جستجوی مقالات مرتبط با کلیدواژه "زمین شیمی" در نشریات گروه "زمین شناسی"

The Cenozoic Urumieh-Dokhtar magmatic arc has characteristics similar to those of Andean-type magmatic arcs. Various types of magmatism occurred in this arc including calc-alkaline and K-rich calc-alkaline magmatism and less of them alkaline magmatism (Shahabpour, 1982). Kerman porphyry copper belt (KPCB) in the southern part of this arc includes two types of granitoids: (1) Jebal Barez-type (late Eocene–early Miocene) associated with minor Cu-mineralization, and (2) Kuh Panj-type (middle Miocene–Pliocene), which is associated with major porphyry copper deposits (Mirzababaei et al., 2016). Kuh-kapout porphyry deposit (Eocene) in the southern part of KPCB is affected by Jebal Barez type granitoids. This deposit has been studied to determine the genesis of magmatism, mineralization and tectonic setting, by the whole rock geochemistry of quartz diorite intrusions, this evaluation is based on trace and REEs geochemistry data.

Regional Geology:

This area is located in the southern part of the Urumieh–Dokhtar magmatic belt and in the Kerman porphyry copper belt. Arc-related magmatism events in this region include Paleocene to Oligocene magmatism and including andesite- dacite volcanic-sedimentary rocks with porphyry texture and quartz diorite intrusions with porphyry texture. In these rocks on the surface, there are intermediate argillic alteration events, and with increasing depth, quartz-sericite-pyrite zone and then potassic and alkali (potassium)-feldspar-sericite-chlorite-anhydrite zone are observed. Quartz diorite rocks include plagioclase and hornblende crystals (about 30 to 40 percent), biotite (10 to 15 percent), and potassium feldspar and quartz. Potassic alteration zone in depth is recognized by hydrothermal biotite, K-feldspar, magnetite and anhydrite. Mineralization in quartz diorite intrusions is more in the form of pyrite, chalcopyrite, and magnetite in association with the potassic alteration zone. Andesite-dacite volcanic-sedimentary rocks and quartz diorite rocks intruded by post-mineralized and barren micro diorite intrusion.

The samples were selected based on field observations and changes in mineralization-alteration rates from the weak alteration section of the quartz-sericite zone. For analyzing trace and rare earth elements, Samples were analyzed by the multi-acid method and used the Microwave Digest. Many of handpick and drill core samples were prepared to form thin sections for microscopic studies

Alteration and mineralization:

In this area, different types of hydrothermal alteration events including potassic, phyllic, propylitic, argillic and K-feldspar- chlorite- sericite, occurred that was influenced by fractures and faults. Quartz diorite intrusive rocks shows intense potassic and phyllic alteration zone, the main type of hydrothermal alteration zone is potassic and contains quartz ± chalcopyrite ± pyrite ± magnetite as mineralized veins and scattered event of pyrite, chalcopyrite, and magnetite. The phyllic alteration zone includes pyrite, which increases with depth. In the quartz-sericite-pyrite alteration zone, abundant chlorite and plagioclase are observed in the groundmass along with the occurrence of pyrite and anhydrite, and Cu mineralization in the form of scattered chalcopyrite.

Whole rock chemistry:

In this study, it seems that due to the presence of phases such as garnet and hornblende in the magma in the origin, a fractionation between HFSEs and LILEs has occurred (Green, 2006). Remaining of HFSEs and HREEs in the origin lead to low amounts of these elements in the resulting magma. The occurrence of negative anomalies in these elements, on the other hand, can be due to crustal contamination with mantle magmatism during their ascent to the surface. Anomaly in trace elements and ratios of REEs and trace elements, emphasizes that magmatism originated from the volcanic arc and subsequent events, according to the Th/Nb-Ba/Th diagrams and the La/Sm-Sm/Yb diagram, including the presence of lower crustal contamination and the significant role of fluid in the production of metasomatized magmatism. According to the studies on data normalized to the primary mantle, a depletion in Ba and Nb values and an enrichment in Rb and Cs have occurred.

