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

The Zhaveh dam is located on the Sirvan River containing two main branches of Gaveh Rood and Qeshlaq. The dam was designed for industrial and agricultural use. Surface sediment samples were collected at 5 selected stations in the two branches of the Sirvan River, Qeshlaq and Gaveh, as well as in the dam reservoir. In this study, nine sediment parameters (different forms of nitrogen and phosphorus, TOC, pH, Eh) were investigated to determine the quality and the prediction of the eutrophication trend of the Zhaveh Dam. The quality of sediments in different stations showed that they contain high organic and mineral pollution. Based on the TOC% of the sediment, the region was considered as slightly to highly polluted, especially in stations 2 and 3, but station 4 (Gaveh Rood branch) was classified as moderate quality. The changes in the OPI and ONI indices and comparison with the organic index standard also indicated the high pollution of the sediments in this region. These conditions are due to the high mean concentration of total phosphorus (2075±178 mg/kg.dw) and bioavailable phosphorus (666±142 mg/kg.dw) in the rivers feeding the dam, which deal with a high risk of eutrophication. In addition, after the water intake of the Zhaveh Dam and the high concentration of organic and mineral pollutants during the retention time of the water, it will be difficult to control the eutrophication

The study area is located in the south of Qorveh (Kurdistan Province), strcuctually in the Sanandaj-Sirjan zone. Based on field observations, the study dykes are type of sin-plotonic dykes and based on petrographical studies mafic and dioritic dykes are included gabbro, gabbro-diorite, diorite, monzodiorite and quartz-monzodiorite rocks. Their main minerals are clinopyroxene, orthopyroxene, hornblende, plagioclase, K-feldspar and quartz. Apatite, esphene, zircon and opaque minerals are their accessory minerals. The discrimination diagrams reveal all of the dykes belong to volcanic arc related to an active continental margin setting. It is implied by enrichment of LILE (such as Cs, Rb, U&Pb), depletion of HFSE (Nb, Ba) and high LILE/HFSE in the spider diagrams. The enrichment of LILE and Pb show the crustal contamination. Concentration La/Nb and La/Ta rations as well as the enrichment of LREE and LILE reveal that dykes were derived from enriched lithospheric mantle. I addition, enrichment of LREE elements relative to HREE represent that there are garnet phase or amphibole in source.

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.

Gneisses of the northern part of the Zayandehrood Dam Lake, structurally, are located in the Sanandaj-Sirjan zone. The gneises with phengitic marble and metabasic bodies comprise a part of high-pressure units in the North Shahrekord metamorphic complex. Minerlogically, the rocks consist of quartz, garnet, phengite, k-feldspar, albite, tourmaline and rutile with zircon grains. Field (alternation of associated rocks), mineralogical and geochemical evidences are used for determining protolith of the gneisses as igneous source (ortho) or as sedimentary source (para). The geochemical evidences are used such as P2O5/TiO2 vs. MgO/CaO digram, and Niggli values c against al-alk, ti and al-alk, the frequency of Cr and Ni. In addition to, the mineral assemblages indicate a sedimentary protolith (para gneiss). The chemical composition of the protolith is caused by the felsic igneous resources of evolved crust which are plotted in the range of the Late Archean until post Archean in the diagram Ni against Cr. Our findings, especially geochemical evidences, show that the paragneises have sedimentary source, in contrast to what was previously suggested that they are orthogneiss. The protolith of the paragneisses have been formed in an active continental margin or the back-arc basin.

