جستجوی مقالات مرتبط با کلیدواژه « سیرجان » در نشریات گروه « زمین شناسی »

The main aim of this paper is to identify the formation environment and the physicochemical conditions of chlorite minerals in Dalayon area by their mineralogical and geochemical features (Ciesielczuk, 2002). The geochemical characteristics, mineralogical and formation mechanism of granitic rocks can be investigated using the biotite hydrothermal alteration to chlorite (Morad et al., 2011). The temperature data obtained from chlorite geo-thermometry can be compared with the data obtained through fluid inclusion (Cathelineau and Nieva, 1985; Kordi and Shahrokhi, 2021; Shahrokhi, 2021).

Regional Geology:

Dalayoun area is located in the east of Drood city and is a small part of Sanandaj-Sirjan metamorphosed zone. Lithologically, the oldest units belonging to the Upper Triassic-Jurassic and are including a relatively uniform sequence of slate, schists with siliceous veins and veinlets, and cordierite and sillimanite mica schists along with black hornfelses and metamorphosed sandstones. (Shahrokhi, 2002).

In order to study the mineralogical and geochemical composition of chlorites in the area of study, 10 thin-polish sections were studied. In addition to, chemical analyses of 10 samples by XRD method and 20 points by EPMA of chlorite mineral as well as the study of the fluid inclusion on 3 quartz mineral samples were carried out. The structural formula was calculated based on 14 oxygens for chlorite.Petrography, Mineral chemistry, Whole rocks chemistryThe intrusive bodies in the studied area have infiltrated volcanic and metamorphic rocks (Shahrokhi, 2020). Based on field Geology and microscopic studies, the mineralogy of these rocks includes quartz, plagioclase, orthoclase, microcline and chlorite as the main minerals and biotite, muscovite, apatite, garnet, rutile, leucoxene, titanium minerals, sphene and zircon as the secondary minerals. Chlorite can be seen in the form of coarse crystals, needles and very narrow in the background of the rocks, and they have been replaced in the remains of crystalline molds of the primary biotite type. Based on this, it can be said that the transformation of biotite to chlorite is associated with the depletion of K2O and the reduction of SiO2 which gave rise to the formation of potassium feldspar (Czamanske et al., 1988). Completely rutile and sphene crystalline can be seen in the process of chlorite cleavage. The presence of a small amount of garnet in the form of crystalline and cubic indicates low pressure or poor magnesium in the primary rock (Yardley, 1989). Also, the study of polished sections shows the presence of minerals such as pyrite, hematite, corundum and Au. The amount of pyrite and gold increases when approaching granodiorites, which can indicate the effect of intrusive bodies and post-magmatic fluids in mineralization in these rocks. X-ray diffraction (XRD) mineralogical study shows that the most important variation in chlorite is in Dalayon area. The main minerals in the host rock include chlorite, quartz, muscovite, illite, microcline, and secondary minerals are rutile and biotite. It can be concluded that biotite has been transformed into chlorite in the presence of hot fluids containing Fe and Mg. With the help of Fe2+/ (Fe2++Mg2+) versus 2*Si diagram (Pflumio, 1991) and also the Si content of Dalayon chlorites is of ripidolite-pychnochlorite type and show the presence of iron-bearing chlorites. The amount of Si indicates the purity of chlorites, and the very small amounts of calcium and also the amount of Xc points to the absence of smectite and the high purity of chlorites (Lori et al., 1988). The very low Ti content of chlorites and the presence of rutile, sphene, and leucoxene indicate that the Ti content of primary biotite is formed secondarily in the form of Ti-bearing minerals and in the form of thin blades parallel to the chlorite cleavage and orthogonal to it (Czamanske, 1988; Parry and Downey, 1982). Considering that the sum of octahedral cations in the samples is very close to 6, which indicates that all octahedral sites are occupied by divalent cations and are of triple octahedral type (Xie et al., 1997). Although the existence of a vacancy cannot be proven with certainty (Jiang et al., 1994), but with the help of the structural formula of ideal chlorite, the vacancy is calculated as 0.26-0.66 apfu (Xie et al., 1997).

The formation conditions of chlorite reflect its structure and chemical composition and can be used as a geothermometer (Jiang et al., 1994). The crystallization temperature of chlorites with the help of T-Al (IV) diagram (Cathelineau, 1988) is in the range of 379⁰C -305⁰C, with an average of 353⁰C and does not show much change. As the available data, display it can be said that by moving away from the granitoid intrusive bodies, the formation temperature of chlorites decreases. Therefore, the points located in the far area and in the metamorphic rocks with ore have a lower formation temperature. The existence of an inverse correlation between the crystallization temperature of chlorites and their silica content can be due to the substitution of silica instead of aluminum. The fluid inclusion studies on the quartz mineral co-growing with the chlorites of the Dalayon area shows the thermal range of homogenization between 305 and 384 ⁰C with an average of 345.6⁰C, which is consistent with the temperature of formation obtained through thermometric chlorites and indicates the effectiveness of the thermometer by chlorites. The fluid inclusions studies and chlorite thermometry show the influence of mesothermal or orogenic hydrothermal fluids in the formation of chlorite and placement within the skarn range, which confirms each other and is consistent with mineralogical studies and field observations. Overall., the formation of chlorite under study at a temperature equivalent to the high temperature of the hydrothermal stage of granites demonstrates the influence of hot fluids derived from the granitic magma and the metamorphic function in the formation of chlorite.