Studying trace and rare earth elements in porphyry copper deposits is useful for determining the mineralization and fertility of magmatism, tectonomagmatism-setting, crustal contamination, and mantle metasomatism. Th-Co diagram (Hastie et al., 2007) and Th/Yb-Ta/Yb diagram (Hastie et al., 2007) indicate that most of the samples in this study area were plotted in the calc-alkaline magma region of the diagrams. Using the Sm/Yb versus La/Sm diagram (Aldanmaz et al., 2000) in the quartz diorite rocks shows a magmatism with higher Sm/Yb ratios than what is usually found for the spinel lherzolite. The plotting of the samples on diagrams indicates that the samples are located near the spinel + garnet lherzolite trend, indicating that the early magmatism originated from the spinel + garnet lherzolite mantle. High values of Ba/Th compared to low values of Th/Nb emphasize the contamination of subducting material or lower crust with magma; the (Dy/Yb)CN-Sr/Nd (Kelemen et al., 2003) diagram indicated that the process of fractional crystallization of plagioclase was effective in the evolution of magma; and finally, the study of samples in this deposit shows the relatively high water content in the magmatism, associated with the presence of garnet in the source and magma contaminated with the lower crust (Temel et al., 1998). In order to investigate the tectonic environment of the deposit, the diagrams of Pearce et al. (1984) were used. The samples are located in the active continental margin and associated with collision magmatism.

analysis of the trace and REEs of the quartz diorite rocks in the region, a magmatism related to the arc with the calc-alkaline series can be recognized. In terms of the evolution of magmatism, according to the interpretation of trace element data, from the origin to the surface, it can be considered a magmatism that originated from the partial melting of magma with the metasomatized spinel + garnet lherzolite composition in the source with the presence of garnet and amphibole phases. In terms of geochemical properties magmatism is more similar to Kuh-Panj type granitoid than the Jabal Barez type; and it is placed in the category of semi-economic to economic magmatism. Based on studies of trace elements from whole rock data, the tectonomagmatism of the rocks in the region is in the range of the active continental margin to collision setting.

Zircon is a significant mineral due to its ubiquitous occurrence, chemically resistant and refractory, that can survive both weathering and transport processes as well as high-temperature metamorphism and anatexis (Ballard et al., 2002). It can, therefore, be found in many igneous, metamorphic, and sedimentary rocks and is particularly common in plutonic rocks. Zircon acts as a valuable archive of geochemical information regarding geochronology studies (Hoskin and Schaltegger, 2003), a record of the parent rock oxygen isotopic ratio (Hawkesworth and Kemp, 2006), provide a proxy for processes such as crustal recycling by Hf isotopic composition (Scherer et al., 2007), reflect the oxidation state of parent magma by Ce and Eu anomalies (Trail et al., 2012), and temperature estimation by Ti content (Hofmann et al., 2014).The Sangan mining district, the largest skarn iron ore district in Iran, is located in the northeastern part of the Alborz Magmatic Arc. Fourteen skarn anomalies occur along the contact of the syenite to the syenogranite Sarnowsar pluton in the north and the Sarkhar and the Bermani plutons in the southeast (Mehrabi et al., 2021).Previous works have used the zircon U–Pb geochronology, whole rock geochemistry, and zircon chemistry to constrain the emplacement age, fertility of magmatism, and petrogenesis of these granites (Malekzadeh Shafaroudi et al., 2013; Golmohammadi et al., 2015; Mazhari et al., 2017; Mehrabi et al., 2021; Ghasemi Siani et al., 2022), but neglected the importance of zircon trace element concentrations when interpreting the parental magma evolution. Here, we examine the trace elements of zircons from Sarnowsar and Sarkhar-Bermani intrusions, to verify the origin of these zircons and the evolution of the parent magma.

Regional Geology:

The oldest rocks in the Sangan mining district include weakly metamorphosed Precambrian slates and metasiltstones. The Lower Jurassic Shemshak Formation consists of chert, weakly metamorphosed and metasomatized shale, siltstone, and red sandstone. The Middle Jurassic rocks are characterized by limestones and marls of the Dalichay Formation. The overlying Upper Jurassic Lar Formation composed of limestone, dolostone, and dolomitic limestone. Cretaceous formations are dominated by massive limestone, conglomerate, and intercalated crystal tuff. These metasedimentary formations are uncomfortably covered by the intermediate to felsic volcanic rocks crosscutting by plutonic rocks. Intermediate to felsic volcanic rocks cover an area of 10 km2 in the southwestern part of the Sangan mining district and extended within central ore bodies. Volcanic rocks include dacite, andesite, rhyolite, latite, and their pyroclastic equivalents.

