Three fundamental goals will be followed in the study of metamorphic terrains including: 1- study of fabric in metamorphic rocks in order to recognize the relationship between metamorphism and deformation, 2- the identification of thermodynamic conditions of metamorphism for evaluating the geothermal gradient, and 3- study of protolites of metamorphic rocks and the recognition of Paleo-tectonomagmatic setting of igneous rocks. Takab-Takht-e-Soleyman-Angouran metallogenic –metamorphic zone located parallel to the Zagros suture zone within the Alpine–Himalayan orogenic belt. Halab metamorphic sequence is located in the Eastern part of this zone. This metamorphic sequence is composed of pelitic, mafic and felsic schists intercalated with marble, mylonitic rhyolite and quartzite which are metamorphosed in amphibolite and green schist facieses. Takab-Takht-e-Soleyman-Angouran metallogenic –metamorphic zone is one of the most important metallogenic zones in Iran. The Zarshouran As–Au deposit, Aghdareh Sb–Au deposit and Angouran Zn–Pb deposit along with some Fe, Pb–Zn, Au, Cu and Mn mineralization were formed within this zone. Most of this mineralization was studied during the past years and valuable information is present about their geological and mineralization characteristics. However, geochemistry and tectonomagmatic settings of metamorphosed volcanic rocks (felsic and mafic schists) were not studied. This research can be divided into two parts including field and laboratory studies. Field studies include the recognition of different metamorphic rocks along with sampling from metamorphic rocks for laboratory studies. In this base, 40 samples were chosen for petrographic and analytical studies. Twenty thin sections were used for petrographic studies and recognition of metamorphic fabrics. For geochemical studies, thirteen samples from felsic and mafic schists were analyzed by XRF and ICP–MS methods in GSI and Zarazma laboratories. Mafic schists are one of the most important metamorphic rocks in the Halab area. Compositionally, these rocks include actinolite schist, hornblende schist and amphibole schist. Felsic schists are the other important rocks in the Halab metamorphic sequence. These rocks include albite-quartz schist, biotite-quartz schist, amphibole-biotite-quartz schist and mylonitic rhyolite. Geochemically, mafic schists show a similar composition to basalt, trachy-basalt, basaltic andesite and basaltic trachy-andesite while felsic schist show rhyolitic composition. All of these rocks have calc-alkaline to high-K calc-alkaline affinity.  Trace elements normalized by primitive mantle (McDonough and Sun, 1995) and NMORB (Gale et. al., 2013) for felsic schists indicate LILE enrichment along with negative HFSE anomaly and distinctive positive Pb anomaly. A similar pattern is observed for most of the mafic schists. Amphibole schists do not show LILE enrichment, as well as positive Pb and negative HFSE anomalies. Chondrite-normalized (McDonough and Sun, 1995) REE patterns for felsic schists demonstrate LREE enrichment along with negative Eu anomaly and flat HREE patterns. Most of the mafic schists have similar patterns without negative Eu anomaly. Amphibole schists indicate a flat REE pattern with less LREE enrichment and relative enrichment in HREE compared with other mafic schists. Comparison of Chondrite-normalized REE patterns of mafic schists with NMORB and EMORB patterns and island arc basalts (Gale et al., 2013) indicate that basic schists of Halab area have similar patterns to EMORB. Based on Ta/Yb vs. Th/Yb and Yb vs. Th/Ta discrimination diagrams, protolites of mafic schists were formed in within plate volcanic zone and active continental margin while protolites of felsic schists were formed within active continental margin. On the Nb/Yb vs. Th/Yb diagram, mafic schists belongs to subduction-unrelated setting and originated from mantle similar to OIB source.  Takab-Takht-e-Soleyman-Angouran metallogenic –metamorphic zone is considered as a micro-continent with similar features to Gondwana (Hajialioghli et al., 2007). The oldest outcrops of metamorphic rocks in this zone are the result of metamorphism of magmatic arc rocks with Neo-Protrozoic–Early Cambrian age (Saki, 2010). As it was mentioned before, mafic and felsic schists of the Halab area demonstrate calc-alkaline to high-K calc-alkaline affinity. High-K calc-alkaline rocks are usually formed in magmatic arcs and post collision setting and are less seen within plate setting (Bonin, 2004). Enrichment in LILE and LREE along with Nb and Ti negative anomalies in spider diagrams are indicators of subduction related magmas which are originated from enriched mantle by metasomatic fluids released from subducted slab (Wang and Chung, 2004). Geochemical characteristics of mafic and felsic schists of the Halab area indicate that the protolites of mafic schists originated from partial melting of metasomatized mantle by past subduction in an extensional setting within a magmatic arc. Felsic schists are the result of crustal partial melting by mentioned basaltic magma.

