mohammadhassan karimpour

Manto-type copper mines occur in the Bardaskan-Doruneh copper belt.  On the basis of structural sedimentary division of Iran, this belt is located in the northeastern part of the Central Iran.  At the southern border of this belt, the Yazd structural block and in the north of it is the Sabzevar subzone. The important regional structures of the region are Doruneh and Taknar faults. The majority of the units in this belt are Tertiary volcanic rocks that is associated with some sedimentary units, also some intrusive units are sometimes visible in the form of dyke and stock structures. The main host-rock of mineralization is conglomerate, which is different in grain size, clasts and cement. The most common sulphide mineral is chalcocite and the most important copper carbonates are malachite and azurite. The intense alteration is not observed in the region, and the chloritic alteration is partial, and the alteration of Fe-Oxide, zeolite, calcite, and silica is just observed locally. Mineral solution is reduced and poor in iron and silica.

The Kalateh Bargh prospect area is located NW of Bardaskan, Khorasan Razavi province. Geology of the erea includes sequence of Eocene volcanic rocks with basalt composition and trachyandesite and andesite. On this sequence, there is a conglomerate unit that its fragments are mainly composed of volcanic rocks. The high porosity of the conglomerate as the host rock provided a suitable space for the formation of Manto copper deposits. Mineralization has formed in conglomerate unit as a particular horizon in the Kalate Barq area. Primary minerals include chalcocite and minor bornite and secondary minerals consist of malachite and covellite. Structure and texture of mineralization are veinlet, open-space filling, disseminated and replacement. Mineralogy of alteration zones is related to mineralization and consist of chlorite and calcite. The average copper geochemical anomaly in surface samples is 1.4 %. The presence of chalcocite and absence or low amount of iron sulfide minerals, the presence of chlorite and calcite as the main gangue minerals and lack of quartz indicate that ore solution is reduced and poor of iron and silica. Based on lithology, alteration, mineralogy and geochemistry of Kalateh Bargh prospect area is similar to manto-type copper deposits.

Sagh mineral occurrence is located southeast of Torbat-e-Heydarieh, Khorasan Razavi province, and in the eastern part of the Khaf-Kashmar-Bardeskan magmatic belt. The rock units of area are divided into two categories: intrusions (monzonite, monzodiorite, diorite, and syenite) in the southern half, and conglomerate in the northern half. One square kilometer of continuous mineralization may be observed as stockwork, while there are other locations where it has a linear trend and is supported by intrusive rocks. Primary minerals include specularite, chalcopyrite, pyrite, galena, and sulfosalt, and secondary minerals include malachite, goethite, hematite, chalcosite, caveolite, and anglesite. The mineralization textures are vein-veinlet, disseminated, replacement, and cloform, mainly with a strong chloritic-silicified alteration. The average amount of copper is 0.8 with a maximum of more than 3%, the average amount of silver is 24.4 with a maximum of more than 113 ppm, and the average amount of gold is 44 with a maximum of 250 ppb. The average amount of lead is 761 ppm with a maximum of 0.4% and the average amount of zinc is 430 ppm with a maximum of 0.1%. The formation temperature of ore-forming fluid is between 159 and 328 °C and the salinity is between 7.2 and 16.7 wt.% equiv. NaCl. The mixing of magmatic fluids with meteoric waters with low temperatures and salinity was the most important mechanism of mineral formation. Based on the evidence of tectonic setting, lithology, type of alteration, shape, and state of mineralization, and the presence of abundant specularity with copper, silver, and gold anomalies, probably the Sagh area is iron oxide Cu-Ag±Au type. 

The geological settings, hydrothermal alteration, and mineralizing fluid compositions vary among the deposits of “IOCG-type” (Hitzman et al., 1992; Sillitoe, 2003). However, they belong to a family of Cu ±Au deposits that include substantial hydrothermal alkali (Na/Ca/K) alteration and a lot of low-Ti iron oxide (magnetite and/or hematite). According to Williams et al. (2005), these deposits likewise exhibit strong structural constraints and a temporal but not a tight geographical relationship with igneous rocks. They formed in rift or subduction settings (Hitzman, 2002) from the Late Archean to the Pliocene (Groves et al., 2010).
Sagh mineral occurrence is located the southeast of Torbat-e-Heydarieh, Khorasan Razavi province, and in the eastern part of the Khaf-Kashmar-Bardeskan magmatic belt (Fig.1). This belt has a high potential for iron oxide copper-gold type deposits and sometimes skarn and porphyry copper (Karimpour, 2004).
The purpose of this research is geological studies and determine the relationship of intrusions with mineralization, examine the total paragenesis sequence, geochemistry, fluid inclusions studies and finally determine the mineralization model, and the formation of mineral occurrences in the Sagh area, for the first time is done.

To investigate the lithology, alteration, and mineralization of the Sagh area, 61 samples were taken mainly from the intrusions. 32 samples for the thin section and 10 samples for the polished thin section and polished block were selected, prepared, and studied. Then, the geological and alteration-mineralization map with a scale of 1:5000 was prepared in Arc GIS software. Furthermore, for geochemical studies of mineralization zones and veins, 24 samples were taken and sent to the Zarazma laboratory for analysis. Analysis was done by the ICP-OES method. Furthermore, 11 samples were selected for gold analysis with Fire assay, and sent to Zarazma laboratory. Using a cooling and heating system made by Linkam Company, model THM 600, microthermometric tests and salinity determination were performed on 2 wafers of quartz minerals and 31 fluid inclusions at Ferdowsi University of Mashhad.

The rock units of the area are divided into two categories: subvolcanic and plutonic intrusions in the southern half and conglomerate units in the northern half. Intrusive rocks are composed of monzonite, monzodiorite, diorite and syenite. Mineralization can be seen in the form of stockwork in a wide and continuous zone with an area of about one square kilometer, but in some places, it has a linear trend (NE-SW and NW-SE trend) which is hosted by intrusive rocks. Primary minerals include specularite, chalcopyrite, pyrite, galena, and sulfosalt, and secondary minerals include malachite, goethite, hematite, chalcosite, covellite, and anglesite. Vein-veinlet, disseminated, replacement, and cloform mineralization textures are seen, with a dominant chloritic-silicified alteration. The average concentration of copper is 0.8%, with a maximum concentration of more than 3%, silver is 24.4 ppm, with a maximum concentration of more than 113 ppm, and gold is 44 ppb, with a maximum concentration of more than 250 ppb, according to geochemical data. The average amount of lead is 761 ppm with a maximum of 0.4% and the average amount of zinc is 430 ppm with a maximum of 0.1%. Based on fluid inclusions studies, the formation temperature of ore-forming fluid is between 159 and 328 °C, and the salinity is between 7.2 and 16.7 wt.% equiv. NaCl.

Comparing the characteristics of Sagh prospect area with other copper-bearing deposits shows that this area is very similar to iron oxide copper-gold deposits. An empiric definition of IOCG deposits is summarized as having the following five characteristics (Williams et al., 2005): (1) copper, with or without gold, as economic metals, (2) hydrothermal ore styles and strong structural controls, (3) abundant magnetite and/or hematite, (4) Fe oxides with Fe/Ti ratios greater than those in most igneous rocks and bulk crust, and (5) no clear spatial associations with igneous intrusions as, for example, displayed by porphyry and skarn ore deposits.
Sillitoe (2003) proposed a close genetic relationship between IOCG deposits in northern Chile, and dioritic plutons. Mineralization in the Sagh area has a close relationship with monzonitic, monzodiorite, and diorite, which are similar to Kuh-e-Zar, Bahariyeh, Namaq, Fadiheh, Chenar, and other KKBMB deposits (Table 3).
The main alteration related to mineralization in the Sagh is propylitic-silicified, and its propylitic alteration is characterized by chlorite mineral. Extensive chlorite alteration in the Sagh area is similar to Monteverde deposit in Peru (Vila et al., 1998), Mont-del-Aigle in Canada (Simard et al., 2006), Kuh-e-Zar Tarbat Heydarieh (Karimpour et al., 2017), and other IOCG type deposits in the KKBMB belt (Almasi et al., 2015; Taghadosi and Malekzadeh Shafaroudi, 2018; Najmi et al., 2023; Sahebi Khader et al., 2021; Behnamnia et al., 2023) and Qala Zari (Karimpour, 2005) in the Lut block, where the temperature and salinity of ore-fluid are lower than some IOCG type deposits in the world.
Based on the available evidence, the mineral occurrence of the Sagh includes 1) the presence of oxidant intrusions formed in the subduction zone in the KKBMB, 2) mineral paragenesis of specularity, chalcopyrite, pyrite, and galena, 3) structural control of mineralization, 4) copper, silver, gold, and lead geochemical anomaly, 5) chloritic-silicified alteration, which is very compatible with iron oxide copper-silver-gold systems. The location of this area in the KKBMB belt, which has great potential for IOCG deposits, and near other IOCG deposits that have many similarities (Almasi et al., 2015; Karimpour et al., 2017; Sahebi Khader et al., 2021; Najmi et al., 2023), is a confirmation of this claim.
Although monzonitic, monzodiorite, diorite, and syenitic intrusions are the host rock of mineralization and mineralization is controlled by structures and faults, this magmatism can be represented of source rock at deep. The mineral paragenesis of the Sagh and the abundance of specularity with sulphide minerals of copper, lead, and silver, which are associated with quartz and chlorite, show that mineralization generated from a high fO2, Fe-Si rich ore fluid.
The metal originated from an oxidan magmatism from deep, and moved up through faults, joints, and fractures. The mixing of magmatic ore solution with higher temperature and salinity with meteoric water with lower temperature and salinity has finally led to the deposition of sulfides, and the formation of mineralization. Temperature-salinity and alteration evidence show that we are currently in the upper parts of the system, and we need more information. The relevance of this magmatic belt in eastern Iran as a significant metallogenic zone for deposits of copper, gold, and silver is growing as more and more IOCG mineral occurrences are found there.

The Kimia copper area is located in the Eocene volcano-sedimentary complex northwest of Bardskan in Razavi Khorasan Province. The geology of the area includes volcanic rocks with andesite-basalt composition, conglomerate with andesite fragments, nummulitic limestone and tuffaceous sandstone. Mineralization is found in andesite and conglomerate units as well as at the border between these units in the form of vein-veinlets, disseminated, replacement and open space filling. Primary minerals are chalcocite, pyrite, and secondary minerals are malachite, caveolite, and iron oxide. The faults in this region are formed in two directions, northeast-southwest and northwest-southeast, with a slope of 45 degrees. The main veins in this zone are calcite-quartz-pyrite, calcite-chalcocite and calcite-barite-pyrite. Alterations related to veins are siliceous and carbonate and are related to igneous, propylitic, carbonate and chloritic units. The amount of copper element ranges between 6950 and 47935 ppm and other elements have low values. Based on fluid inclusion study, the minimum formation temperature ranges between 228 and 368 °C and the salinity is between 10.4 and 16.9 percent. Based on the evidence of the host rock, structure, textures and existing alterations, copper mineralization in Kimia area is Manto type.

