The Alborz-Azerbaijan magmatic plateau (AAMP), in the northwestern part of Iran, is one of the main exposes of magmatic activities in the Cenozoic. The Salavat range is located in the eastern part of AAMP, and widely occur in alkaline lavas and dykes Based on field studies, mineral chemistry, and whole-rock geochemistry, alkaline rocks in the Salavat range are classified into two groupsthat are composed of analcimite, analcime bearing breccias and analcime bearing tephrite pillow lavas (group I), tephrite-phonotephrite and lamprophyre dykes (group II). These rocks cover a broad compositional range from sodic to transitional sodic-potassic and potassic series, all of which are high-K in character. On the basis of whole-rock chemistry, alkaline rocks in the Salavat range resulted from a phologopite/amphibole-bearing peridotite source in garnet-spinel lherzolite transitional zone that underwent metasomatism processes. Geochemical data indicated partial melting of subcontinental lithospheric mantle source, played major roles in the formation and evolution of the Salavat range rocks, whereas crustal contamination seems to be restricted to minor effect. The Salavat range magma was generated in a collision-related extensional setting, following the closure of the Neotethys Ocean in the Cenozoic.

The study area is located in the south of Bardaskan (south west of Khorasan Razavi). Mafic intrusions of Robat-e-Zangiche and Lakh Bargheshi areas from Kooh-e-Sarhangi zone have been injected into granitic basement rocks and Soltanieh dolomite. Plagioclase, amphibole and clinopyroxene are rock forming minerals. According to the petrographic evidences, mineral chemistry and thermobarometry data amphiboles have different generations of igneous and alteration types. The results of amphibole thermobarometry indicate temperature and pressure ranges of 545-911 °C and 2.2 to 5.8 kb respectively. Such wide range of calculated temperature and pressure could be interpreted by various solidification conditions and also secondary altration processes. On the basis of whole rock chemistry, the studied samples are mainly gabbro. The spider diagrams display geochemical signatures of subduction zones magma. Based on tectonic discrimination diagrams, genesis of the studied rocks is related to the both subduction and within plate settings. Furthermore, whole rock chemistry of the studied samples is compatible with spinel lherzolite melting. As the formation of Sabzevar back arc basin was probably triggered by the Neotethys subduction beneath Central Iranian microcontinent, so the Jurassic back-arc magmatism of the Bardakcan area may be affected by the same subduction process and concomitant asthenospheric upwelling in an extensional regime.

This study has focused on provenance of Eslamlu metapelites, NW Iran. Whole rock chemistry analysis has revealed that these metapelites are rich in Iron and Aluminum and as a result the modal abundance of garnet (Almandine) is high. But those samples which are rich in SiO2 are poor in Al2O3, therefore, Eslamlu metapelites have less cordierite and aluminosilicates. The position of different samples in AFM compatibility diagrams is similar, as a result, bulk rock chemistry variable was constant and parageneses are produced due to changes in P and T of metamorphism. Further studies has unraveled that parent sedimentary rocks have been Fe-shale and graywacke. The high concentration of Al2O3 and Fe2O3 shows that the rocks are Laterite.  PIA, CIA and CIW indexes are high showing intense weathering conditions; hence the aluminum content is very high. According to major element composition of metapelites, tectonic environment of igneous parent of sediments, not Ruteh sediments, has been active continental margin.

Picrites are seen within the mantle peridotites in the Darreh Deh area (in the east of Nain ophiolitic mélange). Based on petrography and mineral chemistry, these picrites are composed of olivine (chrysolite), clinopyroxene (diopside) and orthopyroxene (enstatite), showing a cumulate texture, and small amounts (less than 10 volume%) of plagioclase and chromian spinels as accessory minerals. Application of clinopyroxene geothermobarometry methods indicates the equilibrium temperatures of ~1040 to 1205 °C and pressure of 8.6 kbar for the clinopyroxene crystallization in the melt. Amphibole and talc crystallization and the results of amphibole thermobarometry (~675-700 °C, 4.8-6.5 kbar) indicates that these rocks have undergone metamorphismunder amphibolite facies in Jurassic, similar to their host mantle peridotites. Whole rock chemistry and chromian spinel composition confirm high partial melting degrees of mantle and progressive ascending melt/wall rock reactions in a suprasubduction zone in which tholeiitic melts were produced. During the production of this melt, picrites with cumulous texture formed within the mantle peridotites by precipitation of olivine, pyroxenes and minor amounts of intercumulous plagioclase crystals the primitive melt.