The occurrence of tourmaline in the metamorphic complex of the north of Golpayegan is observed within the granitoid mass and schists in contact with granitoid and marbles. Speaking of abundance, tourmaline is less frequently a minor mineral found in granites and granitic pegmatites as well as in low- to high-grade metamorphic rocks (Krmícek et al., 2020). The minerals of the tourmaline group can adjust their composition to adapt to varied settings, and therefore show a remarkable stability range in terms of pressure, temperature, fluid composition, and host rock composition (Van Hinsberg et al., 2011). Since tourmaline displays a negligible intra-crystalline diffusion, it can record the physical and chemical conditions of its setting and preserve this information in geological chronicles. Therefore, tourmaline accurately presents the composition of fluids and the melts from which it crystallized (Marks et al., 2013). Although tourmaline is common in many rocks, it is not common in metamorphosed carbonates (Krmícek et al., 2020).A petrographical and geochemical investigation of tourmalines in the north of Golpayegan was undertaken to know the formation mechanism of this mineral and to determine the differences between tourmalines crystallized at the contact, in granitoid and tourmaline in marbles.

Regional Geology:

The Golpayegan Metamorphic Complex is located in the Sanandaj-Sirjan Zone and the occurrence of tourmaline in this complex is observed in two locations. The first location is on the west side of Ochestan farm where tourmaline is found in three forms:1) In the granitoid mass (Gt); 2) In the amphibole schists (At) in contact with the granitoid mass, and 3) In the mica schists (Mt) in contact with the granitoid mass. The second area is in the north of Esfajerd where tourmaline occurs inside the marbles (Ct).

With the completion of field reconnaissance and preparation of thin sections, a petrographic study was fulfilled to determine the texture and mineralogy of the minerals, and then, some samples were selected for electron microprobe analysis.

Petrography:

The tourmaline in granitoid mass (Gt), appears as idiomorphic and coarse-grained without any inclusions. Micaschists (Mt) in contact with the granitoid mass are sieve-shaped or spongy. Inside the amphibole schists (At) in contact with the granitoid mass, it is idiomorphic without any inclusions.Tourmaline in marbles (Ct) is fine-grained and blue, which can be observed around biotites with corrosion marks, indicating its reaction with fluid.

Tourmaline chemistry:

The tourmalines in Ochestan granite-pegmatite (Gt) are of alkali tourmaline variety with schorl composition, enriched in aluminum, and points to the replacement of Al in the Y (R2) position. The substitution type of these tourmalines is Al(NaFe+2)-1 owing to the high amount of Fe versus Mg,The tourmalines in amphibole schist (At) are alkali tourmaline with schorl-dravite composition and the tourmalines in mica schist (Mt) are alkali tourmaline with dravite composition, and both types are characterized by insignificant amounts of aluminum. This demonstrates the replacement of Al in the position of Y (R2) has not occurred. Due to the change in Mg and Fe content, the At-type tourmalines benefit from both Al(NaFe+2)-1 and Al(NaMg)-1 substitution varieties. However, the substitutions of Mt-type tourmalines are mainly Al(NaMg)-1 due to the high content of Mg versus Fe. Indeed, Fe+3Al-1 substitution can be observed in both types of tourmaline.Tourmalines in marble (Ct) are of the alkaline type of dravite composition and rich in aluminum, which indicates the replacement of Al in the Y (R2) position. Their substitution is Al(NaMg)-1 due to the high content of Mg versus Fe.