Balazard prospecting area is located in eastern Iran, about 120 km south-west of Nehbandan in the Central part of Lut Block. This area consists of exposed Eocene volcanic rocks, intruded by several diorite and monzodiorite dykes and stocks. These intrusive rocks display porphyritic textures with mm-sized phenocrysts, most commonly of plagioclase, clinopyroxene and hornblende, embedded in a fine-grained groundmass with variable amounts of plagioclase, quartz, and opaque minerals. The assessment of geochemical properties of the major elements showed that these granitoids are metaluminous and of high-K calc-alkaline variety. The patterns of trace elements are identical, denoting enrichments in the light REE (LREE) to heavy REE (HREE). Moreover, LILE enrichment relative to HFSE and Nb, Ti, and P show negative anomalies. The Eu/Eu* ratios range from 0.96 to 0.76, which means that the plagioclase is a slag remnant in the origin of magma. The (87Sr/86Sr)i values of the assessed intrusive rocks range from 0.706 to 0.707, assuming an Oligocene age, while the εNdi values are between -1.9 to -3.2. These results manifest that the magmas were contaminated by continental crust. The contamination has probably occurred over the ascent of magma to crustal levels, and geochemical data verifies the preposition that the investigated intrusions were intruded in a volcanic belt resting on a subduction zone. Early magmas were created through the melting of mantle wedge peridotite, occasioning magma differentiation through crystal fractionation and crust contamination as they ascended to crustal levels.

Chah-Nar Pb-Zn deposit is located south of Rutchun plain, 110 km SW Baft, within Sanandaj- Sirjan Zone. Mineralization occurs at calitic-dolomitic marble of Rutchun complex  as epigenetic with structural control. Paragenetic minerals are galena and minor sphalerite  and pyrite associated with quartz, and minor calcite and dolomite,  as gangue minerals. These minerals show veinlets, open space filling, breccia, and disseminated textures. Galena can be seen in the form of coarse grain crystal and cuboctahedral texture and fine grain crystal. Silicification and carbonatization are the most important alteration zones. Galena chemistry indicates galena is Ag, As, Cd and Zn -rich and Sn, Bi-poor. Sb/Bi ratio in galena is close to 3, which is indicator of low temperature deposits. Host rock type, stratabound and epigenetic mineralization, postsedimentary fault controlling, texture, ore types and gangue minerals, and lack of significant correlation between mineralization and igneous activities, chemistry of galena, indicate that Chah-Nar deposit is similar to MVT deposits, although it has some differences with this deposits type.

Bahariyeh deposit is located in the central segment of the Khaf-Kashmar-Bardaskan magmatic belt (KKBMB), NE Iran. This belt is dominated by plutons of Kashmar batholith and associated volcanic rocks along the northern side of the Dorouneh Fault and is one of the most important metallogenic provinces in Iran. Based on geochemical data carried out for the purpose of the present study, the expansion of Cu and other metals mineralization is determined, and on the basis of investigation of trace and rare earth elements behavior, the genetic-lithological relationship of the intrusive rocks is determined in the North of Bahariyeh region.

Method of study:

 About 80 thin sections of intrusive rocks were prepared and 10 least altered 10 samples were selected and analyzed by X-ray fluorescence (XRF; PHILIPS PW 1480) at the Analytical Laboratory of the Kansaran Binaloud Institute of Mashhad, Iran. Also, 10 samples were selected for geochemical analysis by (ICP-OES) at the Zarazma Mineral Studies Co., Mashhad, Iran. Regional Geology Based on field observations a 1:10,000 geological map prepared from the study area, the existing rock outcrops mainly include an alternative of pyroclastic units, Eocene-Oligocene lavas, as well as subvolcanic and intrusive rocks. Field observations show the North of Bahariyeh area is composed of dacite-rhyodacite and andesite volcanic units, and has been intruded by granodiorite, quartz monzonite, monzodiorite-diorite porphyry. These acidic-intermediate intrusive masses have a granular texture and are mainly porphyroid, which have been affected by propylitic, siliceous, argillic, and sericitic alterations. Copper mineralization is observed in the form of veins in different parts of the region, the thickness of these veins varies from about 5 mm to more than 10 cm. Two types of vein-veinlets can be distinguished in the mineralization zone of North of Bahariyeh: 1) vein-veinlets containing quartz + chalcopyrite + specularite + pyrite; 2) specularite-rich veins. Petrography Granodiorite: Granodiorite shows a coarse-grained granular texture with graphic and myrmekitic intergrowths. The main minerals consist of plagioclase, K-feldspar (orthoclase), quartz, hornblende, and opaque minerals. The euhedral-subhedral plagioclase and K-feldspar phenocrysts have been altered to sericite, clay minerals, epidote, and chlorite.Monzodiorite porphyry: This unit has porphyritic and glomeroporphyritic textures with medium-grained groundmass. The monzodiorite porphyry contains up to 45-50 vol.% phenocrysts, consisting of plagioclase (15–20 vol.%), K-feldspar (10–15 vol.%), hornblende (5–7 vol.%), clinopyroxene (5–8 vol.%), and biotite (2–5 vol.%). The same minerals are also present in groundmass. Hornblende and biotite are replaced by chlorite in some places. Also, some plagioclase and feldspar phenocrysts have been altered to sericite, chlorite, and epidote.Quartz monzonite porphyry: The quartz monzonite porphyry has a porphyritic texture (0.1–0.2 mm) with a fine-grained groundmass and normally contains 40–45 vol.% phenocrysts that are 0.1–4 mm in diameter. It is mainly composed of plagioclase (30-35 vol.%), K-feldspar (25-30 vol.%), quartz (15–20 vol.%), and hornblende (5-10 vol.%). The same minerals are also present in groundmass.Diorite porphyry: This unit has porphyritic and glomeroporphyritic textures, with medium-grained groundmass with phenocrysts 0.1–5 mm across, and 40-50 vol.% phenocrysts including 25-30 vol.% plagioclase and 15-20 vol.% clinopyroxene and hornblende with minor biotite and alkali feldspar. The same minerals are also present in groundmass. Its accessory minerals are quartz, zircon, and magnetite (2–3 vol.% and 0.5 mm).

North of Bahariyeh provides important insights for reconstructing the Middle Eocene tectono-magmatic evolution of the NE of Iran. Significant outcomes of this work are:The intrusive sequence in the North of Bahariyeh is inferred as monzodiorite porphyry, diorite porphyry, quartz monzonite, and granodiorite of middle Eocene. and all intrusive rocks belong to I-type metaluminous-peraluminous granites. Major and trace element geochemistry indicate the acidic-intermediate intrusive rocks in the North of Bahariyeh were likely generated by partial melting from the subcontinental lithospheric mantle affected by both slab-derived fluids and lower continental crustal components.The enrichment of LILE (Ba, K, and Cs), depletion of HFSE (Nb, Ti), and the enrichment of LREE relative to HREE indicate crustal contamination and formation of the source magmas in a subduction environment zone by low degrees of partial melting. Trace element geochemistry confirms the evolution of dioritic rocks by a partial melting process (1-5%). Geochemical results, combined with regional geological data, demonstrate a shallow mantle with a clear subduction imprint (metasomatized mantle wedge melts). The post-collisional transtensional tectonic regime favored magma genesis with decompression melting and magma rise through the well-developed fault system and the subvolcanic and intrusive units in the North of Bahariyeh area form the active continental margin-related subduction zone.Overall, the data of the rare earth elements of acidic-intermediate units in the area of study shows that the rocks under investigation were originated by partial melting of enriched mantle under the influence of the fluids released from the subduction blade and then under the contamination of the crust.

Ruchun-Mazar region is located in southern Sanandaj-Sirjan Zone, southwest of Baft city in Kerman province, Iran. Seh Chah, Chah Sorbi, Chah Nar, Zardbazi Dar, and Chah Sorbi Arjmand Pb-Zn deposits located in this region were investigated. The most outcrops of the geological units in the area include the Paleozoic metamorphic complexes of Gol Ghohar (amphibolite, gneiss and micaschist), Ruchun (schist, marble, calcschist, black chert, slate and phyllite), and Khabar (marble, calcschist). Microdioritic, monzodioritic and diabasic dykes have intruded into the metamorphic units. Dolomitic and calcitic marble of Ruchun complex is the host rock for Pb-Zn mineralization. Primary mineralization in Seh Chah, Chah Sorbi, and Chah Nar deposits includes galena, sphalerite, and pyrite ± chalcopyrite along with quartz, calcite, and dolomite ± barite. Vein-veinlet, open space filling, brecciated ± disseminated ± laminate structures and textures can be seen in these deposits. The most important alterations in these deposits are silicification and carbonitization (calcitic and dolomitic alterations). Primary sulfide ore in Zardbazi Dar and Chah Sorbi Arjmand deposits has been weathered and mining has been carried out on nonsulfide ore (supergene ore). The nonsulfide ore formed at the expense of sulfides, and mainly consists of smithsonite, hydrozincite, hemimorphite, and cerussite. It seems that these deposits belong to the direct replacement and, to a lesser extent, wall rock replacement nonsulfide zinc deposits. Based on the geological, mineralogical and alteration evidence, the primary mineralization in the region can be divided into two groups of SEDEX type (Chah Sorbi deposit) and vein type (Chah Nar and Seh Chah deposits). It was concluded that under supergene conditions in some deposits, nonsulfide ore was also formed. Moreover, the deposits of this region can be categorized into primary sulfide (hydrothermal) and nonsulfide (supergene).

