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

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.

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.

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.

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.

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.

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.

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 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.

Bouin- Miandasht granitoid pluton with an area of 40 Km2, outcropped in the north of Bouin Miandasht- Aligoudarz road, was emplaced into Triassic to early Jurassic low to medium grade metapelitic rocks of Sanandaj - Sirjan structural zone. This pluton composed of alkali feldspar granite to leucogranite. For the first time, variation of anisotropy of magnetic susceptibility (AMS) is applied to investigate magnetic fabric of this pluton. The Mean magnetic susceptibility values (Km in µSI) of the different rock groups of Bouin- Miandasht pluton are as follows: alkali feldspar granites (158), fine granites (120), coarse granites (166), and leucogranites (34). The lower Km values for the main compositions of this pluton (

Granitoid rocks of the central segment of Sanandaj-Sirjan zone, occurring in Lorestan Province, are parts of  a continental arc setting intruded during Mid Jurassic time. Ultramafic rocks are adjacent to this felsic rocks with olivine, orthopyroxene, clinopyroxene and amphibole as their major rock forming minerals. Microscopic observations revealed rounded shape and occurrence of embayments in the olivines attesting different degree of olivine assimilation. By applying electron microprobe analyzes, the chemical compositions of the melts in equilibrium with minerals were calculated. It was revealed that Mg# of the melt is linearly increased as the minerals crystallized. In addition to magmatic origin of the olivine, this trend clearly shows an uncommon behavior of Mg# in the magma that increased during fractional crystallization. Two different possibilities are examined to explain the Mg# increasing. 1- high oxygen fugacity of the magma that led to early crystallization of Fe-oxides; 2- olivine assimilation during fractional crystallization. The results obtained by geochemical modeling and the increase of Ni during fractional crystallization revealed that olivine assimilation during fractional crystallization is the factor that increased Mg# and Ni content of the magma.

The Almabulagh complex is located in the Sanandaj-Sirjan structural zone, NW of Hamadan. This complex consists of low-grade metamorphic rocks and two intrusions of felsic and mafic rocks. In this research, we studied the mafic intrusion. The intrusion has ophitic, subophitic and inter-granular textures and is mainly composed of plagioclase, clinopyroxene, amphibole and minor amounts of K-feldspar, quartz and opaque minerals. Secondary minerals include epidote, chlorite and amphiboles formed in the rim of clinopyroxene. Clinopyroxene is of augite type; amphibole is tschermakite; plagioclase is in the range of andesine-labradorite; K-feldspar is anorthoclase; and the opaque mineral is ilmenite. According to the bulk rock geochemistry and mineral chemistry of clinopyroxene, the mafic intrusion of the Almabulagh complex has been crystallized from a calc-alkaline magma and is related to subduction zone. In spider diagrams Nb displays a distinctive negative anomalies compared to the primitive mantle, which suggest a possible subduction-related magmatism. Emplacement temperature and pressure of mafic rocks measured by pyroxene-amphibole thermometer and amphibole barometer indicate temperature and pressure ranges of 750 to 900 °C and 6 to 7 kbar, respectively. Based on Sm/Yb and La/Sm ratios, the parental melt of the mafic rocks of the Almabulagh complex derived from partial melting of garnet–spinel lherzolite. According to the bulk rock geochemistry and mineral chemistry of the mafic rocks, they formed in a subduction area during Late Jurassic-Early Cretaceous before the Neo-Tethys closure in Sanandaj-Sirjan zone.

This opinion exist that basement of the Sanandaj-Sirjan Zone was cratonized during Cimmerian and Laramide Orogenic phases and so, therefore it is considered as an aseismic (or low-sesimicity) zone. The Shahreza area in the central part of the zone is ed as a case study area for investigation on seismicity and recent movements and verifying of this hypothesis. We used Geoinformatic techniques (including: Remote Sensing, GIS and field surveying methods) in this research to detect the structures of the area and their kinematics, to locate earthquake foci, to find neotectonic evidences of active faults, and proofs for high seismicity of the area. Our results shows that the Shahreza fault (and Dehaghan fault located in southwest of study area) having a dextral strike-slip mechanism is the main structural trend in the area. This fault zone is truncated and offset by the Nosratabad fault (with strike N50-70E and sinistral strike-slip mechanism). In the intersection area of these main trends, many earthquake foci (with strike-slip focal mechanism) are located. Other than several earthquakes, neotectonic evidences for fault activity are are observed in the Shahreza area.

