ghodrat torabi

The Godar-e-Siah Eocene monzodiorite stock is located in the southwest of the Jandaq area (NE of Isfahan) and northwest of the Central-East Iranian Microcontinent (CEIM). The main minerals in these monzodiorites are plagioclase, K-feldspar, clinopyroxene, phlogopite, and garnet, which are set in a fine-grained groundmass of feldspars. The main textures are granular, porphyritic, and poikilitic. In some cases, these rocks contain euhedral to subhedral garnet crystals with inclusions of the igneous clinopyroxene and groundmass minerals including feldspar and graphite. These garnets exhibit Ti-andradite and Ca-melanite composition from the solid solution series of andradite-grossular. The chemical zoning patterns of the studied garnets confirm that these garnets have a non-magmatic origin and metamorphic nature. In the investigated monzodiorites, the presence of euhedral garnet crystals with inclusions of igneous clinopyroxenes metasomatic scapolite, and metasomatic phlogopite shows that these garnets are of metasomatic origin, which formed due to the alteration of igneous clinopyroxenes. All geochemical and petrographic evidences from the studied garnets indicate that they have formed as a result of the intrusion of Eocene monzodiotites into the carboniferous limestones (or dolomites), leading to the creation of endoskarn or reactions skarn that can be distinguished at the millimetric scale in microscopic studies.

The Lower Oligocene basic dikes are cropped out in the Chah-e-Alikhan area (Northeast of Isfahan province, North of the Daq-e-Sorkh desert). These dikes show NE-SW and NW-SE trends and cross cut the Eocene volcanic rocks and associated flysches. NW-SE dikes are younger and cut the NE-SW ones. These dikes are similar in petrography and are composed of plagioclase, clinopyroxene, olivine, sanidine, Cr-spinel and ilmenite. Zeolite, serpentine, calcite and magnetite are secondary minerals. These dikes represent the porphyritic, glomeroporphyritic, poikilitic and trachytic textures. Intergranular and granular textures can be seen at the center of the larger dikes. These basalts are enriched in alkalis (Na2O+K2O), LREE and LILE (Cs, Rb, Ba, Pb) and have high values of LREE/HREE ratio (La/Yb=8.9-10). In the classification diagrams, which are based on the incompatible elements and HFSEs, they are classified as alkali basalts. The primitive magma of these basaltic dikes has been produced by partial melting of a garnet-spinel lherzolite of the mantle previously suffered the carbonate metasomatism. The formation of the alkali basalt dikes of the Chah-e-Alikhan area can be ascribed to the former subduction of the Central- East Iranian Microcontinent (CEIM) confining oceanic crust and decompression melting induced by the extensional basin of the Anarak‒Jandaq area in Early Oligocene. The primary basaltic magma has been formed by low degree of partial melting of a metasomatised mantle lherzolite during continental crust extension episode in the lower Oligocene and has been ascent through the faults. 

In the Northwest of CEIM (Central-East Iranian Microcontinent), along the Great Kavir fault, volumes of alkali basalts with the lower Oligocene age are outcropped as volcanic and subvolcanic (Dike) rocks. In this research, the subvolcanic exposures of this basic magmatism in the the Chah-e-Alikhan area is discussed. The Lower Oligocene basic dikes are cropped out in the Chah-e-Alikhan area (Northeast of Isfahan, Northeast of Zavareh, and Northwest of the CEIM). These dikes show NE-SW and NW-SE trends and cross cut the Eocene volcanic rocks and associated flysches. In this paper, the geological and petrological aspects, as well as the geodynamic setting of alkali basalt dikes of the Chah-e-Alikhan area are discussed. Study of these dikes, as a part of the Cenozoic alkaline magmatism from Northwest of the CEIM, will be useful in understanding the geodynamical evolution of the Central Iran.

 The method of study is including petrography (field, library and microscopic studies) and whole rocks geochemical analysis of rocks. 13 fresh whole rock samples of alkali basalts from the Chah-e-Alikhan area were selected for the major and trace elements chemical analyses.
Whole rock geochemical analyses carried out by using a Bruker S4 Pioneer XRF at the Central Laboratory of the University of Isfahan. Trace element compositions of the selected samples were achieved by ICP-MS (Inductively coupled plasma-mass spectrometry) at the Zarazma Mineral Studies Company (Tehran, Iran). 

The rock-forming minerals of the Chahe-e-Alikhan basic dikes are Cr-spinel, olivine, clinopyroxene, plagioclase, sanidine and ilmenite. Zeolite, serpentine, calcite and magnetite are secondary minerals which are formed as a result of the alteration of primary minerals. Petrographical characteristics indicate that these dikes are alkali basalt and represent the porphyritic, glomeroporphyritic and trachytic textures. Intergranular and granular textures can be seen at the center of the larger dikes.
These basalts are enriched in alkalis (Na2O+K2O=4.5-5.4 wt%), LILEs (Cs, Rb, Ba, Pb) and have high values of LREE/HREE ratio (La/Yb=8.9-10). Trace elements ratio diagrams such as La/Nb versus La/Yb, Dy/Yb against La/Yb, Sm/Yb versus La/Yb (Bogaard and Worner, 2003) and Ce/Yb-Ce (Ellam, 1992) are used in order to determination of the depth, type and degree of partial melting of the source rock. Based on the geochemical characteristics and diagrams, the primitive magma of the Chah-e-Alikhan alkali basalts possibly have been produced by about 5 to 10 percent partial melting of a garnet-spinel lherzolite, which is located at the depth of about 105 km, as a part of a mixed asthenospheric–lithospheric mantle. The elevated values of the Zr/Hf ratio and the Na2O + K2O versus TiO2 diagram (Zeng et al., 2010) indicate that the primitive magma of the studied basic dikes previously suffered the carbonate metasomatism.
The Chah-e-Alikhan alkali basalts show high values of the Alkalis (Na2O + K2O), enrichment in LREE, HFSE and LILE. The subducted oceanic slab is the source of carbon and LILEs are the mobile components of subduction (Shaw et al., 2003). Considering that Cs is a highly fluid mobile element, enrichment in Cs relative to Rb suggests that the fluid phases derived from a subducting slab are probably the metasomatic agents.
The lower Oligocene alkaline magmatism in the Chah-e-Alikhan area and the enrichment of the mantle with incompatible elements (metasomatism) can be attributed to two oceanic crust subduction events: (1) Northeast ward Neotethys subduction along the Zagros Thrust Zone beneath the Central Iran from the Triassic to the Eocene (Torabi, 2010); and (2) Subduction of an oceanic crust along the Great Kavir Fault, which is situated to the western margin of the CEIM. The spreading of the last ocean crust started in the Triassic and ended in the Eocene. The remnants of this oceanic crust are found as ophiolitic melanges on the western side of the CEIM, such as the Nain, Surk, and Ashin ophiolites (Rajabi and Torabi, 2012; Torabi, 2010). The geological history and position of the Chah-e-Alikhan alkali basalt dikes suggests that the the carbonate metasomatism of the mantle peridotites can be attributed to the subduction of the CEIM confining oceanic crust.
Several tectonic discrimination diagrams have been used for determination of the tectonic setting of the Chah-e-Alikhan basalts. The La/Yb versus Th/Nb (Hollocher et al., 2012), Ta/Yb against Th/Yb (Gorton and Schandl, 2000) and DF1 versus DF2 (Verma and Agrawual, 2011) diagrams suggest a within-plate (continental) tectonic setting.
The activity of the major faults of the area such as Great Kavir, Chah Mishury and Chah Gireh Faults has been created a suitable inter-plate extensional system to ascending the Lower Oligocene alkali basalt magma in the Chah-e-Alikhan area.

The Lower Oligocene alkali basalts of the Chah-e-Alikhan area is a part of the intra-continental alkaline magmatism crosscuts the Eocene volcanic rocks. The area provides a setting to study the Cenozoic alkaline magmatism of the northwest of the CEIM.
These basalts are enriched in total Alkalis, TiO2, LREE and LILEs. They have been produced by about 5 to 10 percent degree of partial melting of a garnet-spinel bearing lherzolite of a mixed lithospheric-asthenospheric mantle which is previously metasomatised. The mantle enrichment can be ascribed to the subduction of the CEIM confining oceanic crust beneath the Central Iran from the Triassic to the Eocene. The Grate Kavir Fault and related faults have played an important role in the Lower Oligocene alkaline magmatism in northwest of the CEIM.

The authors thank the University of Isfahan for financial support.