The composition of tourmaline in Gt is of schorl type (Fe/Fe+Mg= 0.89-0.91) and has an aluminum replacement in the Y position. The composition of tourmaline in Mt type is of dravite type (Fe/Fe+Mg= 0.45-0.47) and the composition of tourmaline in At type is of schorl-dravite type (Fe/Fe+Mg= 0.49-0.51), which, replacement of aluminum in the Y position does not occur in both types of tourmaline in schists. Consequently, hydrothermal tourmalines have less aluminum (i.e. At and Mt-type tourmalines), and tourmalines in the granite-pegmatite mass have much more aluminum (i.e. Gt-type tourmalines). Based on the values of Fe# (FeO/FeO+MgO), it is possible to determine the formation site of tourmalines. If the amount of Fe# in tourmaline is >0.8, it indicates the closed magmatic system, lack of fluids interference, and their contamination with Al-rich sediments. Meanwhile, if the ratio is <0.6, it means that boron is metasomatic with sediments rich in Al and also is of an extrinsic origin.The Gt tourmaline samples in the range of Li-poor granitoids and related pegmatites and aplites related to them, the At and Mt tourmaline samples placed in the range of Ca-poor metapelites, metapsammites and quartz-tourmaline rocks not coexisting with an Al-saturating phase.The tourmalines in the marbles of the north Esfajard (Ct) are of dravite type with the ratio of Fe/Fe+Mg= 0.42-0.45. In these tourmalines, both aluminum replacement in the Y position and Al(NaMg)-1 substitution can be observed, which manifests the non-magmatic origin of these types of tourmalines. The Ct-type tourmalines in the range of metapelites and metapsammites coexist with an Al-saturating phase.The postmagmatic/residual-hydrothermal fluids related to alkali syenite magma of the north Esfajard along with the fluids from the progressive metamorphism in micaschists, have developed these tourmalines in marble.The discrepancy in the results of two types of thermometers (thermometry based on the amount of Ti in biotite and Mg-Fe exchange between tourmaline and biotite minerals) in meta-carbonates, highlights that at temperatures >566°C biotite, and lower temperatures, Ct-type tourmaline is composed of biotites.

The Marivan region located in the west of Kurdistan province, northwest of Iran and in the structural geological divisions of Iran (Stöcklin and Nabavi, 1973). The Mesozoic volcanic rocks are widespread in the Northern Sanandaj- Sirjan zone in comparison to the central and southern parts of this zone. The basic term of this volcanic belt with a calc-alkaline tendency is dominant where was formed in association with the Sanandaj-Sirjan arc magmatism in the Mesozoic which generated as a result of the subduction of the Neotethys oceanic crust under the active continental margin of Central Iran (Omrani et al., 2008; Azizi and Jahangiri, 2008; Moinevaziri et al., 2015).The studied area located in the Sanandaj Cretaceous volcanic belt (SVB) (Azizi and Moinevaziri, 2009), is characterized by the presence of basalts and andesite-basalts, often intruded shales, sandstones, and Cretaceous limestones. Rahimzadeh et al. (2021) investigated the North of Sanandaj-Sirjan magmatism in two basic and acidic phases and attributed their formation to a continental arc tectonic environment with extension. Also, the general age of the North Sanandaj-Sirjan zone magmatism varies from 110 to 130 million years (Barmian-Aptian). Ali et al. (2016) determined a bimodal model for the volcanic rocks of the Kata-rash region in Iraq Kurdistan (north of the study area), which originated 108 Ma (Albian) in an oceanic arc tectonic environment. The main purpose of the present paper is to study the petrology and geochemistry of the volcanic rocks of the area, in order to determine their tectonic setting.

Regional Geology:

The The studied area is located in the north and east of Marivan city and is a part of the 1:100,000 geological map of Marivan (Sabzehi et al., 2009). Structurally, it is located in the northwestern part of Sanandaj-Sirjan zone. The rock units with Albian age, are a sequence of low metamorphosed volcanic-sedimentary rocks and consist of basaltic lavas, andesite-basalt, rhyodacite, pyroclastic, shale, calcareous shale, metamorphosed limestone, sandstone and minor amounts of conglomerate. A great volume of basic rocks is found in the north of Marivan while the acidic domes are seen in the east of the Marivan. The field relationships of volcano-sedimentary sequence indicates that the volcanic rocks erupted from deep to shallow marine environment (Rahimzadeh et al., 2021).

Eleven samples selected from the Marivan volcanic rocks for chemical analyses. The major elements were measured by ICP-OES method and trace and rare earth elements (REE) were measured by the ICP-MS method in the Canadian MS-Analyses laboratory.

Petrography:

Cretaceous volcanic rocks with bimodal composition are often basic to slightly intermediate and acidic outcrops. The basic phase includes a large amount of basalt and a small amount of basaltic andesite and the acidic phase is composed of rhyolite and rhyodacite. Porphyritic and microlithic-glassy are the common textures in the rocks under study. The presence of zoned-plagioclases, quartz with embayed texture in rhyodacite, regrowth in crystals margin in both basic and acidic phases indicate the chemical imbalance of phenocrysts with melt in the magma forming these rocks.

Geochemistry:

Based on the results of chemical analyses, the Marivan volcanic rocks are classified as the basic and acidic where the bimodality of rocks can be seen. The basic rocks show calk-alkaline with tholeiitic tendency whereas the acidic term display the calc-alkaline nature. The geochemical results in the spider diagrams show that the basic rocks of the region are enriched in LREE and LILE (K, Cs and relatively Ba and Rb), and depleted in HFSE (Nb, Ti, P) except U and Th.The acidic rocks are enriched in LILE (K, Cs, Rb, Th) except Sr and depletion of HFSE (P, Ti, Nb) except U and Zr. Nb and Ti depletion is one of the characteristic features of magmatic arcs. Also, these rocks have an LREE-enriched pattern in both the basicand acidic phases with a high LREE/HREE ratio and a specific negative Eu anomaly are found only in the acidic phase. The acidic rocks were originated from the lherzolitic spinel mantle with a 5 to 8% partial melting degree whereas the basic phase is generated from the lherzolitic spinel-garnet mantle with 10 to 22% partial melting degree.