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 Aderba leucogranite in the Golpayegan metamorphic core complex (GMC)¡ a part of Sanandaj-Sirjan zone¡ host lentiform small (2*4 cm)(Type 1) and large (7*14 cm)(Type 2)tourmaline nodules. In terms of mineralogical features¡ the core of these two types tourmaline nodules is different. The Type 1 composed of small blue-green tourmaline¡ quartz¡ K-feldspar (microcline) and apatite while the Type 2 is characterized by tourmaline coarse crystals accompanied by quartz. Based on major and trace elements data the tourmalines under discussion are classified as alkaline¡ schorl (Type 1) and schorl-dravite (Type 2). The mean REE values displays a negative slope and a negative (Type 1) and positive (Type 2) Eu anomalies. The overall petrographic observations and geochemical results indicate that the Type 1 is likely influenced by two mechanisms of liquid immiscibility in the evolved melt followed by biotite breakdown in the final stages of tourmaline crystallization to complete consumption of B (closed system). For nodules¡ Type 2¡ breakdown of biotite in equilibrium with the external fluid (open system) is proposed.

The Sarab-3 intrusive body is located in the NW of Iran¡ in Sanandaj-Sirjan zone and in the east of Takab city. Based on field observations as well as petrographic features¡ the lithologic composition of intrusion (Miocene age) ranges within the diorite-leucodiorite¡ monzodiorite¡ quartz monzodiorite¡ granodiorite and granite. In terms of geochemical characteristics¡ the rocks studied¡ are I-type¡ with calc-alkaline affinity and meta-aluminous character. Enrichment of LILE (K¡ U¡ Sr¡ Ce¡ Th¡ Pb¡ Ba) and LREE relative to HFSE (Zr¡ Y¡ Ti¡ P¡ Nb) and HREE¡ low Ce / Pb and Nb / U ratios and high Ba / Nb reveal that the rocks under study were originated in an active continental margin subduction-related tectonic setting. The negative anomalies of Ti¡ Nb and P on the spider diagram also confirm this fact. Low ratios of (Na2O K2O / (FeOt MgO TiO2) and (Al2O3 / FeOt MgO TiO2) along with low Rb/Sr concentration (

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

The Kolah Ghazi granitoid is one of the main upper Jurassic intrusion in the Sanandaj-Sirjan zone which intruded Jurassic shale and overlaid by Lower Cretaceous strata’s. The intrusion consists of the monzogranites, granodiorites, Syenogranites, aplitic dykes associate with several tourmaline veins in three separated outcrops. Based on petrographic studies quartz, plagioclase, biotite and alkali feldspar are present as the major minerals and andalusite, sphene, tourmaline, garnet, sillimanite, spinel, kyanites constitute minor mineral phases. Geochemical results show high-K calc-alkaline and peraluminous affinities and S-type. The Kolah Ghazi granitoid belong to subduction-related volcanic arc magmatism, which related to middle Cimmerian compression movement which derived from Partial melting of metapelites in the upper crust materials and emplaced at depths (about 20-30 Km) under low water-vapor pressure (0.5-1 Kbar) and temperature range (in 750 °C).

A NW-SE trending ductile shear zone has been generated in the metamorphic rocks of the southwest Golpaygan. Different pellitic and psammitic schists, meta-carbonates and igneous rocks were strongly deformed in this ductile shear zone and produced mylonites and ultra-mylonites. Structural analysis indicates three stages of foliations in the metamorphic rocks. Geometry and kinematics of the fabrics in Nowgan shear zone are divided into two northeastern and southwestern parts (limbs of Nowqan antiform). Mylonitic foliation moderately to steeply dip towards northeast in the northeastern part but dips to the southwest in the southwestern part. Mineral and stretching lineation, are shallowly to moderately plunging to the east-southeast in the northeastern part of the shear zone and, to the west-northwest in the southwestern part. The microstructural indicators of shear sense cleared that the northeastern part dextrally displaced along strike with normal component and the southwestern part sinisterly displaced with reverse component at the present situation. The fabrics evidence clear that this ductile shear zone were originally right-lateral strike–slip shear zone and during its structural evolution it was rotated around its strike during later folding stage. Structural analysis of the surrounded rocks of the shear zone indicates three superposed foliations. The mylonitic foliation in the shear zone and the axial plane foliations of the second stage folding are sub-parallel. Plunge directions of the second stage folds axes and the mineral/stretching lineation are also sub-parallel. Therefore, the initiation and development of the shear zone were synchronous with the second stage folding event.