In central part of the Mesozoic Ashin ophiolite (Northwest of Anarak, Isfahan province, Iran), the Upper Eocene monzonitic stock cross cuts the Ashin ophiolite and Middle Eocene volcanic rocks. Amphibolite xenoliths are enclosed in the stock and associated Eocene volcanic rocks. Xenoliths are more abundant in the margin of the monzonitic stock. Rock-forming minerals of the stock are plagioclase with andesine to labradorite composition (An=34-60%), Alkali-feldspar with orthoclase composition (Or= 70.8 to 96.1%), diopsidic clinopyroxene with (Mg# =0.71-0.90), and phlogopite mica with (Fe#=0.3). Opaque minerals are magnetite and titanomagnetite (TiO2=1.6-4.4 wt.%). Main textures of samples from this intrusive body are granular, intergranular and poikilitic. Samples from the margin of this stock represent porphyritic texture. 
Geochemistry of minerals and whole rock samples of this stock indicate that they belong to the calc-alkaline magmatic series and are similar to the samples from the continental magmatic arcs.
These magmatic rocks possibly were formed by subduction of the CEIM (Central-East Iranian Microcontinent) confining oceanic crusts (Ashin and Nain oceanic crusts) during Mesozoic and Early Cenozoic eras.

Iran is a part of the Alpine-Himalayan orogenic system, including the Paleozoic to Cenozoic ophiolites, magmatic and metamorphic rocks (Takin, 1972; Berberian and King, 1981; Berberian et al., 1982; Dercourt et al., 1986; Alavi, 1994; Mohajjel et al., 2003; Shahabpour, 2007). The main pulse of the Paleogene and Neogene magmatic (volcanic and intrusive) activities of Iran can be attributed to the two Cenozoic subduction events, including the western Neo-Tethyan oceanic crust subduction beneath the Sanandaj-Sirjan block in the west and the eastern Neo-Tethyan oceanic crust subduction beneath the Central Iran (e.g., Shirdashtzadeh et al., 2022). The former subduction possibly caused to the formation of the Urumieh-Dokhtar Magmatic Arc, but the later subdution results is not well studied yet. 
In the this research, the target region is located in the west of the Yazd block (Central Iran), where the Eocene volcanic and plutonic rocks represent subduction-related characteristics (Jamshidzaei et al., 2021). The investigated subduction-related monzonitic stock that cross cuts the central part of the Ashin ophiolite in the Kuh-e-Kalut-e-Ghandehari region, in the northwest of Anarak (Isfahan Province, Iran). The main lithologies in the Kuh-e-Kalut-e-Ghandehari are Mesozoic lithologies of Ashin Ophiolite, Paleocene limestone, Eocene volcanic rocks, monzonitic stock, Lower Red Formation, and Akhoreh Formation. Ashin ophiolite was formed in the mesozoic (Shirdashtzadeh et al., 2022) and emplaced in the Late Paleocene (~60 Ma; Pirnia et al., 2020; Shirdashtzadeh et al., 2022), before than Eocene volcanism and plutonism. The studied monzonitic stock of the Kuh-e-Kalut-e-Ghandehari intrudes the Mesozoic Ashin ophiolite and Middle Eocene volcanic rocks.
The calc-alkaline affinity of the volcanic and plutonic rocks of the area, tectonic activity of the Great Kavir fault caused to the crushing and mylonitization of the surrounding rock units, as well as the alteration evidences in the field studies point to suitable conditions for the ore deposit exploration in the area (e.g., copper). In this research, the petrology, mineralogy, and whole rock geochemistry of the Upper Eocene monzonitic stock are considered. This research will expand our understanding of the geochemical nature of subduction-related Cenozoic magmatism in Central Iran.

After detailed field studies and sampling, the selected fresh samples were used for microscopic thin section and polished-thin section studies by the polarizing binocular microscope (Olympus BH-2). The microprobe analyses were performed at the School of Natural Systems, College of Science and Engineering, Kanazawa University (Kanazawa, Japan) using a wavelength dispersive electron probe microanalyzer (EPMA) (JEOL JXA-8800R). The mineral analysis was achieved under an accelerating voltage of 20 kV, a probe current of 20 nA, and a focused beam diameter of 3μm. 14 whole rock samples analyses were performed by Brucker S4 PIONEER XRF in the central laboratory of the University of Isfahan and 3 samples were analyzed in the Isfahan Nuclear Technology Center by neutron activation analysis (NAA).

Based on the field relation ships, this gray to light gray pluton intrudes into the Middle Eocene volcanic rocks and belongs to the Upper Eocene. The Middle Eocene volcanic rocks and Upper Eocene monzonitic stock crosscut the Ashin Ophiolite. This Eocene stock and volcanic rocks contain amphibolite xenoliths with the same mineralogy and petrography. Xenoliths are more abundant in the margin of the monzonitic stock. Gradual decreasing of modal plagioclase content indicates that the xenoliths range from amphibolite (plagioclase + amphibole) to hornblendite (only amphibole) in composition.
Rock-forming minerals of the stock are plagioclase with andesine to labradorite composition (An = 34-60 %), alkali-feldspar with orthoclase composition (Or = 70.8 to 96.1%), diopside clinopyroxene with Mg# = 0.71-0.90, and phlogopite mica with Fe# = 0.3. Opaque minerals are magnetite and titanomagnetite with TiO2 = 1.6-4.4 wt%. The main textures of samples from this intrusive body are granular, intergranular and poikilitic. Samples from the margin of this stock represent porphyritic texture. The SiO2 value in the whole rock compositions ranges from 47.9 to 61.65 wt.% (basic to intermediate). The average content of alkalis is 9.75 wt.%). The Kuh-e-Kalut-e-Ghandehari rocks show sodic affinity by higher Na2O than K2O, based on the Na2O/K2O versus SiO2 and K2O/Na2O versus SiO2 diagrams (Jaques et al., 1985). The Eocene intrusive and volcanic rocks of this area are similar in terms of mineralogy and texture. Petrography and whole rocks chemical analyses indicate that the studied stock is geochemically composed of gabbro, monzodiorite to monzonite in composition with metaluminous affinity. Monzonite is the predominant rock.

Various tectonomagmatic discrimination diagrams are used to determine the tectonomagmatic setting of the Kuh-e-Kalut-e-Ghandehari stock. Mineral chemistry and whole rock geochemistry of the Kuh-e-Kalut-e-Ghandehari monzonitic stock indicate a calc-alkaline magmatic series similar to the subduction-related magmas in the normal continental magmatic arcs formed during the mantle metasomatism. According to the the temporal and geological situation, as well as the geochemical characteristics of the Kuh-e-Kalut-e-Ghandehari stock, it is considered as a part of an arc magmatism, related to the subduction of Neo-Tethyan oceanic crust beneath the CEIM (Central–East Iranian Microcontinent) during the Late Mesozoic and Early Cenozoic eras.

We are grateful to the University of Isfahan and the Department of Geology of Kanazawa University (Japan) for their supports. We are also grateful to anonymous reviewers for their useful comments and suggestions that improved the quality of this paper.

The Kuh-e-Kalut-e-Ghandehari is located about 40 Km northwest of the Anarak (northeast of Isfahan). This area is a part of the Central Iran that is situated in west of the Yazd block; near to the Ashin ophiolite and drastic directional changes of the Great Kavir Fault. In the northwest of Anarak, the Ashin ophiolite is covered by the Cretaceous limestones, and crossed by the Eocene volcanic rocks. The Upper Eocene gabbro-diorite stock cross cuts the Eocene volcanic rocks. Andesites are the predominant unit of the Eocene volcanic rocks. They are grey to dark- grey in colour and have amphibolite xenolith. The main textures of these volcanic rocks are porphyritic, poikilitic, trachytic, sieved texture and glomeroporphyritic. The main phenocrystic minerals of andesites are plagioclase, amphibole and clinopyroxene situated in a matrix of the same minerals and sanidine, magnetite and apatite. Secondary minerals are formed as a result of the hydrothermal alteration and comprise zeolite, chlorite, epidot, sericite, kaolinite and calcite. Mineral chemistry indicates that plagioclases are andesine to labradorite (An= 30-52%), K-feldspars are sanidine (Or= 68-71%), amphiboles are calcic with pargasite composition (Mg#= 0.58-0.71), and clinopyroxenes are diopside (Mg#= 0.91-0.93) in composition. Whole rocks chemical analyses indicate that these andesite and trachy-andesite rocks have calc-alkaline property. The chondrite and primitive mantle-normalized REE and multi-element patterns show LREE and LILE enrichment and HFSE (Ti, Ta, Nb) depletion, which are characteristics of the subduction-related magmas. These data indicate that the primary magmas were genarated by medium degrees of partial melting of the lithospheric mantle spinel lherzolite. Subduction of the Central-East-Iranian Microcontinent (CEIM)-confining oceanic crusts (Naein and Ashin oceanic crusts) are possibly the reason of this volcanism. Geochemistry of these volcanic rocks are similar to the arc-related ones.