Tectonic setting:

This volcanic complex is a part of the Sanandaj-Sirjan magmatic arc, which shows both subduction and extensional components. Extension in the continental arc happened relation to roll-back or slab collapse (Wei et al., 2017; Rahimzadeh et al., 2021). Rollback occurs as a result of its pressure, the subducting crust turns back and breaks, and extension occurs for a short period. So, in this geodynamic environment, bimodal volcanism can be happened where basic term show the tholeiitic affinity. It’s happened from continental arc position. In this tectonic setting environments, most of the volcanic rocks are basaltic rocks while in a typical continental arc such as the Andes arc and the Urumieh-Dokhtar abundant andesite rocks are widespread (Gill, 2010).

Marivan volcanic rocks are part of the northern Sanandaj-Sirjan zone continental arc, which is roll-back happened in the Albian and as a result occurred the local extension in the regional compression setting. Its signs include the presence of shales associated with volcanic rocks, the abundance of basalts over andesites, the tendency of calc-alkaline to tholeiitic nature in most of the basic rocks and as the several geodynamic diagrams display. However, the obvious evidence of subduction in the region can be seen as the depletion of Nb and Ti elements and enrichment of LILE and LREE compared to HFS elements.

The Churan gold and copper deposit located 70 km northeast of Sirjan in the Dehaj-Sarduyeh structural subzone of the Urumieh -Dokhtar magmatic arc. Lithologically, the area mainly consists of the Middle Eocene volcanic rocks with dominant andesite to andesite-basalt crosscutting by the intrusive rocks and quartz dioritic to granodioritic dykes belonging to the Oligocene-Miocene time. The host granitoid rocks are classified as meta-aluminous I-type granitoid with high potassium calc-alkaline affinity dominated by plagioclase, biotite, hornblende, alkali feldspar, quartz and apatite, zircon, and opaque as accessory minerals. The rocks under study are characterized by large ion lithophile element (LILE) enrichment, high field strength element (HFSE) depletion, and high LREE/HREE ratios. On tectonomagmatic discrimination diagrams, the Churun granitoids are scattered on active continental margins to post-collisional fields. Mineralization occurred as gold and copper-bearing quartz vein and veinlets in the quartz diorite intrusive. Hydrothermal alterations associated with the mineralization contain silicification, sulfidation, tourmalinization, and sericitization. Ore mineral assemblages in the deposit consist of pyrite, arsenopyrite, chalcopyrite, bornite, sphalerite, galena, covellite, malachite, and iron hydroxides. The mineralization criteria as well as the spatial relationship between ore-bearing veins and alteration zones granite-granodiorite intrusion suggest that gold mineralization in the investigated area is related to granite-granodiorite emplacement and likely originated from those rocks.

Solid waste is one of the unavoidable products of every society that necessitates the establishment of municipal solid waste management system. Because of variability in quantity and composition of municipal solid wastes, several management scenarios are considered. Assessing the environmental impacts of the life cycle of these scenarios will have a significant role in reducing and resolving urban service management problems. The aim of this study was to compare different scenarios of municipal solid waste management in Sirjan city using life cycle assessment (LCA) approach. LCA methodology is used to evaluate the environmental performance of the waste management of Sirjan for different scenarios, according to the ISO standards 14040 series 2006.

After identifying the quantitative and qualitative characteristics of the produced wastes within the scope of the study, the quadratic steps of the LCA method are followed in relation to each of the scenarios. The stages of life cycle assessment in the present research are as follows: 1. Determining goals and scope: Our goal is to compare environmental impacts of scenarios that include different methods of disposal. The boundaries of the study start from the collection of municipal solid wastes from the transfer station and ends with the final disposal of waste (Figure 1)
Figure 1. System boundary
Four scenarios have been investigated and evaluated in the environmental field (Table 1).
Table 1. Disposal solid waste scenarios
Scenario
Compost (%)
Recycle (%)
Incineration (%)
Landfill (%)
1
2
3
4
0
68.4
17.1
0
0
19.2
15
19.2
0
0
55.9
69.8
100
12.4
12
11