The metapelites of North of Golpayegan show that these rocks can be divided into four categories based on mineral assemblages: chloritoid- garnet- biotite- schist, garnet- biotite- muscovite- schist, staurolite bearing garnet- biotite- muscovite schist and Kyanite bearing staurolite- biotite- muscovite- schist. The appearance of chloritoid in chloritoid- garnet- biotite schists shows green schist facies. Garnets in garnet- biotite- muscovite schists shows 3 stage of growth and syn-tectonic formation. The appearance of staurolite in staurolite bearing garnet- biotite- muscovite schists signifies the beginning of amphibolite facies. The absence of zoning in the staurolite contained in these schists suggests the formation and growth of this mineral in a prograde metamorphism. The thermodynamic study of these rocks shows that North of Golpayegan's metapelites were formed within a temperature range of 480 – 560oC and a pressure range of 1.6 – 4.1 kbar. These results are consistent with the mineral's paragenetic evidence and show that effect of metamorphism on North of Golpayegan's pelitic sediments is to lower amphibolite facies (Epidote amphibolite).

Metamorphic rocks of Dehnow area mainly consist of gray to black fine-grained schists. Garnet schists are closer to the tonalitic body than the garnet chloritoid schists. There is a thin layer of staurolite and andalusite bearing hornfels between these schists and the Dehnow tonalitic body. Garnet schists and garnet chloritoid schists of Dehnow area are mineralogically comprised of quartz, biotite, muscovite, garnet, chlorite, chloritoid, tourmaline and ilmenite. Geothermobarometry results indicate that hornfels (550oC, 4.3 kbar) and garnet chloritoid schist (486-497oC) have formed in lower equilibrium condition in comparison with garnet schist (569oC, 5.3 kbar).

The metamorphic rocks of the Surian complex occurred along the Bavanat Valley، northeast of Fars province at the eastern edge of the Sanandaj-Sirjan zone. The complex is located between the Surian fault in the northeast، and Jian fault in the southeast، and consists of chlorite epidote schist، chlorite actinolite schist، quartz chlorite schist، mica schist and andalusite muscovite schist. Geochemical data (Al2O3، CaO، MgO، Ni، P2O5، TiO2 and REE) contents reveal that the primary rocks of andalusite muscovite schist، quartz chlorite schist and mica schist were formed in sedimentary environments، whereas those of the chlorite actinolite schist and chlorite epidote schist have igneous origin. The concentrations of major immobile elements (e. g. Al، Ti)، REE and Highs Field Strength Elements (HFSE) (e. g. Nb، Y، Zr)، indicate that the rocks of sedimentary origin were formed in active continental margin setting in association with turbidites of deep sea floor and those of igneous origin show tholeiitic basalt nature of rift basins.

The magmatic-metamorphic Tutak Complex, as a part of the Bavanat belt, is located in the high pressure-low temperature metamorphic belt of the Sanandaj-Sirjan Zone. The complex contains schists, marbles, granite gneiss, meta-granitoid, meta-aplite granite, amphibolites, and meta-dolerite with different ages and degrees of metamorphism. Based on field evidence, the rocks are not uniformly distributed throughout the complex, thus, the Tutek Complex can be divided into central and marginal sub-zones. In the central sub-zone, most of the metasediments are calcschist, micaschist, garnet-muscovite-schist, and quartz-feldspathic-schist, and types of metabasites include amphibolite and garnet-amphibolite. In the marginal sub-zone, most metasediments are biotite-epidote-schist and meta-basites including of schist-amphibolite and amphibolite. Combining field evidence and microstructures in the metasediments and the metabasites from both sub-zones suggests that the rocks have mainly undergone metamorphism and deformation under the amphibolite to green-schist facies conditions in the central sub-zone and green-schist facies conditions in the marginal sub-zone.