The Dumak ophiolitic mélange in the Baluchistan region is one of the ophiolitic mélanges that contains all of the components of a complete ophiolite, located in the middle parts of the western margin of the Eastern Iranian range. Field studies indicate the presence of a large volume of pillow lavas in different parts of the Dumak mélange. The outcrop of sheeted dikes associated with the Dumak mélange is limited to the Shuru region. These dikes present below the pillow lava and Cretaceous pelagic sediments. Compositionaly, most of pillow lavas and sheeted dikes are basalt. Variations in SiO2 to FeOt/MgO in the pillow lavas and sheeted dikes indicates a tholeiitic trend for their productive magma. The pattern of REE elements and amounts of (La/Sm)N in these rocks are similar to E-MORB. The study of pillow lavas and sheeted dykes of Dumak ophiolitic mélange shows that the MORB ophiolitic body in Dumak has been gradually and continuously evolved in a supra-subduction zone environment and beginning of intra-oceanic subduction. Considering structural evidence of the region, after adding the Dumak ophiolite to the Lut block, during the continuation of tectonic movements related to orocline bending, a new mélange has formed with the presence of Eocene carbonate blocks.

Along Toveireh Fault, in the northwest of Central-East Iranian Microcontinent, the Oligocene alkali-basalt outcrop was investigated for petrography and mineral chemistry. They include phenocrystals of chrysolite (Fo70–90), augite-diopside (Mg#=0.82) and labradorite (An30-70) in a fine-grained matrix of the same minerals as pheoncrysts, together with sanidine and secondary minerals (serpentine and zeolite), as well as opaque minerals. These rocks contain sillimanitite xenoliths which are mostly composed of fibrous and prismatic sillimanites, together with minor amount of corundum, and secondary minerals (chlorite and scapolite). Xenoliths show granoblastic, nematoblastic, poikiloblastic, and corona textures. These high-Al and moderately silica-rich xenoliths were probably formed by metamorphism of continental crust sedimentary rocks, conveyed up to the earth's surface by ascending alkali basalt magma. Fibrolite formation around some of the prismatic sillimanits and Al-rich spinels (Mg#=0.4-0.5) formation in the contact of xenolith and host basalt indicate that pressure-temperature decreased during magma ascending and reaction of basaltic magma with xenolith.

The Gooreh Mountain is located about 55 km northwest of Anarak (northeast of Isfahan) and in the western margin of the Central-East Iranian microcontinent (west of the Yazd block). The field studies show that the Eocene volcanic rocks in this area present two lithologies of gray-colored dacite and light-colored rhyolite. Dacite lavas cross-cut the rhyolite ones and are younger. Petrography indicates that dacites contain the major minerals of plagioclase (labradorite and bytownite), clinopyroxene (augite) and quartz, and rhyolites are mainly composed of plagioclase, sanidine and quartz. Chlorite, calcite, hematite and limonite are the secondary minerals in both rock units, formed by the alteration of clinopyroxene, plagioclase and magnetite. The main textures of these rocks are porphyritic, glomeroporphyritic, anti-rapakivi, sieved and poikilitic. The crystallization order of minerals in dacites is magnetite, clinopyroxene, plagioclase and quartz, and in rhyolites, is plagioclase, sanidine and quartz. Whole rock geochemical analyses show that the studied volcanic rocks of the Gooreh Mountain are sub-alkaline (calc-alkaline magma series) in nature. Moreover, the chondrite and primitive mantle-normalized diagrams are characterized by the enrichment of LREEs and LILEs and depletion of HFS elements (e.g., Ti, Nb and Ta). The negative TNT (Ti, Nb and Ta) anomalies probably indicate subduction-related volcanic arc magmatism. The dehydration of subducting slab and partial melting of the mantle wedge spinel peridotites produced a basic magma that, during ascent through the lower and middle continental crust, led to melting of amphibolites and formation of acidic magmas.

In the northeastern part of the Isfahan province and 65 km northeast of the Anarak city (Kal-e-Kafi area), an I-type granitoid pluton cross cut the Paleozoic metamorphic rocks and Eocene volcanic rocks. In the contact of this granitoid body with sourrounding rock units, skarn and hornfels have been formed (Ahmadian, 2012; Ranjbar, 2010). The Kal-e-Kafi Eocene intrusive body presents a wide range of mineralogical and petrological compositions, from gabbro to alkali-feldspar granite. Presence of mafic to acidic rocks in this mostly-granitoid body indicates that fractional crystallisation has played an important role during magma evolution. The field and petrographical studies indicate the presence of anorthosite veins within the gabbro section. The mafic and basic parts of this pluton have not been studied yet. The mineralogy and chemistry of rock-forming minerals in the anorthosites and gabbros are the subject of this research study.

The mineralogical and petrographical studies have been done by using Olympus BH-2 polarizing microscope in the mineralogy laboratory of the University of Isfahan. EPMA and LA-ICP-MS analyses were used to obtain chemical characteristics of rock-forming minerals. Major-elements composition of minerals were performed by JEOL JXA-8800, WDS microprobe electron analyzer with accelerator voltage of 15 kV, current of 15 nmA, diameter of 3 μm, and a counting time of 40 seconds at the Kanazawa University of Japan. Natural and synthetic minerals and compounds were used as standards. The ZAF program was used for data correction.Trace element values of plagioclases and clinopyroxenes were analyzed by LA-ICP-MS (laser ablation-inductively coupled plasma-mass spectrometry) using an ArF 193 nm Excimer Laser coupled to an Agilent 7500S at the Earth Science Department of the Kanazawa University, Japan. The diameter of the analyzed points was 110 µm at 10 Hz with energy density of 8 J/cm2 per pulse.Mineral abbreviations in tables and photomicrographs are adopted from Whitney and Evans (2010). 

The Eocene Kal-e-Kafi pluton includes a wide range of rocks from gabbro to alkali-feldspar granite, which points to an extensive magmatic differntiation. Field relationships indicate presence of at least 4 magmatic phases, and gabbro is the first and oldest phase. The most predominant rock unit in the Kal-e-Kafi intrusive body is granitoid. However,  in the northern parts, the gabbro and anorthosite present substantial exposures. The anorthosites and gabbros are associated with each other in the field. Anorthositic veins with up to 15 cm thickness cut the gabbro.Gabbro is composed of bytownite and anorthite plagioclase (An= 84 – 94 %; some of them have been altered to bytownite, andesine and oligoclase), clinopyroxene (diopside, Mg#= 0.75), orthoclase (Or0.88), apatite, magnetite, and prehnite. Anorthosite rock-forming minerals are anorthite plagioclase (An= 89 – 95 %; some anorthite plagioclase have been altered to bytownite and labradorite), sphene and zircon. The main texture of these rocks are granular, intergranular and poikilitic. Field studies suggest that anorthosites are associated with gabbros which have filled the fractures of gabbros.Very simmilar petrography and chemical composition of plagioclases in the anorthosites and gabbros possibly reveal their cogenetic nature. It seems that the primary magma in the magma chamber, first crystallized the clinopyroxene and plagioclase, which caused formation of gabbros. In the next stage, by occurrence of a tectonic activity, the gabbros have broken and the remaining magma which was rich in plagioclase components, crystallized the anorthosites in the fractures. This reveals that the anorthosites of the study area are the plagioclase rich part of the primary basic magma which have formed the gabbros.According to the field relationships, it is generally believed that anorthosites are differentiates of gabbroic magmas. The studied anorthosite veins and gabbros of the Kal-e-Kafi area are consanguineous. These anorthosites are perhaps generated by the process of collection of plagioclase crystals from a gabbroic magma under the action of gravity and tectonic activity (filter pressing).Pyroxene is one of the common minerals. The chemical composition of this mineral provides valuable information about the nature of magma, H2O content, Oxygen fugacity, type of magmatic series, tectonic setting, as well as temperature and pressure of crystallisation (Schweitzer et al., 1979; Leterrier et al., 1982; D’Antonio and Kristensen, 2005).Chemistry of clinopyroxens within the gabbros of the Kal-e-Kafi  area shows that the parental magma belongs to the sub-alkaline and calc-alkaline magmatic series and these rocks are similar to those of volcanic arcs. The time and place of formation of these plutonic rocks possibly indicate that they are formed by subduction of the Central-East Iranian Microcontinent (CEIM) – confining oceanic crust beneath the CEIM. AcknowledgmentsThe authors thank the University of Isfahan for financial supports.