2. Collecting data and life cycle inventory (LCI): Various tools have been developed for LCI, one of which is the IWM-2 model. The IWM-2 model is one of the lifecycle assessment models that can be used to define different scenarios and then to compare the environmental impacts of each scenario. At this stage, the data from physical analysis, the amount of waste produced, the stages of separation at source, collection, transportation and final disposal, were collected and analyzed and the amount of contamination caused by each of the scenarios and energy consumption were determined.
3. Life cycle impacts assessment (LCIA): Assessing the impacts of the life cycle is a step of life cycle assessment, aimed at understanding and assessing the magnitude and significance of the potential environmental impacts of a product or service. At this step, the various information and data obtained at the LCI stage are reduced to less indicators and impact categories in order to facilitate the interpretation of this information and provide clearer outcomes to decision makers and managers. In this step, input data are allocated to the five impact categories of energy consumption, greenhouse gases, acid gases, photochemical gases and toxic emissions.
4. Interpretation of results: At this stage, the results of the LCI and LCIA will be evaluated so that the stages or points which have the greatest and least harmful impacts on the environment in the production and consumption of the product have been determined. Finally, conclusions and solutions are explained.

Results of the model were allocated to five categories consisting of energy consumption, greenhouse gases, acid gases, photochemical gases and toxic emissions. In every category, the ecological index as a quantitative measure to compare scenarios was calculated.

In this study, the life cycle assessment approach was used as a decision tool for choosing the appropriate waste disposal scenario in Sirjan city. The second scenario (68.4% compost, 19.2% recycling, 12.4% landfill) was selected as the preferred option for municipal waste disposal in Sirjan city. Also the results of this study show that in an integrated municipal waste management system, increasing the rate of separation and recycling will significantly reduce the release of environmental pollutants../files/site1/files/142/5.pdf

The Gol-e-Gohar anomaly#3 of Sirjan was initially formed by synchronous submarine basaltic volcanism and sedimentary rocks (basalt, shale, carbonates, sandstone, marl, chert-iron hydroxide-oxides) during Neoproterozoic (Ediacaran) and subsequently metamorphosed to greenschist facies during Cimmerian orogeny. The anomly contains 643 million tonnes iron ore with an average grade of 52.70% Fe, 0.76% S and 0.11% P and is enclosed by alternation of quartzite, sericite schist, chlorite schist, talc schist, biotite schist, actinolite schist. Magnetite occurs as massive, banded, cataclastic and disseminated ore and is associated with pyrite, minor chalcopyrite and bornite. Pyrite occurs as, layered, banded, folded and cataclastic and minor within the magnetite crystals. Minor minerals are tourmaline, apatite, zircon and garnet. Geochemical data demonstrate that enrichment of Cu, Pb,Co, Sn, As and Sb in magnetite ore is 2-10 times higher than the crustal abundance. The enrichment of Cu, Mo, Pb, Zn, Cr, Ni, Co, As and Sb in sulfide minerals is 3-67 magnitudes higher than the crustal abundance. The alternation of different schist bands with banded magnetite-pyrite ores, the presence of dropstones and Al-Fe-Mn, V-Ti and V/Ti-Ni/Ti diagrams indicate that the iron mineralization in anomaly#3 is similar to the Ediacaran-type banded iron formation.

The Golgohar iron mine is located at 55 km southwest of Sirjan in the Sanandaj-Sirjan structural zone. The host rocks of the ore deposit include metamorphosed rocks in green schist and amphibolite facies. The mineralization is massive or disseminated in adjacent rocks. The metabasic rocks are classified into amphibolite, epidote amphibolite, epidote-biotite amphibolite and biotite amphibolite types. Base on major, trace, and rare earth elements, the protolithsof these rocks are basic igneous rocks varying from basalt, basaltic andesite, trachy basalt, basaltic trachy andesite compositions. The trace elements pattern shows enrichment in large-ion lithophileelements and depletion in high field strength elements, suggesting their island arc signatures. LREEs enrichment and relatively flat HREEs patterns further support this interpretation. According to geochemical data these rocks were derived from depleted mantle that was contaminated by the melts of subducted sediments. The relative age of these rocks does not match with the tectonic setting. It seems that the Neo-Tethyan subduction along the northern subduction zone caused the emplacement of the study rocks in the Upper Triassic time. In this case, geochronological data may be helpful.

Quartzofeldspathic schists of the valley of Sovordydosha are situated in the shear zone of the north Shahrekord, in the central part of Sanandaj-Sirjan Zone. The metamorphic rocks show lepido-granoblastic texture. The most important of minerals are quartz, feldspar, and biotite. The samples indicate nature of greywacke to shale on the log (Na2O/K2O) versus log (SiO2/A12O3) diagram for their protolith. According to the geochemical characteristics, the source material of the rocks is the result of erosion, transportation, and deposition of evolved felsic igneous rocks and granitoid rocks. The average of the chemical index of alteration (CIA) and chemical index of weathering (CIW), as well as the binary diagram of Al/Na versus CIA show moderate weathering in during formation of the sedimentary protolith of the rocks. Moreover, based on SiO2 versus (Al2O3⭣븵궎) diagram, the paleoclimate of the region was dry at the time of the formation of the source material. The Mn* index and U/Th ratio determine oxidant conditions of the sedimentary basin in past time. Geochemical data indicate that tectonic setting of the protolith of the schists has been an active continental margin and continental arc