The most important Manto-type deposits are located in the Coastal and Central Cordillera, northern Chile. Manto-type copper deposits have been reported in Iran in Saveh-Jiroft zone, the volcanoes of eastern Iran, the volcanic-intrusive complex of Alborz-Azerbaijan, Sabzevar zone, and Sanandaj-Sirjan zone. Nasim copper deposit is located in the northwest of Bardaskan, northeastern Iran. The deposit is part of the Iranian Plateau, Sabzevar Subzone, and Oryan region, located at the end part of the Khaf-Kashmar-Bardaskan magmatic belt. The geological units in the area include the Late Tertiary (Paleocene-Eocene), volcanic rocks, and sedimentary rocks including conglomerate and limestone. In Nasim deposit, mineralization has been done in conglomerate unit as a particular horizon. This unit is composed of volcanic fragments with carbonate and volcanic cements. Chalcocite is the most important and main sulphide mineral in the study area. Alteration can be divided into pre-mineralization and syn-mineralization stages. Pre-mineralization includes Celadonite, Carbonate, Silicified, and Propylitic alteration. Syn-mineralization consists of small amounts of Chlorite, Zeolite, and Calcite. In this system, the chemistry of solution is different from those of other systems such as IOCG, massive sulfide, porphyry etc., due to completely reduced and iron and silica-deficient solution.

Nasim deposit is located in northeastern Iran, 50 kilometers northwest of Bardaskan. The study area is part of the Iranian Plateau, Sabzevar subzone, and Oryan region, which is located in the end part of the Khaf-Kashmar-Bardaskan magmatic belt. The most important Manto-type deposits of Iran are located in Bardaskan region. The study area includes Paleocene-Eocene volcanic rocks, major volcanic and minor intrusive fragments. In this study, the chemistry of solution was investigated based on alteration and paragenesis in Bardaskan region.

This study was done in two parts: field studies and laboratory works. Sampling and structural studies were done while doing field studies. Logging drill cores was done for about 1000 meters in 20 boreholes. After field work, a total of 150 thin sections and 50 polished sections were prepared and studied to investigate petrography and mineralogy and to prepare geological map.
 

Geology of the area includes sequence of volcanic rocks of basalt, basaltic-andesite and andesite, respectively, formed in a non-marine environment. Conglomerate and limestone units formed after volcanic activity. Mineralization occurred only within the conglomerate unit due to useful porosity. Mineralization formed clearly post-dates conglomerate and limestone in the region. Chalcocite is the most important primary copper mineral in Manto Chalcocite systems, which has a high amount of copper and lacks iron. Mainly in the conglomerate unit, due to the good porosity of the conglomerate, the solution has risen up through the faults and penetrated into the conglomerate. Limited mineralization is observed in the carbonate rock. The mineralizations have no time and origin relationship with the volcanic cycle and the time of conglomerate formation. The porosity in the conglomerate and the fault structure in the region have played an important role in the mineralization.
Manto copper solution is a solution poor in iron and poor in silica, and it is completely reducing. This solution cannot react with lime under any conditions; so the mineralization rate is very low in lime, and this shows that the solution has a special chemistry.
Some exploration consultants have used the word agglomerate instead of conglomerate in Bardaskan. This is not acceptable because agglomerate is created during volcanic activity and its fragments consist of only one type of composition and have a rounded state (volcanic bomb). But conglomerate is formed during the erosion cycle and all the pieces are rounded when transported by river water or on the seashore. The use of the term agglomerate becomes a fundamental problem regarding the time and manner of formation of copper mineralization. Not knowing the exact time of Qata mineralization challenges the exploration.
 Alteration assemblage do not consist of epidote and quartz due to the lack of iron and silica in the solution. Moreover, the reducing solution is due to the presence of organic substances. Some researchers (e.g., Wilson and Zentilli, 2006; Tosdal and Munizaga, 2003) suggest a volcanic origin for Manto-type deposits. The volcanic rocks contain at least 5% primary magnetite. If the rocks are the origin, the solution will be rich in iron, but there is no evidence of iron-bearing minerals such as chalcopyrite and pyrite in the area.
Other researchers (e.g., Palacios, 1986; Oliveros et al., 2008) see intrusive rocks as the origin of these deposits. If the rocks are the origin, solution will be definitely rich in silica, iron, and aluminum, but there is no evidence of quartz-chalcocite mineral assemblage. Therefore, the determination of the origin of the deposits requires further studies and consideration of other factors.

We would like to thank Ferdowsi University of Mashhad and Kome Madan Pars Company for cooperating and supporting this research. We thanks the reviewers and editor(s) for their thoughtful contributions.

Granites are the most important components of the continental crusts. As an important part of the Alpine-Himalayan global belt and the result of the Tethys evolutionary cycle, the Urmia-Dokhtar Magmatic Arc (UDMA) has formed during different magmatic periods. The most important magmatic episode of UDMA igneous rocks, which is the result of lithospheric extenssion and extensive magmatism, occurred during 55 to 37 Ma (Moghadam et al., 2015). In order to enhance our understanding of tectonomagmic evolution of the continental crust during this period, in this research, the intrusive masses of Aftabru and Qlichkandi will be investigated using geochemical data and the isotopic composition of neodymium and strontium. The mentioned intrusive masses are located in the southwest region of Buin Zahra in Central Iran zone.

Urmia-Dokhtar magmatic arc with Cenozoic intrusive and Eocene-Quaternary extrusive rocks shows different levels and rock outcrops in terms of time of origin and erosion rate, same what is seen in the subduction arc of the Andean continental margin. The lithospheric stresses caused by the interaction of the African-Eurasian-Indian lithosphere led to the emergence of Paleogene extensive magmatic activity and a magmatic flare-up lasting 30 Myrs during Eocene and Oligocene. As a result, more than 4 km of Paleogene igneous rocks formed in Saveh, Zarandiyeh, and Tafresh regions. In the south of Bouin Zahra region, pyroclastic outcrops and Eocene lava with a width of about 5km2 and 10 km2 are found in Aftabru and Qlichkandi areas, respectively.

After field observations and detailed textural and petrographic studies, 12 suitable samples with minimal weathering and alteration were selected from intrusive rocks and analyzed by XRF and ICP-MS methods for major, trace and rare earth elements. 6 whole rock samples were analyzed for Sr-Nd isotopes.

Petrography:

In Aftabru and Qlichkandi areas, quartz monzonites intruded the lower-middle Eocene volcanic and pyroclastic rocks.

Petrological observations show that the Aftabru intrusion contains 7-16 Vol% quartz, 25-30 Vol% K-feldspar, 39-54 Vol% plagioclase, 5-10 Vol% pyroxene, 8-15 Vol% amphibole, as well as 1 Vol% accessory minerals.

Qlichkandi:

The medium-grained Qlichkandi intrusive rocks with granular texture, composed of quartz 9-15 Vol% quartz, 25-28 Vol% K-feldspar, 35-45 Vol% plagioclase, 1-5 Vol% pyroxene, 5-10 Vol% of the common mafic mineral of amphibole, 5 Vol% biotite, and less than 1 Vol% accessory minerals.

Based on new geochemical and isotopic data, we will investigate the tectonic location, genesis and magmatic processes affecting the parental magma and the possible source rock of the intrusive masses in the south of Bouin Zahra region.Tectonic-magmatic zone:As  the pattern of rare earth elements and the spider diagrams of enrichment in LILE and LREE elements and depletion of HFSE and HREE elements display, the most important characteristic of intrusive rocks in the studied area is their similarity to continental margin arc rocks.   Generation and magmatic processes:Some incompatible trace elements ratios, such as Y/Nb, Nb/Ta and Nb/La that are less affected by diffrentiation are good indicators for investigation of the magma origin and the crustal contamination effect on the magma. The higher amounts of Y belong to crustal melts or impregnation with crustal materials, and the higher amounts of Nb belong to melts derived from the mantle. In the studied intrusive rocks, Y/Nb ratio is 1.6 on average with a range of 0.6-3.6, which probably indicates mantle with crustal mixing in the magama origin. The Nb/La value is 0.1 in primary mantle and 0.46 in the crustal rocks (Morata et al., 2005), it is about 0.86 on average and equals to the range of 0.1-0.52 in the intrusive rocks of the southern region of Buin Zahra (Qlichkandi, Aftabru). This value indicates a mantle origin for the studied rocks. The Nb/Ta value in mantle rocks is 17.5 and in crustal rocks it is equal to 11-12 (Green, 1995). This ratio is 15 on average (ranging from 8 to 8. 26), supporting the mantle origin as well.Neodymium model age (460-550 Ma) and positive ԑNd(t) indicate the Cadomian origin of lithospheric rocks of the Aftbaru region, while the model age of the samples from Qlichkandi region is 0.9. It shows ԑNd(t) less than zero. This difference is probably due to the high magma mixing with crustal materials in Qlichkandi region, which is confirmed by the diagram of ԑNd versus Sr isotope. 143Nd/144Nd ratio for the Aftabru samples is 0.51270-0.51280. But in the Qlichkandi samples, it is 0.51252-0.51242, which is a sign of contamination with the lower continental crust materials and a tendency towards lower crust. 87Sr/86Sr ratio is 0.70472-0.70510 in Aftabru and 0.70631-0.70607 in Qlichkandi samples. Therefore, according to the intrusive rock petrologic diagrams, it shows signs of contamination with the underlying crustal materials.

The Zangalou mine area, a part of NW Bardaskan magmatic assemblage, located south of Sabzevar and northwest of Bardaskan cities in Khorasan Razavi province. The rock units of the area are dominated by sedimentary and volcanic racks (andesite, trachyandesite, latite and andesitic tuff). The dominant minerals are plagioclase, hornblende, pyroxene and alkali feldspar locally affected by argillic and propylitic alterations and the main textures are porphyritic, glomeroporphyritic, amygdaloidal and fine grain. The rocks under study formed in continental volcanic arc related to subduction zone, are calcalkaline in nature, metaluminous in composition and classified as shoshoite series. LREE and LILE enrichment compared to HREE and HFSE of the investigated rocks indicate their magma generation in subduction setting. Both Zr/Ba and Sm/Yb ratios point to lithospheric mantle origin and the rare or the absence of garnet in the origin respectively. The parent magma formed from partial melting of an enriched phlogopite spinel lherzolite. The geochemical properties of Zangalou share many signatures with those of the volacic rocks distributed in other parts of NW Bardaskan volcanic assemblage indicate high similarity in geochemical signatures of volcanic rocks. Studying geochemistry of volcanic rocks in these areas indicates formation of these rocks in a subduction setting.