Subduction-related magmas are characterized by enrichment of large ion lithophile elements (LILEs), light rare earth elements (LREEs) and depletion in high field strength elements (HFSEs) (Harangi et al., 2007). These geochemical signatures of magmatic rocks are commonly explained by the addition of hydrous fluids from subducting oceanic lithosphere combined with the flux of melts from subducted sediments to the mantle wedge, lowering the mantle solidus and leading to magma generation (Aydınçakır, 2016). Asthenospheric mantle, subcontinental lithospheric mantle and/or lower crust may be the principal source of these rocks (Eyuboglu et al., 2018). In addition, magma differentiation processes, such as fractional crystallization, crustal contamination, and magma mixing may also play an important role in the genesis of these rocks.This research study presents new petrological and geochemical data from the volcanic rocks with NW–SE trending, which are situated in the northwestern margin of the Central –East Iranian Microcontinent (CEIM) (south-east of Khur, Isfahan Province) which have been formed during the peak activity of Eocene. Study of this typical small volume subduction- related magmatism will be useful in understanding the origin and geological evolution of the Central Iran in Cenozoic.

The petrographic investigations on Eocene volcanic rocks from the SE of Khur area were carried out with an optical microscope (Olympus-BH2) in the petrology Laboratory of the University of Isfahan, Iran. Major and trace element concentrations of samples from whole- rocks were obtained by a combination of inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) at the Als Chemex Laboratory of Ireland. The chemical compositions of 4 samples (B865, B866, B867, and B868) were determined by Neutron Activation Analysis (NAA) in the Isfahan Activation Center. The detection limit was 0.01% for all major element oxides and 0.01 ppm for rare earth elements. Mineral abbreviations were adopted from Whitney and Evans (2010).

Eocene volcanic rocks with trachy-basalt and trachy-basaltic andesite composition are exposed in the northwestern part of the Central-East Iranian Microcontinent (CEIM) (SE of Khur, Isfahan Province, Central Iran). These rocks which have a dominant northwest-southeast trend crosscut the Cretaceous sedimentary rocks.Petrography and mineral chemistry analyses indicate that the predominant rock-forming minerals of volcanic rocks are olivine, plagioclase, clinopyroxene and orthopyroxene. Phenocrysts set in a fine to medium grained matrix of the same minerals plus sanidine with minor amounts of opaque minerals. Secondary minerals are chlorite and calcite. The most common textures of these rocks are porphyritic, microlitic porphyritic, poikiolitic and glomeroporphyritic. Geochemical analyses of whole rock samples show that these rocks have been enriched in alkalies and large ion lithophile elements (Cs, K, Rb, Sr, Ba,), and have been depleted in high field strength elements (HFSE) (Ta, Nb, Ti). All samples indicate moderate to high fractionation in LREE patterns. These geochemical signatures point out to the subduction-related calc-alkaline nature of these rocks and their similarity to volcanic rocks of continental arcs or convergent margins (Yu et al., 2017). Pb enrichment and low values of Nb/La, Nb/U and Ce/Pb ratios reveal that crustal contamination has played an important role in magma evolution (Srivastava and Singh, 2004; Furman, 2007). The large volume of hydrous fluids coming from the subducted slab rather than sediments have caused enrichment and metasomatism of the subcontinental lithospheric mantle source. The geochemical characteristics of the studied rocks suggest that the parental magma have been derived from partial melting of a metasomatized spinel lherzolite of lithospheric mantle, which was previously modified by dehydration of a subducting slab. The tectonic environment, in which these rocks were formed has probably been a volcanic arc. Subduction of oceanic crust around the Central-East Iranian Microcontinent (CEIM) is the most reasonable mechanism which can be used to explain enrichment in volatiles of the mantle, and the calc-alkaline magmatism of the study area in Eocene times.

Granitoids are the main rock units in the continental crust. Study of granitoids reveals significant information on tectonic mantle and upper crust. Many researchers have investigated petrogenesis and origin of granitoids (e.g., Chappell and White, 2001; Barbarin, 1999; Frost et al., 2001). For example, Chappell and White (1992), Pitcher (1993) and Chappell et al., (1998) have divided granites into two major groups of: (1) I-type granites (high-temperature or Cordellerian granitoids, including low-K granitoid to high-Ca tonalite, without inherited zircons) formed by partial melting of mafic rocks at >1000 ℃ in mantle or subduction zones of continental margins, and (2) S-type (low-temperature or Caledonian granitoids with inherited zircons) granites formed by partial melting of felsic crust at ~700-800 ℃. Northeast of Iran is a key location for studying the Cimmerian Orogeny, which is related to the Late Triassic collision between it and Eurasia, and the closure of the Paleo-Tethys (Samadi et al., 2014). Mesozoic Mashhad granitoids have cropped out along with the Paleo-Tethys suture zone. Distinct granitoid suites, i.e., monzogranite, granodiorite, tonalite, and diorite occur in Mount Khalaj located in the south of Mashhad. It comprises of monzogranite and granodiorite. However, monzogranite is the most abundant. To study the plutonic events during the Turan and Central Iran collision, the origin and tectonic setting of monzogranite of Mount Khalaj are investigated in this study based on whole rock geochemical data.

This research study is based on field studies and petrography. Fresh thin sections samples were selected for geochemical analysis. Whole rock composition was measured on pressed powder tablets by X-ray fluorescence (XRF) using a Philips PW 1480 wavelength dispersive spectrometer with a Rh-anode X-ray tube and a 3 MeV electron beam Van de Graaff Accelerator, at the center for Geological Survey of Iran. The trace element data of a sample was measured at the Activation Laboratories, Ontario, Canada (ActLabs). Samples were digested by lithium metaborate/tetraborate fusion and analyzed with a Perkin Elmer Sciex ELAN 6000, 6100 or 9000 ICP/MS. GCDkit 4.1 and CorelDraw software packages were used for plotting diagrams and calculation of saturation temperatures.

The Khalaj granitoid is mineralogically composed of quartz, potassic feldspar, plagioclase, mica, and accessory minerals of zircon and apatite. Geochemically, it is an unaltered acidic intrusion with ~72-73 wt.% SiO2. It is a granitoid (monzogranite) based on various classification diagrams (e.g., Cox et al., 1979; etc.). It shows the peraluminous nature (A/CNK~ 1.08-1.24) with negative Eu anomaly of ~0.62-0.73 (Eu/Eu*<1), low HREE and high LREE and LILE contents.

Geochemically, the low HREE and high LREE and LILE content in the Mount Khalaj monzogranite indicate a more differentiated melt for it. Monzogranite samples from the Khalaj-Khajeh Morad regions are similar to ferroan alkali-calcic, felsic peraluminous S-type granitoids based on discrimination diagrams by various researchers (e.g., Chappell and White, 2001; Villaseca et al., 1998). In fact, the Mount Khalaj monzogranite is a collisional granite (based on diagrams by: Batchelor and Bowden, 1985; Sahin et al., 2004), produced by anatexis and partial melting of felsic upper crust pelitic sediments (based on diagrams by: Almeida et al., 2007; Patiño Douce, 1999). It is classified as a low-temperature S-type granite formed at 730-800 ℃ (based on the diagram of Rapp and Watson, 1995), with TZr of ~732-745 ℃ (by using GCDKit software). Therefore, S-type syn- to post-collisional Mount Khalaj monzogranite is a consequence of partial melting (anatexis) of hydrous sedimentary rocks of upper crust after Paleo-Tethys subduction under Turan plate and continental collision and compressional tectonism.