The Kolah-Ghazi granitoid assemblage is located in the south of Esfahan and in the Sanandaj-Sirjan magmatic-metamorphic zone. The Sanandaj-Sirjan zone is extended for 1500 km from Sirjan in the southeast to Sanandaj in the northwest of Iran and is situated in the west of Central Iranian terrane.
The Sanandaj-Sirjan zone represents the metamorphic belt of the Zagros orogeny which is part of the Alpine- Himalayan orogenic belt. The Kolah-Ghazi granitoid assemblage consists of granodiorite, granites, quartz-rich granitoid and minor tonalite. The aim of this paper is to represent the mineralogy, geochemistry, petrogenesis and tectonic setting of this plutonic assemblage.

More than 60 samples representing all of the rock units in the study area were chosen for microscopic studies. Then, 22 samples were selected for geochemical studies. The major elements were determined with XRF in the Naruto University, Japan. The trace and rare earth elements were analyzed by ICP-MS in the Acmelab, Canada. The geochemical results are presented in Table 1.

The Kolah-Ghazi granitoid assemblage intruded into the Jurassic sedimentary units and overlaid by lower Cretaceous sandstone and conglomerate which suggest Upper Jurassic as the possible age of the Kolah-Ghazi intrusion. Based on the modal studies, this granitoid assemblage is comprised of granite, granodiorite, quartz-rock granitoid and tonalite with different igneous textures including symplectic, myrmekitic, rapakivi, poikilitic and porphyroid. There are some xenoliths, microgranular enclaves and sur micaceous enclaves in the Kolah-Ghazi granitoid assemblage. Xenoliths are mostly derived from Jurassic shale and sandstones which have been trapped in the magma. The sur micaceousenclaves have tonalite composition. The sur micaceous enclaves are biotite-rich rock fragments which display metamorphic texture. The sur micaceous enclaves are classified as restite since they are poor in quartz. The essential minerals in this magmatic assemblage are quartz, plagioclase, alkali-feldspar and biotite as the only ferromagnesian mineral. There was no hornblende in the studied samples. The presence of andalusite, sillimanite and garnet in these rocks point to the sedimentary source of these granitoid melts. Zircon, apatite and opaque minerals occurred as accessory minerals. The secondary minerals included sphene, tourmaline, clay minerals, chlorite and opaque minerals. The Kolah-Ghazi rock samples plot on the granite and granodiorite fields on the geochemical classification diagrams. The geochemistry of these plutonic rocks show peralunimous, high K-calc alkaline features. On the Harker variation diagrams, it can be observed that the Al2O3, FeO, MgO, TiO2 and CaO contents decrease with the increase in SiO2, whereas K2O and Na2O show an ascending trend with increasing SiO2. Moreover, the fractionation of plagioclase and the crystallization of alkali-feldspar caused the observed trends of Rb and Sr in the Harker diagrams. Ba contents decrease with increasing SiO2 which is relevant to the biotite fractionation. All of the analyzed samples show similar patterns in the chondrite-normalized trace elements and the REE diagrams. All samples show LILE and LREE enrichment and HFSE and HREE depletion. The negative anomaly of Sr may be related to the lack of calcic-plagioclase in these samples or suggest the plagioclase rich restite during partial melting of the parental rock. The latter is in agreement with the Eu anomaly that appeared in the REE diagram. All of the Kolah-Ghazi samples show linear trends in the major and trace elements versus SiO2 diagrams and display similar REE patterns suggesting close relationship in the source and magmatic history.
The field, petrography and geochemical evidences such as pegmatit veins in the pluton, biotite rich enclaves, lack of hornblende and titanite, occurrence of metamorphic minerals (e.g., garnet, andalusite and sillimanite), the predominance of ilmenite, A/CNK values (A/CNK >1), and crondom contents (more than 3% in norm) suggest that the Kolah-Ghazi plutonic assemblage can be classified as S-type granitoids. Moreover, all of the Kolah-Ghazi samples plot on the S-type field of the granite classification diagrams (Whalen et al., 1987; Chappell and White, 1992) which is in good agreement with mineralogical evidences.
The sedimentary source, mostly shale and greywacke, can be suggested for Kolah-Ghazi melts according to the Rb/Sr vs. Rb/Ba diagram (Sylvester, 1998). Several discrimination diagrams such as Rb vs. Ta (Pearce et al., 1984) and R1-R2 (Batchelor and Bowden, 1985) were used to determine the tectonic setting of the Kolah-Ghazi granitoids. The Kolah-Ghazi samples lied between the fields of magmatic arc and syn-collisional granitoids in the discrimination diagrams.
The geochemistry of the studied samples suggest a syntectonic environment for the Kolah-Ghazi granitoids which may be related to the late Cimmerian orogenic phase.