The study area is located in NW of Piranshahr town، Western Azerbaijan province. Based on the petrography، mineralogy and textural relations، the peridotites studied are classified into two groups: serpentinized peridotites and serpentinites. The second type، on the base of serpentine polymorphs and texture can be classified into three subgroups in turn: a) hydrated serpentinites which are characterized by low temperature serpentine polymorphs (chrysotile and lizardite)، b) antigorite (high temperature serpentine polymorph) bearing serpentinites which formed at relatively high T and P conditions having interpenetrative texture and c) listwanitic serpentinites with brecciated texture containing of minerals as serpentine، chlorite and high amounts of carbonates. Distinguishing of serpentine polymorphs in the investigated rocks has been done using Raman spectroscopy and microprobe analysis. Formation of low-T serpentine polymorphs in the hydrated serpentinites are most likely related to the in-situ alteration of oceanic crust whereas antigorite in the metamorphic serpentinites is formed due to regional metamorphism during subduction and/or subsequent closure of ocean. Tremolite، clinochlore/picnochlore and Fe-rich spinel are coexisting minerals with antigorite. Temperature and pressure of the antigorite bearing serpentinites are obtained on the basis of equilibria reactions using THERMOCALC، as 550ºC and 7 kbar، respectively. On the base of olivine and pyroxene norm، the protolith composition of the Piranshahr metaperidotites is determined as harzburgite and less lherzolite. The high MgO and relatively low CaO and Al2O3 contents of the investigated rocks indicate ophiolitic characteristics of the Piranshahr metaperidotites. Considering the location of the Piranshahr ophiolites at the end of the northwestern part of the Zagros ophiolitic belt، it can be concluded that hydrated serpentinites and antigorite-bearing serpentinites are formed in relation with static oceanic floor alteration and subsequent dynamic metamorphism during subduction and/or closure of the Neotethys ocean، respectively.

The Ghalilan granitoid pluton is located in SW- of Qorveh and in the Sanandaj-Sirjan zone. Based on petrographic studies، the body includes three rock units، composing of granitoid، porphyritic granite and diorite. These rocks are mainly composed of plagioclase، alkali-feldspar، quartz and amphibole. The composition of the studied plagioclase is An 14-50 (the minimum value in granite) to An 41. 4-58 (the maximum value in diorite) and some samples display normal zoning and rapakivi texture. The results of electron microprobe analysis (EMPA) indicate the amphiboles studied are magnesio hornblende in composition implying I-type nature of magma. Application of different barometers and thermometers (e. g. Al-in-Hornblende، Plagioclase-Amphibole) exhibits a pressure of ~ 1 to 3. 3 kbar and temperatures of 690-804°C for the intrusion. The reaction of these variations is reflected by the growth of minerals such as large zoned plagioclase crystals in the porphyrtic granites. In addition، the presence of the zoned plagioclase implies the PH2O variations at the time of crystallization and emplacement of the magma in the depth of ~8 km. The composition of hornblendes suggests their formation in high oxygen fugacity condition، which is in accordance with their mineralogical characteristics and tectonic setting of Ghalilan body (subduction in active continental margin).

The Goshti-Heneshk, Goli and Cheshmeh Esi iron-manganese deposits are located in the northeast of Dehdib (Safashahr), 175 km northeast of Shiraz. These deposits are situated in the Heneshk Shear Zone, which is a part of the Complex Deformation Subzone of the Southern Sanandaj- Sirjan Zone. The oldest outcrops in the area consist of the metamorphosed Permian shale, sandstone and crystalline limestone. The Middle Triassic dolomite units (equivalent to the Shotori Formation) have been thrusted on the Upper Triassic metamorphic and deformed volcano-sedimentary rocks and chert by thrust faults. The ore-bearing dolomites are often repeated due to imbricate thrust system in the area. The host rock to the ore is only dolomite, and ore bodies formed as lenses concordant by layering. The ore texture is massive, open space filling, lamination, and disseminated. The ore minerals include hematite, magnetite, goethite, kriptomelan, psilomelan and ramsdelite together with dolomite, calcite, quartz and barite. In the geochemical studies to determine the source of mineralization, Mn/Fe, Si/Al and Na/Mg ratios of major elements indicated that Fe-Mn ore formation occurred through the hydrothermal processes in shallow marine volcano-sedimentary environment. The trace element diagrams show low contents of elements such as Ni, Co, and Cu in the Fe-Mn ores. In these diagrams, the deposits of the study area plot in the field of hydrothermal deposits. Rare Earth Element distribution patterns of the deposits are quite similar to those of hydrothermal deposits. Two ore types are distinguished based on geometry and shape of the ore bodies: primary mineralization occurred parallel and concordant with layering of the host rocks. The ore textures of this type include massive, laminated and disseminated occurring in folded chert and dolomite. The vein-type mineralization is associated with the faults and has brecciated or cataclastic texture occurring in the Middle Triassic dolomite and Permian metacarbonates. Based on the stratigraphic location, layer form of the ore body, texture, paragenetic sequence, ore-bearing chert-dolomite facies and geochemistry, the iron-manganese ores of the northeast Dehbid are stratabound carbonate-hosted deposits, which were precipitated in the shallow marine environment in the dolomites equivalent to the Middle Triasssic Shotori Formation.

