---

The Mashhad ultramafic complex with a Permo-Triassic stratigraphic age is exposed at the NE of Binaloud Mountain and the SW to NW of Mashhad city. This area is mainly composed of mafic and ultramafic rocks, metamorphosed carbonate and pelitic rocks and granitoids in a NW- SE trend. Serpentinized amphibole-peridotites are the main types of ultramafic rocks in this area. Minerals in these rocks include olivine, orthopyroxene, clinopyroxene, brown amphibole and opaque minerals as the original minerals and serpentinite group minerals, tremolite, actinolite, chlorite, talc and carbonate minerals are the secondary minerals. The amphiboles are commonly of two types. One comprises brown to red-brown subhedral  pargasites. The second type is seen as colorless or pale green unhedral tremolite-actinolite. Variations in the cation proportions of Al, Fe, Cr and Ti  in structure of amphiboles are strongly influenced by adjacent minerals (e.g. olivine and pyroxene, especially iron-bearing phases such as chromite). Petrographic (textural relationships between minerals) and mineral chemistry data indicate that the pargasites in amphibole-peridotite in the study area compatible with metasomatized mantle peridotites in a subduction zone.

---

The Kamyaran ophiolite complex as a part of the Kermanshah ophiolite is located in western Iran, along the Zagros orogeny and Neotethys suture zone. The Kamyaran ophiolite complex includes serpentinized harzburgites, isotropic and layered gabbros, diabasic dykes and pillow basalts. The diabasic dykes have experienced upper green schist facies metamorphism. Based on mineral chemistry of the diabasic dykes, plagioclases are oligoclase to andesine and clinopyroxenes are diopside in these rocks. Tetrahedral site is occupied completely by Si and partially by Al (AlIV) in the clinopyroxenes. Oxygen fugacity during crystallization of the diabasic dykes magma, calculated using crystallization composition, points to effects of subduction process on diabasic dykes of the Kamyaran ophiolite complex. Clinopyroxene crystallized at less than 5 Kbar pressure in the presence of almost 2.5 percent H2O. Chemistry of clinopyroxenes indicates IAT characteristics for the original magmas, showing a supra-subduction environment for generation of the Kamyaran ophiolites.

---

The Takht-e-Soleyman complex is formed from various rock types including metapelites, metabasites and marbles which are metamorphosed under green schist through amphibolite to granulite facies. The amphibolites have been melted partially under high temperatures and mafic migmatites are formed in this regard. The pick metamorphic minerals of garnet amphibolites have been completely replaced by the low temperature plagioclase-hornblende symplectite. So, the pick metamorphic P-T conditions of these rocks (M₁) have not been recognized due to the lack of proper mineral assemblage and chemistry of phases. The retrograde P-T conditions (M₂) have been determined on the basis of textural evidence, equilibrium mineral assemblage and mineral chemistry as two stages: (1) the retrograde metamorphism as strong decreasing of pressure (M_2-a) and (2) cooling and decompression stage during exhumation of the rocks (M_2-b). The temperature and pressure conditions during M_2-a and M_2-b have been obtained as 650°C-700°C at 7-8 kbar and 510°C-570°C at 5.5-6 kbar, respectively. Considering textural evidence, mineral assemblage, thermobarometry estimations and clockwise retrograde P-T paths of the investigated rocks it can be considered that the first section of P-T path with deep dP/dT sleep indicates strong decreasing of pressure most probably related to thrust faulting resulted from crustal thickening during continental collision, whereas the second part of P-T path has been formed by cooling of the rocks related to crustal thinning and exhumation processes. So the retrograde metamorphism and exhumation of the Takht-e-Soleyman garnet amphibolites is consistent with the crustal thickening and its subsequent thinning due to compressions and extensions related to the Laramid orogenic phase during closuring of Neotethys.