About 75% of world copper, 50% of molybdenum, and 20% of gold are produced from porphyry copper deposits (Sillitoe, 2010) with an average ore grade of 0.45–1.5% Cu, 0.007–0.04% Mo and up to 1.5 ppm Au. Porphyry copper deposits are commonly associated with intermediate composition arc-related igneous rocks with high Sr/Y and La/Yb ratios (Richards, 2011). Igneous rocks having ratios of Sr/ Y > 25 and Y < 10 ppm are considered adakitic type.The aim of this work is to modify the name of Urumieh-Dokhtar magmatic belt (UDMB), petrological studies of granitoids from Saveh to Jiroft, determination of the genetic relationship between porphyry copper deposits and adakitic and non-adakitic granitoids, and comparison of Miocene-Pliocene adakitic volcanic rock in different parts of Iran with barren adakitic granitoids. The role of a thermal gradient, depth of dehydration, water content, source rock, partial melting percentage, and oxygen fugacity in the formation or non-formation of mineralization, grade, and reserve of porphyry copper deposits are also investigated.

The information used can be divided into three parts: 1) data related to I-type magnetite series granitoids related to porphyry copper deposits of Miocene age in Saveh-Nain-Jiroft magmatic belt (SNJMB) which in Table 2 are presented, 2) data related to barren I-type magnetite series granitoids of Miocene age of SNJBM are reported in Table 3. In addition, radiogenic isotope information of barren and fertile SNJMB granitoids and volcanic rocks is presented in Table 4. 3) Information related to Miocene-Pliocene adakitic volcanic rocks, which is shown in Table 5.

Granitoids show the characteristics of subduction zone magmas. So that the enrichment of LILE elements and the depletion of HFSE elements can be seen. Also, enrichment of LILE elements and depletion of HFSE elements of fertile granitoids is more than barren units. Dalli deposit samples show a moderate pattern between barren and fertile granitoids (Fig. 3). All the evidence presented shows that all granitoids are I-type and magnetite series.In the fertile granitoids, the ratio of (La/Yb)n is between 15 and 38. However, this is between 2 and 14 (mostly below 10) in barren granitoids (Tables 2 and 3, Figs. 5A and 5B). Negative anomalous values ​​of Eu are seen in Miocene barren granitoids (Eu /Eu* value between 0.43 and 1 with an average of 0.65) (Table 3). While fertile granitoids have positive to slightly negative Eu anomalies (Eu / Eu* value between 0.82 and 1.3 with an average of 1.2).The initial values of 87Sr/86Sr of Miocene fertile granitoids vary between 0.704253 and 0.704702; while in barren granitoids, it is between 0.705 and 0.7085. Fertile Miocene granitoids have positive εNd (i) (0.29 to 3.39 mean 2.15) and in barren units is between 3- and 2.6 (Table 4).The value of the ratio (La/Yb)n of all volcanic units is between 13 and 78 and mostly above 20. They have positive to slightly negative Eu anomalies (Eu/Eu * values between 0.89 and 1.72) (Table 5). Figure 9 shows the fertile granitoids of the SNJMB similar to adakite volcanic rocks are located in the adakite field. In addition, Figure 11 show that all samples are high silica adakitic type. However, barren granitoids, which are mainly located between Saveh and Nain, are non-adakitic and are plotted within the normal arc range (Fig. 

In this paper, the name of UDMB was changed to Saveh-Nain-Jiroft magmatic belt (SNJMB) based on the evidence of lack of magmatism between Saveh to the extent of Takab and absence of air magnet anomaly. Magmatism of Urumieh to Takab is a continuation of the western Alborz magmatic belt. Based on the characteristics of magmatism and mineralization, SNJMB can be divided into two distinct belts: 1) Saveh-Nain Magmatic Belt (SNMB), which mainly consists of non-adakitic barren I-type magnetic granitoids. Based on the ratio (La/Yb)n, these granitoids originate from a depth of 60 to 80 km, and a mantle wedge and based on the amount of Eu/Eu*, conditions were oxidant. The initial 87Sr / 86Sr ratio indicates that they had a lot of contamination with the continental crust. The crustal thickness in SNMB is less than 48 km, 2) Nain-Jiroft Magmatic Belt (NJMB) which hosts porphyry copper deposits. The Miocene granitoids of this belt are magnetite series and I-type adakite. Based on the ratio (La/Yb)n, these granitoids originate from the depth of garnet stability (more than 90 km) and partial melting of slabs and are based on Eu/Eu* Oxidizing conditions have been established at the place of origin. The initial 87Sr / 86Sr ratio indicates slight contamination with the continental crust. The crustal thickness in NJMB is 48 to more than 52 km.Geochemically, adakitic volcanic rocks are similar to the fertile adakitic granitoids of NJMB, but these units do not contain any mineralization. The characteristics of the oceanic slabs of Neo-Tethys varied considerably during the SNJMB, leading to various magmatism and mineralization. The thermal gradient, depth of dehydration, amount of water, source rock, and the percentage of partial melting along the belt control the type of magmatism and the formation of mineralization. Note Figure 15.

The Chah Noghreh is a part of volcanic-intrusive zone of Lut block and is located in southwestern of Seh Qaleh city in South Khorasan province. The area comprises outcrops of Eocene volcanic rocks (rhyolitic to dacitic tuff breccia, andesitic tuff breccia and andesite), which was intruded by subvolcanic unit with pyroxene diorite porphyry composition. The mineralization as vein type (with trending NW-SE) with breccia and open space filling textures was formed in four stages, including: (1) quartz-sulfide, (2) barite-sulfide, (3) calcite-sulfide and (4) dolomite- sulfide. Alterations of argillic, silicification, calcite and dolomitization were formed in margins of vein with linear trend. Hypogene sulfide minerals in veins contain galena, sphalerite, fahlore and pyrite. Due to the influence of oxidation processes on the primary ore, secondary minerals of cerussite, anglesite, rhodochrosite, covellite, malachite, hematite and goethite are developed. Maximum geochemical anomalies of veins decrese from lead (158000 ppm) to zinc (25507 ppm) and copper (1295 ppm). Microthermometric measurements show temperatures of 210 to 281, 195 to 225 and 145 to 180ºC and salinity of 16.8 to 19.2, 11.7 to 17.2 and 13.4 to 15.8 NaCl wt. % equivalent, respectively. Temperature decreasing, mixing between magmatic derived hot and saline ore fluids with cold and low saline meteoric waters and boiling lead to the metal deposition. Based on evidences such as structurally controled mineralization, type of alterations and heir linear expansion, simple mineralogy of ore, depth of formation (700 meter) and thermometry data, Chah Noghreh deposit seem to be similar to lead-zinc epithermal deposits.

The granitic rocks are divided into magnetite and ilmenite series (Ishihara 1977), coinciding spatially with the I-type (εNdi0; (87Sr/86Sr)i~0.704-0.706) and S-type granites (εNdi<0; (87Sr/86Sr)i~0.708-0.765), respectively (Takahashi et al., 1980). Most porphyry Sn deposits are associated with ilmenite (S-type) granitoids (Ishihara, 1977; Neiva, 2002). The published concepts on the origin and tectonomagmatic setting of Sanandaj-Sirjan Zone (SaSZ) Jurassic granitoids of 178-160 Ma are (1) metaluminous I-type granites formed in a magmatic arc of an Andean subduction system (Khalaji et al., 2007; Tahmasbi et al., 2010; Ahadnejad et al., 2011; Esna-Ashari et al., 2012), (2) subduction-related extensional basin (Shahbazi et al., 2010), (3) continental crust melting by roll-back of Neo-Tethys oceanic crust (Zhang et al., 2018), and (4) subduction-related S-type granites (Bayati et al., 2017). In this research, the origin and tectonomagmatic setting of Jurassic granitoids (from 178 to 160 Ma) in Sanandaj-Sirjan Zone and the tin mineralization potential are investigated based on the available geological, geophysical and isotopic geochemical data.

We used an integrated collection of published geochemical data (major, trace and rare earth elements of 102 samples), isotopic (e.g., (87Sr/86Sr)I of 50 samples, ƐNdi of 64 samples), geochronological (U-Pb dating of zircons), and geophysical data (airborne magnetic intensity) for the SaSZ granitoids of 178-160 Ma.

The SaSz Jurassic granitoids include granite, monzonite, diorite, Syenogranite, tonalite batholiths. The (87Sr/86Sr)I>0.707, N-MORB normalized patterns with enrichment in Low- and High Field Strength Elements (LFSE and HFSE) and depletion in P and Ti contents, chondrite-normalized patterns with flat heavy rare earth elements (HREE) patterns, magnetic susceptibility <10-5x100 (ilmenite series), no alteration, and no Sn, Cu, Pb, and Zn anomalies in whole rock composition of granitoids nor in the associated river sediments, absence of volcanic rocks, and occurrence of metamorphic rocks (slate and schist) during Cimmerian orogeny indicate the SaSZ granitoids are S-type granitoids formed in a continental collision zone.

Geological, geophysical and geochemical characteristics of granitoids in Sanandaj-Sirjan Zone (such as the absence of volcanic arc and volcanic rocks, continental crust thickening (56-52 km) and the formation of large-scale (batholith) granitoids at depths >4 km, regional metamorphism at ​​green schist facies (and amphibolite) following Cimmerian orogeny, low (Eu/Eu)N (reducing conditions), magnetic susceptibility <100x10-5 (ilmenite series), negative εNdi and (87Sr/86Sr)I >0.707) show that, unlike previous studies, these granitoids are S-type granitoids formed by melting the continental crust in a collisional zone. Therefore, tin mineralization might probably occurred in connection with them. However, there is ample evidence of the absence of tin mineralization by the magma that forms these S-type granitoids, that are including the lack of hydrothermal fluids and consequently mineralization potential (due to the absence of alteration minerals in ASTER satellite images), low content of tin, copper, lead and zinc elements in these granitoids Sanandaj-Sirjan Zone and associated river sediments, (Eu/Eu)N value > 0.2, Rb/Sr <3, low Y (10-75 ppm), Ba > 200 ppm, as well as the geological, geophysical and geochemical similarities to barren S-type (ilmenite series) granitoids in Lut block (in Najmabad, Sorkh kuh to Shah kuh areas) which have formed in a continental collision system during the Cimmerian orogeny.

Introduction  :                                                                                            
The study area is located in the Khorasan Razavi Province, NW of Gonabad between 58° 33˝- 58 ° 38˝ to the east and 25° 34˝ - 25° 38˝ to the north. Geotectonically, the area is located in the northern part of the Lut Block. The Lut Block is the main metallogenic province in the east of Iran (Karimpour et al., 2012). There is a significant outcrop of Tertiary intermediate volcanic and pyroclastic rocks in the northwest of Gonabad. This region is rich in clay (kaolin) mineralization. The source of these kaolin deposits (argillic alteration) is related to a granitic dyke that intruded into the Shemshak Formation.