Zircon from Sarkhar and Bermani granitoids were analyzed at the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, using a laser ablation system, ICP-MS instrument (Agilent 7700a ICP-MS instrument). Also, samples from Sarnowsar granitoids were analyzed at the Nanjing Hongchuang Geological Exploration Technology Service Co. Ltd., China. Zircons were analyzed for trace elements using a laser energy density of 3.6 J/cm2, a spot size of 30 μm, and a repetition rate of 5 Hz.

Analytical data of zircon trace element concentrate are presented in the supplementary Table. Results are plotted against the 206Pb/238U date for each zircon grain. Zircons from the intrusions have scattered geochemical signatures that show no correlation with U–Pb dates. Conversely, some geochemical parameters of zircons from the intrusive rocks show distinct temporal trends. For example, zircon Yb/Dy and Ce/Nd values broadly increase with age younging. It should be noted that the Th/U and Ce/Nd of the Sarnowsar zircons are higher than those of Sarkhar and Bermani intrusions.

Correlations between rock type and the trace element compositions of zircon from a wide range of igneous rocks can be illustrated with a series of discriminant plots. For example, plots of Nb vs. Ta, Y versus Yb/Sm, and Y vs. Ce/Ce* and similar plots (Belousova et al., 2002) indicate that the studied zircons are classified as granitoid igneous type as a parental magma. The uniformly high Hf contents of zircons in this study point to their crystallization derived from a more evolved felsic magma, particularly Sarkhar and Bermani intrusions. The accompanying low Eu/Eu* ratios are indicative of plagioclase crystallization. The U/Yb ratio of zircons can be used to distinguish their origin (Grimes et al., 2015). Continental-arc zircons have U/Yb ratios mostly between 0.1 and 4, and low U/Yb ratios (<0.1) are characteristic of zircons derived from a mantle source. In the discrimination diagrams of U/Yb vs. Hf and U vs. Yb, all the obtained data are plotted in the continental-series area and are distinguishable from ocean crust zircons. In the U/Yb versus Nb/Yb diagram, both the whole-rock and zircon compositions show the characteristics of a magmatic-arc array. Overall, a continental-crust source for the zircons, mirroring the origin of the parent magma. The disparate geochemical behaviors of Hf, Th, and Nb within zircon provide a potential method for establishing the tectonic setting of host magma. The Nb content of arc magmas is depleted relative to magmas formed in within-plate settings (Pearce and Peat 1995), and as such, arc zircons possess lower Nb/Hf and higher Th/Nb ratios at a comparable degree of magmatic fractionation. Accordingly, bivariate discrimination diagrams of Th/U vs. Nb/Hf and Th/Nb vs. Hf/Th are meaningful tools for distinguishing within-plate (anorogenic) from arc-related (orogenic) settings (Hawkesworth and Kemp, 2006). The majority of zircons are plotted in the orogenic field, signifying a magmatic-arc or orogenic setting and a calc-alkaline parent magma.

Based on the trace-element composition of zircon grains, whole-rock trace-element contents, and patterns of two granitoid intrusions in the Sangan mining district, the following conclusions can be drawn:- The disparate geochemical behaviors of U, Hf, Th, and Nb indicate a continental-crust source in a magmatic-arc tectonic setting. All of the studied zircons are located in the granitoid igneous rocks fields with a series of discriminant plots.The studied zircon grains of the Sarnowsar show relatively high Ce4+/Ce3+ ratios, pointing to their formation in an oxidized magmatic medium.

