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

The Qorveh batholith, in the N-Sanandaj-Sirjan Zone, comprises several gabbroic, dioritic and granitic masses intruded the Jurassic metamorphic assemblage (i.e., schist, amphibolite and marble). In spite of a number of studies which have been carried out on the various aspects of these rocks, but none of them has been studied the Mixing/Mingling model. Thus, the purpose of present study is to examine the development of the magmatic mixing process in the rocks under study based on geochemical data obtained from the enclaves and their host rocks as well as their field relationship.

In order to study the geochemical properties of intrusive rocks, 10 samples of enclaves and their host rocks. The rock composition with the least amount of alteration was selected and sent to the Pennsylvania State University of (USA) to determine the amounts of major elements by ICP-AES method, and rare and rare earth elements by ICP-MS method.

Field observations:

The enclaves, in the intrusive masses under study, are finer than that of their host rock. Therefore, they belong to the group of mafic fine-grained enclaves or microgranular mafic enclaves. (MMEs). The (MMEs) are in rounded and elliptical shapes in the host rocks and generally they have a sharp contact with their host and are composed of igneous minerals.

Petrography:

The host rocks include granite, granodiorite and monzonite, and the enclaves are dioritic and gabbroic in composition. There are similar minerals in the enclaves and their host rocks, but they often differ in the amount of minerals. They are mainly composed of mafic mineral and plagioclase. While their host rocks are characterized by smaller amounts of these minerals, the host rocks instead have higher amounts of quartz alkali feldspar. The transfer of plagioclase crystals at the common boundary of the enclave and the host rock is evidence of the magmatic mixing process in the nature of the intrusive masses studied. A number of enclaves contain megacrystals of feldspar potassium and quartz taken from the host rocks. This supports the formation of enclaves by mixing.

Geochemistry:

Geochemical studies indicate that these rocks are metaluminous, belonging to calc-alkaline magma series, having I-type characteristics. In Harker diagrams, mafic enclaves have higher MgO, TiO2, P2O5, Na2O, FeO(t), Al2O3, MnO and CaO contents than that of the host rocks, and lower K2O and SiO2 contents. The higher contents of CaO, MgO and FeO(t) in the enclaves, compared to their host, confirms their more mafic nature, which is usually proportional to the higher contents of mafic minerals in the modal of the enclaves than that of the host. The enrichment of the studied enclaves in Co, Cr, Ni display that these rocks are globules of mafic magmas mingling to felsic type.

According to field observations as well as petrographic studies, the effective factor in the evolution of magma forming intrusive masses has been mentioned as magmatic mixing. The presence of mafic fine-grained enclaves with evidence of disequilibrium textures such as feldspar with poikilitic texture, the presence of mafic masses and needle apatite, small blades-shaped plagioclase within large plagioclase or two types of plagioclases, and zoning all confirm magmatic mingling/ mixing processes. Considering that the magnesium number (Mg#) in the mantle is about 0.7 and the studied enclaves with a high magnesium number of 0.52-0.62 are evidence of the involvement of mantle-derived mafic magma. High values of Mg# in enclaves compared to their host rock (0.34-0.48) shows the mixing of magmas from the mantle with the crustal magmas. Magma mixing model has also been considered by geochemical differentiation diagrams. The trend of the samples is a curve and indicates that the effective process in magma evolution is most likely magmatic fusion. Numerous studies have shown that mafic microgranular enclaves are globules of a mantle derived mafic magma that crystallize rapidly in the injected felsic magma from the crust and, as a result, become more viscous, forming separated magmatic bubbles. In addition to the mentioned geochemical features, the enclaves are poor in LREE and LILE and enriched in Ti compared to the host rocks. Therefore, they seem to have originated from two different magmas and are placed together due to magmatic mixing.

The host rock units in the studied intrusions include granite, granodiorite, monzonite and gabbroic, dioritic enclaves. The constituent magma of this complex is in I- type, metaluminous and is in the calc-alkaline series. Based on the studies, the dominant process in the evolution of magmatic mixing. Some new findings include the presence of reversals in submerged slabs and the penetration of fleshy compounds. Which naturally have different temperatures and compositions compared to higher crustal horizon magmas, provides conditions for the occurrence and the development of the magmatic mixing process.