According to studies most of the rocks in this region are volcanic rocks which mainly consist of trachyte, andesite, trachyandesite, dacite, rhyodacite, pyroclastics rocks of agglomerate and tuff and some subvolcanic masses and dykes of acidic to intermediate compositions. Sedimentary rocks in the study area are slightly metamorphosed. The oldest metamorphic rock is exposed in the south- east of the study area which consists of Jurassic slates and quartzite. At this area green schist facies have led to the formation of slate and quartzite. The intrusive bodies, composition are monzogranite porphyry to diorite porphyry. The main fault zones which make specific types of structure are strike-slip.

Alteration and mineralization:

The volcanic and subvolcanic rocks have been affected by hydrothermal fluids via the phenomenon which has caused alteration in the rocks.The alteration zones are propylitic, silicification, argillic, and quartz-sericite-pyrite. The silicification has occurred with higher intensity in the northern and central parts of the investigated area. Propylitic alteration has spread all over the area with higher intensity in the northwest and southern parts of the study area. The clay mineral deposits (argillic zones) have been mined. The mineralogical compositions of this clay deposits are quartz, kaolinite, dickite, montmorillonite and hematite.

Ten doubly polished wafers (0.3mm thick) of fluorite, barite and quartz crystals were prepared for fluid inclusion studies, and examined petrographically. They were studied using standard techniques (Roedder, 1984, 1992) and Linkam THM 600 heating–freezing stage (from -190 to 600 °C) mounted on an Olympus TH4–200 microscope stage at the Ferdowsi University of Mashhad, Iran.The accuracy is estimated to be ±0.2 °C on freezing, ±2 °C below 350 °C and about ±4 above 350 °C on heating. The salinity of the fluids trapped in fluid inclusions is calculated based on the temperature of final ice melting (Tm) and the equation of Bodnar (1993). Densities are calculated using the Flincor software according to microthermometric data (Brown and Lamb, 1989).

Microthermometeric investigations were conducted on 126 fluid inclusions in two types of liquid-rich (L+V) fluids in silicified cap of Rokhsefid and Baghsia kaolin mines. Homogenization experiments revealed a temperature range of 186–326 °C for the studied inclusion. Salinity variations could not be determined because of the small amount of fluids. The homogenization temperature and depth of formation from the first type of inclusions are 186- 256°C and 250 meters, respectively. The second type of inclusions have Th between 275 to 326°C and are 500 meter in depth. Microthermometric study of fluid inclusions on quartz-sericite-pyrite and sulfide- silicified mineralization in Kalatehno indicates that two types of hydrothermal fluids were important in the formation of mineralization. These two types are involved. First, Th between 289- 354 °C, salinity range from 10.86 to 10.98 wt.% NaCl equivalent, and the average depth of about 600 meters. Second, Th between 266- 377°C, salinity ranges from 11.7 to 13.07 wt.% NaCl equivalent, and average depth of about 600 meters. Microthermometric study of the fluid inclusions in fluorite veins were conducted on fluorite, barite and quartz minerals. The results obtained from the fluorites indicate Th between 184- 360°C, and Salinity ranges from 0 to 3.2 wt.% NaCl equivalent. Fluid inclusion studies consisting of quartz veins and quartz- sulfide- copper carbonate in Kalatehno copper mineralization involve two types of fluids with homogenization temperatures and salinity range from 260- 300 °C and 1.5- 3.23 wt.% NaCl equivalent and 193- 240 °C and 4.1- 5.86 wt.% NaCl equivalent.

Fluid inclusion studies on fluorite samples have shown a temperature homogenizations (Th) between 186-326 °C. These studies indicate the average formation temperature of 280°C for argillic alteration. Fluid inclusion studies on Kalateno Cu mineralization show two types of mineralization fluids with the temperatures of 193 to 240 and 260 to 300°C with salinity between 1.5-3.23 wt. % 4.1- 5.86 wt.% NaCl equivalent, respectively. The temperature ranges obtained are similar to those of epithermal systems.

The Robaie copper area is located 95 kilometers South of Damghan in the Semnan province. The study area has coordinates between 54˚30΄37˝to 54˚30΄42.71˝ latitude and 35˚22΄29.41˝ to 35˚23΄47.54˝ longitude. Geotectonically, the study area is located in the central Iran and in the northern part of the Torud-Chahshirin volcanic-plutonic belt (Houshmandzadeh et al., 1978). The Torud-Chahshirin volcanic-plutonic belt is a Tertiary magmatism in central Iran which is composed of volcanic rocks with dominant andesite composition and granodiorite intrusive with dominant diorite composition (Fard et al., 2001). Torud-Chahshirin volcanic-plutonic belt has created a favorable geological situation for base metals such as copper, lead, zinc, gold, silver and other precious and base metals, such as the Robaie copper area, Chah Messi (Cu±Pb-Zn; Imamjome et al., 2009), Kuh-Zar (Cu-Au; Rohbakhsh et al., 2018) and other instances. The main objective of this study is geology, petrography, U-Pb zircon dating and Sr-Nd isotope and also alteration, mineralization, geochemistry and fluid inclusion in the study area.

60 samples were collected from the study area. Petrographic studies were done on 40 thin sections. Mineralization and paragnesis of the system were studied based on 10 polished-thin sections and 6 polished sections. The measurements were conducted on a Linkam THMSG 600 at the Ferdowsi University of Mashhad. REE (ICP-MS method-ACME Laboratory in Vancouver, Canada) elements were analyzed for 3 samples of diorite dykes. Eight  sampels for geochemistry and four samples for fire assay were analyzed at the Zar Azma Company. U-Pb dating in zircon of diorite dyke was conducted by the ICP-MS method in the Arizona LaserChron Center. Sr and Nd isotopic compositions were determined at the Laboratório de Geologia Isotópica da Universidade de Aveiro, Portugal.

The geology of the area is dominated by volcanic rocks (andesite and trachyandesite), which were intruded by diorite dykes. Alteration zones are propylitic, argillic, sericitic and carbonate. The Copper deposit in the study area occurs as ore veins situated along fault zone with NS-SW trending. Vein thickness varies from 1-5m. Vein thickness varies from 1-5m. The primary minerals are chalcopyrite, pyrite and chalcocite, covellite, bornite, malachite, azurite, hematite, goethite and limonite are secondary minerals. The amount of Cu is between 0.01 to 5.6 % and amount of Ag, Sb, Pb, Zn, As elements is low. The homogenization temperature (Th) values ranged from 165 to 300 oC. Salinities of ore-forming fluids ranged from 7 to 16 wt. % NaCl equivalents. Diorite dykes in the Robaie area have characteristics of enrichment in LREE versus HREE, enrichment of LILE and depletion in HFSE. The initial 87Sr/86Sr and 143Nd/144Nd ratios of biotite-hornblende diorite are 0.705664 and 0.512486, respectively. The εNdI value is -1.7. In the εNdI versus initial 87Sr/86Sr diagram diorite dykes of the Robaie area plot to the right part of the mantle array. The mean age of diorite dyke is 50.49±0.49 Ma. Therefore, the U-Th-Pb zircon dating indicates that diorite dyke formed in the early Eocene (Ypresian) era.

Diorite dykes originated from mantle-derived magmas. The parental melt would have originated in a non-depleted mantle source. Isotopic data from diorite dykes show that subduction source with contamination to continental crust. In tectonic setting diagrams (Pearce et al., 1984) diorite dykes plot on the fields of the volcanic arc granites (VAG). In the Dy/Yb vs. Dy system (Shaw, 1970) diorite dykes of Robaie area were formed by 15-20% partial melting of spinel-phlogopite lherzolite. According to Yh/Yb vs. Ta/Yb (Pearce et al., 1984) and Ba/La vs. Th/Nd diagrams (Shaw, 1970) diorite dykes were formed from slab-drive fluid in the active continental margins.Fluid inclusions data of the Robaie area manifest that the ore-forming fluids were medium to low temperature and medium to low salinity. The pressure determined for the Robaie area was approximately < 10 MPa, which is equivalent to a depth of approximately < 1 km assuming lithostatic pressure. Fluid inclusion studies indicate that there is a positive correlation between homogenization temperature and fluid salinity, similar to the process of fluid mixing. The decrease in salinity has been the most important factor in the precipitation of copper in the area. All of evidence shows that mineralization in the Robaie area is of epithermal type deposit.

The investigated area in northeastern Iran that is known as the Tarik Darreh arsenopyrite-Au-W prospecting target is situated in the Kopeh Dagh zone (Fig. 1). Most of the study area is covered with black slate rocks which most authors have referred to as Upper Triassic with Norian age (e.g., Behroozi et al., 1993). Plutonic rocks with gabbro, diorite, and quartz diorite and monzodiorite composition were introduced in the slate rocks. The previous studies in the Tarik Darreh are the preliminary report of arsenopyrite with Au-W quartz lode mineralization carried out by Taghizadeh (1965). Since then, the Geological Survey of Iran (e.g., Alavi Naini and Mossavi-Khorzughi, 2006) a few geologic companies and the universities (Shafi Niya, 2002) and Ghavi et al. (2013) have been studying in the area. In the present study, we provide more information, complete with new information about the geology of the Tarik Darreh area.

Expansive field geology surveying to draw a geology map in 1:8000 scale and sampling from plutonic rocks was performed and two main fault system were distinguished in Tarik Darreh (Figs. 2 and 3). Thin section microscopic studies were carried out following field investigations. Magnetic susceptibility was measured with a portable Model KT-10 and GMS-2 Fugro instrument (precision of 0.0001 SI units).Sixteen samples of intrusive bodies and dykes were analyzed for major and trace elements using 4E-Reserch package (INAA, FUS ICP-OMS, ICP-MS) at the Acme Lab (Canada). Gabbroic units were selected for U-Pb geochronological study. In the heavy liquid process, zircon crystals were separated, hand-picked under microscope. Zircon grains for Th-U-Pb dating were examined by an Agilent 7700 quadrupole ICPMS at the University of Tasmania (Australia).