The rhyolitic and trachytic domes in south of Dastgerd in Qom province, contain garnet phenocrysts. Based on the micro-probe analysis, garnets are almandine rich, and poor in other components. Considering the whole rock chemistry, the magmas of the area have continental origin or at least contaminated with a continental source. Based on chemical composition of biotites, the magmas are peraluminous with continental origin. Several evidences such as lack of any metamorphic xenocrysts or xenoliths, homogeneous composition of garnets, compositional equilibrium between garnet and biotite, lack of metamorphic inclusions in garnet and lack of reaction rims, in addition with the origin of host rocks and whole rock composition, indicate that garnets in the area could be crystallized from a peraluminous magma and they are igneous garnets.

The purpose of this study is to explore the influence of whole rock chemistry of metamorphic protolith on the crystal size distribution curve of garnet in metapelites. With this aim, perfect mosaical photograph from two groups of metapelites have been prepared: regional (Shahindezh schists) and contact (Dorbeh Oshnavieh aureole) metamorphic rocks image processed and their patterns illustrated. They show that the nuclei numbers in the hornfelses are one fourth of schists, but when they start to grow, it is more than 40 times. These content in addition to high degree of overstepping during regional poly-phase metamorphism, show the important role of effective water fluid presence at the contact aureole and inhibitor role of it at nucleation which help ion transportation on the nucleation sites. Considering the similar composition of garnet in two groups (almanden), it is the symptom of suitable whole rock composition of hornfelses per schists to garnet grew.

Ophiolitic mélange of south Dehshir is a slice of Nain-Baft ophiolitic belt. Blocks of metamorphic rocks that consist of amphibolite, banded Px-Ep amphibolite, Grt-Px amphibolite, Grt-Am gneiss and Grt-Ep hornblendite are cropped out along with crustal and mantle sequence of ophiolites from south Dehshir. Thermoberometry results of three samples of Grt-Px amphibolite, Grt-Am gneiss and Grt-Ep hornblendite are compatible and indicating an average temperature and pressure of 664°C and 8.8 kb, respectively. PT conditions of metamorphic rocks of south Dehshir ophiolitic mélange are in accordance with the conditions of those from the other worldwide ophiolitic sutures. Intimate spatial relation between investigated metamorphic rocks and adjoining ophiolites, PT conditions of metamorphism and whole rock chemistry indicate that these rocks representing oceanic lithosphere of suprasubduction zone and have derived from sole metamorphism event in the subduction initiation setting.

Temperature and pressure of pelitic metamorphic rocks (metapelites), from the Jandaq area in NE Isfahan, are studied using pseudosection approach. The data used in this research are from already published data by other researchers; however the applied method is reported for the first time. The metamorphism temperature is estimated to be about 400 to 670°C and pressure to be 2-6 kbar in the published study. Our study confirming these results, indicates the pressure and temperature more precisely. Also garnet and biotite chemical zoning is studied. Since garnet and biotite are the main ferromagnesian minerals in these rocks, the chemical zoning are determined for these two minerals, based on Fe and Mg content, and the P-T is estimated using Fe and Mg mole fraction in the minerals. Using the whole rock chemistry, the stability of the mineral phases is modeled considering metamorphic grade increase.

Siliceous dolomites of the Jolbar area are metamorphosed during the intrusion of the Balestan alkali granite, Early Cenozoic. The main observed mineral paragenesis is Cal+Tlc+Srp±Tr±Di. Talc is the first mineral which is formed at the contact aureole and accompany the other calcareous minerals and some detrital quartz produced serpentine as a common mineral at the area. We plotted the position of chemical composition of the calcsilicates on the compatibility diagrams of the SCM system. Almost all of the samples are located on the Cal-Srp (Atg) tie line which shows that the above paragenesis was in the equilibrium with the whole rock chemistry. Considering that no olivine or brucite are crystallized and assuming 2kbar pressure for contact metamorphism, the highest estimated temperature at the aureole was 500±50 ºC. Serpentine is stable in the calc-silicate rocks, only if the composition of the present fluid is enriched by H2O. Therefore the X CO2 of fluid at the Jolbar area is considered to be <0.05.

Basalts in the Gasht-Masuleh area crop out in the SW Fuman, Gilan Province, and are exposed in the Jurassic and Late Cretaceous units in this area. Whole rock chemistry shows that the rock samples have Mg numbers between 30 and 31.7. Rare earth element patterns (REE) indicate light REE (LREE) enrichment and heavy REE (HREE) depletion (LaN/YbN= 7.7-9.8). Nb, Ta and Ti negative anomalies in primitive mantle normalized multi-element diagrams indicate the formation of parent melt in an arc-related tectonic setting. Clinopyroxene phenocrysts have diopside compositions, crystallized from a calc-alkaline basic parent melt in an extensional tectonic setting. These geochemical features indicate that the basalts of the Gasht-Masuleh area probably formed in an extensional related tectonic setting and inherited their arc signatures from a previous subduction event, possibly of the Paleo-Tethys Ocean crust subduction.