---

The Qohrud granitoid is a part of the Urmia-Dokhtar magmatic assemblage. The main rock types are Miocene granite and tonalite. The hydrothermal activities were effective due to intrusion. Hydrothermal activities were more intense in the southern part of the pluton. This has produced relatively large automorph quartz crystals. The alteration of the granitoid wall rocks was accompanied with alteration of K-feldspar, plagioclase and biotite, which has released Sr, K, Rb and to the lesser amounts Al from the mineral structures into the hydrothermal fluid. ICP-MS analysis of quartz samples reveals increase in concentration of some elements including Li (10.33 ppm), Al (6900 ppm), K 9600 ppm) and considerably two elements Rb (1.2 ppm) and Sr (3.35 ppm), along with positive anomaly of HREE in comparison to LREE that all indicate an hydrothermal origin for the studied quartz crystals.  Using Ti content of quartz or TitaniQ thermometer gives temperatures of 307 to 547°C with an average of 371°C for crystallization of the quartz crystals. This temperature is in good agreement with temperatures calculated by fluid inclusions (306 to 550° C).

---

The Ghikhlar area is located at the NW Marand town, East Azarbaidjan. The wide range of Plio-Quaternary volcanic activites with volcanic and associated volcano-clastic rocks having compositions mainly as andesite to silica-undersaturated rocks (leucite basanite, leucite-tephrite and tephrite) have been covered mostly the rock units prior to the Cenozoic. The phenocrysts in andesites are amphibole, plagioclase and clinopyroxene which occurred in microcrystalline and microlithic matrix. The main characteristic of these rocks is bearing various enclaves as autholiths and xenoliths. The clinopyroxenes in the host andesite and cumulative enclaves are diopside to augite. The autholithic andesitic and dioritic enclaves indicates compositions as augite and dipside, respectively. Investigation of mineral chemistry and magmatic features for the host andesitic rocks and their enclaves are the main goal of this research. Variety of magmatic enclaves are including homogenic, cumulative and gabbroic ones. They all show similar mineralogy with host andesitic rocks whereas they are different texturally. Homogenic and gabbroic enclaves are more fine and coarse grained than host andesite, respectively. Cumulative enclave has been formed as aggregation of coarse grained ferromagnesian crystals similar with phenocrysts of andesite. On the basis of mineral chemistry data, composition of the host andesite as well as homogenic and cumulative enclaves are subalkaline with arc magmatic tectonic setting feature. However gabbroic enclave with alkaline characteristic corresponds to interior plate tectonic setting. Considering mineralogy, textural evidence and mineral chemistry data from the host andesite and their magmatic enclaves it can be concluded that the homogenic and cumulative enclaves are autoliths. The homogenic enclave corresponds to chilled margin of magma reservoir which disjoined during upward ascending of andesitic magma and their falling into magma chamber. Cumulative enclave resulted from aggregation of magmatic minerals in the magma chamber. About genesis of the gabbroic enclave it seems that gabbroic enclave has exotic genesis. Gabbroic rocks fall into andesitic magma during magma passing upward.

---

The Qotur metamorphic complex consists of metabasites, gneisses, marbles and calc-silicates as well as serpentinites which is cropped out at the west border of West Azerbaijan and Turkey. The amphibolites from the Qotur metamorphic complex can be classified as two types of ortho- and para-amphibolites. Minerals in this ortho-amphibolite are hornblende, plagioclase, zircon, titanite, and opaque minerals. The para-amphibolites are characterized by presence of calcite and quartz in addition to amphibole and plagioclase in their mineral assemblages. Tremolite/actinolite, chlorite and sericite are the retrograde phases of the green schist facies. Granoblastic and nematoblastic textures are the common textures of these rocks. Investigation of mineral chemistry and P-T estimations of amphibolites are the aim of this project. Based on electron microprobe analyzes on amphibolites, the amphibole and plagioclase compositions are determined as magnesio-hastengsite and oligoclase, respectively. Plotting of amphibole and titanite compositions on Ti vs. Si and Fe vs. Al diagrams respectively, shows their metamorphic genesis. The thermobarometry results of amphibolites have been obtained on the basis of amphibole and plagioclase compositions as well as utilizing of petrogenetic grids and experimentally determined phase diagrams. The peak metamorphic temperatures and pressures are estimated about 550-650°C and 6-8 Kb. The geothermal gradient is calculated about 25 °C/Km for the obtained temperatures and pressures which corresponds with continental collision conditions. It seems that Cretaceous closure of the Neotethys and its subsequent continental collision during Late Oligocene- Miocene formed the studied amphibolites at the continental crust of the Qotur area.

