فریبرز مسعودی

Damavand is a young volcanic edifice with an elevation of 5610 meters formed in the middle of the central Alborz Mountain range (N Iran) during the Quaternary. Its edifice is composed of trachyte and trachyandesite rocks, pyroclastic fall and flow deposits and lahars, formed during several eruptions and under different magmatic conditions. To investigate the crystallization trends in the Damavand magma chamber and its evolution over time, plagioclase internal textures in lava flows, pyroclastic flow and ash deposits were studied. Samples from six different lava flows and pyroclastic fall and density current deposits with different ages were collected. Plagioclase crystals with similar dimensions and sizes but with completely different textures, and plagioclases with different dimensions but similar textural characteristics were observed. Twenty-eight different texture types were observed in plagioclase crystals from lava flows, whereas only three texture types were distinguished in the pyroclastic deposits. A large population of plagioclase in pyroclastic deposits reveal the non-equilibrium crstallization in the Damavand magma chamber(s), while in lava flows, a series of plagioclase cumulates present both equilibrium and non-equilibrium crystallization conditions in the magmat chamber. Plagioclase crystals in the source magmas of lava flows have repeatedly remained in a non-equilibrium state without eruption, letting the crystals to overgrow. Changes in the rate of magma ascent, small- and large-scale convection cells in magma chambers, varying temperature and/or pressure, and different volumes of (non-)eruptible mush/melt, are some of the parameters that are revealed by our textural studies. In the period between about 7-450 ky ago, the magma chamber that led to the buildup of the young Damavand volcano, was in non-equilibrium conditions as demonstrated by individual crystals textures and chemistry. However, these conditions have not always led to volcanic eruptions.

Intrusive masses are exposed in the Bostanabad-Mianeh axis with the northwest-southeast trend. The rocks are known as granite in general geological maps. Detailed studies in this study have also shown the presence of syenites which their petrology was considered in order to investigate the Zagros orogeny development in northwestern of Iran. The magmatic rocks of the region are the result of magmatism of the Uromieh-Dokhtar magmatic belt and include intrusive, volcanic and pyroclastic rocks with sedimentary units. Syenites of the Bostanabad-Mianeh axis are along with large volume of granites. Syenites provides important information about the interaction of the crust-lithosphere mantle, magma evolution processes, tectonics and crustal growth. In this study, syenites are divided from granitic rocks and their geochemical properties have been investigated to determine their tectono-magmatic and Petro-genetic conditions.

During field study, samples from the syenite and granite outcrops were collected for petrography, geochemistry and determining magmatic series and the magma origin. For geochemical studies, 13 samples of intrusive rocks with the lowest degree of alteration were chemically analyzed by ICP-MS and ICP-OES methods in the Act Lab Ontario Canada.

The Bostanabad-Mianeh axis in northwestern of Iran and in the East Azerbaijan province is part of the Cenozoic magmatism of the Lesser Caucasus towards southeastern Iran. Magmatism is related to the subduction of the northern ocean of Neotethys during the collision of the Arabian Plateau with Eurasia and its subsequent events. The presence of arc-type magmatism in the regions of Azerbaijan, the Alborz Mountains, Talesh and the Lesser Caucasus all indicate the subduction of the Neotethys branch with the Eurasian plate. Due to the LILE and LREE enrichment and the HREE depletion, the source of the magmas for the studied syenites are originated from an enriched mantle source in the continental lithosphere in the subduction zone belonging to post orogenic extension events. Consequently, the formation of the intrusions is related to mantle melting which is enriched and fed by fluids and melts and finally contaminated with crustal material during the ascent.