The study area is located in the central part of Urumieh-Dokhtar Magmatic Arc and south of Mamouniyeh, Iran. Oligocene-Miocene intrusive rocks have combined domain of gabbro, diorite and monzonite with calc-alkaline nature which have characteristic features of continental margin subduction zones. Extensive siliceous, propylitic-chlorite, sericitic, argillic, carbonate and tourmalinization alteration be seen which mineralization has occurred mainly in siliceous zones in the sulfide-oxide veins form. Chalcopyrite, pyrite, bornite, magnetite, Specularite and Ti-oxides are main minerals of the hypogene stage and chalcocite, covellite, azurite, malachite, chrysocolla, tenorite, hematite, goethite and limonite related to supergene-oxidation stage. The study of 138 fluid inclusions in ore-bearing silica veins shows homogenization temperature from 80-345°C, salinity 0.88 to 11.40 wt% NaCl and formation depth between roughly 1 km and 500 m compared to the water table and the hydrostatic pressure is 10 MPa. Evidences such as fluid inclusions with different liquid-vapor ratios, accompanying vapor-rich fluid inclusions, quartzes with comb-cokade texture, fine-grained muscovite and illite indicate gentle boiling of fluids which together with other evidences such as the and partial mixing of fluids and the instability of sulphide complexes have caused the deposition of copper minerals related to the low sulphidation epithermal mineralization system in the Mamouniyeh.

The ​​Karat iron deposit is located in the vicinity of Sangan mining district, in the Northeast of Iran. The basement rocks of the Karat area include hornfels, metamorphosed limestone, marble, sandstone, siltstone and red shale with interlayers of marl, shale and marl, thick-layered red conglomerate and alluvial deposits. The intrusion of a granite batholith in the sedimentary units of the Karat iron deposit has led to the formation of iron deposits in the margin of this batholith. The most important ore minerals include magnetite, hematite, goethite, limonite and a small amount of sulfide minerals such as pyrite and chalcopyrite. Geochemical data indicate a strong correlation between the Ni, Mg, and V to Fe in mineralization zone, which indicates the magmatic origin of the Karat iron deposit. In order to investigate the characteristics of the ore-forming fluid of the skarn Karat iron deposit fluid inclusions of quartz veins were analyzed. The results show that fluids are mainly (L+V) type, low to medium salinity (4.48 to 16.42% NaCl) and the homogenization temperature of 200 to 390 degrees Celsius. Mineralogical, geochemical, and fluid-inclusion data show that the magmatics, meteoric and metamorphic fluids are responsible for Fe-mineralization in the skarn and Isothermal mixing and surface fluid dilution are main evolution factors in mineralization fluids. It seems that the main phase of mineralization has been occurred during the retrograde stage skarn.

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.

The Tatros kaolin deposit (southwest of Dansfahan, Qazvin Province) is a product of the alteration of rhyodacitic volcanic rocks of the Middle Eocene age. Mineralogical studies show that kaolinite and quartz are the main mineralogical phases and illite, rutile, pyrophyllite, dickite, alunite, and chlorite are accessory mineralogical phases of this deposit. The decrease in the chemical index of alteration (CIA) and the increase in the ratio of (SiO2+Fe2O3+MgO+CaO+Na2O+K2O)/(Al2O3+TiO2) from the center to the outside in the studied profile indicates the existance of alteration and hydrothermal zoning in this  deposit. The distribution pattern of rare earth elements (REE) normalized to chondrite indicates the strong diferentiation and enrichment of light rare earth elements (LREE: La-Eu) related to heavy rare earth elements (HREE: Gd-Lu) and the occurrence of strong negative Eu and Ce anomalies in the studied kaolin samples. Calculations of mass changes assuming Ti as an immobile monitor element show that kaolinitization of rhyodacite rocks is accompanied by enrichment of elements of Al, Sr, Zr, Hf, Ta, Nb, U, Th, Y, La, and Pr, leaching-fixation of Sm, Nd, and HREE, and depletion of Si, Fe, Mg, Mn, Ca, Na, K, P, Rb, Cs, Ba, Pb, V, Cr, Zn, Eu and Ce. The obtained results reveal that the behavior of elements during the development of kaolinitization processes is controlled by factors such as changes in pH and temperature of fluids responsible for alteration, residual concentrations, surface absorption, scavenging by metalic oxides, and the presence of mineralogical phases resistant to alteration. The occurrence of negative Eu anomaly during kaolinitization indicates the destruction of plagioclase by high-temperature hydrothermal fluids. The presence of diaspore, dickite, and pyrophyllite, the enrichment of LREE related to HREE, the differentiation of HREE from each other, and the occurrence of strong negative Ce anomaly in the studied samples clearly suggest the role of hypogene processes in the development and evolution of the Tatros kaolin deposit. Other evidence such as strong positive correlations (La/Yb)N-LOI and P2O5-LOI along with the values of some geochemical parameters such as Ce+La+Y, Nb+Cr, Rb+Sr, and Y/Ho support this idea.