---

The pre-Eocene Allahyarlu ophiolitic- metamorphic complex is exposd in the core of the Allahyarlu anticline in the northwest of Iran and northeast of Meshginshahr. This complex consists of a variety of schist, gneiss, amphibolite and metadibase rocks with serpentinite and tectonic slices including gabbro, dunit, marble and diabase. Amphibolites can be divided into garnet-free amphibolite and garnet amphibolite. Hornblende and plagioclase are the main phases in the garnet-free amphibolite. Titanite, calcite, rare biotite, epidote, Fe-oxides and zircon constitute the minor phases. In garnet amphibolites, in addition to these minerals, garnet is also present. Porphyroblastic and nematoblastic are the common textures in these rocks. The study of mineral chemistry and determination of temperature and pressure conditions of amphibolites are the subject of this study. Based on the results of microprobe analyses in garnet-free amphibolites and garnet amphibolites, the amphiboles are of magnesium hornblende and tschermakite types, plagioclase composition ranges between andesine and albite, and in garnet amphibolites garnet has an almandine-rich nature. Based on the variations of Ti versus total Al (Alt), the studied amphiboles in the amphibolites of the Allahyarlu metamorphic complex are medium pressure amphiboles. The results of thermometry and barometry calculations on these rocks, based on the chemistry of amphibole, garnet and plagioclase, were obtained. The P-T estimates indicate an average pressure of 8Kbar and temperature of 600C for the peak of metamorphism. This is in accordance with Barrovian metamorphic gradients, indicative of crustal thickening (in volcanic or island arcs) or a collisional tectonic setting.

---

The process of migmatitization in the Ghareh Naz has resulted in the formation of various rate of partial melting and eventually the formation of a large spectrum of metatexite and diatexite migmatites. Mineral chemistry studies by EPMA method shows that amphibole composition is magnesio-hastingsite and has a metamorphic origin and feldspar composition is andesine to oligoclase. Effective reactions in the formation of the melt and Leucosome part of migmatites are include fluid-present reactions and fluid-absent reactions. High grade mineral assemblages are probably formed by the decomposition of lower-grade minerals by fluid absent reactions. The mineralogical composition of the leucosome is similar to that of tonalite to granodiorite resulting from partial melting and corresponds to the crystallization origin of the melt. Based on the thermobarometry of these rocks. the temperature is about 767 to 868 °C and the pressure is about 5.7 to 7.7 Kbar.
 

---

East Salmas gneisses are located in the northernmost parts of the Sanandaj-Sirjan zone and are seen in banded and deformed with the 6 different groups of lithological diversity. Their protolith is of paragneiss type with arkosic sedimentary rock type.Texturally, they are immature. Based on this study, chemical maturation trend of protolith of the present investigated gneisses are in the arid to semi-arid boundary climatic conditions with average granite composition and chemical alteration index of about 55%. The linear trend in the diagrams of major oxides variations of the parent gneisses in the region confirms the partial melting and granitization of the genesis in these rocks. According to the pattern of normalized diagrams, these rocks show good agreement with typical paragneiss diagrams of the world. Investigating the various diagrams reveals that the tectonic setting of the gneisses is mainly of continental margin type with passive sedimentary trend.