Biotite is a common rock-forming mineral and accepts a variety of elements in its structure. The valuable information of crystallization conditions of the biotite mineral obtain on natural biotite composition. The biotite mineral is one of the main mineral phases of pelitic rocks which are formed in a wide range of geological conditions. In this research, microscopic mineralogy, Raman spectroscopy, and X-ray diffraction of biotite minerals from hornfels and migmatites from the Borujerd granitoid aureole in the Sanandaj Sirjan zone investigated. On microscopic studies, mica crystals display common biotite characterizations but the mineral is uniaxial not biaxial as ordinary mica with a monoclinic system. Based on X-ray diffraction, the biotite crystals form in hexagonal crystalline habit. The Raman spectroscopy also reveals the variations in number and shifts on peaks in the range of 500 to 750 cm-1. Based on XRD data, the unit cell lattice parameters have revealed hexagonal mica crystals for the Borujerd migmatite and hornfels. Previous works reported temperatures in the range of 642 to 750 C° for the studied rocks. Investigation on synthetic biotite mineral suggests temperature above 700 C° for monoclinic to hexagonal transformation which confirm the formation of the high-temperature metamorphic event in the Borujerd region.

Zircon is an stable mineral during post crystallization processes and preserves characters of magmatic events. Zircon morphology can give some information about temperature, nature, and source of the magma. Study of the zircon morphology of Cretaceous granitoids and acidic volcanics from the southeast Saqqez area reveals that most of the crystals are P5 and S25 types with high alkalinity (I.A.) and temperature indexes (I.T.) in the range of 672.9 and 637.9 respectively.The minimum temperature of zircon crystallization is estimated to be in the range of 600 to 750 °C based on the morphology, saturation of Zr, and whole-rock chemistry. The presence of apatite inclusions and the mineralogical composition indicate that the source of the magma was relatively hydrous. Typological evolutionary trend (T.E.T.) shows the granites as I-type with calc-alkaline nature, which are in line with geochemical data. The zircon mineral morphology indicates that the granites in the SE Saqqez formed from hybrid magma with crustal and mantle origin.

The composition of skarn's mineralizing fluids is closely related to the physicochemical conditions prevailing during the cooling and crystallization of magma. Biotite is an effective indicator for determining the physio-chemical conditions prevailing during the cooling and crystallization of magma. In this study, the biotite composition of Sarvian biotite quartz diorite from Urmia-Dokhtar magmatic arc was investigated to estimate the magma crystallization conditions and also to determine the petrological and metallogenic characteristics of the granitoid rocks.

The study area is located 15 km northeast of Delijan city and in Markazi province (Figure 1). Miocene Sarvian quartzdiorite rocks are classified into three subgroups: quartzdiorite, micro quartzdiorite and biotite quartzdiorite. In this study, 21 spots of Sarvian biotite quartzdiorite were analyzed at the Iran Mineral Processing Research Center (Table 1).

The biotites of Sarvian granitoid are crystallized at a temperature of about 750 ° C, oxygen fugacity is between 10-11 and 10-13 and the pressure is about 0.6-1.1 kbar. The mentioned crystallization conditions indicate that the biotite quartzdiorite rocks of Sarvian crystallized at high temperature, shallowly and under high oxygen fugacity conditions. In addition, it shows that Sarvian biotite quartzdiorite has a high chance of mineral exploration. Placement of Sarvian biotite quartzdiorite rocks in Cretaceous limestones and Eocene pyroclastics, crystallization at a pressure of about 1 kbar and the mentioned crystallization conditions, indicate the formation of skarns in the region. The formation of skarn iron ores in the area is a confirmatory examination that has been performed on the studies.

Emplacement of Sarvian biotite quartzdiorite rocks are at shallow depth and crystallization at high temperature conditions. High magnesium calc-alkaline magmatic series, high oxygen fugacity and type I orogenic granites from subduction of the oceanic crust below the continental plate leads to magma which is the result of melting and mixing of crust and mantle. So it has created suitable conditions for the formation of metal skarns.

Dehgolan region is located in the northwest of Iran. In geological classification it is a part of the Sanandaj-Sirjan zone. In this region, several intermediate to acidic volcanic rocks with Upper Miocene-Pliocene age are outcropped such as Sheida- Akhikamal and Kaniderezh. The volcanic rocks from this region rocks are mainly andesite, trachy andesite and dacite. White to gray dacitic ash has been thrown around the outcrops have pozzolanic functon. Main phenocrysts are plagioclase, hornblende and biotite. Clinopyroxene with a very low frequency is also detectable in phenocrysts. In this research, mineral chemistry is used in order to investigate kinetic of the crystallization and genesis of rock forming minerals.