Razgah, Kalibar, and Bozghosh intrusive rocks, located in East Azarbaijan province, are among the most important alkaline nepheline syenite rocks known in Iran. Several theories reported regarding the geochemical characteristics as well as the geotectonic environment of the Tertiary igneous rocks exposed in the Ahar-Arasbaran belt (Jamali et al., 2012). Some workers have considered the magmatism of this belt as an important extensional phase of the late Cretaceous, while, some others believe it is related to subduction zones. Although the mineralogy, petrology, geochemistry, and petrogenesis of these rocks have been studied by several people (i.e., Esmaeili, 1997; Ameri, 2004; Ashrafi, 2009), in none of them the origin and geotectonic setting of the area has been discussed in detail. Thus, for the present study, mineralogical, petrological, and geochemical studies are applied to understand the origin, the petrogenesis, and the geotectonic setting of the intrusive rocks from the nepheline syenite exploration areas, particularly the Razgah intrusive rocks.

 Regional Geology:

The Razgah intrusive. a part of the Western Alborz-Azarbaijan zone lies on the southern edge of the Ahar-Arasbaran volcanic belt. Geologically, the Eocene volcanic rocks cover the Jurassic-Cretaceous flysch is intruded by the Oligo-Miocene plutonic rocks (Mahdavi and Fazli, 2008). The Razgah nepheline syenite intrusive intruded the sediments of evaporate basins including gypsum marl, limestone marl, sandstone, and the Miocene conglomerates. Their contact with previous rocks has vanished due to weathering and erosion of itself and the Quaternary sediments surrounding it. Copper mineralization (malachite and azurite) can be identified in the western part of Razgah intrusive. In addition, a number of dykes are distributed especially in the western and northwestern parts. Also, numerous silica veins were observed in different parts, mainly along, in parallel, and in contact with dykes, more widespread in the western part.

Following the sampling (150 rock pieces) and preparation of 70 thin sections for petrographic and mineralogical investigations, trace and REE were determined on 93 samples using the ICP-MS method.

Petrography:

The Razgah intrusive rocks are dominated by olivine-bearing nepheline gabbro, nepheline monzosyenite, pseudolucite syenite, and K-feldspar nepheline syenite. Also, basic dykes (lamprophyre), similar to their host (altered syenite nepheline), syenite and microsyenite dykes and finally altered dykes with siliceous and mineralized veins are present. Nepheline, pseudolucite, potassium feldspar, plagioclase, clinopyroxene, and olivine are among the most important major minerals. Apatite, zircon, and iron-oxide are the minor while chlorite, calcite, adularia, and hematite along with sericite, epidote, kaolinite, and biotite present as secondary minerals. Granular and porphyroid textures, as well as poikilitics, graphics, and replacements (causing pseudomorphous forms), are the common textures of the rocks under study. Lamprophyre dykes with porphyry texture and olivine, pyroxene, and Kaersutite (brown amphibole) are present. The other dykes, to some extent, have similar mineralogical characteristics as nepheline syenites, in which clay minerals occur.

The Co and Th contents, the amount of Ce/Yb, Ta/Yb, and Th/Yb ratios along with low TiO2 content point to the nature of the parent magma as a high potassium calc-alkaline type (shoshonite). The pattern of REE, LILE, and HFSE, the negative Nb, Ti, and HFSE anomalies as well as Pb and LILE positive anomalies, indicate the mantle metasomatism process or continental crust contamination occurrence (Rollinson, 1993; Soesoo, 2000). In addition, the decrease in P solubility with the high level of K and REE gave rise to the separation of apatite from the parent melt (Green and Adam, 2002). The similarity of REE patterns indicates the same magmatic processes involved in the generation of the rocks under study. The mineralogical and geochemical data on Razgah intrusive rocks and the associated lamprophyres point to 1% partial melting of a spinel lherzolite source. Based on the presented tectonic model, following the Arabian plate subduction beneath the Iranian plate, several processes including the slab breakoff, extensile regime, magma formation from the enriched mantle, and subducted slab melting took place which followed by crystal fractionation and contamination at the base of the crust and finally differentiated melts intruded the high levels. As the gases release, the lamprophyre dykes injected into the fractured roof and the other dykes crosscut the Razgah intrusive rocks.