The Kal-e-Kafi area is located at 65th km of northeast of the Anarak city (Isfahan province). Metaperidotites of this area and associated Anarak Paleozoic metasediments are in contact with the Kal-e-Kafi Eocene intrusive body. Metaperidotites of Paleozoic age are remnants of the Paleo-Tethys oceanic crust. Petrography study shows that these rocks are consist of metamorphic minerals of olivine (forsterite-chrysolite) (CaO According to the results from the field study, petrography evidences, mineral chemistry and thermobarometry calculations, it can be concluded that peridotites of the Kal-e-Kafi area and Anarak sediments, have suffered a regional metamorphism in P-T condition of green schist facies in the Paleozoic, then in the Eocene the intrusive phases of the Kal-e-Kafi, caused to a progressive contact metamorphism in 680 to 770 °C and at pressure 0.5 kbar. This T-P conditions of metamorphism points to the metamorphism in pyroxene hornfels facies. Partial serpentinization of some metamorphic olivines and orthopyroxenes, and formation of late-stage chlorite around of some of tremolites, indicate occurrence of the retrograde metamorphism.

In this study, some mantle lherzolites of Ashin ophiolite are investigated which contain evidence of a geotectonic/metamorphism during exhumation and obduction of oceanic lithosphere on the continental crust, after closure of Neo-Tethys Ocean. Based on petrography, their primary rock-forming minerals are orthopyroxene, clinopyroxene, olivine, and chromian spinel. Mineralogy and geothermobarometry indicate that these 4-phase lherzolites were formed in the lithospheric mantle (at pressures ~ 21.6 to 8.6 kbar) by melt/wall rock reactions (at temperatures ~ 1012-1183 °C). Then, they were emplaced and obducted on the continental crust along the fault zone of this region, and consequently deformed. The first ductile deformation event occurred in the depth of lithosphere and resulted in high-temperature mylonitization at temperatures higher than 600 to 800 °C. Mineralogical features confirm pressure decreasing of this stage by subsolidus reaction of pyroxene and spinel and substitution of plagioclase and olivine. Therefore, petrography and thermobarometry data are indicative of the spinel to plagioclase lherzolite facies for these rocks. Finally, they partially underwent brittle and cataclastic deformation at temperatures below 600°C and lower pressures and depth during exhumation. However, most of plagioclases were replaced by with prehnite, pumpellyite, chlorite, hydrogrossular and xonotlite minerals by further alterations.

The Eocene volcanic rocks are exposed in Dastgerdo and Molla Ahmad areas (East of Isfahan province); the middle part of Urumieh - Dokhtar magmatic arc (UDMA). In this area, the UDMA width is about 13 kilometers which is one of its narrowest parts. These Eocene rocks consist of lava (trachyte, dacite, andesite, basaltic andesite and basalt) and pyroclastic rocks (littic tuff, tuff breccia and ignimbrite) which cross cut by Oligocene granodiorites. Andesites are the predominant rock unit with good outcrops. The main rock- forming minerals of andesites are clinopyroxene (augite), orthopyroxene (enstatite), plagioclase (andesine to bytonite), amphibole (magnesian hornblande), biotite, quartz, magnetite, ilmenite and sphene. Secondary minerals which are produced by alteration are chloritized olivine, malachite, chlorite, calcite, epidote, actinolite, albite and montmorillonite. The geochemistry of volcanic rocks show that the volcanic rocks of Dastgerdo to Molla Ahmad areas have a wide range of SiO2 (50.4 to 65.5 wt%) and belong to the calc-alkaline magmatic series. These rocks are more enriched in light rare earth elements (LREEs) than the heavy rare earth elements (HREEs) and represent evident negative anomaly of Eu. Whole rock chemistry and horizontal pattern of HREEs reveal that the spinel lherzolite is the source rock. Petrography and geochemistry of minerals and whole rock samples indicate that the studied andesites are formed by the same petrogenetic processes and are affected by magma mixing and contamination during crystallization. The field, petrography and geochemical data show that Dastgerdo to Molla Ahmad volcanic rocks belong to volcanic arc tectonic setting and are formed by subduction of Neothetys oceanic crust beneath the Central Iran.

The Esmaeilabad granitic body with the Late Triassic age is situated in the central part of the Posht-e-Badam block (Central- East Iranian Microcontinent), in the northeastern of the Yazd Province. This granitic body cross cut the metamorphic rocks of the Posht-e-Badam complex and covered by the Cretaceous limestone. Rock forming minerals of the studied granites are K-feldspar (orthoclase), plagioclase (andesine, oligoclase), quartz, amphibole (magnesio-hornblende), biotite, apatite, titanite and zircon. According to the mineral chemistry analyses, amphiboles represent the igneous nature. Biotites are rich in Magnesium. Chemical characteristics of biotites indicate that they are primary biotites which are generated by calc-alkaline magma. Chemical composition of the amphiboles and biotites in the Esmaeilabad granites suggest that they belong to the I-type granites and generate in an environment with high fO2. Geothermobarometry estimations yield temperatures between 550 to 700 oC and pressures in the range of 2 to 3.8 kbar. Based on the geological position and age of the studied rocks, generation of this granitic body can be related to the subduction and closure of the Paleo-Tethys Ocean in the western part of the Central- East Iranian Microcontinent, which can be the reason for granitic plutonism in this area.

Granitoids are the most common igneous rocks that are found in all parts of the continental crust and play an important role in the formation and evolution of the Earth’s continental crust (Clarke, 1992). Granitoid plutons contain useful information on factors and processes related to their generation and differentiation (Castro, 2013). The wide range of sources and processes that may be involved in the formation of granitoids is reflected in their compositional range. Although yet there is a long way to achieve a consensus about the origin of granite, different interpretations of the geochemical granitoid data represents geological understanding of the complexities of these rocks. Large parts of Iran and Central - East Iranian Microcontinent (CEIM) structural zone have suffered from the Eocene granitoid magmatism. Toveireh granitoid intrusive body cropped out in the southwest of the Jandaq city (NE of Isfahan Province) and is one of the Eocene granitoid bodies. It is hoped that this mineralogical and petrological research will be useful in understanding the nature of Eocene acidic magmatism of Central Iran. Material and methods: Chemical analyses of minerals in the Toveireh granodiorites were carried out by a JEOL JXA- 8800R (WDS) electron probe micro-analyzer (EPMA) at the Cooperative Center of Kanazawa University, Kanazawa, Japan. The analyses were performed under an accelerating voltage of 20 kV and a beam current of 20 nA with a counting time limit of 40 seconds. Natural minerals and synthetic materials were used as standards. The ZAF program was used for data correction. The amounts of Fe2+ and Fe3+ contents of minerals were estimated by assuming ideal mineral stoichiometry in structural formula. Mineral abbreviations in petrographic photomicrographs and tables are taken from Whitney and Evans (2010). Petrographic studies show that the Middle Eocene Toveireh granitoid intrusive consists of granodiorite and granite. Granodiorites are coarse grained, mesocratic and have microgranular mafic enclaves in hand specimen. They are composed of plagioclase, amphibole, quartz, orthoclase and biotite. Accessory minerals are zircon, apatite, sphene and magnetite. Chlorite, actinolite, epidote and sericite are present as the secondary minerals. In the study area, the most dominant texture of the granodiorites are granular but graphic, perthite, anti-perthite, anti-rapakivi textures are common. The plagioclase (An0.8-48) occurs mainly as medium to coarse grains, subhedral, with zoning and polysynthetic twinning that represent varying degrees of saussuritization. Quartz occurs commonly as medium to fine anhedral grains. Graphic texture intergrowths of quartz and feldspars are present. Graphic texture possibly indicate rapid and simultaneous crystallization of quartz and K–feldspar from an under-cooled liquid at shallow depths (Clarke, 1992; Barker, 1983). Hornblende is present as subhedral to anhedral grains and in some cases partly altered to chlorite and actinolite. Biotites are subhedral and sometimes altered to chlorite, titanite and epidote. Based on mineral chemistry data, amphiboles in the investigated plutons are calcic in composition and classify as magnesio-hornblende and actinolite. Amphiboles are characterized by Mg# 0.67 to 0.47 and present geochemical features of subduction zone-related amphiboles. Biotite is characterized by variable and high Fe contents, with Fe# [Fe2+/(Fe2+ + Mg)] ratios between 0.52 to 0.60. Using the nomenclature scheme of Foster (1960), they are Mg-biotite, and have composition range of the calc-alkaline granites among the different granitoid suites in discriminative trend defined by Abdel-Rahman (1994). Chlorites are brunsvigite in composition and have negligible K2O and TiO2 but show similar Fe/(Fe+Mg) ratios with amphibole and biotite. Therefore, it can be concluded that they are alteration products of mafic minerals. Chlorite alteration temperature is estimated to be 245 to 262°C from chlorite geothermometry. The chemistry of hornblende and biotite imply that Toveireh granodiorites have I-Type nature and are products of crust-mantle, mixed-source magma crystallization. Barometry calculations of amphiboles indicate that these rocks were emplaced at an average pressure of 1- 1.5 kbars corresponding to approximately 3.5-6 Km depth. Plagioclase-amphibole and biotite thermometry suggests an equilibrium temperature of 700 to 800°C. Estimation of Oxygen fugacity by Fe# of amphibole and biotite indicate high value of Oxygen fugacity (+1< ΔFQM < +2.0) and suggest that the Toveireh granitoids belong to the magnetite-series of granites. Petrography and mineral chemistry of the studied rocks indicated their subduction-related tectonic setting. Acknowledgments: The authors thank the University of Isfahan and Kanazawa University for financial supports and laboratory facilities.