In this study, after field sampling and preparation of thin sections and petrographic of the samples, in order to study the chemical composition of the minerals of plagioclase, amphibole, clinopiroxen and biotite minerals in Dehgolan volcanic rocks, Eleven samples of the freshest rocks were selected for EMPA point analysis and about 80 points of four types of minerals were analyzed.

The results of the EPMA analysis of minerals indicate that plagioclases have a composition of andesine to oligoclase, Most have polysynthetic macles and also zoning is present. Their zoning is mostly normal, with the calcium content decreasing from core to rim. The amphiboles of the study area are calcic (calcium-rich and titanium-rich) and mainly of edenitic hornblende and magnesiohornblende types. Clinopyroxene are of augite type and based on clinopyroxene data, most of the samples in the study area are in the volcanic arcs (VAB) and (WPA). Biotites are Mg-biotite and are mostly of primary magmatic type and located between phlogopite and annite poles. The magma oxygen fugacity was high during the magma crystallization. Based on biotite composition, the Dehgolan volcanic samples belong to calc-alkaline magmatic assemblages of the orogenic environment. Clinopyroxenes in intermediate-acidic volcanic rocks in Dehgolan region show mainly crystallization at medium pressures and crystallize on average at 5 to 6 kb at temperatures of about 1000 to 1110 ° C, amphibole crystalized at 4 to 6 kb and 723 to 861 °C respectively. While the estimated temperature for plagioclase is between 550 to 750 °C and for biotite this is 715°C.

Volcanic rocks north of Dehgolan have a predominantly riodasite and sometimes andesitic composition with Calc-Alkaline nature, which erupts with large volumes of acid ash. The magma of the Adakitic rocks in northern Dehgolan was dehydrated during its formation, and only high-temperature, water-free minerals such as pyroxene and plagioclase were crystallized. In the following or on higher horizons collision with water in the crust iccurs and the crust is contaminated. The preponderance of xenolite confirms this, Oxygen fugitives are rised and biotite and amphibole minerals are crystallized. The biotite and clinopyroxenes geochemistry is indicative of the Calc-Alkaline Magmatic nature of the region, which erupted in the periphery of the active continental margin at the last phases of neotethys subduction in the northern Sanandaj-Sirjan region during the Mio Pliocene.

Fariman metamorphic complex located in Northeast of Iran and indicative different metamorphism and deformation phases. This area is similar to many others Precambrian metamorphic rocks in central Iran that metamorphed in upper amphibolite facies and Sillimanite zone. In this research microfabric of andalusite schists and magmatic rocks investigated in order to constrain P-T path during metamorphic events. Studied metamorphic complex contain metasandstone (metapsemites), metagraywack and metacarbonates are as interlayered with metapelitic rocks that are major part of metamorphic rocks in study area. The metamorphic volcanic rocks also are seen that named Sibac complex and are in contact with granitic and gabbroic rocks. For petrography and microfabric studies, 80 oriented samples selected from andalusite schists and igneous rocks from Sibac complex. The samples cut and thin sections prepared. Metamorphic rocks of Fariman have effected by two deformation phases, D1 and D2. D1 phase related to M1 that is a regional metamorphism event and D2 as an active deformation is related to dynamothermal metamorphism of M2. M2 reveals emplacement of nap and outcropping of lower crust and present an erosion window of neoprotrozoic rocks that are appeared as an uplift formation from central Iran basement that emplaced close to Paleozoic-Cenozoic sedimentation. The retrograde event has affected metamorphic rocks after M2. Evidences of this retrograde metamorphism are change andalusite to chlorite and muscovite or sericite and muscovite, growth of chlorite and talc in rim or on the other mineral, forming of tourmaline in rim of andalusite or in the veins. The D1 phase created schistosity S1, D2 has folded S1 and has formed S2 schistosite. Microstructure evidence, mineral paragenises and estimated Pressure and temperature show an anticlockwise P-T path that involving advective heating in result of intrusive abundant magma into lower- middle crust. The peak of Metamorphism followed by isobaric cooling. The affect of shearing motion is not equal in throughout of study area and in different rocks. Microtectonic evidences indicate a deformation in both ductile and brittle conditions with dextral component. Shear zones spatially can be observed in south and southwest of study area and has been made mylonites and phylonite type rocks. In Fariman area, first high T-low P metamorphism occurred, and followed by dynamothermal metamorphism with shear zones.