In the east and northeast of Sanandaj in the Qorveh-Bijar-Takab axis، there are series of basaltic composition volcanoes with Quaternary age. The study area is part of the Sanandaj-Sirjan zone and is located between 47°52'' and 47°57'' E longitudes and 35°26 and ''35°30'' N latitudes. Due to the location of the volcanic cone on Pliocene clastic sediments and Quaternary travertine، the age of these volcanoes is considered to be Quaternary. The cones mostly consist of low scoria، ash، volcanic bombs، lapilli deposits and basaltic lava (Moein Vaziri and Aminsobhani، 1985). Petrological and geochemical studies have been carried out to evaluate Quaternary magmatism in the area and to determine the nature of the lithological characteristics، such as the evaluation of source rocks and magma type، degree of partial melting and the tectonic setting of Ghezel Ghaleh rocks (Moein Vaziri، 1997). Simplified geological map of the study area is characterized by ER-Mapper software. In the course of field studies in the region، 40 samples were taken، 30 thin sections were prepared and polished. XRD analyses were performed on some whole rock samples. All major، minor and trace elements were assessed by ICP-MS at Lab Weft Laboratory in Australia. Based on the classification of structural zones، the area is located in the Sanandaj-Sirjan zone، hundred kilometers away from the main Zagros thrust along the NW-SE direction. After early Cimmerian orogeny، andesitic volcanic activity took place (Moein Vaziri and Aminsobhani، 1985). A major secondary mineral in these rocks is iddingsite، formed by hydration and oxidation of the olivine (Shelley، 1993). According to SiO2 against Na2O + K2O (TAS) diagram (Irvine and Baragar، 1971) and cationic R1 and R2 diagram (De La Roche et el.، 1980)، volcanic rocks of the area indicate alkaline series. To obtain more information on the tectonic setting of these rocks، the Zr/Y-Zr diagram by Pierce (Pearce and Norry، 1979) as well as Nb/Y versus Ti/Y diagram of Pierce (Pearce and Cann، 1973)، show that alkali basalt rocks in the study area are fitted in the field of within plate basalts. To determine the genesis of rocks from melting curve of Aldanmaz and Colleagues (Aldanmaz et al.، 2006) based on changes in REE (La on Sm/Yb)، the samples show approximately 1 to 5% partial melting of garnet lherzolites. The spider diagrams indicate that the studied rocks are enriched in LREE and LILE، depleted in HFSE with no Eu anomaly، Cs، Sr، and Pb positive anomalies which are the characteristics of alkaline magmas and high concentrations of incompatible elements and alkaline elements in the lava، implying the melting of the lower part of the mantle source. Light rare earth elements، are incompatible with the primary crystallized phases such as olivine، clinopyroxene and plagioclase، consequently focused increasingly during phase crystallization and fractionation in the remaining fluid (Hirschman، 1998). Based on microscopic and geochemical data، these rocks are alkali basalt، basanite and tephrite. The rocks contain olivine، pyroxene، feldspar، and minerals such as iddingsite، opaque and secondary minerals، calcite with porphyritic texture and microlitic and glassy matrix، vesicular and some glomeroporphyritic، vitrophyric and amygdaloidal textures. Most minerals have undulose extinction which indicates mantle deformation. Geochemical data for the rocks indicate high-K alkaline characteristic of the primary magma. The spider diagrams indicate that the studied rocks are enriched in LREE and LILE، depleted in HFSE with no negative Eu anomaly، positive anomalies of Cs، Sr، Pb which are characteristics of alkaline magmas. These rocks are produced by partial melting of garnet-lherzolite rich under lithospheric mantle. Based on tectonomagmatic diagrams، they are within plate basalts and by magmatic series graphs are alkali basalts. Microscopic evidence such as disequilibrium textures in the minerals (zoned state، solution and twinning) shows a magmatic contamination in mixing volcanic mass.

The Aligoudarz granitoid occurs in the central part of the Sanandaj-Sirjan Zone, western Iran. It comprises three distinct facies mainly of tonalite, granodiorite and granite composition. Magmatic microgranular enclaves (ME) extensively occur in granodiorite. Field, textural, whole rock and mineral chemistry data of the ME and the host rocks does not support magma mixing as the ME-forming mechanism. Major and trace elements variation diagrams, similarities in spider diagrams and geochemical modeling indicate the cogenetic relation of the ME and host rock. Fractional crystallization is the main process in the geneses of ME. Rapidly-cooled borders of the magma chamber can best explain formation of the ME. ME are the result of later fragmentation and dispersal of the rapidly-cooled borders in the host magma. These enclaves recorded the least degree of chemical exchange with the host. Biotite and amphibole crystallize with more rapid nucleation rates in rapid cooling zones. This process can explain different chemical behavior of the ME and the host rock.