Deformed granitoid rocks North Saman represent part of magmatic activity in the Sanandaj-Sirjan zone during the Mesozoic. The granitoid rocks intruded as separate intrusions into the metamorphic rocks with protolith ages of the Palaeozoic and Mezosoic. These granitoids are deformed as a result of subsequent tectonic activities. Zircon U-Pb ages of crystals separated the granitoid rocks gave ages of 182 ± 4 Ma and indicate that the granitoid rocks crystallized at the Toarcian stage of the lower Jurassic. The major and trace element goechemistry suggests a subduction-related, active continental margin setting for the granitoid bodies. The occurrences of numerous Jurassic granitoids reveal the importance of magmatic activities during this period in the Sanandaj-Sirjan zone.

Waste disposal, is a method in which wastes are buried on sinkholes. The buried wastes caused environmental problems. One of these environmental problems is leaches mainly due to influence of precipitation and sometimes surface waters entering the wastes. The leaches consist of various materials. In this study, chemical properties of groundwater of upstream regions of Sanandaj landfill, regarding the suitability of water for drinking is examined.Hence, 5 wells around Sanandaj landfills were selected and 10 water samples were collected and evaluated during 2 seasons based on physical and chemical parameters such as odour, turbidity, colour, pH, TDS, TH, chloride, sulfate, sodium and nitrate. In order to determine the quality of water for drinking purpose, the results were compared with Standard index and Schoeller diagram for the classification of ground water. The result shows most samples are suitable for drinking purpose.

The area studied is located north of Azna (Lorestan Province) in a small portion of the Sanandaj – Sirjan structural zone (Mohajjel et al., 2003).This area is part of the Zagros orogenic belt, formed by the opening and closure of Neotethyan ocean. From NE to SW, it consists of three parallel tectonic regions: the Orumieh-Dokhtar magmatic belt, the Sanandaj-Sirjan structural zone and the Zagros thrust-fold belt (Ghasemi and Talbot, 2005).
The Sanandaj-Sirjan structural zone is a metamorphic belt composed mostly of greenschist, amphibolite and eclogite facies rocks. The development of the zonetook placeduring the opening of the Tethys ocean and its subsequent closing during the Cretaceous and earlyTertiary convergence of the Afro-Arabian and Eurasian plates (Mohajjel and Fergusson, 2000). The second stage of metamorphism and deformation of the zone, designated D2, is the most important, resulting from the opening and closure of the Neotethyan ocean and the collision of the Arabian plate with the southwestern part of central Iran in the Late Cretaceous to Tertiary (Laramideorogenic phase) (Ghasemi and Talbot, 2005; Aghanabati, 2004; Mohajjel et al., 2003; Mohajjel and Fergusson, 2000; Alavi, 1994). In the Sanandaj-Sirjanzone, which includes the Azna area, Cretaceous granitic intrusions into the schists were followed byfolding and faulting. The intrusions produced contact metamorphism, and have lens-shaped outlines, trendingNW-SE. Consequently, the Azna area has a varied petrologic assemblage with polyphase metamorphism and deformation, including schists, metabasites and mylonitic granites. The phases include: 1. Deformation D1, and dynamothermal metamorphism (M1),a result of the subduction of Neotethysoceanic crust beneath the Iranian plate in the Late Jurassic. 2.Deformation D2, and thermal metamorphism (M2),a result of Paleocene continental collision and 3. Deformation D3, and dynamic metamorphism (M3). This deformation is a progressive deformation that hasproduced the current morphologyof the Sanandaj-Sirjan zone (Shabanian Borujeni, 2008).
In this paper we focused on petrography and mineral chemistry and thermodynamic conditions of the metapelites.
The chemical compositions of minerals were determined by a CAMECA SX100 electron microprobe (EMP) at Universität Stuttgart (Germany). The instrument is equipped with five wavelength dispersive spectrometers. The beam current and acceleration voltage were 15 nA and 15 kV, respectively.
Discussion and The Azna regional metamorphic rocks include quartz-feldspar schists, mica schists, andalusite-bearing schists and quartzites.
The Azna metapelites are schists, containing quartz, feldspars, andalusite, muscovite, biotite, muscovite, chlorite and garnet, in variable proportions, characterized byporphyroblastic and lepidoblastic textures. Based on mineralogy, minerals of these rocks contain andalusite, garnet, feldspar, muscovite, biotite, quartz and chlorite. Microprobe analyses show that the mineral compositions are as follows: White micas in the andalusite-bearing schists are muscovite, plagioclases are albite-oligoclase, garnets are almandine-spessartine with weak chemical zoning and biotites are siderophylite-annite.
Based on geothermobarometry, these rocks formed in the hornblende-hornfels facies and the low pressure part of the amphibolite facies,with temperatures about 562-692 °C and pressures1.07-4.12 kbar. After the regional metamorphism of these rocks,granitoidintrusions causedthermal metamorphism of these rocks and the formation of andalusite-bearing schists.