Plutonic rocks in the Tarik Darreh area are in the form of bodies and dykes. The plutonic bodies are mostly gabbro, gabbro diorite, diorite (hornblende pyroxene diorite, biotite hornblende diorite and hornblende biotite diorite), biotite hornblende monzodiorite, quartz diorite, and quartz monzonite in composition. However, it is diorite with granular textures as a common rock (Figs. 4 and 6). Other rocks as dyke have more hornblende diorite composition with porphyritic textures. Common mafic minerals in the plutonic rocks in the Tarik Darreh include pyroxene, hornblende and biotite. The alteration assemblages of uralite, chlorite, calcite and sericite are very common gabbroic-diorite rocks (Fig. 5). The plutonic rocks have SiO2 with values in the range of 46 to 56% (Table 1). Therefore, these rocks are intermediate in composition.  Most of these rocks also have high K-calc-alkaline composition with metaluminous characteristic (Fig. 7).Enrichment in LREE relative to HREE, low La/By ratio, enrichment in LILE and negative anomaly of Eu, Ti, Zr, Y and Ba are shared in all of the studied plutonic rocks and dykes (Figs. 8 and 9). All the plutonic rocks have low values of magnetic susceptibility (less than 3×10-3 SI). Two main systems of fault have affected the area (Fig. 10). Plutonic rocks from the Tarik Darreh area are placed within the volcanic arc to within plate’s environment in tectonic setting discrimination diagrams (Fig. 11).Zircon U-Pb dating results on the gabbroic rocks are shown in Table 2. Zircon grains through cathodoluminescence imaging show euhedral, clear crystals with no visible heritage cores. However, some of them have inclusions. Zircon U-Pb dating indicates that the gabbroic rocks formed at 215.5±0.9 Ma (late Triassic) (Fig. 12). Thus, it is obvious that the country rock (called Miankuhi Formation), must be older than the late Triassic plutonic rocks rather than Norian age as previously thought.The variation of major elements with SiO2 in the plutonic rocks from Tarik Darreh (Fig. 13) indicates that the primary magma of these plutonic rocks underwent fractional crystallization from gabbro to quartz monzodiorite. Geochemical characteristics such as low ratios of (La/Yb)N (<13), high contents of MgO (7%), high Mg# (57) and high Sr (on average 572 ppm) indicate that the magma of the studied rocks have probably originated from partial melting of garnet-free source from mantle or low continental crust. However, the presence of slate as country rocks suggest possible assimilation of country rocks that indicate processes such as assimilation were more likely to be responsible for the evolution of plutonic rocks in the Tarik Darreh area.

This research study is based on  knowledge-driven approach to synthesize the different parameters which rule on the formation of carbonate hosted zinc and lead deposits. The analysis of available data sets of the north Irankuh district demonstrates the complexity of decision making due to the different anomalous prospects introduced by geophysical, geochemical and surface evidences.Five known deposit/active mines, namely Gushfil, Zone 1 Gushfil, Blind, Tapeh Sorkh and Zone 5 Romarmar with total geological resources quoted as 13.4 million tons at 5.53% combined lead and zinc (Fig. 10) were selected to be examined in order to asset a knowledge-driven approach to the exploration of carbonate hosted zinc and lead deposits. The diversity of geometry, mineralogy and host rock of the deposits is tightly confined by the parameters surrounding the genesis of MVT deposits such as genetics of solutions, temperature of deposit formation, tectonic channel ways, different episodes of deposition of sphalerite and galena, hydrologic system of area, solution direction, wall rock reactions (Leach et al., 2010), depth of solution penetration, solution response to the Magnesian regime and metal bearing.

The present study consists of detailed  underground and surface mapping, reinterpretation of district geology, detailed logging of about 100000 meters’ diamond drilling, ore geology, tectonic settings, deposits geometry, geochemical and geophysical survey within 7 square kilometers of north Irankuh district between the Gushfil and Tapeh Sorkh deposits.

Five known deposits in the north Irankuh district occur in the area of an intense detachment faulting (Fig. 1 and Fig. 5). The Gushfil, Zone 1 Gushfil and Blind deposits occur in north Irankuh reverse fault and Tapeh Sorkh and Zone 5 Romarmar in the trust fault. The deposits are confined to a certain stratigraphic unit locally called K3D (Figs. 2 and 3). Widespread regional selective dolomitization shows an extensive lateral movement from NW to SE and the depth of dolomitization in certain units drastically decreases. Two main regimes of solutions initially started with sphalerite and they were subsequently followed by galena the later of which is found in the secondary porosity. Mineralogy of the deposits is simple but the pyrite amount of the deposits varies from 2% to 20% which reflects the higher temperature of the solutions responsible for sulphide precipitation (Marie et al., 2001), geometry of the deposits and their distance to the current topography effect on chargeability values (Fig. 20).Sparry dolomite is found in three types as barren, with pyrite and light color sphalerite that occur in country rocks of all deposits except for the blind deposits. They can be used as a guide, addressing potential deposits.EPMA analysis revealed a considerable amount of Cadmium, Silver, Antimony, Arsenic and Copper within Sphalerite and Galena minerals (Fig. 12). Because of the semiarid climate in the area the decomposition of sphalerite, galena (Hitzman et al., 2003) and carbonate host rock has caused widespread distribution of Zn, Pb, Ag, Cd, Sb, As, Cu, Mn, Mg, Fe and Ca in the secondary halo of the area. The soil samples have been studied based on the static and machine learning methods (Figs. 13–A and B) by different researchers (Zekri et al., 2019). The anomalous areas based on geochemical studies have been tested by core drilling and the results are considered to be negative even in the area called Zone 3 which coincides with both geochemical and geophysical anomallies. In a different approach to understand the structure of geochemical elements the distribution of Zn, Pb, Ag, Cd, Sb, As, Cu, Mn, Ba together with elements such as Mg, Fe and Ca has been compared (Figs. 14, 15 and 16).The soils are heavily polluted due to widespread mineralization and no background value (Reimann and De Caritat, 2012) can be recognized.The comparative analysis of element concentrations in 5 selected populations in the studied area (Fig. 15) did not show any signs that could help  recognize important anomalies from the false anomaly. However,  it seems that the sudden decrease of Mg content (Fig. 17–C) in the area of Zone 3  (Zekri et al., 2019) is meaningful. Two geochemical profiles of soil samples crossing along this population and the next one crossing an active mine (Zone 5 Romarmar) (Fig. 18) provide us with a better understanding of the important anomalies versus the false anomaly since in the false anomaly the increase of Zn, Pb, Ag, Cd, Sb, As, Cu coincides with a sudden drop of concentration of Mg, Fe and Ca (Figs. 18–A and B). Recognition of ore containing strata (Sangster, 1995) is very important (Figs. 2 and 3) in locating successful drill holes in the exploration of carbonate hosted zinc and lead deposits. Eventually the use of data driven methods even opting advanced machine learning methods is not properly sufficient  to recognize  productive areas and we recommended the knowledge -driven approach.

The Shurk area located in the west of Birjand city is a part of the Lut Block volcanic-plutonic belt. Preliminary prospecting in the area using ASTER satellite data processing in method of spectral angle mapper enhanced propylitic, argillic alteration and iron oxides. The area comprises outcrops of Eocene volcanics, which was intruded by subvolcanic intrusions with gabbro to diorite composition. The vein mineralization was formed in two stages, including: 1) quartz-pyrite-chalcocite-chalcopyrite-bornite-fahlore-sphalerite that are associated with argillic-silicified alteration and 2) quartz-chalcocite-sphalerite accompained with silicified-carbonate alteration. Primary fluid inclusions of quartz in paragnesis with minealization in the first and second stages of vein mineralization, have an average of homogenization temperatures 267°C and 215 °C respectively. Based on freezing studies, the average of final ice melting temperature (Tfmice) equals to 19.4 and 11.1 wt.% NaCl respectively. Mixing, dilution with meteoric water and boiling have been effective during the evolution of hydrothermal fluids and the formation of ore-bearing veins. Based on evidences such as structural control of mineralization, the type of alteration, simple mineralogy of ore and thermometric data, the Shurk deposit is similar to those of epithermal deposits. The presence of numerous Cu veins on a large scale indicates significant economic potential of area.

Jalambadan area is located northwestern Sabzevar, Khorasan Razavi province, and southwestern Quchan-Sabzevar magmatic belt. Geology of the area includes of andesitic-trachyanesitic volcanic rocks, which is intruded by monzodioritic to dioritic subvolcanic intrusive rocks. The texture of igneous rocks is porphyry and the main minerals are plagioclase, alkali fldespar, pyroxene, hornblende, and magnetite. Age of intrusive rocks determined 44.7 to 45.2 Ma (Middle Eocene-Lutetian), using zircon U-Pb method. Geochemically, igneous rocks of the area are calc-alkaline and were formed at subduction zone. Relativelly, enrichment in LREE relative to HREE and enrichment of K, Rb, Cs, and Sr relative to Ti and Nb elements are observed in all of samples. Eu anomaly and Sr/Y ratios can be attributed to the presence of residual plagioclase and a few garnet in a source. (87Sr/86Sr)i (0.703708 to 0.704444), (143Nd/144Nd)i (0.512858 to 0..512933), and εNd I (5.42 to 6.88) values of intrusions and geochemical signatures of volcanic rocks indicate magma is drived from partial melting (7-5% for intrusions and 15-25% for volcanic rocks) of spinel lherzolite mantle wedge above subducted slab, which is assimilated slightly with upper continental crust very little.