The Ravanj intrusive, with tonalite, quartz-diorite, and microquartz-diorite composition, is exposed in the West of Ravang Village, NE Delijan, in Urmia-Dokhtar zone. Plagioclase is observed in three different sizes (coarse, intermediate, and microcrystalline) in the composition of in Ravanj intrusive. Most of the coarse crystals are zoned while intermediate and microcrystalline show polysynthetic and pericline twins. The lack of inclusions in the center of plagioclase and An versus K2O with a linear trend indicate that plagioclase is the main magma phase. The chemistry of polysynthetic crystals is in the range of An30.96 to An58.75, and the variation of Fetotal is the same as An, which determine normal crystallization state with temperature equilibrium. The chemistry of zoned plagioclase with oscillating zoning are analyzed from rim to rim, which is the minimum and maximum of An in microquartz-diorite is An36.58 to An60.94 and in tonalite is An41.92 to An54.12 respectively. The rim-to-rim trend of An and Fe, Mg, and Ti elements in the zoned plagioclase shown oscillatory zoning which indicate that crystallization process of fractional crystallization accompanied by the recharges of mafic magma in the state temperature equilibrium. The recharges of mafic magma in the center of intrusive are higher than the margin.

Niabad-Qalaje ophiolitic complex is part of Sarvabad ophiolites in Kurdistan that exposed in northwest of Iran and the north of Kermanshah Ophiolites. The complex located in north of Zagros orogeny, consists of lens form, tectonically dismembered ophiolitic sequences located along the main Zagros trust. The ultramafic part includes serpentinized dunite and wherlite, serpentinite and chromitite that outcropped as consecutive lenses. Small lentiform chromitites present podiform and shear fabrics. The major minerals in peridotites are olivine (Fo= 88-91), clinopyroxene and chromian spinels.  Low Ti value and high content of Al and Cr# in peridotite chromian spinels reveal a high rate of partial melting (25-35%). Mineral chemistry and whole-rock chemistry clearly indicate that the Kurdistan ultramafic cumulates and chromitites record an episode of boninitic magmatism.  Boninitic melts in Niabad-Qalaje ophiolites were formed by partial melting of a depleted peridotite which made up the residual mantle after MORB-type melt extraction. The chemistry of peridotites shows the abyssal to supra-subduction zone source. Comparing the lithological and geochemical characteristics of the studied ophiolites with some other complexes in the world denotes that the Kurdistan ophiolitic complex formed in a fore arc basin close to the Sanandaj-Sirjan zone continental margin.

Opal, known as Aghigh in Persian, is one of the main semi-precious rock in Iran that is present in Bayag active mine in NW of Torbat Heidarieh. Mineralogy of agate is crucial for its treatment and cutting. In this research, mineralogy of agate in Bayeg mine investigated using SEM, Raman analyses and ICP methods.  Chalcedony introduced as the main constituent of agate in literature. However, this research revels opal, chalcedony and moganite are main minerals of Bayeg mine respectively. In hand specimen, chalcedony show white and milky color, and opals are gray to dark. ICP-MS analysis showed that amounts of AL and Na, Ba and Sr present as trace of meteoric and hydrothermal fluids and igneous activities during the formation of opals

Monitoring quiescent volcano such as Damavan is vital. In this research, we investigate the changes of land surface temperature (LST) around the Damavand volcano during 23 years period. The evaluations were done on the thermal anomaly areas related to geothermal activity and results compared with non-anomalously thermal areas. The surface thermal anomalies were detected on the basis of processing of Landsat day and night-time images and combination with geological information layers. The average of calculated values for geothermal heat flux (GHF) in the geothermal areas was 42 W/m2 (in the day-time image) and 20 W/m2 (in night-time image). The total radiant GHF in thermal anomaly areas estimated 50 MW (in night-time image) and 119 MW (in the day-time image). The thermal anomaly areas have a close spatial relationship with faults, hot springs, lithology, hydrothermal alterations, active deformation regions and subsurface high heat flow data. After determining thermal anomaly areas related to the geothermal activity, the changes of LST patterns were compared in the six TM and ETM+ images (captured from the same month and overpass time) during 1988- 2011. The highest temperatures were recorded in 2002 and 2007 images, that in line with seismic events and changes in hot springs chemistry. The thermal infrared remote sensing can be used as a cost effective and concise method for monitoring of quiescent and even dormant volcanoes of Iran.