Varcheh gabbroic pluton is located in Markazi Province and is part of the Sanandaj-Sirjan zone. This pluton is gabbro to monzo-gabbro of alkaline nature. Based on condrite normalized spider diagrams, the REE pattern displays enrichment of LREE (100 times) and HREE (10 times). In addition, based on primitive mantle normalized spider diagrams, they display enrichment of HFS elements (Zr, Ti, P). Absence of negative anomaly of Nb is due to alkaline nature. Behavior of Zr, Nb, Yb, La, and Sm elements show that the primary magma is derived from enriched mantle by the partial melting of 10%-15% of the spinel - garnet lherzolite, respectively. This magmatism can be related to deep faults and crustal thickening by the Neotethys subduction. The Plagioclase composition in gabbroic pluton is in the range of oligoclase to labradorite and clinopyroxene composition is mainly diopside. The clinopyroxene composition shows that they were crystallized from an alkaline magma. On the basis of geothermobarometry, crystallization-temperature of diopside is estimated to be about 1150°C to 1200 °C and crystallization-pressure for the diopside is between 3 - 7 kb.

Geomorphotourism is one of the tourism branches base on nature which have high potentials for tourism planning by combining ecological, historical and cultural inheritances. In the other words, geomorphotourism introducing the geomorphological landforms to tourists by keeping the local identity. In this relation, this research tries to study the tourism capabilities of Sirjan geotops using Fassoulas and Comanescu models. The used values in Fassoulas model consist of scientific, ecological and protective, cultural, aesthetics, economical and utilization potential values and in Comanescu model consist of management, yield economic, cultural, aesthetics and scientific values , that each of these values have some sub-standard that have been determined from 1 to 10 for Fassoulas model and 20 for Comanescu model by standard score system. The results of this research indicate that geotop of Sirjan salt desert with 18.8 score in Fassoulas model and 0.78 in Comanescu model have the maximum score for tourism development. Also, according to results, the troglodytic geotop with 12.2 score in Fassoulas model and 0.34 in Comanescu model , have the minimum score among studied geotops. According to research results, the maximum score of Sirjan desert geotop relate to scientific value and aesthetic and suitable access this salt desert.

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

Pir-abad amphibolotes in the northest Azna locates sanandaj –Sirjan zone. The amphibolites show a discontinuous outcrops as pods and lenses. Sometimes have lineation and foliation. Amphibole and plagioclase are main mineral constituents in the rocks. The amphibolites have igneous source. Their protholite is basalt with sub-alkaline and tholeiitic nature. Chondrite normalized-REE diagram show LREE enrichment relatetoon to HREE. Primitive mantle- normalized trace elements diagram show depletion of HFSE and HREE. Tectonic discrimination diagrams, negative Nb-Ta anomalies and high Th and Ba/Yb display the back-arc basin setting or supra-subduction zone environment.

Garnet amphibolite is a member of the Hamedan regional metamorphic rocks (the Sanandaj-Sirjan zone). The present study is the first report of mineral compositions and P-T condition of the Hamedan region area garnet amphibolites. The garnet amphibolites can be divided into two varieties based on their mineral assemblages including epidote garnet amphibolite and biotite garnet amphibolite. Electron microprobe analysis show that they contain magnesio- hornblende, andesine and syderophyllite biotite and their garnets have chemical zoning with almandine and pyrope increasing towards the rims. Thermobarometry studies indicate that these rocks have been metamorphosed to lower to middle-amphibolite facies but the biotite bearing samples endured higher metamorphism degree that is consistent with their mineral assemblages. Although, regarding the relatively small differences between the estimated pressures and temperatures, different chemical composition of their parent rocks should be considered as a factor for determination of their final mineral assemblages. Whole rock analysis together with the mineral assemblages show that the garnet amphibolites are of para-amphibolite type and high K2O contents of the biotite bearing ones is the most important difference between these rocks which can be attributed to high impurities of the parent rocks. Overall, the thermobarometry results are consistent with high T-low P metamorphism (andalusite-sillimanite series) that is characteristic for the Sanandaj-Sirjan zone.

Gabbrodioritic pluton is located in S-Qorveh in nourthern parts of the Sanandaj-Sirjan Zone. Petrographically, amphibole and plagioclase are main minerals in these rocks. Amphiboles are calcic-type, and their composition varied between ferro-hornblende to magnesio-hornblende. Anortite contents in plagioclases are between 81 to 39 (%) and these crystal are labradore -oligoclase in composition. According to coexist hornblende-plagioclase and Al in amphibole geothermometry methods, temperatures of crystallization are yielded ~723°C. In the later method, data indicates that the investigated rocks were emplaced at average pressure of 3.5 Kbar corresponding to a depth of ~12 Km. Oxygen fugacity was high in magma. Na2O content in amphibole and their calc-alkaline nature show gabbroic diorites are related to subduction setting. Mg#, Al2O3 and TiO2 contents in hornblende indicate mixing of crustal and mantle sources to generate magma of the Darvazeh gabbrodioritic magma. Variations in the composition of plagioclase may be related to H2O content in environment and the role of chemical variation due to input of crustal materials.