This is the first report on the presence of podiform chromititeLenses associated with the Marivan ophiolite. These ore deposits with granular massive fabric are hosted by dunite and harzburgite occurred in south Marivan city. Chemistry of chromian spinel in the chromite Lenses indicated that Cr#  for two ore occurrences is high (0.85) with very low TiO2, but for the other ore occurrence is lower (0.67) with higher TiO2 (0.05). The finding shows that the chromite ore Lenses and consequently their host ophiolite were developed in two different geotectonical settings. Geochemical data indicated that some of the studied ore deposits occurred during the opening of oceanic crust in a Mid Oceanic Ridge setting from a tholeiitic magma while the others were fractionated form a boninitic melt in a Supra Subduction Zone. Formation of these ore Lenses and the host rocks occurred in response to the very fast divergence and then convergence of Neo-Tethys oceanic crust. A wide range of gabbros including coarse-grained gabbro, melagabbro and microgabbro host ilmenite, magnetite and titanite in three regions at the northwest of Kamyaran (Yakhtekhan village), the east of Sarvabad (Mianeh village) and the south of Marivan (Dragashikhan-Vyseh villages). Ilmenite is found in all the three regions, but magnetite and titanite are only found in the east of Sarvabad. Plagioclase (andesine-labradorite) and diopside, the main rock-forming minerals with minor augite, olivine and amphibole are the minerals of the host rocks. The chemical composition of the ilmenites showed that the average concentration of TiO2 increases from Kamyaran (43.19 wt.%) to Sarvabad (46.09 wt.%) and then to Marivan (47.42 wt.%). These minerals occur as interstitial fine to medium grains (up to 1.5 mm) and often in the amoeboid, anhedral and to a lesser extent as subhedral forms. Based on textural and mineral chemistry evidence, mineralization of titanium occurred as the result of magma oxidation. The oxidation of magma resulted in the formation of iron-titanium immiscible liquid droplets, following the plagioclase crystallization.

Kurdistan dam watershed with an area of 120.15 km2is located in the northeast of Saqez city.The purpose of this study is to analyze the tectonic activity of the basin and the relationship between faults and landslide risk using the information value model. First, the region is divided into 15 sub-basins using ArcHydro software and morphotectonic indexes including Stream Length Gradient Index (SL), Asymmetric Factor (AF), Hypsometric Integra (Hi), Transverse Topographic Symmetry Factor (T) and basin shape ratio (Bs) are calculated and the results are calculated. Their evaluation was evaluated with active tectonics index (IAT). In order to evaluate the relationship between faults and landslide risk, first a map of faults and maps of factors affecting landslides were prepared by processing satellite images of Landsat 8 sensor and ENVI software and field observations. Then, using the information value model, landslide hazard map of the basin was prepared and combined with the fault map and the relationship between faults and landslide risk in ArcGIS. 10.3 environment was reviewed. The results of calculating the relative active tectonics indices show that 77.77% of the basin is tectonically active in the active class and in the information value model 55.55% of the occurrence of landslides is in the range of high instability risk. Distance coefficients from faults in both positive models and most landslides occurred at a distance of less than 1000 meters and due to active tectonics there is a significant relationship between faults and areas with high landslide risk in the basin. The results showed that the information value model has better performance for landslide risk zoning. In general, diversity of lithology, topography, abundant national and local faults and climatic conditions can be mentioned as the most important factors in the occurrence and distribution of landslides.