Application of mathematics increasing in science in recent years, cause the mathematical models use to explain the geological processes. The researchers introduced a method based on mathematical calculations and algebraic model for metamorphic reactions. Pelitic metamorphic aureole is formed in North of Borujerd granitoid complex in the region east of Borujerd city. In this research for the first time, using a mathematical method for metamorphic reactions for high temperature of Pelitic metamorphic aureole based on algebraic model. Based on petrography, mineral assemblages of a rock are known and a thermodynamic system and components could be drive. SiO2, Al2O3, MgO, FeO, K2O and H2O Accepted as components and the system KFMASH chosen for calculation. Based on mineral assemblages, metamorphic reactions calculated using 6 by 6 and 6 by 8 matrices. Components put in Matrix and when Matrix’s elements below the diagonal are zero, then the calculation is applied over the second matrix to find metamorphic reactions. Equilibrium reactions could be written based on both microprobe analyses and general mineral formula. The main reactions in the intermediate zones toward the contact, in order from low to high temperature, are cordierite formed after reaction of biotite, quartz and andalusite followed by equation of andalusite to sillimanite. Potassium feldspar appears in the same rocks with sillimanite. Potassium feldspar and cordierite formed close to the contact zone, Petrographic result confirmed paragenetic minerals which appeared in algebraic analysis. The results show that reactions constrain based on algebraic analysis, could be used to estimated pressure and temperature in petrologic grids

Qorveh-Bijar area is east of Kurdistan province, located in northern part of Sanandaj-Sirjan zone in northwest of Iran. Quaternary volcanic rocks composition include of Basanite-tephrite to olivine basalt, basalt and trachyte. These rocks main phenocrysts are clinopyroxene, olivine and plagioclase. Plagioclase, biotite, hornblende and apatite are the main phase of mesostase. The EPMA results show that the plagioclases are show delicate zoning and have oligoclase to labradorite composition. Amphibole have magnesian-hastingsite composition and clinopyroxene with magnesium-calcium element ploted in diopside field. Olivine show the chrysolite type near to the magnesium pole, Mica is a phlogopite type and opaqius minerals shown the titano-magnetite composition. Based on the composition of amphibole and biotite, the magma have been the high rate of oxygen fugacity during the crystallization. According to the chemical composition of clinopyroxene, the basaltic rocks show the alkaline nature and was formed in continental within plate with extensional conditions. The magma temperature during the clinopyroxene crystallization is between 1150 to 1200°C and in the 5 to 8 kb pressures. Also the reange of magma temperature during the plagioclases crystallization have been 650 to 900°C.

Aliabad-Damagh region in SE of Hamadan contains both regional and contact metamorphic rocks. Garnet crystals present in many metamorphic rocks such as garnet schist, garnet- staurolite schist, amphibolite and metasandstone. In this study, garnet zoning in metasandstone investigated in order to interpret the origin and tectonic evolution of Hamadan metamorphic complex in Aliabad-Damagh region. Mainly dark metasandstones outcrops in south of Aliabad- Damagh are in the form of thin layers without schstosity within amphibolites and metapelites. The textures of metasandstones are granoblastic and granolepidoblastic. Main minerals are quartz, feldspar, mica and garnet. Garnet crystallized directly from the clay parts of the matrix in the medium grade metamorphic condition. Garnets are euhedral and based on fabric studies, garnets are formed during regional metamorphism. Point analyses from core to rim of garnet porphyroblasts show the main composition of almandine for garnets which Mn decreases and Fe and Mg increase from core to rim. Based on distribution of Fe, Mg and Mn the zoning patterns of crystals were normal and well preserved. The preservation of normal zoning in metasandstone garnet crystals indicate that the temperature of the regional metamorphism was not very high and metamorphism occurred maximum in the upper Greenschist facies and below the Amphibolite facies. The distribution of the elements in garnet zoning is reverse when the exhumation rate is low in orogenic trains. The presence of normal zoning in studied garnet crystals, confirm fast exhumation occurred after regional metamorphism in the area. Occurrence of dynamic metamorphism (P>>T) after pick of regional metamorphism in the Aliabad-Damagh could be evidence for such a rapid uplift.