The late Triassic metabasites in the southeast of Borujerd area in the middle part of Sanandaj Sirjan zone (SaSZ) are associated with marble and locally intersected by mafic dykes. Metabasites rocks are metamorphosed in the lower green schist facies and are mainly composed of plagioclase and amphibole. However, they locally preserve ophitic and porphyritic igneous textures. The electronmicroprope analysis showed that feldspars are albite, oligoclase and anorthoclase. Also, according to this analysis, type of amphiboles is calcic and includes actinolite, actinolite-hornblend, magnesiohornblend and tschermakit-hornblend to tschermakit. According to geochemical studies, these rocks have alkaline magmas characteristics. The chondrite normalized REE patterns show enrichment in LREE and the Primitive-Mantle normalized multi-element patterns show uniformly enriched LREE, Th, Nb, Ta. These characteristics are similar to those of basalts derived from OIB-like mantle sources. Trace-element ratios, including Ce/Nb (1.22– 2.20), Hf/Nb (0.08–0.2), Zr/Nb (3.63–6) and high TiO2/Yb and Nb/Yb ratios, indicate that these magmas were derived from a deep OIB reservoir, i.e. an enriched asthenospheric mantle source. These rocks underwent slight crustal contamination. These geochemical characteristics of these late Triassic metabasites suggests that they formed in an intra-continental rifting regime.

The geochemical separation pattern and environmental behavior of rare earth elements (ΣREE) have been investigated in 5 different sedimentary systems related to the Dar-e-Allo copper mine. For this purpose, the total concentration and sequential patterns of ΣREE elements were determined using multi-acid digestion and mBCR (Modified Community Bureau of Reference, European Commission) selective extraction method. The normalization patterns of the total concentration of ΣREE are drawn based on the average North American Shale Composition (NASC) and Upper Continental Crust (UCC). General trends of concentration changes in the five sedimentary systems are very similar to each other, and the concentration of LREEs is higher than that HREEs, just a sample taken from under the rock dump that contains sulfide-leached elements shows a pattern different from other samples and standard patterns. Opposite of the changes in the concentration of ΣREEs, more enrichment is seen in HREEs compared to LREEs. This pattern of enrichment changes is consistent with the higher tendency of HREEs than LREEs for mobility during weathering and oxidation. The geochemical separation patterns of ΣREEs in natural sediment and samples containing iron and manganese oxides are mainly dominated by the residual fraction. Surprisingly, considering the different conditions of formation and stability in the samples taken from the waterways leading to the mine, evaporite deposits and sediments washed from the rock dump, the separation pattern of ΣREEs is controlled mainly with two parts soluble in Acid and reducible fraction. According to the enrichment trends, the trend of mobility and bioavailability from LREEs to HREEs increases with an upward slope. These results show that speciation, geochemical separation pattern and environmental behavior for ΣREEs without considering key environmental factors lead to a lack of understanding or even misinterpretation. The results of this study can be used as a reference in organizing the mine development and environmental planning of the Dar-e-Allo copper mine.

The aim of this research is to investigate the primary mineralogy and the type of diagenesis systems in the south-west of Lorestan based on elemental geochemistry. The Talezang F ormation is formed in this section with a thickness of 84.5 meters and the predominant lithology is limestone and sandy limestone. From this section , 20 samples were selected for EDS and EPMA analysis. The change trend of Sr element to Na compared to Mn showed that the studied samples are in the range of Gordon aragonite limestones of Tasmania . Also, the trend of changes of Mn element against Sr in the studied samples showed that are in the same range as the primary mineralogy of the aragonite of the Mo zdooran Formation, which is a proof of the aragonite mineralogy of the primary limestones of the formation. The high ratio of strontium to manganese (average 63.70) strontium to calcium (average 21.01), low amounts of iron elements (average 1.75 ppm) manganese (average 24.70 ppm), the high concentration of Sr (average of 750.35 ppm) in the studied samples and the plotting of Sr / Ca values ​​against Mn , Mg, Fe indicate a closed to slightly open diagenesis system with exchange of water to rock bottom. (W/R) is for carbonates of Talezang Formation. The relatively open diagenesis system in this formation can be due to the influence of atmospheric fluids due to the presence of an erosional discontinuity that is at the top of the Talez ang Formation.