The Ebrahim-Abad iron deposit, consisting of Paleozoic metamorphic rocks, Mesozoic plutonic bodies and metasomatic rocks, occurred in the northwest of Divandere and the Sanandaj- Sirjan structural zone.The metamorphic rocks including micaschist and marble are cut by plutonic intrusive rocks (granodiorite to milonitic and cataclastic granite). Mica schist and associated detrital sediments have been changed in the low- grade greenschist facies. Marbles and plutonic rocks have also undergone cataclastic metamorphism along shear zones. Metasomatic rocks are garnet- amphibolite to garnititic skarn composition crosscutting by magnetic veins. Iron mineralization as magnetite, chiefly occurred as lenses, veins and veinlets as well as dissimented grains. Massive, dissiminated, replacement, and network textures are the main textures of this deposit. Magnetite developed as amorphous, fine (less than 1 mm), or dissiminated. Chlorite, trermolite- actinolite, epidote, garnet, and quartz with minor clay minerals and calcite are the gangue minerals of the studied ore deposit. Iron oxide grade varies from 14 to 47 FeO%. Fe shows a negative correlation with S, and Si, Al, Mg, Mn, Ca, K oxides but positive correlation with Cr and Co. Ti/Ni+Cr and Ni/Cr diagrams point to the hydrothermal origin of the iron ore under study. The variations in the cobalt, nickel, vanadium, and titanium contents indicate that the skarn- hydrothermal origin of the Ebrahim- Abad iron deposit. It seems that the iron oxide remobilized by hot hydrothermal fluids originated from intrusive bodies and redeposited in marble, mica schist, greenschist, and skarn.

The Iranian plateau is part of the Alpine-Himalayan orogenic belt, which consists of several continental fragments separated from each other by major boundary faults and/or ophiolitic suture zones (Gansser, 1981). Generally, the tectonic evolution of Iran has been controlled by the opening and closure of the Proto-Tethys, Paleo-Tethys and the Neo-Tethys during the Precambrian-Cambrian, Paleozoic and Cenozoic, respectively.The study area is located in the northwest of Iran (the Kurdistan province) and 20 km northeast of the city of Saqez. This area is a part of the northern Sanandaj-Sirjan Zone (Aghanabati, 2005). This belt is response to opening and subduction of Neo-Tethyan oceanic crust beneath the Central Iran (Alavi, 1994). During Cretaceous-Tertiary eras, numerous granitoid bodies were formed in this belt. The Saheb granitoid is one of these granitoid bodies which mainly consists of monzogranite, quartz monzonite and quartz monzodiorite. The aim of this research study is to discuss the evolution of the Late Cretaceous-Early Paleocene Saheb granitoids in the Sanandaj-Sirjan zone based on geology, petrography and geochronology results.

In this study, 70 rock samples were collected from different types of intrusive rocks from which 30 thin sections were prepared for petrographic studies. Furthermore, four samples from the granitoid bodies (quartz monzonite, quartz monzodiorite and monzogranite) were selected for U-Pb dating. Approximately 100 to 150 zircon grains were hand-picked by a binocular microscope from each sample. Cathodo-luminescence imaging and dating of zircon grains were examined at the China University Geosciences (Wuhan branch). Geochronological analysis were performed by using the (LA)-ICP-MS method at the China University Geosciences (Wuhan branch). The detailed analytical method is presented in Liu et al. (2010a, 2010b).

Geology of the study area:

The Saheb granitoid body is located in the Sanandaj-Sirjan zone. According to the geological map of Chapan (scale: 1/100000, Kholghi khosraghi, 1999), the Precambrian to Quaternary units are exposed in the study area. The oldest units are the Kahar, Bayandor and Soltanieh Formations with Precambrian to Cambrian age. The Permian sediments, the Ruteh and Doroud Formations, include sandstone, shale and carbonate. The Jurassic units are found in the northwest of the region, and include sandstones and shale. The Cretaceous sedimentary units are located in the south of the study area. These sediments contain sandstone, limestone, silty-limestone, shale and dolomitic limestone. During Late Cretaceous-Early Paleocene era the Saheb granitoid intruded within the oldest units and caused Fe skarn type deposits in the Saheb area. The Saheb granitoid have been cut by a series of diabasic dikes.