Gabbroic intrusions are located about 40 Km southeast of Fariman in Central Iran zone along the Fariman- Torbatjam road that could be seen at the end of Bardoo river and in Chahak village. Previous studies have emphasis on the age and genesis relationship between granites and gabbroic rocks. So in order to investigate this matter, granites and gabbroes dated by using U-Pb method in Oslo University. Granites show the age of 548.3 Ma that is concarrent with the formation of schists during high temperature metamorphism in Fariman area. Dating of gabbroic rocks suggest an age of 471.14 ±0.85 mainly Early Paleozoic age that is younger than magmatism formed granites. Introducing Ordovician plotunism in this area is very important for reconstruction of Caledonian event. It seems that the formation of Gobbroic rocks is as a result of a short orogeny event due to opening of paleotethys during ordovician and Silurian.

Muteh district is located in the central part of Sanandaj- Sirjan Zone. It consists of two active mines, including the Chah Khatoon and Senjedeh open pits. Exposed rock units in the area underwent greenschist to lower amphibolite metamorphism. They consist of deformed and metamorphosed volcano-sedimentary and acidic volcanic rocks. Gold mineralization is hosted in metamorphic rocks and pyrite is the most important Au-hosting mineral in the Muteh minig district; therefore, pyrite from the Senjedeh gold deposit was investigated using a combination of ore microscopy, including back-scattered imaging (BSE), and electron probe microanalysis (EPMA) with the aim to investigate gold and trace elements (Se, As, Pb, Bi, Sb, Co, Ag, Te, Zn, Cu, Ni) distribution. Based on our studies, there are two generations of pyrite: medium-grained, anhedral and deformed of first generation of pyrite that is characterized by abundance of microfractures, contains high level of gold ( up to 810 ppm) and coarse grained, euhedral of second generation of pyrite, contains low- medium level of gold (bdl- 110 ppm). Results of this study show that there are no systematic differences between the trace element compositions of two generations of pyrite. According to BSE, visible gold is widespread and present as irregular grains of native gold mostly along grain boundaries or filling microfractures of first generation of pyrite. Element mapping indicates that Co is incorporated in pyrite crystal lattice and shows compositional zoning in pyrite grains. Ultramafic, and to a lesser extent, mafic rocks are typically strongly enriched in Co; in contrast, felsic rocks usually contain low Co concentrations. Therefore, high Co concentrations should be a good indicator of a high proportion of mafic to ultramafic over felsic rocks in the fluid source area. Co concentrations in pyrite ,possibly linked to mafic/ultramafic metamorphic rocks, provide further evidence for the orogenic gold deposit affinity.

The study area is located in northeastern Delijan, in Urumieh Dokhtar magmatic belt Central Iran and consists of Intrusive, subvolcanic, volcanic, Sedimentary and Pyroclastic rocks. emplacement of intrusion in Carbonate sedimentary and Pyroclastic rocks caused iron skarn mineralization and alteration of the host rocks. Remote sensing method is used to investigate the alteration zones and evaluate the patterns of iron skarn mineralization by using different processing on satellite images of Landsat ETM sensor. Accordingly, band ratio, principal component analysis and matched filtering methods are the best algorithms to observe alteration zones, and colour composite, Crosta technique and LS-Fit algorithm methods can provide acceptable results for iron minerals detection. These Remote Sensing methods are recommended to determine alteration zones and find iron minerals in general exploration, also because of clay alteration isn’t associated with skarn deposits, this type of alteration is not useful in iron skarn exploration.