---

East Salmas Metabasites, as one of the most extensive units of the metamorphic complex, is located in the northwest of Sanandaj-Sirjan zone. These metabasites are mainly composed of amphibolite and green shist, alternating with geniss, metadiorite and marble metamorphic rocks. Metabasites are structurally oriented and mass, and grain size varies from small to medium. According to microscopic studies, the region's metabasites are classified into 6 amphibolitic and 4 schist subgroups. Amphibole, plagioclase, mica, spinel, and quartz are the main minerals from the microprobe results of metabasite samples. According to the chemistry of minerals, amphiboles are composed of magnesium hornblende and ferrotschermakite, plagioclase with component of andesine, mica with type of phlogopite and spinel groups with component of Al-spinel. Chemical composition of amphibole and plagioclase minerals was used for themometry and barometry of metabasite rocks in the region. Thereforet the results show that regional metamorphic rocks are formed in moderate temperature (550-600 ° C) and pressure (4-6 kbar) ranges, Barrovian-type amphibolite facies, 30 ° C / Km geothermal gradient and in the intra-continental orogenic environments.

---

The amphibolites of east Salmas, as one of the widest units of the metamorphic complex, are located in the northwest of Sanandaj-Sirjan zone, which according to field studies are mainly oriented and foliated amphibolites. Based on microscopic studies, amphibolites include amphibolites, biotite-amphibolites, epidote-amphibolite, biotite-epidote-amphibolite, tremolite-actinolite-amphibolite, and biotite-clinopyroxene-amphibolite. Amphibolite specimens of the region have maximum parallel pattern based on the variation diagrams of rare earth elements normalized to chondrite, EMORB and primary mantle and are similar to intra-plate basalts in terms of geochemical properties. According to the results of whole rock chemistry, the study amphibolites are mainly ortho-amphibolites with a basaltic protolith and calc-alkaline magmatic series, which are located in the intra-plate tectonic position.

---

The study area is located near the Zeinabad village, NW Tabriz. Precambrian to Cretaceous sedimentary units form the dominant outcropping rocks in this area. The investigated basic rocks including lava and diabasic dikes are intruded within the Late Triassic-Early Jurassic sandstone, conglomerate and shales of the Shemshak Formation. The basic rocks are extremely alterated and have abundant vesicles filled by secondary minerals of chlorite, calcite, Zeolite and opaque phases. Petrographic studies of the basic rocks reveal that the plagioclase forms the main constituent mineral and Fe-Mg bearing minerals (most probably hornblende) are completely altered to the calcite, chlorite, epidote and opaqe phases. The most significant textures are porphyry, glomeroporphyry, amygdaloid, sieve and sub-ophitic. Geochemically, the basic rocks are basalts with alkaline signitures. On the basis of variation diagrams, the compositions of analysed rocks are rich of U, Th and LILE (such as Ba, Rb). Positive anaomaly of Pb in these diagrams can be interpreted by the continental crust distribution and/or mantle wedge metasomatism related to the released fluids from subducted oceanic crust. Considering the REE diagrams, the rocks are rich in the LREE but poor in the HREE. High La can be related to Yb contents and can be interpreted to reveal their formations from the garnet bearing mantle sources. Tectonic setting of Zinabad basic rocks is determined as within plate setting. They form in relation with the extensional phases after continental collision during Cimmerian Orogeny in the Azarbaijan continental crust, NW Iran.
 

---

Contact metamorphism of Mishu is about 1 km wide and  is surrounded the  Cadomian Mishu granites. This Contact metamorphism is located in the southwest of Marnd city, Azerbaijan Province northwest of Iran. Based on injection of granites into Kahar Formation, the contact metamorphism facies can be identified easily, respectively albite-epidote hornfels to pyroxene hornfels facies. At high grade, hornfels with appropriate component show evidence of partial melting.  Contact rocks of Mishu that are exposed in south west of Eyshabad village spans a wide range in grade and proceeding upgrade metamorphic's phase that occurs such as: 1) slates which were regionally metamorphosed relate to Kahar Formation, 2) biotite cordierite hornfels that first appear by occuring biotite and cordierite in the spot slate, 3) andalusite cordierite  biotite hornfels with abundant porphyroblasts of cordierite and andalusite and 4) developments of K-feldspar-sillimanite hornfels and rocks with appearance of anatectic migmatites. This paper focus on contact rocks  from the view point of mineralogy, texture, chemical composition and tectonic setting of protolith are distinguish.