The Bavanat (Jian) pelitic-mafic- / Besshi-type Cu-Zn-Ag volcanogenic massive sulfide deposit locates in the Bavanat area, South Sanandaj-Sirjan zone. Mineralization occurs as two stratigraphic ore horizons discontinuously within the Surian metamorphosed volcano-sedimentary complex through more than 35 km in the area. Stratigraphicaly, footwall toward hangingwall, four ore facieses were distinguished within the Bavanat (Jian) orebodies including: 1) vein-veinlets or stringer, 2) vent complex, 3) bedded-banded, and 4) hydrothermal-exhalative sediments. The ores have various primary and secondary textures and structures, although most of the primary ones were obscured during metamorphism and deformation. The relict primary textures include massive, semi-massive, banded, brecciated, disseminated and vein-veinlet ores. In the stringer and specially in the vent complex facies, chalcopyrite replaced pyrite indicating influx of a hot copper-rich fluid into the pyrite-rich massive ores during zone refining process. Also, a metal and mineralogical zonation is obsereved in the Bavanat deposit. The major wall rock alterations in the Bavanat deposit center to margins are silicic, quartz-chlorite, chloritic, chlorite-carbonate and chlorite-sericite, which show zonal pattern. Based on electron microprobe studies, chlorite is of iron-rich type. The abundant pyrrhotite in the Bavanat deposit might be due to low oxygen and sulfur fogacity, and occurrence of abundant chlinochlor in the alteration zones may indicate low pH (between 4.3 and 5.3) conditions for the ore-forming fluids. The high amounts of Cu and Zn, and low amounts of Pb, along with fluid inclusion studies results indicate high temprature (300-350 °C) for the ore fluids. Based on this study, the ore fluids responsibe for formation of the Bavanat deposit were hot, reduced and acidic, which entered into a confined marine basins, followed by ore deposition.

Studied metabasites of The Zayandehrood River and Dam margin are located at about 100 km West of Isfahan town. These metabasites are part of the Sanandaj-Sirjan Structural zone including eclogites, amphibolites and green schists. Studies suggest that the eclogites were formed at high-pressure condition in eclogite facies and were finally changed to eclogitic amphibolites under the retrogressive metamorphism. Geochemical characteristics of immobile trace elements that are less affected by alteration and High-Pressure deformation suggest that the origin of these metabasites are mid oceanic ridge basalts (MORB). In fact, these eclogites are the same Neo-Tethys MORBs that caused by the subduction of the oceanic crust to beneath of the Iranian microcontinent were formed during a high to medium temperature, progressive dynamo-thermal regional metamorphism and then returned to the surface were transformed to the eclogitic amphibolites caused by retrogressive metamorphism. Along with final collision between Neo-Tethyan oceanic crust and the Iranian microcontinent at Late Cretaceous, an intense metamorphism phase occurred in the region and deeper high pressure metamorphic rocks were uplifted to the Surface.