Khunrang intrusive complex, as a one of the largest complexes in the southern part of the Sanandaj-Sirjan zone, is located at northwest of Jiroft, in Kerman province. The complex mainly consists of acidic-intermediate rocks such as diorite, quartzdiorite, tonalite, granodiorite, and granite with subordinate amounts of mafic members such as hornblende gabbro and microgabbro. Field studies together with mineralogical and geochemical evidence show that the Khunrang intrusive complex belongs to calc-alkaline series and its felsic members are metaluminous to weakly peraluminous which display features typical of I-type granites. On the primitive mantle-normalized spider diagrams, all mafic and felsic samples are enriched in LILE (such as Rb, Cs and K) and depleted in Ti, Ta and Nb which is a main characteristic of subduction-related magmas. Based on geochemical data, the mafic rocks seems to be formed by melting of metasomatised mantle wedge; whereas felsic rocks are formed by melting of lower crust metabasic rocks as a result of the injection of mantle derived mafic magmas. It can be concluded that the Khunrang intrusive complex was formed in a volcanic arc setting due to subduction of the Neotethys oceanic crust beneath the Central Iranian Micro-continent in the Middle-Jurassic time.

The Sanandaj-Sirjan zone is a NW-SE trending orogenic belt immediately north of the Zagros suture, which represents the former position of the Neotethys Ocean. This zone includes a Pan-African basement similar to the various terranes to the north in Central Iran. The crystalline basement is nonconformably overlain by the Paleozoic-Triassic platform sediments, which in turn are unconformably covered by sedimentary and volcanic strata of the Jurassic arc. The Cretaceous carbonates overlie the older rocks with a regional angular unconformity. The Chadegan high-P metamorphic complex exposed along the upper Zayanderoud and consists of quartz schists, amphibolites, gneisses, marbles and eclogites, and is nonconformably underlain by the fossiliferous Permian carbonates, suggesting a Pre-Permian age. In this paper we present new data including whole rock major and trace element compositions, mineral chemistry and radiogenic isotope data for the selected metabasites. The high field strength element (HFSE) abundances and Sr-Nd-Hf ratios suggest tholeiitic compositions with distinct within plate affinity rather than MORB. We also present new 206Pb/238U zircon age of 568.0 ± 5.3 Ma for a crosscutting orthogneiss reconfirming the Late Neoproterozoic age for the granitic protolith. We conclude that previously presented Ar-Ar ages for white-micas in eclogites and gneisses are indicative of metamorphic crystallization due to the regional plutonic arc activity. A comparison is made with the well-investigated Menderes Massif in Turkey where an orthogneiss-metabsite association with similar age and chemistry makes extensive exposures. We also conclude that this rock complex is extended from Zayanderoud to Khoy and beyond to the Menderes Massif and discuss the connection with the final amalgamation tectonics of the Gondwana near the beginning of the Cambrian Period.

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

A wide range of plutonic rocks, ranging from mafic to felsic compositions, including various gabbros, diorites, tonalites, granodiorites, monzogranites, syenogranites and leucocratic granitoids, occur in the Alvand plutonic complex, Sanandaj-Sirjan zone, Iran. Age of this complex is middle Jurassic. In this complex, granitic and dioritic rocks occur as major constituents. Granites contain plagioclase, K-feldspar, quartz and bitite and diorites comprise plagioclase, hornblende, biotite and minor titanite and apatite. In some outcrops, contaminated granites and diorites occur which contain abundant large undigested xenocrysts of andalusite (partly to wholly converted to sillimanite) with spinel-rich and feldspathic reaction rims around them. These xenocrysts resulted from disintegration of minerals from pelitic rocks and their incorporation into host magmas. The 87Sr/86Sr isotope ratios in the studied granitic rocks vary from 0.7101 to 0.7245 and in the contaminated diorites from 0.7084 to 0.7079 (Sri more than 0.704). The range of 143Nd/144Nd ratios in granitic rocks is from 0.51234 to 0.51240 and for contaminated diorites from 0.51244 to 0.51252.The εNd(t) values for the studied granites vary from -3.2 to -3.98 and for contaminated dioritic rocks from -0.78 to -2.35.  In the 143Nd/144Nd versus 87Sr/86Sr diagram, granites plot in the field of crustal rocks; also diorites with mantle origin, in response to contamination by meta-pelitic rocks, are shifted towards rocks with crustal origin. These results indicate the importance of recognizing contamination of plutonic rocks by upper crustal (meta-pelitic) material when interpreting petrogenesis of such rocks.