The “adakite” term was used for the first time by Defant and Drummond (1990) to display Cenozoic arcs igneous rocks with intermediate composition (SiO2> 56 wt.%), which were produced by partial melting of subducted oceanic crust. The adakites are series of intermediate to acidic rocks, with composition range from hornblende-andesite to dacite and rhyolite; and basaltic composition are lacking. In adakitic magmas, phenocrysts are mainly plagioclase, hornblende and biotite; while orthopyroxene and clinopyroxene phenocrysts are known only in mafic andesites (Calmus et al., 2003). Geochemically, adakites are identified with SiO2> 56 wt.%, Al2O3> 15 wt.%, MgO< 3 wt.%, Sr> 400 ppm and enriched LILE and LREE and depleted Y and HREE (Y< 18 ppm, Yb< 1.9 ppm) and high ratios of Sr/Y> 40 and La/Yb> 20 (Castillo, 2006 and Castillo, 2012). By using geochemical data, adakites were classified into high silica adakites (HSA, SiO2> 60 wt.%) and low silica adakites (LSA, SiO2< 60 wt.%) main groups. The high silica adakites were produced by partial melting of subducted oceanic crust basalts and the resulting melts also interact with peridotite during their ascent through the mantle wedge. While, low silica adakites were produced by melting of mantle peridotite that were metasomatized by melts resulting from slab (Martin and Moyen, 2002). The intrusion bodies with porphyritic texture has been studied and reported in different areas (e.g. Lan et al., 2012; Zhang et al., 2015). This intrusion bodies are often in a stock shape and the texture is porphyritic due to fast crystallization. The study area (Kuh-e- Godar-e Siah) is located in southwest of Jandaq (northeast of Isfahan province) and northwest of Central-East Iranian Microcontinent. The quartz monzodiorite intrusion with stock shape cross cutting by Eocene dykes swarm with trachy andesitic composition. In this paper, the petrology and chemical characteristics of quartz monzodiorites and trachy andesitic dykes are discussed. Material and methods: The chemical compositions of minerals from quartz monzodiorites and dykes were conducted by a JEOL JXA-8600 (WDS) electron probe microanalyzer (EPMA) at the Kanazawa University, Japan. Analyses were performed by an accelerating voltage of 20 kV and a beam current of 20 nA. The Fe2+ and Fe3+ contents of minerals were calculated by assuming mineral stoichiometry. The Fe2+# and Mg# parameters of minerals are Fe2+/(Fe2++Mg) and Mg/(Mg+Fe2+) atomic ratios, respectively. Representative chemical analyses of the minerals are listed in Table 1 and 2. To obtain whole rock chemical data, eighteen samples of the studied rocks were analyzed at the ALS-Mineral Company of Canada, by a combination of inductively coupled plasma spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) methods. The whole rocks geochemical data are presented in Table 3 and 4. Also, X-ray diffraction analyses were carried out in order to typify the K-feldspar mineral using an XRD D8 ADVANCE, Bruker machine, at the Central Laboratory of the University of Isfahan. The FeO and Fe2O3 concentrations are recalculated from Fe2O3 *, using recommended ratios of Middlemost (1989). Mineral abbreviations are from Whitney and Evans (2010). The main texture in quartz monzodiorites is porphyritic; and Eocene dykes are granular, intergranular and porphyritic in texture. The quartz monzodiorites consist of plagioclase (albite), sanidine, quartz, biotite, muscovite, chlorite, magnetite, calcite and apatite. The minerals in trachy andesitic dykes are plagioclase (andesine and labradorite), clinopyroxene (diopside and augite), sanidine, phlogopite, quartz, amphibole, magnetite, calcite and apatite. The chondrite-normalized REE patterns and primitive mantle-normalized multi-elemental diagram of the quartz monzodiorites and trachy andesitic dykes show enrichment in LREE and LILEs and depletion in HFSEs such as Ta, Nb and Ti. There is no evident positive or negative anomaly of Eu. Petrographical and geochemical characteristics of quartz monzodiorites and trachy andesitic dykes show that these rocks have been derived from different sources. The quartz monzodiorites have high content of La/Yb= 17.49-41.89, SiO2= 64.60-68.80 wt.%, Sr= 434- 1855 ppm, Sr/Y= 53.58-168.63 and low content of MgO= 0.16-1.10 wt.%, Y< 11 ppm and Yb< 0.95 ppm that show characteristics of high silica adakites which have been produced by melting of subducted oceanic crust. The trachy andesitic dykes have La/Yb= 33.45-59.76, SiO2= 53.40- 57.60 wt.%, Sr= 859-2050 ppm, Sr/Y= 50.82-125, MgO= 1.93-4.53 wt.%, Y< 13.8 ppm and Yb< 1.14 ppm, which display characteristics related to low silica adakites, produced by melting of metasomatized mantle peridotite. Acknowledgments: The authors thank the University of Isfahan for financial supports.

IntroductionLamprophyres are mesocratic to melanocratic igneous rocks, usually hypabyssal, with a panidiomorphic texture and abundant mafic phenocrysts of dark mica or amphibole (or both) with or without pyroxene, with or without olivine, set in a matrix of the same minerals, and with alkali-feldspar restricted to the groundmass (Woolley et al., 1996). Lamprophyres are frequently associated with orogenic settings and a mantle modified by dehydration of subducted slab (Gibson et al., 1995).
Small outcrops of lamprophyres with Paleozoic to Oligocene age are reported from the central parts of Iran (Torabi 2009 and 2010). The primary magmas of these lamprophyres were derived from decompression melting of the mantle induced by a tensional regime of continental crust (Torabi, 2010). Bayat and Torabi (2011) called the western part of the CEIM (Central-East Iranian Microcontinent) (Anarak to Bayazeh) a “Paleozoic lamprophyric province” and suggested that the lamprophyre magmas were formed by subduction of Paleo-Tethys oceanic crust from the Early to late Paleozoic which resulted in the mantle metasomatism and enrichment.
Lamprophyric dykes and stocks of the Kal-e-kafi area (Central Iran, Northern part of Yazd Block) cross-cut the Eocene volcanic rocks and other older rock units such as Cretaceous limestone. These lamprophyres are mainly composed of hornblende (magnesio-hastingsite), clinopyroxene (diopside) and plagioclase (labradorite to bytownite) as phenocryst, in a matrix of fine to medium grained of the same minerals and orthoclase, apatite, magnetite, chlorite and epidote.
In this paper that is a report on the first study on the calc-alkaline lamprophyres of Central Iran, the petrography and mineral chemistry of calc-alkaline lamprophyric dykes of the Kal-e-kafi area are discussed.
Materials and methodsChemical composition of minerals were conducted at Kanazawa University (Kanazawa, Japan) using the wavelength-dispersive electron probe microanalyzer (EPMA) (JEOL JXA-8800R), with 20kV accelerating potential, 20 nA beam current and a counting time of 40 seconds. Natural minerals and synthetic materials were used as standards. The ZAF program was used for data correction. The Fe3 content of minerals was estimated by stoichiometry. The Mg# and Fe# were calculated as [Mg/(Mgᗭ)], and [Fe2(Fe2)] atomic ratio of minerals, respectively.
Trace element values of phenocrystic clinopyroxene, amphibole and plagioclase were analyzed by LA-ICP-MS (laser ablation-inductively coupled plasma-mass spectrometry) using an ArF 193 nm Excimer Laser coupled to an Agilent 7500S at the Earth Science Department of the Kanazawa University (Japan). The diameter of the analyzed points was 60 micrometers for clinopyroxene and 120 micrometers for amphibole and plagioclase.
Mineral abbreviations are adopted from Whitney and Evans (2010).
Results and DiscussionLamprophyres of the Kal-e-kafi area (Central Iran, West of Yazd Block) are exposed as dykes and stocks which cross-cut the Eocene volcanic rocks and other older rock units such as Cretaceous limestone. Field studies indicate that calc-alkaline lamprophyric dykes of the Kal-e-kafi (east of Anarak) are younger than the other igneous rocks.
According to the results of petrography and mineral chemistry, the mesocratic lamprophyres of Kal-e-kafi area are calc-alkaline spessartite.
Unique values of Al2O3 and TiO2 associated with oscillatory zoning of clinopyroxenes reveal the crystallization of clinopyroxenes during ascending of magma.
Plagioclase phenocrysts are labradorite to bytownite in composition and the plagioclases of matrix are labradorite. Chemical composition diversity of plagioclase indicates the fractional crystallization of these lamprophyres.
Amphibole thermometry estimate average temperature of 860°C and barometry by Anderson and Smith (1995) shows 1.5 to 3 kbars pressure. Clinopyroxene thermobarometry calculate 1150 °C temperature and pressure between 2 to 5 kbars.
The geochemical features and thermobarometry of the Kal-e-kafi spessartite minerals suggest that the primary lamprophyric magma was derived from partial melting of a lithospheric mantle spinel lherzolite. Changes in values of pressure, water content, and Oxygen fugacity during magma ascending lead to oscillatory zoning minerals.
Based on the mineral chemistry, it can be concluded that the Kal-e-kafi lamprophyres were formed in a subduction-related environment by a calc-alkaline magmatism.