The mylonitic granitoids of Gole Gohar, south east of Sirjan, are located in a key area which their study is important for understanding the history of Precambrian basement of Sanandaj- Sirjan zone and its metamorphic and magmatic evolution during the subduction of Neo- Tethys. Field studies show that these granitoids are located in the basement of the metamorphic rocks such as metapelite, calc schist and amphibolite. In this Study the granitoidic intrusions are classified in two types based on lithology and their geochemistry. Type I is garnet- biotite granitoid and type II is hastingsite granitoid. Both of these granites show some evidence of mylonitic fabric, which is more clear in garnet- biotite granitoid. These plutons are Meta aluminous, I Type granitoid and have high K calc-alkaline nature. Based on U-Pb dating of zircon, the age of all granitoids is between 538.6–580.7 Ma (Late Precambrian- Early Cambrian). Based on the results of this study, despite the mineralogical and geochemical differences, all granitoidic intrusions formed in the Precambrian during the Pan African orogeny. The old age of the granitoids is similar to those introduced in other parts of Sanandaj-Sirjan zone that may indicate the presence of Precambrian basement in almost the entire Sanandaj-Sirjan zone.

The Garmab copper deposit is located northeast of Qaen (South Khorasan province) in the1:100,000 scale map of Abiz in the eastern tectonic zone of Iran. It is hosted by Late Paleocene-Eocene lava flows consisting mainly of andesite, trachy andesite, andesite-basalt and basalt lavas, as well as pyroclastic rocks, including tuffs and ignimbrites. The Lut Block has undergone intense magmatic activitywith a variety of geochemical characteristics due to changing tectonic conditions (e.g., compression during subduction followed by tensional conditions; Karimpour et al., 2012; Zarrinkoub et al., 2012). The Lut Block has a great potential for the discovery of new mineral deposits, like the Mahrabad and Khonik porphyry copper-gold deposits (Malekzadeh shafarodi, 2009), the Dehsalam porphyry copper deposit (Arjmandzadeh, 2011), high sulfidation epithermal gold deposits such as Chah Shalghami (Karimpour, 2005) and IOCG deposits such as Kuh-E-Zar and Qaleh Zari (Mazlomi et al., 2008).
After field studies of the Garmab area, 32 thin sections and 21 polished sections were prepared for petrological and mineralogical studies.In addition, 10 least-altered and fractured samples of volcanic rocks were selected for geochemical studies. Major oxides were determined using XRF analyses at the Zarazma laboratory. Induced polarization and resistivity geophysical data were collected and correlated with geological and alteration maps. The geophysical datawere collectedfrom 420 individual points, using a dipole-dipole arrangement along five profiles separated 60m apart.This covered the study area entirely. After a change in the mineralization trend was observed,additional profileswere designed, twoon bearings of 25º and three on 75º.
The Garmab volcanic rocks exhibit typical geochemical characteristics of subduction zone magmas including strong enrichment in LILE and depletion in HFSE. Based on the discrimination plot of Irvine and Baragar (1971), all samples belong to the calc-alkaline series, and based on the TAS diagram of Cox et al., 1979, the volcanic ore host rocks of Garmab range from andesite to basaltic andesite to trachyandesite.
Hydrothermal alteration, associated with deposition of copper sulfide mineralization, occursmostly along the fault zones. .Mineralization also occurs disseminated and as veinlets, restricted to uppermost parts of the volcanic sequences. The deposit has the form of a layer of supergene enrichment characterized principally by chalcocite as the main ore mineral accompanied by digenite, covellite, bornite and chalcopyrite.
The locationof the anomalies has been determined from their medium chargeability and low to medium resistivity values. This can be attributed to the presence of sulfide minerals in the mineralized zones. The average sulfide mineral grain size was determined using the results of time constant parameter. Since the results of raw data do not indicate accurate information about the depth and geometry of mineralization, smooth inverse modeling was applied to determine probable zones and vertical and horizontal extension of mineralization.Geophysical studies show that zones of mineralization are small and scattered.