The Muth-Golpayegan metamorphic complex is situated at north of Golpayegan city in the Isfahan province. This complex is constituted from different metamorphic rocks including variety of pelitic schists, amphibolite, gneiss, quartzite and marble. Garnet schists are dominant lithology in the area and contain different minerals, such as garnet, quartz, chlorite, muscovite, biotite, staurolite, andalusite, kyanite and sillimanite. Lepidoblastic, porphyroblastic, poikiloblastic, augen and millipede are the main textures in these rocks. The degree of metamorphism increases from SW to NE in a way that slate and phyllite at SW change gradually to chlorite schist, biotite schist, garnet schist, staurolite schist, sillimanite schist and kyanite schist. The occurrence of these schists is accompanied by appearance of chlorite, biotite, garnet, staurolite, sillimanite and kyanite mineralogical zones in the field. The succession of these zones is compatible with Barrovian regional metamorphic gradient. Chlorite, biotite and garnet zones belong to the greenschist facies and staurolite, sillimanite and kyanite zones belong to the amphibolite facies. Temperature range calculated for these rocks by garnet-biotite thermometry is 471-581 C. This metamorphic gradient is a result of continental collision.

Shahneshin area is located in southwest of Zanjan at the border between Zanjan and Kurdestan provinces. Based on petrographic investigation, Shahneshin basic schists could be divided into actinolite schist, actinolite pyroxene schist, actinolite pyroxene garnet schist and actinolite epidote schist. Actinolite schists are the most abundant rocks among basic schists and are composed of amphibole, muscovite, chlorite and albite as major minerals. Amphiboles occurred in two different fabric including inclined and parallel to the main schistosity. Optical characters of amphibole changes from core towards rim in which birefringence and extinction angle decrease and ppl color changes from green-blue to the pale green. In the other hand, chemical analysis of the same amphibole from core towards rim shows that core has richerite-winchite composition while rim has actinolite composition. Therefore, there is clear relation between optical and chemical characters in which reverse glaucophane substitution (CaM4 MgOctAlOct) and plagioclase substitution (CaM4 AlT) occurred. P-T calculation using chemical composition of amphibole cores show that they formed under 14 kbar pressure and 440 OC temperature while their rims formed under pressure of 4 kbar and temperature of 520 OC. Thus optical and chemical zoning observed in amphiboles in Shahneshin basic schists could be formed due to changes in pressure and temperature of the metamorphism.

The study area is situated in the west of Soltan Abad prom NE Sabzevar (Razavi Khorasan province). There is an exposure of metamorphic complex that contains greenschist, blueschist, amphibolite and eclogite (?) facieses rocks. Gneissic body is located in the middle part of this complex (Koh-e-Chili). Protolith and foliation intensity are variable in this body. Field evidences, whole rock geochemistry, geochronological data and nearly the same metamorphic pressure conditions of gneisses and blue schists (Gneiss: P = 10.9 Kb and Blueschist: P = 11-14 Kb) indicate that protolith of the gneisses have been differentiated series of oceanic crust and have experienced subduction zone metamorphism along with mafic series of Sabzevar oceanic basin (blueschists) as a consequence of north-ward movement of central Iranian microcontinent in the Upper Eocene.