The Saheb granitoid consists of several intrusive bodies containing quartz monzonite, quartz monzodiorite and monzogranite. The major minerals in the quartz monzodiorite consist of plagioclase (35- 40%), quartz (15- 20%), orthoclase (20- 25%), and mafic minerals such as biotite and amphibole (10-15%) with granular texture. The quartz monzonitic rocks show granular and poikilitic textures. Plagioclase (25- 35%), quartz, orthoclase (30- 40%), biotite and amphibole (10-15%) are the main important minerals in the quartz monzonite. Plagioclase (20-25%), quartz (20-30%), orthoclase (30-40%), biotite and amphibole (15%) are the major minerals in the monzogranite.Zoning in zircon crystals from all four samples is well developed representing their magmatic origin (Hancar and Miller, 1993). Measurements of U-Pb in the Saheb granitoid zircon grains of quartz monzonite samples show their ages to be 62.03±0.56 Ma and 58.9±0.9 Ma. The age of monzogranite is 67.9±1.3 Ma and the age of quartz monzodiorite is 61.1±0.56 Ma. Generally, the age of this granitoid body indicates that the Saheb granitoid has occurred during the Cretaceous- Paleocene time.

Based on field and microscopic studies, the Saheb granitoid bodies have been divided into three types of quartz-monzonite, quartz-monzodiorite and monzogranite. The field and mineralogical studies suggest that the Saheb granitoid is an I-type granitoid. The mineralogical variations in this granitoid suggest that the fractional crystallization has played an important role in differentiation of different compositional phases in the Saheb granitoid.According to the geochronological results, during Late Cretaceous to Early Paleocene, the Saheb granitoid intruded within the Permian and Cretaceous units in the magmatic-metamorphic Sanandaj-Sirjan zone. These granitoids were formed by subduction of Neo-Tethys Ocean beneath the Iranian plateau. It should be mentioned that the intrusion of these granitoids into the Permian carbonates and Cretaceous carbonate and shale caused formation of skarn type iron oxide mineralization.

The Ahmadabad, Tahmoures and Ghareh-toreh volcanoes are part of the volcanic centers located on the Qorveh-Bijar axis and constitute a part of the magmatic outcrops of the northern arm of the Sanandaj Sirjan Zone, Hamadan-Tabriz. Volcanic rocks have basaltic composition and show porphyritic, microlithic porphyry and glomeroporphyritic textures. Major phenocrysts include clinopyroxene and olivine. The abundance of clinopyroxene is found to be lower in Ghareh-toreh basalts, olivine is major phenocryst in this center. Clinopyroxene phenocrysts show normal, in some cases, reverse zoning and gulf corrosion indicating disequilibrium with the host's melt. The results of thermobarometric calculation (temperature and pressure) using clinopyroxene mineral indicate the temperatures of 1100-11300 °C and pressures of 3 to 11 kbar for Ahmadabad and Tahmoures volcanoes, and volcanic basalts at Ghareh-toreh reveal the temperature of 800 Up to 1100 °C and pressure of 0 to 3 kbar. The high oxygen fugacity in these rocks and the coherence of the temperature and pressure of the olivine phenocryst in this region with the temperature and pressure of the clinopyroxene in Ahmedabad and Tahmoures, all show that clinopyroxene crystals of Ghareh-toreh volcano formed at a lower depth and possibly in a shallow reservoir

At the structural of Sanandaj - Sirjan, Zone of Iran (Kurdistan providence) Kuh-Siyah and Tahmoures young volcanic rocks are exposed. The main phenocrystals of these rocks consist of olivine and clinopyroxene. These metaluminous rocks are combinations of trachy basalt, basalt to havaiite have shoshonitic to alkaline affinities. Based on geochemical studies, the partial melting of a garnet - spinel Lherzolitic source was responsible for the magma generation. The basic rocks, have LILE enrichment and low content of HFSE. Enrichment of LREE can influence magmatic evolution (High depth and low partial melting degree) and tectonic setting of the formation of rocks, attributed. Significant depletion of HREE could be as a result of residue of the mineral garnet phase in the liquid production process. The studied alkali-basalts have all the high Nb basalts signatures such as Nb>18 ppm, Sr/Y>25, La/Yb>14, low Rb/Sr and Yb. Hence these are high Nb basalts, but isotopic investigations are required to confirm it.