The Cheshmeh Khuri area is located in the north of the Lut Block volcanic–plutonic belt, in eastern Iran, about 111 Km northwest of the city of Birjand. Extensive Tertiary magmatic activity in the Lut Block, is spatially and temporally associated with several types of mineralization events (Karimpour et. al., 2012). The episode of Middle Eocene to lower Oligocene (42–33 Ma) was very important in terms of magmatism and mineralization (Karimpour et. al., 2012). The North Khur area includes numerous cases of Cu±Pb±Zn vein-type mineralization, such as the Shikasteh Sabz, Mir-e-Khash, Rashidi, Shurk, Ghar-e-Kaftar, Howz-e-Dagh, as well as kaolin deposit (Cheshmeh Khuri area). We present and discuss alteration, ore petrography, geochemistry, fluid inclusion micro thermometry, and sulfur isotope geochemistry, which help clarify the ore genesis of the Cheshmeh Khuri area. The present study involves detailed field work and study of thin and polished sections from the intrusive rocks and ore samples under the optical microscope. Metal concentrations were analyzed at the IMPRC laboratory of Iran using the ICP-OES techniques on fifteen samples. Five samples were analyzed for Fire Assay analysis and four samples for XRD analysis at IMPRC laboratory of Iran. Twelve spot analyses (microanalyses) were performed on an X-ray Analytical Microscope at IMPRC laboratory. Doubly polished wafers (150 μm thick) were prepared from five samples taken from surface and trenches. Micro thermometric measurements were carried out using a Linkam THM 600 heating–freezing stage mounted on an Olympus TH4–200 microscope stage at the Ferdowsi University of Mashhad, Iran. Two pyrite samples from quartz-sulfide veinlet were analyzed for the sulfur isotope compositions after careful hand picking and purification at Iso–Analytical limited, United Kingdom. The main alterations consists of propylitic, argillic, quartz-sericite-pyrite and silicified. The mineralization is mainly observed as vein and is disseminated in quartz-sericite-pyrite, argillic- silicified and propylitic alteration zones and is disseminated in the argillic alteration zone. Pyrite is the only primary sulfide mineral in the area. Due to the great influence of weathering processes on the primary ore, secondary sulphide and oxide mineralization (malachite, azurite, chalcocite, covellite, goethite, and hematite) are widely spread and have finally created lithocap (Sillitoe, 1993; Sillitoe et. al., 1998). The maximum anomalies of copper (654 ppm) and lead (1622 ppm) are associated with quartz-sericite-pyrite alteration. Primary fluid inclusions of quartz in paragenesis with mineralization in quartz-sericite-pyrite zone, argillic-silicified zone and calcite in paragnesis with mineralization in propylitic zone have an average of homogenization temperatures of 321°C, 305 °C and 263 °C, respectively. Based on freezing studies, the average calculated temperature of last melting point of these is equal to 12, 11.6 and 7.9 wt.% NaCl, respectively. Homogenization temperature and salinity of the fluids shows a shifting trend from relatively high in quartz-sericite-pyrite zone to relatively low homogenization temperatures in the propylitic zone, which can be due to physicochemical changes in the fluid such as cooling and mixing with meteoric water (Naden et al. 2005). According to the textural evidence, boiling has also been effective during the evolution of the fluid. The amount of δ34S for pyrite has a range between 2.35 to 2.46 and the amount of δ34 equilibrium with pyrite has a range of 1.25 to 1.36 that show a magmatic origin for sulfur (Ohmoto and Rye, 1979; Lesage, 2011). The expansion of propylitic and argillic alteration zones on the surface, the limited quartz-sericite -pyrite zone, the absence of potassic alteration, the existence of lithocap, geochemical anomalies, the range of temperature and salinity of the fluid inclusion can be indicative of the upper part of a porphyry copper system.

The Simorgh prospect area is located in 113 km southwest of the Nehbandan in South Khorasan province. This area is part of the Tertiary volcanic-plutonic rocks in the center of the Lut block. The Lut Block, which is located at the eastern part of the Central Iranian Microcontinent (CIM), is famous by its complex tectonic evolution and extensive magmatic activities with a range of interesting geochemistry. Extensive magmatic activities in Lut Block have produced several types of mineralization events (Karimpour et al., 2012). Around the Simorgh prospect area, various mineral deposits, including Cu-Mo porphyry Dehsalm in 90 km southwest of Nehbandan have been reported (Arjmandzadeh and Santos 2013) and Mahoor copper (Miri Beydokhti et al., 2015).
Until now there has not been a detailed studies on the Simorgh prospect area especially on granitoids. In this study, we present field investigations, geology, alteration, mineralization, geochemical exploration, Petrogenesis, zircon U-Pb geochronology and Hf isotopes of sub-volcanic rocks in the Simorgh prospect area. 1- Preparation of 336 thin sections for the study of petrography, alteration and mapping of geological and alteration maps.
2- Preparation and study of twenty-five polished thin sections and thirty-two polished blocks for mineralization studies.
3- Analysis of forty-five chip composite samples in the Zar Azma laboratory by using the fire assay method for Au element and ICP-OES for thirty-four elements. The solubilization method of 4- Acid (1EX) was used.
4- Analysis of one hundred and sixty core samples in the Zar Azma laboratory by using the fire assay method for Au element and ICP-OES for 34 elements (method 1EX).
5- Chemical analysis of seventeen samples of syn-mineralization sub-volvanic intrusive rocks with at least alteration, by ICP-MS for thirty-one trace and rare earth elements with LF100 method (alkali fusion) at the AcmeLabs Laboratory.
6- Separation of three samples from syn-mineralization sub-volcanic intrusive rocks for U-Pb zircon geochronolg by Quadruple Laser-Ablation ICP-MS at the CODES, the Tasmania University of Australia.
7- Analysis of three samples of syn-mineralization sub-volvanic intrusive rocks for Lu-Hf isotopes with multi-collector ICP-MS at the CCFS of Macquarie University of Sydney, Australia. Petrographic studies indicated that the composition of sub-volcanic rocks in the Simorgh area are diorite porphyry and pyroxene diorite porphyry stocks with granite porphyry and granodiorite porphyry dikes. Several alteration zones such as: propylitic, argillic, silicified quartz-sericite-pyrite (QSP) and carbonate-quartz-sericite-pyrite (CQSP) based on field and laboratory studies are identified Major oxides analysis shows that intrusive units are metaluminous to peraluminus, calc-alkaline to high-K calc-alkaline. More of these rocks belong to the I-type granitoid (Chappell and White, 2001), and they have been formed in a volcanic arc granitoids (VAG) tectonic setting (Pearce et al., 1984). Mantle-normalized, trace-element spider diagrams display enrichment in large ion lithophile elements, such as Rb, Sr, K, and Cs, and depletion in high field strength elements, e.g., Nb, Ti, P. Enrichment of LREE versus HREE and enrichment of LILE and depletion in HFSE indicate magma formation in the subduction zone. In the subduction zones, high oxygen fugacity leads to the depletion of Ti. All of the intrusive rocks have a negative Eu anomaly. The amount of Eu/Eu* in sub-volcanic units of the Simorgh area varies from 0.49 to 0.91. Therefore, negative Eu anomaly can be evidence of the partial presence of plagioclase in the origin (Tepper et al., 1993).
Three types of mineralization occur in this area such as: veinlet, disseminated and hydrothermal breccia among which hydrothermal breccia is the most important. Pyrite is the most sulfide mineralization in the sub-volcanic and hydrothermal breccias.
Compositional variations of elements within the Simorgh prospect are as follows: Cu = 2-240 ppm, Mo = 0.5-49 ppm, Zn = 9-935 ppm, Pb = 7-582 ppm, ppm, As = 2-207 ppm and Au = 1-93 ppb.
In the Simorgh area, zircon U-Pb geochronology was carried out on syn-mineralization sub-volcanic intrusive rocks. The age of two granite porphyry dikes are 25.37±0.56 Ma and 25.94±0.76 Ma and the age of pyroxene porphyry diorite is 24.85±0.51 Ma (Chattian). Diorite porphyry is pre-mineralization because it is cut by granite porphyry dikes and pyroxene diorite porphyry, so diorite porphyry is the oldest sub-volcanic intrusive rock in this area. The low positive values of εHf(i) indicate that the origin of these sub-volcanic intrusive rocks is mantle, which has low contamination with the crust.
According to the above evidence, the sub-volcanic units of this area are related to porphyry systems, and the hydrothermal breccias are the main host rock mineralization in this system. This system does not have any valuable mineralization expect pyrite, from the surface to 180 m depth.

Mississippi Valley-Type (MVT) deposits are epigenetic zinc and lead deposits with minor copper hosted by dolostone, limestone, and locally sandstone in platform carbonate sequences inboard of major orogenic belts (Leach and Sangster, 1993; Leach et al., 2010). The Irankuh-Ahangaran Belt, which is the most important Pb-Zn mineralized zone of Iran, is situated within the Sanandaj-Sirjan tectonic zone. This belt is 400 km in length and 100 km in width. Three deposits including Irankuh mininig district, Ahangaran and Hosseinabad deposits were studied in this article (Fig. 1). The aim of this research is study of thermal gradient of subducted slab and age of formation of Pb-Zn deposits at Irankuh-Ahangaran belt, which is contrary information has been published so far on the type and their formation. Also, chemistry of ore-fluid in MVT deposits and impact of dolomitic and shale host rock on paragenesis, alteration, style, reserves and grade of deposits were discussed.These parameters will certainly be useful for exploration of the hidden MVT type deposits in the Irankou-Ahangan belt. Result and Discussion: The Irankuh mineralization is hosted by Cretaceous dolostone and minor Jurassic shale rocks as epigenetic. The constructive thrust fault, which has been cut the Jurassic and Cretaceous host rocks, has played a major role in the rising of fluid and formation of mineralization. Mineralization is occurred as replacement and open space filling (fault breccia, veinlets and cavity of rock) in dolostone and breccia, veinlet and open space filling in shale host rock. The mineral assembelages are Fe-rich sphalerite, Feand Mn-rich dolomite, ankrite, galena, minor pyrite, bituminous, calcite ± quartz ± barite within carbonate host rocks, whereas quartz, pyrite, Ferich sphalerite, galena, minor chalcopyrite, low Fe-dolomite, bituminous, ± barite ± calcite are important primary minerals at clastic hos rocks (Karimpour et al., 2018). The Ahangaran deposit is very similar to Irankuh in host rock, alteration, paragenesis, and form of mineralization. Thrust fault has a constructive role for occurrence of mineralization and later destructive strike slip and normal faults have caused the displacement and destruction of mineralization. The Hosseinabad deposit is hosted by Jurassic shale, siltstone, and sandstone rocks as veinveinlets, breccia and open space filling with structural control. Alteratin consists of silicification, chlorite, bituminous, and minor siderite, dolomite and ankerite similar to mineralization hosted by shale in Irankuh district. The mineral assemblages are galena, Fe-rich sphalerite, pyrite, chalcopyrite and minor phyrotite. Due to the lack of a proper dolostone unit in the Husseinabad deposit, mineralization is concentrated in particular areas with low-grade and low-reserves. Based on lithology, alteration, mineralization style, structural control by thrust faults, mineral paragenesis, and comparison with differnet types of Pb-Zn deposits, all deposits of Irankuh- Ahangaran belt are MVT-type. Deep-seated thrust faults formed during the early stages of subduction (~ 70 to 75 Ma), and played an important role in the upward migration of hydrothermal fluids from the basement to shallow depths. The geochronology of pyrite in Irankuh district based on Re-Os method indicate age of Irankuh Pb-Zn mineralization is 66.5 ± 1.6 Ma (Liu et al., 2019). Since the thrust faults have been cut the Jurassic to Upper Cretaceous rocks, and according to the absoulte age determined in Irankuh, the mineralization of this belt have been formed in the age range of 66 to 56 million years ago, mainly in the Paleocene (Fig. 15). Karimpour and Sadeghi (2018) suggested the hydrothermal fluid originated from the dehydration of a hot and young oceanic subducted slab, which liberated Pb, Zn, and other metals, and may have removed metals from rocks and organic material of the continental crust. More than 90% of all the water within the oceanic slab was released in the depth zone of the forearc region (depth of 30 to 50 km) (Karimpour and Sadeghi, 2018). In the depth zone, Mg-rich silicate minerals (such as antigorite, hornblende, chlorite, talc) have broken and the produced fluid is rich in Mg and Fe (Fig. 17). The ore-fluid of MVT deposits is Si-poor and Feand Mg- rich. Such fluid is mineralized on the hosts of the dolstone (Irankuh and Ahangaran) or Shale-Siltstone (Hossein Abad, and part of Irankuh and Ahangaran). There are significant differences in the type of paragenesis, alteration, shape, dimensions, reserves and grade in the deposits of this belt, which is controlled by the host rock type. Based on all lithological evidence, alteration, shape of mineralization, existence of thrust faults, mineral paragenesis and specific geological and geographic location, it can be used to exploration of the hidden MVT deposits in this belt.