The occurrence of blueschist metamorphic facies is believed to mark the existence of former subduction zones. This facies is represented in the main constituents of subduction-accretion complexes, where it occurs in separate tectonic sheets, imbricated slices, lenses, or exotic blocks within a serpentinite mélange (Volkova et al., 2011). The evidence of the presence and maturity of Paleo- Tethys oceanic crust in the CEIM (define this) in Paleo-Tethys branches, subduction and collision has been studied by various authors (Bagheri, 2007; Zanchi et al., 2009; Bayat and Torabi, 2011; Torabi 2011). Late Paleozoic blueschists have recognized in the western part of the CEIM (e. g. Anarak, Chupanan and Turkmeni) in linear trends. Metamorphic rocks of the Turkmeni area (SE of Anarak) are composed of blueschist and meta-greywacke and are situated along the Turkmeni-Ordib fault associated with Paleozoic rock units and serpentinized peridotite bodies. Turkmeni blueschist and meta-greywackes have not been studied by previous workers. The Turkmeni blueschists consist of albite, winchite, actinolite and epidote. Granoblastic, nematoblastic and lepidoblastic are main textures in these rocks. Winchite is found in the matrix and around epidote grains. This sodic-calcic amphibole serves as an index mineral in blueschist facies. Actinolite and epidote formed during retrograde metamorphism of blueschists in the greenschist facies. The mineral assemblage of albite, epidote, chlorite and phengite ± garnet is present in meta-greywackes in the Turkmeni blueschists. Veins of garnet, muscovite, quartz and opaque minerals are extensive in these rocks. Epidote and chlorite formed in meta-greywackes by retrograde metamorphism in the greenschist facies. The aim of the present study is to determine the petrological and geochemical characteristics, P-T condition of blueschists and meta-greywackes, as well as the geotectonic setting of primary basaltic rocks of the Turkmeni blueschists. This study is based on field observations and petrographical and analytical studies. Satellite images and a geological map were prepared. About 20 thin sections were supplied for petrological studies. Mineral chemical analyses were carried out by a JEOL JXA-8800R electron probe micro-analyzer (EPMA) at the Cooperative Center of Kanazawa University, Japan. The analyses were performed under an accelerating voltage of 15 kV and a beam current of 15 nA with 3µm probe beam diameter. The Fe3+ contents of minerals were estimated by assuming ideal mineral stoichiometry. The representative mineral compositions are given in Tables 1-3. Major oxides, rare earth elements (REE) and trace elements of five blueschists samples were analyzed by the ICP-MS method (Kanpanzhouh Research Company, Tehran, Iran) of the SGS laboratory of Canada. Whole rock chemical data are presented in Table 4. Petrographical and geochemical characteristics of Turkmeni blueschists reveal that they were derived from a similar mantle source and underwent analogous melt extraction and post magmatism occurrences. According to the trace and rare earth elements contents, the protolith of blueschists should be formed by crystallization of tholeiitic basalt and have sub-alkali basalt nature. Blueschists have LREE values more than HREE. High amounts and evident variations of LIL elements are obvious. Negative anomalies of HFSE such as Nb, Hf, Zr and Ti are evident in Turkmeni blueschist. REE trends of these rocks resemble as the back arc basin basalts. Based on the Nb/La ratio and REE contents, the original magma has been generated by low to medium degree of partial melting of a lithospheric mantle spinel lherzolite. Geochemical characteristics and normalized diagrams reveal that primary magma of protolith has been nature near to IAB and E-MORB. The related processes to subduction of Paleo-Tethys oceanic crust led to mantle enrichment and carbonate metasomatism. The Paleo-Tethys Ocean spreading in CEIM commenced in Late Ordovician and terminated in the Late Paleozoic-Triassic. Association of meta-greywackes with blueschist and LILE/HFSE contents shows that Paleo-Tethys oceanic crust subduction zone at Turkmeni region was been immature. Mineral chemistry and assemblages of the blueschists and meta-greywackes units reveal that they suffered different metamorphic evolution: (M1) greenschist metamorphism by existence of actinolite and albite in basaltic rocks, and then they passed a prograde metamorphism in the blueschist facies by existence of winchites (M2) which is followed by a retrograde metamorphism P-T condition in the greenschist facies (M3). Variscan tectono-metamorphism occurrence has been main metamorphic phase in Anarak region and it has led to metamorphism in blueschist facies of Turkmeni rocks. Acknowledgments: The authors wish to thank the University of Isfahan University for financial supports.