changes can be traced from margins to center of galena and chalcopyrite. These chemical changes demonstrated that the hydrothermal fluid was high in iron, manganese, zinc and cadmium content (with the development of pyrite and sphalerite), followed by arsenic and lead concentration (with the development of galena, chalcopyrite and high As pyrite), indicating higher chemical composition changes at the incipent stage of mineralization than later stages. Chemical composition of sphalerites and its comparison with sphalerites in hydrothermal and skarn deposits of Japan confirming (high sulfidation) hydrothermal vein type mineralization resulted from magnetitic-type granitoids.

One of the potential areas for metal indices such as iron is located in the North East part of Isfahanand. There are extensive outcrops of granitoid mass in the studied area and its surroundings (karkas granite) which have been cut most stratigraphic units before Oligo-Miocene. Lithology of the area consists of fine to coarse sandstone, massive dolomite, and cream-colored limestone with fossils and massive intrusive in the region. According to its frequency, quartz monzonit, quartz monzodiorite, granodiorite and granite are the most abundant which are formed from subduction zone before collision and are the type (VAG). In terms of magmatic arc these are calc-alkaline series (CAG), which dactial tails has penetrated through these granites. Volcanic rocks include porfirodacite, andesite and quartz latite with the age of Pilocene to Miocene. Iron was originated from semi-deep magma with high heat, passing fiuids with elements to above horizons and attack limestone and dolomites creating skaran, with mineralogical composition of andradite, gersular, hesonite, epidote, lipidcrolite, zeoizite, and hedenberzite. In addition, hydrothermal fluids resulting in minerals alteration and formation of kaolinite, chlorite, montmorillonite and sericite. The supergene phenomenon has important role in enrichment of iron ore in surface, which main evidences is cap iron (gossan). Kamoo iron mine is located above it and mainly consist of iron ore minerals such as magnetite, hematite, limonite, goethite and other Parageneticmenirals.Magnetite and sulphide mineral such as pyrite and chalcopyrite and with magmatic origin are the first generation of skarn mineralization. Alteration by magmatic fluids is the second generation and supergene phenomenon are third generation of mineralization (forming hematite, limonite, covelite and goethite) in kamoo region. Thus, the main genesis of iron ore in kamoo is epigenetic hydro-thermal.

The Saghand mining district is a part of Bafq- Saghand metallogenic zone in the Central Iranian geostructural zone which is located in northeast of city of Yazd. This area is known to be more susceptible to mineralization of U and Th radioactive elements, but in fact is that its main importance is for relatively large iron deposits. However, in this region similar to some of the ore deposits within the Bafq area, rare earth elements have a high anomaly. Alkali-metasomatism occurs in a large variety of environments and geological periods. It can be spatially associated with ore deposits, as for some IOCG deposits or exists in barren systems such as metasomatism within the ocean crust (Johnson and Harlow, 1999). Although average U and REEs contents of the ore bodies associated with alkalimetasomatism are not high, they represent a promising exploration target because the resources of such deposits are relatively large (Cuney et al., 2012). The alkali-metasomatism could take place in all kinds of rocks. In addition to wide distribution in granite and granodiorite, it could be also identified in all kinds of metamorphic rocks, pegmatites, subvolcanic and volcanic rocks, and they all have mineralization (Zhao, 2005). After field studies, host rocks and metasomatites were sampled from outcrops, trenches, and core drillings. Since the rare earth elements and radioactive elements are present within the same mineralogy (Samani, 1985), surface spectrometry measurements were used in the selection of appropriate samples. For microscopic studies, 210 samples were prepared and studied. Ore minerals were investigated in polished and polished thin sections using optical microscope and Scanning Electron Microscopy (SEM) analysis was done in the Iranian Mineral Processing Research Center. An LEO-1400 SEM with energy dispersive X-ray spectrometry and back-scatter electron (BSE) imaging capabilities was used (accelerating voltage, 17-19 kV, and beam current of 20 nA). The 16 samples were analyzed by the ICP-MS method at Zarazma Mineral Studies Company, Iran, for major and trace elements at the various radiations and lithological ranges. The detection limit and precision for determination of REE, U and Th concentration were 0.2 to 1 ppm and 1 to 0.1 ppm, respectively. Discussion and results: Based on field evidence and microscopic studies, four main stage of metasomatism with continuous evolution have been distinguished in the Saghand area, including: 1) Na-metasomatism, 2) Ca-Mg metasomatism, 3) K-metasomatism, and 4) Epidote±chlorite±calcite±quartz vein and veinlets. All metasomatic zones are generally enriched in U and REE and compared with the host rocks but economic grades are less widespread and limited to Ca-Mg metasomatite zones near pinkish to red color albitites. The major Ti-REE-U(Th) minerals are davidite and brannerite, which have mainly crystallized during the Ca-Mg metasomatic stage. Ti or Tibearing minerals as paragenesis with davidite and brannerite are also deposited in amphibole-albite metasomatic zones. All these minerals are usually fractured and along fractures and its margin is replaced by titanite, leucoxene and rutile. In this study, geochemical analysis results of igneous rocks in the Saghand ore deposit, confirm the active continental margin arc setting and the nature of calc-alkaline magmatism in the region. The good adaptation of the REEs patterns in granites with the quartzdiorite-diorite rocks, can be a strong reason for their common tectonomagmatic origin. This Geodynamic environment had been the appropriate background in terms of protolith, heat engine for metasomatism cycle and supply hydrothermal solution and controlling structural pathways. The proximity of mineralized metasomatic rocks with the granitic rocks and intrusion of the granite apophysises into the metasomatic rocks, mobility of REE elements in the metasomatic environments, adaptation of geochemical properties of REE, U and Th elements in the mineralized metasomatitic rocks with the granitic rocks and finally, there was no evidence of intrusion of unusual magmas such as the carbonatite or alkaline magmas at the current level of ore deposit outcrops. Thesesuggest a close relationship between mineralization and metasomatic events with the granite intrusion. Fluids differentiated from the Douzakh-Darreh granite have entered the fault and crushed zones in a tectonically active regime of marginal continental arc. Due to reaction of the high temperature fluid with the protolith rocks, the ratios of Na+/K+ and Na+/H+ in fluid in equilibrated to feldspars of protolith rock elevated (Cuney et al., 2012). A basically alkaline medium to low temperature hydrothermal fluid is a suitable environment for the activation and transfer of U and REE in the form of hydroxyl complex (Romberger, 1984). Conversely, Th remained essentially immobile during the metasomatic processes (Cuney et al., 2012) and therefore, cannot be in abundance carried by this fluid. Hematite pigmentation of albite and transfer of U shows that oxygen fugacity in the early hydrothermal fluid has been quite high. These geochemical conditions simply allow U, and REEs enter from wall rocks to fluids and form hydroxyl complex of these elements, which are sustainable and are portable. Titanium bearing minerals within the quartzdiorite-diorite rocks and Douzakh Dareh granite easily decompose under hydrothermal activity and form titanium hydroxides, which is a very strong absorbent for U. After mineralization of albite and hematite, oxidation degree of fluid quickly drops and as a result, conditions for instability of complexes containing Ti, REE and U are provided. Acknowledgements: This paper is based on a part of the first author's Ph.D thesis at Shahid Beheshti University. This research was also supported by Skam Company and Iranian Mines & Mining Industries Development & Renovation Organization.