IntroductionStudy of the petrology of the ophiolites as the relics of ancient oceanic lithosphere, is a powerful tool to reconstruct Earth’s history. Mantle peridotites have mostly undergone alteration and serpentinization to some extent. Thus, the relics of metamorphic signatures from the upper mantle and crustal processes from most of the peridotites have been ruined. Several recent papers deal with the mantle peridotites of Nain Ophiolite (e.g. Ghazi et al., 2010). However, no scientific work has been carried out on the metamorphosed mantle peridotites. The study area of the Darreh Deh that is located in the east of the Nain Ophiolite, is composed of huge massifs of metamorphosed mantle peridotites (i.e. lherzolite, clinopyroxene-bearing harzburgite, and harzburgite, and small volumes of dunite), characterized by darker color, higher topographic relief, smaller number of basic intrusives, lower serpentinization degree, and amphibolite-facies metamorphism. In this study, the petrography and mineralogy of metamorphosed peridotites in the Darreh Deh has been considered based on geochemical data.
Geological SettingThe Mesozoic ophiolitic mélange of Nain is located in the west of CEIM, along the Nain-Baft fault. As a part of a metamorphosed oceanic crust, it is mainly composed of harzburgite, lherzolite, dunite and their serpentinized varieties, chromitite, pyroxenite, gabbro, diabasic dike, spilitized pillow lava, plagiogranite, amphibolite, metaperidotites, schist, skarn, marble, rodingite, metachert and listwaenite (Shirdashtzadeh et al., 2010, 2014a, 2014b). Geochemical investigations indicate a suprasubduction zone in the eastern branch of the Neo-Tethys Ocean (Ghasemi and Talbot, 2006; Shirdashtzadeh et al., 2010, 2014a, 2014b).
Materials and MethodsChemical analyses of mineral compositions were carried out using a JEOL JXA8800R wavelength-dispersive electron probe micro-analyzer (accelerating voltage of 15 kV and a beam current of 15 nA) at the Centre for Cooperative Research of the Kanazawa University (Kanazawa, Japan). The Micro-Raman spectroscopy (a HORIBA Jobin Yvon, LabRAM HR800 system equipped with a 532 nm Nd:YAG laser of Showa Optronics co., Ltd, J100GS-16, and an optical microscope of Olympus, BX41, Kanazawa University) were used in determination of serpentine minerals.
ResultsThe lherzolite is primarily composed olivine, orthopyroxene, clinopyroxene and Cr-spinel, but secondary hydrous and non-hydrous Mg-silicate minerals have been formed during the further serpentinization and metamorphism. Lherzolite is including of olivine (~70 Vol%, forsterite-rich), orthopyroxene (~15-20 Vol%, enstatite – bronzite), clinopyroxene (5-7 Vol%, diopside - augite), and vermicular brown Cr-spinel (60-70 Vol%, chrysolite), orthopyroxene (~30 Vol%, bronzite), a small amount of clinopyroxene, and subhedral dark brown Cr-spinel, talc, tremolite, magnetite, and chlorite. Dunites are composed exclusively of olivine, minor amounts of subhedral, dark brown Cr-spinel, serpentine, metamorphic tremolite, talc and chlorite. The rocks show secondary textures of mesh, poikiloblastic, nematoblastic and jack-straw textures, but original granublastic and porphyroclastic textures are well preserved. Pyroxenes show kink bands, warped cleavages, and undulatory extinction related to metamorphic condition of upper mantle. Petrographical features indicate that a metamorphism at amphibolite facies occurred after serpentinization and chloritization of the Darreh Deh peridotites. Chrysotile cut the primary phases of olivine and pyroxene, but not the metamorphic phases of olivine neoblasts, tremolite, talc and chlorite. Some chlorite crosscut the serpentine veins, and some are in the rim of Cr-spinel and clinopyroxenes. They are mostly replaced by tremolite. Metamorphic olivines have recrystallized as fine-grained neoblasts with lower CaO content (in comparison with the primary and replacive olivines), because they have been formed at the expense of Ca-free mineral of serpentine. Tremolite were produced after chrysotile, talc, and chlorite, wherever enough Ca2 ions were released from the associated olivine and/or orthopyroxene by serpentinization.
DiscussionPetrographical and geochemical studies indicate a greenschist-facies stage (serpentinization and chloritization) followed and overprinted by amphibolite-facies metamorphism. The regional metamorphism is verified by the formation of antigorite after lizardite and chrysotile, metamorphic olivine neoblasts after serpentines, chlorite after Cr-spinel, talc after olivine and orthopyroxene, and tremolite after pyroxene, talc, serpentine, and chlorite. The metamorphism imprints on harzburgite and dunite indicate that metamorphism has occurred after melt-rock reactions.

The Nabar area that is a part of the Urumieh- Dokhtar volcano- plutonic belt is located in the south of Kashan. Research works such as Emami (Emami, 1993) and Abbasi (Abbasi, 2012) have been done about the geology of this area.
Rock units in the study area contain middle- upper Eocene intermediate to acidic lavas and pyroclastic rocks, green marl, shale and sandy marls of Oligo- Miocene, limestones of Qom formation, intrusive granitoids with Oligo- Miocene age and quaternary travertine and recent alluvium (Emami, 1993). The volcanic and sub volcanic rocks of this area are composed of andesite, trachyandesite, dacite, rhyolite and porphyric pyroxene diorite along with pyroclastic rocks.
In order to achieve the aims of this work, at first field surveying and sampling were done. Then, thin and polished thin sections were prepared. Some of the samples were selected for microprobe analysis and clinopyroxene minerals were analyzed by using JEOL- JXA-8800 analyzer with a voltage of 20 Kv and a current of 12 nA in the Kanazava University of Japan and Cameca-Sx100 analyzer with a voltage of 15 Kv and a current of 15 nA in the Iranian mineral processing research center, Karaj.
On the basis of petrographic investigations, porphyritic, porphyroid, fluidal, amygdaloidal and porphyry with microlitic groundmass are common textures of these rocks. Also plagioclase, clinopyroxene, amphibole, biotite, sanidine and quartz are essential minerals, opaque, zircon and apatite as accessory minerals are observed in the studied rocks. Clinopyroxenes are observed with corona texture that resulted during the uralitization process. On the basis of minerals’ chemistry, pyroxenes are Fe- Mg- Ca type in composition (Morimoto et al., 1988). These clinopyroxenes are augite. Investigations indicate that mineral composition of clinopyroxene can be effectively used to evaluation the P-T conditions during crystallization. Previous research works have proposed several methods such as Soesoo (Soesoo, 1997) and Putrika (Putrika, 2008). Thermobarometric studies of clinopyroxenes reveal that Nabar rocks were formed at temperatures of 900 -1200 ˚C and the pressure of 2-5 kbar. According to the Aoki and Shiba (Aoki and Shiba, 1973) and Helz (Helz, 1973) approaches, the pyroxenes of the studied rocks are in a range of low to medium pressure that shows crystallization of clinopyroxenes during ascending of magma in different depths. Also according to Helz (Helz, 1973), the water vapor content in the crystallization of clinopyroxenes is more than 10 percent. Using AlIV versus AlIV 2Ti Cr diagram which depends on the amount of ferric iron in pyroxenes, we can get oxygen fugacity. Based on this diagram, the pyroxenes which crystalized at high oxygen fugacity, has been situated above the line of Fe3. Furthermore, Cameron and Papike (Cameron and Papike, 1981) have mentioned to the distances of the samples from the Fe3 line and noted that further distances of the samples from this line are indicating more oxygen fugacities in their geological setting. On the basis of this diagram samples were located above the line of Fe3橷 these rocks are formed in high oxygen fugacities. Pyroxene composition depends on the chemical composition and tectonic setting of the host lava which can be used widely to determine tectonic setting of the rocks. On the basis of approaches of Le Bas (Le Bas, 1962) and Sun and Bertrand (Sun and Bertrand, 1991), the chemical composition of clinopyroxenes shows that the studied rocks are related to calc-alkaline series and orogenic settings.
On the basis of mineral chemistry, pyroxenes are Fe-Mg-Ca type in composition. These clinopyroxenes are augite. Thermometric studies of clinopyroxenes reveal that Nabar rocks are formed at temperatures of 900-1200 ˚C. According to the distribution of aluminum in clinopyroxenes, these minerals were formed at 2-5 k bar pressure and water vapor content of more than 10 percent. Therefore, pyroxenes of the Nabar rocks are in a range of low to medium pressure that shows crystallization of clinopyroxenes during ascending of magma in different depths. Moreover, the volcanic rocks in Nabar were formed in high oxygen fugacity. The chemical composition of clinopyroxenes reveals that these rocks are related to calc-alkaline series and orogenic settings.