Scoria cones are one of the main parts of East of Kurdistan volcanoes. Olivine, Pyroxene, Plagioclase and Biotite are main phonocrystals with Amygdaloidal-glassy matrix. This paper was studied processes of bubbles nucleation and grow during the eruption of scoria's unite using the Bubble Size Distribution (BSD) method including study of population density, bubbles volume, 3D modeling, nucleation and bubble growth. For selected sample from different cone, in total was measured 3623 bubbles and drawn that bubbles volumes calculated from 40 to 85 percent. Using the 2D bubbles shape renovated 3D bubbles schematic shape and compared together. Most population for four samples bubbles shapes are near to sphere and for other four samples are ellipsoid. Longest ellipsoid bubbles shape has 1:3.2:8 diagonals ratio that it’s flat ellipsoid. The longest diameter (L) is perpendicular to the surface and parallel to lower pressure dictated on magma and bubbles could be growth more than other sides. Presence of 2-5 peaks in frequency distribution versus bubble size diagram, suggesting unimodal, polymodal, exponential and power low events for bubbles generation in the east of Kurdistan Scoria's. Nucleation density increased from first to lasts generation but bubbles growth reduced. Recur of bubble forming in macroscopic samples, microscopy, SEM and nucleation and grow model suggested fractal model.

Metamorphic area, which is a subject of this study, is located in S-Qorveh (Zarineh region), northwest of the Sanadaj-Sirjan zone. According to the recent dating, the S-Qorveh plutonic body consists of a complex of granitoids, granodiorites, quartz monzonites, and gabbros, have intruded into the host metamorphic rocks, about 149-152 Ma and have generated contact metamorphism. Intrusions of various masses and protolites, such as politic and basic layers, have made metamorphic rocks of this area to be different. Regional metamorphic rocks include slates, schists, and amphibolites which are metamorphosed in the range of middle green schists to the early amphibolites facies. Contact metamorphic rocks include spotted slates, mica hornfels, and cordierite hornfels which have been subject to metamorphism from albite-epidote hornfels to hornblende- hornfels facies. In cordierite hornfelses facis, by getting far from the intrusion, cordierite crystals become smaller in size and larger in number. According to the petrographic evidence, metamorphic rocks of this area have been subject to 3 phases of metamorphisms including probably high pressure regional metamorphism, regional metamorphism, and medium contact metamorphism. To estimate the metamorphism pressure-temperature state of this zone, TERMOCALC computer software and also linear calibrations have been used. Pressure-temperature calculations for regional metamorphic M1, have shown 3.9 Kbar pressure and 539°C temperature. For contact metamorphism M2, by using the software, average pressure of 4.3 Kbar and average temperature of 607°C have been calculated. Also, for the contact metamorphism M2, using the experimental calibration of biotite-muscovite equilibrium, the temperature estimated to be 581.3°C and using chlorite-muscovite equilibrium for this phase (stage) of metamorphism, pressure and temperature have been yielded 3.65Kbar and 620°C, respectively. In generally, results of temperatures for all metamorphic rocks are acceptable and satisfactory, but in contact metamorphic rocks, data of pressure may be higher due to emplacement of the granitoid intrusive body.