Dividing the structural ones, the studied area has been located in the central Iran and in Makmaei Uromieh- Dokhtar zone. This range has been located in a scene ETM No. 164 - 37 and ASTER linear bad prediction satellite image No. AST_L1A:002:ASTL1A 0108220733380109011021. Such measured images in different band combinations will be used for extracting the geological structures and types of alterations (iron oxide, Argillite and Carbonate) and for detecting different stones and minerals of the ground, a spectrum range of 1.5 to 2.5 μ is very important. This range includes short to average IR range covering six linear band predictions (SWTR bands). According to results of XRD analysis, Albite, andradite, chlorite, gibbsite and Moscuit minerals and silica alterations were also dissociated. On the other side, to use spectral reflectance curves of such minerals in USGSENVI spectral library for spectral analysis, it is necessary to resample the curves to the spectral range of ASTER. Linear Band Prediction methods, LS-Fit, Matched Filtering and BandRATIO used of ASTER images for all minerals and iron alterations and for iron oxides there were also used visual interpretations and ETM images were used in band combination of RGB:531. The resalts identified in the remote sensing study in the aera (Kamoo) identide as follows : Alteration of iron (Gotit, Hematit and jarosit and limotit), alteration of argilic (maolinite, mottmoriolotit, ilite and halozite), carbonate (calcite and dolomite)

Early Cambrian rhyolite hosts the Choghart iron oxide-apatite (IOA) deposit. The ground radiometric and spectrometric surveys of alteration zone on the margin of the magnetite-apatite ore body show that the radioactive anomaly of thorium occurs in the breccia zone. The chemical analyses of the breccia zone samples by ICP–MS show thorium mineralization. The mineralogical studies by transmitted- and reflected-light microscopey and EPMA indicate that the main thorium minerals in thorium mineralization zone are thorite and sphene. The alteration mineral assemblages related to thorium mineralization of Choghart is consisted of albite ± orthoclase + calc-silicate (actinolite- augite- diopside) + carbonate (calcite) + magnetite + pyrite ± chalcopyrite ± galena + sphene + rutile ± microcline ± apatite (Na-Ca-Fe alteration). The occurrence of paragentic magnetite, pyrite and chalcopyrite with thorite and negative Eu anomaly in the thorium mineralization zone indicate a reduced condition for thorium mineralizing fluids. The similarity in chondrite- and mantle-normalized REE patterns of host rhyolite and the thorium mineralization zone suggests that thorium is originated from continental-arc rhyolitic magma.