The Mazraeh manganese deposit (southwest of Maku, north of West-Azarbaidjan Province, NW Iran) is developed in the form of scattered lenses at the contact of pillow basalts and pelagic limestones, belonging to the Khoy-Maku ophiolitic complex. Mineralogically, the ores mainly contain pyrolusite, psilomelane, manganite, and braunite which are accompanied by lesser amounts of hematite, goethite, quartz and calcite. The distribution pattern of REE normalized to chondrite along with some geochemical parameters related to lanthanides, such as La/Ce, (La/Nd)n and (Dy/Nd)n, show a hydrothermal origin for this deposit. This idea is supported by some geochemical diagrams (Co/Zn vs. Co+Ni+Cu, Zn-Ni-Co, and Mn-Fe-[(Co+Ni+Cu)]×10) and elemental ratios such as Mn/Fe, SiO2/Al2O3, U/Th, and Co/Zn. The high concentration of lanthanides in ores (on average of 767 ppm), compared to known hydrothermal manganese deposits, reveals the effects of diagenetic processes on this deposit. The occurrence of negative anomalies of Eu and Ce indicates the low-temperature hydrothermal fluids, responsible for the mineralization. The presence of detrital materials in the ores can be inferred by the concentration values of oxides like Al2O3 and TiO2.

Intrusive rocks are exposed in southwest of Naqdeh in the Sanandaj-Sirjan zone, northwest Iran. There are mafic-intermediate appinitic rocks with calc-alkaline affinity. The accompanying granite is strongly evolved with the affinity of calc-alkaline and rich in potassium. The geochemical analysis of appinite and granitic rocks display LREE enrichment relative to HREE, enrichment of LILE elements, and negative Th and Nb anomalies. According to discrimination diagrams, appinite and granite rocks formed in the continental arc tectonic setting. The appinitic rocks have a lithospheric mantle with subducting slab fluids source. The granitic rocks have an asthenospheric-lithospheric mantle with metagreywaky continental crust contamination. We suggest that appinitic magma formed by roll-back of subducted Neo-Tethys oceanic lithosphere and granitic magma formed by breck-off the subducted Neo-Tethyan oceanic slab. The asthenospheric upwelling would also have provided enough heat for the partial melting of continental crust. It is possible that magma formed at a great depth and underwent a long period of fractional crystallization. Finally, evolved granitic rocks have been placed at a shallow depth of the crust.

The Aralan intrusion is located about 35 Km southwest of Marand in northwestern part of the Central Iran. This intrusion is composed of Codomain granitoid rocks that intruded into Precambrian Kahar Formation. The composition of the intrusion varies from Alkali feldspar granite to granite and mineralogically includes quartz, alkali feldspar, plagioclase, zircon and opaque minerals. These rocks display granular, perthitic, granophyric and myrmekitic textures. Evidences such as decreasing in grain size, cracking, fracturing, twin bending, kinking, recrystallization and myrmekitization indicate the role of shear zone in the study area, which has partly caused some deformation in the study rocks. This intrusion, based on textural evidence, is a hypabyssal intrusion and probably emplaced at low level crust. The study rocks have hypersolvus to transsolvus alkali feldspar textures, calc-alkaline to high K calc-alkaline affinity, high LILE+LREE and low HREE. Comparing with the standard spider diagram pattern for several tectonic setting, the Aralan intrusion is compatible with post-collision and within-plate tectonic setting. The study rocks belong to the A2-type subgroup of A-type granitoids. The Aralan intrusion is associated with tensional phase after finishing the compressional phase of Pan-African orogeny.

Study area is located in Eastern Azerbaijan province, 27 km far from east Bostanabad, and the north of Qarehchaman geological map. According to field tracking and surveys, host rock of mineralization is a Subvolcanic rocks of Oligocene period. Based on microscopic studies, the most important of supergene part, containing primary oxide minerals (Magnetite), secondary oxide minerals (Malachite, Hematite and Goethite) and also sulphide minerals such as Chalcocite, Covellite, Pyrite and insignificance Chalcopyrite. Among the most important alterations, argillic, silicification, carbonization and propylithic can be noted. Geochemical studies shows that host rock of mineralization with Monzosyenitic composition, placed in high chalc-alkaline to shoshonitic and metaluminous range. Formation environment of host rock of mineralization is a volcanic arc of subduction zone that confirmed by normalized rare earth elements diagrams.