Jalal-Abad iron deposit is located about 38 km northwest of Zarand town in Kerman Province. It contains 200 Mt iron ore with average chemical composition of
Fe = 45%, S =1.18% and P = 0.08%. Iron mineralization occurs in an Early Cambrian volcano–sedimentary sequence of Rizu series which is composed of sandy siltstone, siltstone, volcanoclastic rocks and dolomite. Small intrusive bodies of gabbro and dioritic dykes are exposed in the area. Iron mineralization at Jalal-Abad is concealed with scarce outcrop. The main ore mineral is magnetite, which is located deeply, and  has been oxidized to hematite in shallow dopth and along fractures. Pyrite and chalcopyrite are the main sulfide minerals and bismuthinite, arsenopyrite and covellite are present in minor amounts. Cu mineralization occurred in sulphide and oxide stages as dissemination, veins, veinlet and open space filling. Malachite, azourite and atacamite are common minerals at oxide stage. Native gold was detected as inclusions smaller than 50 µm in pyrite, chalcopyrite and magnetite hosts. Alteration in Jalal-Abad is widespread and sodic-calcic, chloritic, sericitic and silicic alteration halos formed around orebody. Sodic-calcic alteration (actinolite,tremolite, magnesiohornblend and magnetite assemblage) is common in the deep levels. The main gangue mineral is quartz in association with talc, chlorite, ferroactinolite and calcite. Fluid inclusion investigation in quartz shows that inclusions are formed at three phase (L+V+S) with halite as a solid phase. Homogenization temperature varies from 260 to 440 ºC and salinity varies from 30 up to 52 NaClwt% equivalents. The high salinity and homogenization temperature of fluid inclusions is similar to fluids with magmatic origin. Mineralogy, alteration, geochemistry and fluid inclusion studies indicate Jalal-Abad deposit is similar to IOCG deposits.

Along 80 Km length of Tehran-Qom highway, a complex of post Eocen volcanic rocks include basalt, trachyte-basalt, andesite-basalt, dacite, rhyolite and pyrocalstic rocks (tuff and ignimbrite) with sedimentary rocks are exposed. The region turned to horst and graben system by NW-SE fault systems. Grabens are covered by Pliocene-Quaternary sediments and various volcanic rocks outcrop in horsts. Volcanic rocks are mostly calc-alkaline, alkaline and rarely tholeiitic. Geochemical features of these rocks are similar to those of subduction tectonic setting and in spider diagrams, the HFSE (Nb, Ti, Y, P) show negative and the LILE (K, Rb, Cs, Sr, Ba, Th, Pb) show positive anomaly. However, Ta and Nb do not present obvious negative anomaly. Comparing the spider diagrams of the studied rocks with N-MORB shows that their magmas originated from mantle melt similar to N-MORB mantle, but from higher depth than MORB in which garnet was stable (Y negative anomaly) and plagioclase were absent (Eu positive anomaly). Spider diagrams normalized with primary mantle also confirm such a mantle source (Eu positive anomaly) that was affected by mantle driven fluids (positive anomaly of Cs, Th, K, La, Pb). Chemical composition variations of the Eocene volcanic rocks from Qom to Tehran shows that there is no geochemical polarity in this volcanic trend similar to those of subduction zones. The disagreement in geochemical results could probably be due to the slab detachment of ocean plate in the upper Cretaceous that caused a delay in subduction and continued with lower angel subduction to form a magmatic isotropy in the Central Iran. Furthermore, the presence of local extension forces with transitional effects and block rotary movements that are formed as a function of strike-slip faults above the oblique subduction zone must be considered

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

The study area is the part of Sanandaj – Sirjan zone and is located in the north of Songhor. This area consists of various metamorphic rocks with igneous and sedimentary protoliths. All types of existing rocks are metamorphosed in the greenschist facies. The metamorphosed rocks consist of metagranite, metavolcanics, marble, schist, calc-schist, calc-silicates, green schist, slate and phyllite. The textures of present rocks are often blastoporphyric, granoblastic and lepidoblastic. On Harker diagrams, the K2O values are increasing while SiO2 increasing, whereas, TiO2, MgO and FeOt are decreasing, therefore, the differentiation is probably the most important process in the chemical development of the rocks. Volcanic rocks are calc- alkaline and enriched in large ion lithophile elements such as K, Rb and depleted in high field strength elements such as Ti, Nb. The intrusive bodies are granites intruding the metamorphic rocks. Granites are weakly peraluminous and calc-alkaline and according to tectonic diagrams belong to within-plate granites (WPG). The rocks were deformed by tectonic forces and different microstructures formed that is indicating the existence of different phases of deformation in the area.