The study of the past glaciers and its effects are the most important subjects of the quaternary period. The most important climatic evidence of the quaternary is also in the mountains of Iran, especially in the Alborz, west and northwest of the country is glaciers and related landforms. Geomorphologic studies focusing on glacial and periglacial landforms allow us to get a better insight into the spatial diversity of present and past climates. The Chehelcheshmeh and Saral Mountains are among the coldest mountainous regions in the country.These regions during the quaternary period was mainly influenced by glacial processes. The aim of this study was to reconstruct the quaternary snowline and morphodynamic zones based on glacial evidence.
2- Chehelcheshmeh and Saral Mountains are located 46 degrees, 28 minutes to 46 degrees and 58 minutes east longitude, and 35 degrees and 34 minutes to 36 degrees north latitude. The method of this research is analytical-descriptive and data collection method is library and field. The data used in this study includes aerial images, DEM, topographic maps and geological maps, and analysis tools including Arc Map version 10 and Gradistat version 4 software. In this research to recreate the glacier zone we used Wright and Porter methods. The permanent snowline in the Wright method is equivalent to an elevation of 60% of the cirques in the area above that height. For calculation of ELA in the method of cirque-floor altitudes, a mode has been used for classified data. For laboratory studies in this research, we used two granulometry and microscopic methods for three sediment samples. For granulometric Process, we used Seave analyzes for particle with a diameter of more than 2 mm and Laser analysis for sediment grains with a diameter of less than 2 mm. Then, based on laboratory studies and field observations (to better control and identify the landforms) and with the help of aerial imagery, the study of elevational digital model and the study of geomorphologic landforms was identified evidence of each of glacial and periglacial morphodynamic zones.
3- In the survey of the study area, 25 glacier cirques were identified, some of which are well seen by the surrounding landforms. Distribution of glacier cirques showed that the glacier extent was down to 1280 meters high. In accordance with the Porter's cirque floor altitude, the final limit of the quaternary snowline was 2483 meters above sea level, which considering the active glacier valleys, glacial evidence was also seen below this elevation. In the field observations, it was found that glacial deposits are located in the Ghezel Ozan river and at a height of 1900 meters. To determine the sedimentation environment, the results of Laser and Sieve analysis on the samples showed that the studied area is affected by the processes of freezing and melting in a cold environment by preserving plant remains and heterogeneous distribution and particles bad sorting. Maintaining feldspar minerals is another result of laboratory work, which indicates severe mechanical erosion and very low chemical erosion in the study area. The lack of clay and colloidal sediments confirms this.The glacial and periglacial morphodynamic zones in this research were studied using their evidence that was identified many of the relevant landforms including Cirques, Glacial valleys, Tills, Erratic rocks, Solifluction lobes, Rock cracking , Moraines, Avalanches and Rock steps.
4- Investigation of glacial and periglacial evidence showed that quaternary snowlines in the mountains of Chehelcheshmeh and Saral compared to the investigations carried out on the Alborz, Zagros and central iran mountains at lower altitudes. Different climate of Kurdistan mountains compared with other parts of Iran is one of the main reasons for the low elevation of snowline in the region, so that the minimum temperatures in the synoptic stations of Zarrineh Obato and Heazrkanian that located in two catchment basins in the cold seasons it is mostly critical and one of the coldest parts of the country. Sedimentological evidence and laboratory analysis also indicate a cold environment in the study area mainly influenced by snow melting processes and mechanical processes, in many instances, irregular arrangement and bad sorting are observed and coarse particles constitute the highest weight percent. In the study of field evidence, many landforms and processes were identified that, considering the distribution of glacial evidence in the present, lower boundary of the periglacial morphodynamic active zone was introduced the 2750 contour.

The Qahr-abad fluorite deposit is located ~58 km southeast of Saqqez city, Kurdistan province. This deposit is developed as scatter lenses, veins, and veinlets (stockwork structure) within carbonate rocks. Violet, green and colorless fluorites are recognized. Quartz, dolomite, calcite and barite are gangues. REE geochemistry of the depositshows that the REE content of the fluorites lies between 20.18 and 48.38 ppm. The relatively higher concentration of LREEs in violet and colorless fluorites suggests that they formed at the first stages of mineralization. Calculation of Eu anomalies indicates that the fluorites formed in an alkaline to neutral and to some extent oxidizing conditions because the Eu anomaly cover a narrow range around 1. Negative Ceanomaly also confirms the oxidizing conditions for mineralizing fluids. Finally, by the studies of REE geochemistry it can be concluded that the Qahr-Abad fluorite deposit is a product of hydrothermal activity of epithermal type and the mineralizing fluids were of magmatic or a basin fossil fluids origin.Magmatic activities in this district, can explain the hydrothermal nature for the deposit.