The study area is located in the central Iranian tectono-magmatic zone, which is known for its world-class IOA-type Iron ore deposits. The Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER) and Landsat Enhanced Thematic Mapper Plus (ETM+) image-processing techniques, were used in satellite imagery through conventional and also modern processing methods including band ratios, color composite ratio images and spectral angle mapper to study the spectral discrimination of metasomatically altered rocks based on their mineral assemblages and to investigate critically the link between the distribution of Na-metasomatism and occurrence of REE mineralization through plotting the image processing results on preexisting airborne radiometric data. The achieved information points the matter that the distribution of the metasomatized rocks, in common, and Na-metasomatized rocks, in particular, are coincide with the areas with high radioactivity revealed during an airborne radiometry program. A stage of field study associated with ground spectrometry survey carried out to control some localities and showed such correlation mainly around and within some magnetite ore deposits through which two phases of albitization were revealed, namely, a widespread albitization phase within which the spectrometric survey showed normal amounts of radioactive elements and another phase that affected smaller areas and showed REE anomaly and the Na-metasomatites of which are, experimentally, more reddish in colure (meaty color in hand specimens). The Iron deposits are, chronologically, hosted in upper Proterozoic-lower Cambrian volcano-magmatic units associated with a widespread phase of Na-metasomatism, economically, resulted in enrichment of the host rocks in REE bearing mineral phases.

Bondar Hanza porphyry copper deposit occurs 150 km southeast of Kerman, in southern part of the Urmia-Dokhtar zone and in Dehaj-Sardoiyeh zone. This ore deposit has formed in diorite to granodiorite rocks. The present paper deals with the study of fluid inclusion on quartz and hornblende samples as well as the measurement of isotopic ratio of oxygen and hydrogen with the aim to recognize characterization of hydrothermal fluids effective in mineralization. The studied veinlets are divided into five groups. Veinlet I: fluid of high pressure (>300 MPa) and medium to high temperature (250°C-300°C) with salinity of 38-45 Wt%NaCl that includes molybdenum mineralization. This veinlet contains halite and anhydrite and has resulted in potassic and sodic-calcic mineralization in deeper parts of the ore deposit. Veinlet II: high pressure (>300 MPa), high salinity (33-47 Wt%NaCl) and high temperature (250°C-420°C), containing copper and molybdenum mineralization as well as potassic alteration. Veinlet III: high salinity (40-56 Wt%NaCl), high pressure (>300 MPa) and high temperature (200°C-500°C), containing copper mineralization. Veinlet IV: medium to low salinity (6-7 Wt%NaCl), medium temperature (approximately 170°C), low pressure (0/7-0/8 MPa), containing no mineralization. The study performed indicate that the boiling occurred in the initial magma, as a result of pressure and temperature changes and mixing with meteoric waters, caused copper and molybdenum mineralization. Results obtained oxygen and hydrogen isotopic analysis in quartz show δ18O to vary 3.9 to 6.3 per mil. Considering its formation temperature and based on thermometric study (130-400°C), the amount of δ18o in mineralizing fluid is 5.26 to 6.19 per mil, being indicative of magmatic origin of mineralization fluids like the other porphyry copper deposits of Iran and the world. While results of hydrogen analysis existed in fluid inclusions of quartz mineral illustrate a range between -88 to -90 per mil, being indicative of a decrease in the amount of mineralizing fluid deuterium. These values are traceable to the effect of meteoric waters, given the propylithic and sodic alterations accompanied with potassic alteration in mentioned veinlet.

Bleeding during functional endoscopic sinus surgery (FESS) remains a challenge for both surgeons and anesthesiologists despite several modalities available for improving the surgical field. In spite of demonstrated favorable effects of Tranexamic acid (TA) on bleeding tendency in cardiac, major orthopedic, transplantation and prostate surgeries, Its IV use in FESS has never been examined. This study was conducted to evaluate the efficacy of intravenous TA in improving the surgical field in FESS.

In placebo-controlled clinical trial a total of 88 ASA physical status I-II patients, aged 15-66 years, undergoing endoscopic sinus surgery under general anesthesia were allocated based randomly table number, to receive either intravenous TA 15mg/kg or sterile water 200 cc as a bolus dose immediately before induction of anesthesia. Anesthesia and surgery protocols were the same in both groups. Bleeding and satisfaction scores were obtained from the surgeon and his aid and compared between two groups.

In view of the surgeon, the median (range) bleeding scores in the TA group was 98.41 (51.35) and in placebo group was 148.98 (71.75) (pvalue= 0.01). Accordingly the surgeon was more satisfied with the surgical field in the TA group than placebo group.

Intravenous TA can not clinically reduce bleeding during FESS.