The Balestan iron deposit is located about 55 km southeast of Urmia city. The main host rock is the quartz sericite schist unit of the Early Precambrian age. Major mineralization occurred along the schistocytes of the host rock. However, open space filling structure is also abundantly observed in the fault zones. Based on field evidence and microscopic studies, the dominant iron mineralization is in the form of magnetite, which is observed along with pyrite and chalcopyrite. Geochemical investigations revealed that the distribution patterns of trace elements and major oxides are very similar to other hydrothermal iron deposits. The microthermometric studies of fluid inclusions shows an average homogenization temperature and salinity of about 276°C and 7.3 wt% NaCl equivalent, respectively.The variation trends in salinity and Th of fluid inclusions can be explained by a cooling and pressurization of ore-bearing fluids. Also, these data show that the Balestan iron ore deposit is located within the field of mesothermal ore deposits.

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.

Kalateh Pialeh prospect area is located in the Kopeh Dagh zone, approximately 15 km northeastern of Esfarayen city. The area is composed of sedimentary rocks deposited during the Jurassic, Cretaceous, and Tertiary periods, which include microconglomerate, dolomitic limestone, sandy limestone, limestone, conglomerate, and marl. Mineralization occurs as epigenetic deposits hosted by dolomitic limestone and limestone. Two mineralization stages were identified. The first stage consists of a pyrite-galena-sphalerite assemblage with replacement and breccia textures, and the second stage comprising a galena-sphalerite assemblage with vein-veinlet, open space filling, and replacement textures. Dolomite and calcite are the most abundant gangue minerals associated with lesser amount of quartz and barite. Main alterations consist of calcitization and dolomitization. Galena mineral exhibits maximum geochemical anomalies of 1843 ppm for zinc, 7 ppm for arsenic, and 11 ppm for copper. Microthermometric studies on primary fluid inclusions (LV) reveal homogenization temperatures ranging from 180°C to 265°C for stage 1, and from 167°C to 214°C for stage 2. Salinities for these stages were found to be between 7.8 wt.% to 14.5 wt.% NaCl equiv., and 11.7 wt.% to 12.2 wt.% NaCl equiv., respectively. Based on evidence such as structurally controlled mineralization, the type of alterations and their linear expansion, simple mineralogy of ore, geochemistry, and fluid inclusion data, Kalateh Pialeh prospect area is similar to lead-zinc epithermal deposits.

The Gano bauxite deposit is located 90 km northeast of Semnan city in the eastern Alborz Mountains, northern Iran. The bauxite ores occur as stratiform discrete lenses with a length of 6 km and thickness of 2–20 m along the contact between carbonates of the Elika Formation and shale, sandstone, siltstone, and coal of the Shemshak Formation. Mineralogical analyses revealed that the bauxite ores consist of diaspore, hematite, kaolinite, chlorite, anatase, illite, zunyite, goethite, quartz, and dolomite minerals. Fluctuations of the groundwater table level, acidic atmospheric waters, and an increase in pH of the weathering solutions close to carbonate bedrocks played an important role in the concentration of Fe-poor ores in the upper parts and Fe-rich ores in the lower parts of the studied profile. An increase in oxidation, the possible presentence of secondary phosphate minerals, fluctuations of the groundwater table level, and the role of carbonate bedrock as an active buffer played an important role in the extent of Ce anomaly in the ores (0.79–12.25). The pH variations of weathering solutions, fluctuations of the groundwater table level, the role of carbonate bedrock as a geochemical barrier, and simultaneous precipitation of Fe-bearing minerals and preferential scavenging of LREE(La–Eu) by hematite played an important role in the distribution and fractionation of rare earth elements in the bauxite ores. According to geochemical considerations (Eu/Eu* vs. TiO2/Al2O3 and Sm/Nd bivariate diagrams), the Gano bauxite deposit probably derived from the weathering of intermediate igneous rocks.