Arsenic is one of the most toxic and dangerous soluble substances in natural water. It has long-term ill effects on human health. Arsenic-contaminated water resources have been reported many parts of the world and Iran, particularly the Kurdistan province in the west of the country. The aim of this study is to identify the source of arsenic and mechanisms of its release into groundwater resources of the Chahardoli plain aquifers. Groundwater resources in this plain supply much of the water needs for drinking, agriculture and industry. Therefore, 31 water samples were collected the plain aquifer and chemically analyzed for major and minor ions in the Hydrology Laboratory of Earth Sciences Department of the Tabriz University. Also, the trace elements were analyzed in the Kurdistan Waste Water Organization Laboratory. The results show high arsenic concentrations in the groundwater of the area. The highest arsenic concentration (270 µg/L) is related to a well located in the northwest part of the area which supplies water for agricultural purposes of Delbaran sector. According to the results obtained multi-variable and graphical methods, there is a meaningful correlation between arsenic and major ions such as Na and K as well as silica, indicating that the source of arsenic is volcanic rocks. It is therefore a geogenic rather than an anthropogenic phenomenon. The mechanism of arsenic releases into the water can be related to competitive adsorption of dissolved SiO2 in adsorption sites such as oxides of iron, aluminium and manganese.

Separation of high grade from low grade veins and veinlets is very important operation in vein type deposits, especially in gold deposits because low value variations are very significant in their mineral exploration. In this paper, Concentration-Volume (C-V) fractal model was utilized for separation and classification of gold veins in the Qolqoleh deposit, which is located in the Kordestan province, NW of the Sanandaj- Sirjan metamorphic structural zone. Based on the obtained results from the model, different populations consisting of wall rocks, low grade, moderately grade, high grade and enriched zones were separated in the deposit. Rock types of the deposit were correlated with resulted mineralized zones by log ratio matrix. The most parts of the deposit have Au values lower than 3.98 ppm including low and moderately grade veins. However, mineralized veins hosted in chlorite-schists and this can be one of the exploration keys for gold prospecting in other parts of the Sanandaj-Sirjan zone.

The Plio- Quaternary volcanoes are located in the NE-Qorveh (Kurdistan) in the Qorveh-Takab volcanic belt, in the Hamedan-Tabriz Zone (HTZ). The volcanic rocks consist of basalt to olivine-basalt. The electron microprobe (EMP) analyses of pyroxenes show occurrence of one type of clinopyroxene, as diopside (Fs 2.65-6.42 En 40.44-50.47 Wo45.97-53.14) with Mg # = 84-98. The compositions of the pyroxenes suggest that rocks belong to alkaline-subalkaline magmatic series.  Considering different methods of geothermometry of clinopyroxene, the temperature of  crystallization stage for pyroxene was 800-1300°C. Distribution of Al in octahedral and tetrahedral sites of pyroxenes displays that this mineral is crystallized from a magma with ˂ 10% water contents, in low-medium pressure which is in accordance with their formation the depth of 18-30 km. Fe+3 content of clinopyroxenes  implies crystallization in high oxygen fugacity condition.

In the northeastern part of Kurdistan province، there are many volcanic cones that are basaltic in composition. Petrographic investigations reveal these rocks are dominated by clinopyroxene and olivine phenocrysts and plagioclase and pyroxene micro crystals، while space between them is filled by opaque mineral and brown glass. The presence of zoned pyroxenes and sieve texture in these rocks are evidences of crustal contamination and magmatic unequilibrium. The studied rocks with 5-14% normative nepheline are alkaline nature. On Harker diagrams fractional crystallization is indicated by MgO decreasing while CaO، FeO، Ni، TiO2 and Cr and SiO2 increase. On discriminated diagrams the tectonic environment of the samples is inter continental extensional zone. Geochemical characteristics such as LILE، LREE enrichment، Nb، Ta and Y negative anomalies، positive anomalies of Ba، Pb، Th and Th/Yb enrichment suggest that the basaltic lavas studied derived from lithospheric mantle that contaminated by subduction fluids. Also، Zr/Hf and Hf/La ratios are evidence for upper crustal contamination. High (Th/Yb) N، (La/Yb) N and high Nb anomaly (0. 37-0. 98) show that the magma generated from a garnet lherzolitic source.