The study area is located in the northeast of Iran (the Khorasan Razavi province) and 28 km northwest of Bardaskan city and in position of 57° 46΄ to 57° 52΄ latitude and 35° 21΄ to 35° 24΄ longitude. The study area is a part of Taknar zone. The Taknar geological-structural zone is situated in the north Central Iranian microcontinental and it is a part of Lut block (Fig.1). Taknar plutonic complex that is situated in the Taknar structural zone is located in the northern part of Iranian microcontinent. Chemical analysis of REE and minor elements of samples of the Bornaward diorites and gabbro’s took place in the ACME Lab. in Vancouver, Canada, by the ICP-MS method (Table. 1). For the Bornaward diorite dating by the U-Pb method, zircon grains of material remaining in the sieve, Bromoform were isolated from light minerals by cleaning and were isolated with a minimum size of 25 microns, and then studies took place in the Crohn's Laser Lab Arizona (Gehrels et al., 2008). Measurement of Rb, Sr, Sm and Nd isotopes and (143Nd/144Nd)i , (87Sr/86Sr)i ratios and ƐNd (T=552), ƐNd (T=0), ƐSr (T=552) and ƐSr (T=0) took place in radioisotope Laboratory, University of Aveiro in Portugal. Geology of study area The study area forms the central part of the Bornaward plutonic complex. This complex is a granitoid assemblage including granite, granodiorite, tonalite and granophyre.tscentral part has been formed by intermediate and basic intrusive rocks such as diorite, quartz diorite and gabbro units (Fig. 2). From the genetic point of view, the intermediate and mafic rocks of the Taknar plutonic complex does not have any relationship with granitoid rocks of this assemblage, and they are related to a similar magmatic phase but are separated from this granitoid assemblage. However, these mafic and intermediate units are older than granitic units at the rim of the complex that are called Bornaward granite. Petrography The main minerals in the diorite and quartz diorite rocks are plagioclase and hornblende and we can see biotite in the quartz dioritic rocks. Quartz exist as tiny grains and anhedral and in the matrix rock. The amount of Quartz in the quartz diorites is 5 to 20%. Plagioclases usually have normal zoning and are highly altered to sericite. Most of the plagioclases were saussuritized. Altered minerals resulted from plagioclase and hornblende are sericite, epidote, chlorite, zoisite and clinozoisite. The main minerals in the gabbro are pyroxene, hornblende, and fine grains plagioclase. Minor minerals in the rocks are apatite, magnetite and other opaque. The main texture of intermediate and mafic rocks in this assemblage is medium granular to coarse grain and especially in the intermediate rocks and gabbro rocks, we can see scattered poikilitic, intersertal, sub-ophitic and porphyroid texture. Geochemistry The area diorite and gabbro is located locate in Tholeiitic and Calc-alkaline series (Fig. 9). Shand index (Al2O3/(CaO+Na2O+K2O)) is obtained under 1.1, in Metaluminous field (Fig. 7) and Itype granite field (Chappell and White, 2001). Based on the TAS diagram (Middlemost, 1985), all the diorite and gabbro samples are located in diorite, gabbro-diorite and gabbro-norite groups (Fig. 6). The diorite and gabbro’s show enrichment LREE and low ascending pattern ((La/Yb)N =1.40-6.12 and LaN =12.26-75.81). U-Pb zircon geochronology Measurement of U-Th-Pb isotopes of the Bornaward diorite zircons of BKCh-03 sample (Table 2) show that its age is related to 551.96±4.32 Ma ago (Upper Precambrian (Neoproterozoic) (Ediacaran) (Fig. 14). Sr-Nd isotopes The ( 87Sr/86Sr)i and ( 143Nd/144Nd)i content of Bornaward diorite and gabbro rocks is located in the range of 0.7038 to 0.7135 and 0.51203 to 0.51214, respectively (Tables 3 and 4). It shows that the diorite and gabbro rocks can be affected by hydrothermal alteration because their (87Sr/86Sr)i is above (Fig. 16). The numeral amounts of ƐNd(T=552) of Bornaward diorite and gabbro are 2.0 to 4.0. Petrogenesis The Bornaward diorite and gabbro rocks show a widespread enriched pattern of Rb, U, K, Pb, La and Th elements than chondrite, while Ba, Ti, Ta, Sr and Nb elements show reduction as a result of fractional crystallization (Fig. 11). The rocks of this complex are formed at the continental margin and VAG environment (Fig. 18) which is related to the subduction of the oceanic crust that exists between the Iranian microcontinent and the Afghan Block. This assemblage with age of Late Neoproterozoic is the result of extensive magmatism in the northern part of the Iranian microcontinent due to Katangahi orogeny event. The similar magmatism in the northern part of the Iranian microcontinent is existing as Khaf-Kashmar-Bardeskan volcanoplutonic belt. Based on the geochemical investigations, the magmatism of these rocks has been tholeiitic and calk-alkaline and have formed the coexistent rocks with I-type granites. Alumina saturation index for intermediate and mafic rocks of Bornaward complex is metalumina. These are medium-K rocks and enriched in the LILE such as Rb, Pb, U and Th while depleted of the Nb, Ti, Ta, Sr and Ba. Therefore, it shows that these rocks have resulted from the mixing by the lower crust. The low (87Sr/86Sr)i Bornaward diorite and gabbro rocks and the numeral amounts of Ɛ0Nd(present) of these rocks from -0.2 to 4.0 show that production of such intrusive masses can be attributed to the source of upper mantle or contaminated lower continental crust. Environment of formation of the intermediate and basic rocks of the Bornaward plutonic complex is active continental margin and volcanic arc environment.

The Firouzeh mine is located in the Northwest of Neyshabour in the Khorasan Razavi province, Northeast of Iran, and eastern side of the Quchan- Sabzevar Cenozoic magmatic arc. Widespread magmatic activity in the Quchan-Sabzevar arc, is spatially and temporally associated with several types of mineralizations such as IOCG, Cu-Au porphyry and Kiruna types (Ghiasvand et al., 2016; Karimpour et al., 2011; Fatehi, 2014; Zarei et al., 2016). The aim of this investigation is to provide an understanding of the geology, alteration, mineralization, geochemistry, fluids evolution and genesis of the Firouzeh mine. Two hundred and fifty thin and polished sections were prepared for microscopic study. Twenty-nine samples were analyzed by X-ray fluorescence (XRF) method at the laboratory of Zar Azma company, Tehran, Iran. Twenty-one samples were analyzed by the X-ray Diffraction (XRD) method at the laboratory of Kansaran Binalood company, Tehran, Iran. Sixty samples were selected for 55- elemental analysis by composition of ICP-AES (Inductively coupled plasma atomic emission spectroscopy) and ICP-MS (Inductively coupled plasma Mass Spectrometry). Moreover, Sixty samples were selected for Au analysis by Aqua Regia Digestion at the SGS Laboratories, Canada. Six doubly polished sections of quartz mineralization were prepared for microthermometric analysis. Homogenization and last ice-melting temperatures were measured using a Linkam THMSG 600 combined heating and freezing stage at the Ferdowsi University of Mashhad. The Firouzeh mine contains various Middle- Eocene subvolcanic rocks as dykes which have intruded into Paleocene-Eocene volcanic rocks. Important altrations consist of silicified, argillic and carbonate among which silicified is the most extensive. Primary minerals are magnetite, specularite, pyrite, chalcopyrite and bornite and secondary minerals are hematite, alunite, covellite, turquoise and limonite. Mineralization has occurred in the cracks and fractures at the surface and in tunnels, mainly as disseminated, stockwork, vein-veinlet and hydrothermal breccia. Geochemical explorations showed anomalies of copper (up to ppm 1074), gold (up to ppb 699), iron (up to over percent 30), cerium (up to ppm 464), lanthanum (up to ppm 227), uranium (up to ppm 243) and cobalt (up to over ppm 10000) that has many similarities with IOCG type deposits (Corriveau, 2007; Zamora and Castillo, 2001; Marschik et al., 2000). Fluid inclusions are relatively simple liduid+vapor types, with homogenization temperature from 147 to 278ºC and average temperature of 203ºC and Salinity containing 5.56 to 17.08 wt. percent NaCl equiv. which has resulted from fluids with KCl, CaCl2, MgCl2 and NaCl compositions. Mixing process between hot and saline fluid with cold and low saline fluid and also, boiling process can caused deposition of elements. Firouzeh mineral deposit has magmatichydrothermal source and is related to tertiary magmatic activities of subduction of Neothetys Sabzevar oceanic crust beneath the Turan crust. Fluid mixing has played an important role for precipitation during mineralization and includes the source of hot and saline magmatic fluids with high contents of metallogenic elements and the mixing with cold and low saline meteoric waters resulting in the formation of deposit (Bastrakov et al., 2007; Simard et al., 2006; Wilkinson, 2001; Beane, 1983). Based on geological characteristics, alteration, mineralization, geochemistry, geophysics and fluid inclusion studies, Firouzeh mine is a great mineralization of iron oxide copper-gold-U-LREE which has similarities to the hematite-dominant section of Olympic Dam IOCG deposit. Acknowledgments: The Research Foundation of the Ferdowsi University of Mashhad, Iran, supported this study (Project No. 3/18303). We would like to thank the Iranian mineral processing research center and laboratories of Zar Azma, Kansaran Binalood, ACME and SGS. We also thank rural cooperation of Firouzeh mine for its liaison in field survey.