Migmatites have formed an important part of high-grade metamorphism in the Boroujerd area aureole (north of Sanandaj-Sirjan zone). Migmatitic complex including: migmatites, schist migmatites and hornfelse migmatites with a different range of structural and mineralogical compositions. These rocks are observed as light (leucosome), dark (melanosome) and dark and light (mesosome). Leucosomes mainly composed from quartz, plagioclase, K-feldspar, biotite and muscovite and also have perthite, poikiloblastic, granoblastic, graphic and myrmekite textures. Melanosomes formed from minerals such as biotite, garnet, andalusite, tourmaline and sillimanite have lepidobalastic, porphyrolepidoblastic and lepidoporphyrobalastic textures. Mesosomes formed from dark and light minerals and show porphyroblastic, lepidoblastic and granoblastic textures. According to petrographic studies and whole rock chemical analyses for these rocks revealed that dominant protolith is pelitic rocks. The thermobarometry results showed temperature range of of 568°C to 662 °C and pressure of 2.8 to 3.3 kbars. According to the calculated temperature and pressure, the geothermal gradient of schist migmatites and hornfels migmatites determined 48 °C/km and 60 °C/km, respectively. Heat release of the Bourojerd pluton, mafic magmatism in area (that enclaves of them can be seen in the granitoids) and subduction fluid causes migmatites that it shows the main factor increasing geothermal gradient is the presence of hot igneous plutons and enter intrusion fluid in the magmatic arcs.

Noghan granitoid intrusion is located at the NW of Boin- Miandasht and lies in the Sanandaj-Sirjan structural zone (SSZ). Body shape is a stretched ellipsoid with NW-SE strike. The meta-granite body is extremely deformed and displays mylonitic structure such as lineation and foliation. Mylonitic texture is main texture but also show seriate granular and lipido-granoblastic textures. The main minerals are quartz, K-feldspar, plagioclase, Biotite and muscovite. Chlorite is an accessory mineral. The biotite is magmatic and recrystallized. The chlorites are alteration product. The geothermometry of biotites and chlorites shows the temperatures of 397-549°C and 231-252 °C that show good correlation with microstructure in the rock. Therefore, mantle microstructure including recrystallized subgrains in porphyroclast rims that result to Grain boundary migration and chessboard undulose extinction with fine blocky grains and amoeboid grain in quartz grains show formation temperature close to 500 ž°C. Microstructures such as undulose extinction, pressure solution and in quartz, tensile fracture and bookshelf sliding in feldspar, brittle fractures and displacement of folded pieces in biotite display that temperature is lower than 300°C

The Kolah Ghazi granitoid body is located in the south-southeast of Isfahan and lies in the Sanandaj-Sirjan zone. The pluton is predominately composed of monzogranite, granodiorite and syenogranite. Quartz, plagioclase, K-feldspar, biotite, tourmaline, cordierite andalusite, sillimanite, kyanite, spinel and garnet are major and minor minerals of the pluton. The presence of kyanite in granodiorite enclaves may be due to melting of the pelitic rocks of the area which gave rise to formation of alumina rich restite. The occurrence of sillimanite these granitoid rocks can be related to metasomatism process. The inclusion of biotite and sillimanite needles in the cordierite indicates that the alteration of these minerals, during congruent melting, is responsible for the origin of cordierite. Further, cordierite crystallized during anatexis conditions under 660-770 °C and 3.5 kbar condition. Growth of spinel around the aluminosilicates with symplectites texture represents conditions of high temperature, low content of SiO2, high ƒO2 in the Fe-enriched meta-argillite. The assemblages of cordierite, sillimanite, biotite and tourmaline with unusual common blue pleochroism in the Kolah Ghazi granitoids indicate the breakdown of tourmaline under temperature higher than 750 °C. The origin of the garnet with almandine component in the Kolah Ghazi granitoids is magmatic source and refers to the pressure of 4 to 5 kbar, corresponding to depth of more than 18 km and temperature less than 850 °C. As it may be observed from the mineralogical relationship, geochemistry of feldspar and Zr vs. SiO2 the pluton developed under 700-900 °C and over 2 kbar PH2O.