The studied mylonitic granitoid is part of the granitiod batholite of south of Qorveh. Range of lithology of this complex is including granite, aplite with less abundant, biotitegranodiorite. These rocks are emplaced in a shear zone after they formed. Based on differences rate of strain, they are deformed as mylonitized and deformed rocks. Observations of field, petrographical and geochemical data imlpy they belong to I- type, poorly peraluminous and calalkaline series. Geochemical evidence of trace elements such as enrichment for large ion litophile elements (LILEs) and Pb, along with the negative anomaly field strength elements (HFSEs) and Ba and low ratios of Al2O3/(FeOt + MgO+TiO2) and meduim –high (Na2O+ K2O)/ (FeOt+ MgO+TiO2) indicate that origin of initial magma is continental crust that created in a margin of convergent plate. This magma may be formed by partial melting of protolites of lower crustal (e.g. greywacke).

The studied shear zone is located in E-Qorveh (Kurdistan). The rocks of this zone are granite and granodiorite in composition. In present paper, deformed rocks, protomylonites and mylonites, are investigated in Sangin-Abad, Koh-e-Gazgaz and Poloserkan areas. Petrographic studies show that evidence of tectonic activities are such as myrmekite, recrystallized and slide alkali feldspars, fractured plagioclases, dynamic quartzes, perthitic orthoclase, feldspar crystals with enriched rim from alkalis (mantled texture) with Or 91.19 - 91.54. Comparing geochemical data of whole-rocks and primary rock (protolith) reveal that there are varieties in abundances of main elements such as increasing of CaO، MnO، TiO2 & P2O5 in protomylointes and mylonites. Also, quartz-rich veins and plagioclases altered have observed in the zone. These examples are interpreted to present activities of hydrothermal fluids and open system. The Feldspars are sodic-potsic and sodic in composition in Sangin-Abad & Koh-e-Gazgaz, and Poloserkan. Overall, relationship field, microstructural, textural, geochemical and mineral chemistry characteristics confirm role of the shear zone for formation of these features.  Many of researchers have approved relationship between forming of microstructures with stress/ strain and hydrothermal fluids. The studied biotite crystals with content of (∑FeO + MnO ≈ 13.4-42.21) are neoform. They may be occurred by post-magmatic fluids of the Qorveh granitoid batholith. Formation temperature of biotites is ~550 to ~750 ºC which corresponds to this deformation temperature.

Statistical measurements of crystal size distributions (CSD) are the new method for studying physical and petrological properties of igneous rocks. With emphasis on this method، the Plio-Quaternary lavas volcanic in the NE- Qorveh city are investigated. The lavas are basaltic in composition and there are pyroxenes with sieve texture، skeletal olivines، quartz with gulf corrosion and gneissic xenoliths. Quantity textures are studied in the CSD method. The rate of nucleation and growth timing of crystals are determined by pyroxene crystals size distributions. Timing of growth of pyroxene crystals between 17-36 years suggesting stability of crystallization conditions during eruption in the area. We used the logarithmic population density vs. crystal size diagrams with processing the software CSD correction. In the basaltic rocks of Qezelje-Kand village magmatic contamination occurred. In other volcanoes، such as the Qare-Bolaq volcano، residence time of magma was short.

The study area is located northwest of Iran (38 km SW of Qorveh); which is a part of Sanandaj-Sirjan Zone. The lithology of this pegmatite complex varies from pegmatitic syenogranite to granodiorite, which were intruded in the dolomitic marbels of the area. Field observation, thin sections studies, XRD, XRF and ICP analyses on minerals and rocks in the area show that the composition of these pegmatites vary from the rim to the center. In the center of the pegmatitic dyke, the grains are coarser and concentrations of quartz and feldspar increase, while the mica decreases. The geochemical study on the minerals indicate high amount of Ta (92-93.5 ppm), Tl (9 ppm), Ti (5275 ppm), Zn (668-724 ppm), Ag (29-33 ppm) and Nb (1620-1710 ppm) in biotites and Ga (212-214 ppm), W (33-40 ppm) and Sn (85-87 ppm) in muscovites. Also garnets which exist in pegmatites are almandine-spessartine enriched in Y (1120-1150 ppm) and the amount of HREE/LREE elements in these garnets is high. In the analyzed beryls the amount of Ni (15-17 ppm), V (9-12 ppm), Cu (22-29 ppm) and Cs (108-123 ppm) elements is high.