The study area is located in the Shurab area that is about 50 Km Southeast of Qom. Volcanic rocks of the Shurab area have basaltic composition that is associated with salt and marl units. Igneous rocks of the Shurab area have not been comprehensively studied thus far.
Clinopyroxene composition of volcanic rocks, and especially the phenocrysts show Magma chemistry and can help to identify magma series (Lebas, 1962; Verhooge, 1962; Kushiro, 1960, Leterrier et al., 1982), tectonic setting (Leterrier et al., 1982; Nisbet and Pearce, 1977) as well as temperature formation and pressure of rock formation. Some geologists have estimated temperature of clinopyroxene formation by clinopyroxene composition (Adams and Bishop, 1986) and clinopyroxene-olivine couple. So, clinopyroxene is used in this study in order to identify magma series, tectonic setting, plus the temperature and pressure of volcanic rocks of the Shurab.
Material and Clinopyroxene analyses were conducted by wavelength-dispersive EPMA (JEOL JXA-8800R) at the Cooperative Centre of Kanazawa University (Japan). The analyses were performed under an accelerating voltage of 15 kV and a beam current of 20 nA. The ZAF program was used for data corrections. Natural and synthetic minerals of known composition were used as standards. The Fe3 content in minerals was estimated by Droop method (Droop, 1987).
In the Shurab area, the volcanic rocks area with basaltic composition are located 50 km Southeast of Qom. Their age is the early Oligocene and they are associated with the salty marl units of the Lower Red Formation (LRF). The hand specimens of the studied rocks look green. These rocks are intergranular, microlitic, porphyric, vitrophyric and amygdaloidal and they consist of olivine, pyroxene and plagioclase. Accessory minerals contain sphene, apatite and opaque.
According to Wo-En-Fs diagram (Morimoto, 1988), clinopyroxenes indicate diopside composition.
Clinopyroxenes are representatives of magma composition and they are usually used for identifying magma series. There are several diagrams that are used for this purpose as follows.
1 - Al2O3 – SiO2 diagram (Lebas, 1962): According to this diagram, the studied clinopyroxenes were plotted in sub-alkaline field.
2 - Al2O3 – TiO2 diagram (Lebas, 1962): In this diagram, the studied clinopyroxenes show to be calcalkaline.
Some diagrams that are used for determining tectonic setting according to clinopyroxene composition are as follows: 1 - F1 – F2 diagram (Nisbet and Pearce, 1977): Based on this diagram, the Shurab clinopyroxenes rocks lie between volcanic arc and mid ocean ridge basalt fields.
2 - Al2O3 - SiO2 diagram (Lebas, 1962): Using this diagram, the studied clinopyroxenes are located in the sub-alkaline field.
Some methods that are used for determining temperature formation and pressure of clinopyroxene are as follows: 1 – Kretz method (Kretz, 1994): Using this method, temperature formation of clinopyroxene is about 1200- 1250oC.
2 – Soesoo method (Soesoo, 1997): Using this method, pressure formation of clinopyroxene is about 6-10 Kb.
In Al�븊 against Na diagram, Clinopyroxenes are located above the Fe=0 line (Schweitzer et al, 1979). This case and abundant hematite and magnetite in the Shurab area rocks confirm that oxygene fugasity is high. Based on Helz diagram (Helz, 1973), the content of magma water during clinopyroxene formation is about 2-5 percent.
Using various methods, the temperature and pressure of clinopyroxene formation are about 1200 oC and 6-10 Kb, respectively. Clinopyroxene composition and the abundant hematite and magnetite in the studied rocks confirm that oxygene fugasity is high. According to Helz diagram, the amount of water is about 2-5 percent.
Additionally, the parent magma of the studied area rocks is calc alkaline and tectonic setting is subduction-related based on the clinopyroxene composition.

The Eocene Chapedony metamorphic core complex, is located in western part of the Posht-e-Badam block. This complex is consisting of migmatite, gneiss, amphibolite, marble, micaschist and various types of granitoids. In middle part of this complex (Kalut-e-Chapedony), an Eocene granitic rock unit cross cuts the other rocks. The minerals of this granite are plagioclase (An9Ab87Or4), potassium feldspars (orthoclase), quartz, euhedral garnet (Alm77Sps13Prp9Grs1), zircon, apatite, fibrolitic sillimanite and muscovite. Petrology and geochemical studies reveal calc-alkaline, peraluminous and S-type nature of the studied granites. Chondrite-normalized REE patterns represent evident negative anomaly of Eu and low values of the REEs. Continental crust and North American shale composite (NASC) - normalized multi-elements spider diagrams indicate trace elements depletion. These granites are formed by melting of continental crust sedimentary rocks, resulted by emplacement of mantle-derived magma at the bottom of continental crust which formed the Chapedony metamorphic core complex. The source rock of these granites should be a clay-rich sedimentary rock with low amount of plagioclase and CaO/Na2O ratio.

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.

Geological background Ophiolites have played a major role in our understanding of Earth’s processes ranging from seafloor spreading، melt evolution and magma transport in oceanic spreading centers، and hydrothermal alteration and mineralization of oceanic crust to collision tectonics، mountain building processes، and orogeny. They provide the essential structural، petrological، geochemical، and geochronological evidence to document the evolutionary history of ancient continental margins and ocean basin. Ophiolites include a peridotitic mantle sequence، generally characterized by high-temperature plastic deformation and residual chemistry، and a comagmatic crustal sequence (gabbros، diabase dikes، and submarine basalts)، weakly or not deformed. According to this interpretation، ophiolites were allochthonous with respect to their country rocks. They were assembled during a primary accretion stage at an oceanic spreading center، and later tectonically emplaced on a continental margin or island arc (Dilek، 2003). The indigenous dikes of pyroxenites and gabbros that were injected into a melting peridotite، or intrusive dikes of pyroxenite and gabbro that injected when the peridotite was fresh and well below its solidus، are discussed in different ophiolite papers. Pyroxenite formation and contact of gabbro and mantle peridotite are discussed in different articles (Dilek، 2003). When a gabbro intrude a fresh mantle peridotite could not significantly react with it، but if intrusion occurs during the serpentinization، the gabbro will change to rodingite. Geological setting: The Naein ophiolitic melanges comprise the following rock units: mantle peridotites (harzburgite، lherzolite، dunite، with associated chromitite)، gabbro، pyroxenite، sheeted and swarm dikes، massive basalts، pillow lava، plagiogranite، radiolarian chert، glaubotruncana limestone، rodingite، listvenite، and metamorphic rocks (foliated amphibolitic dike، amphibolite، skarn، banded meta-chert، and succession of schist and marble) (Davoudzadeh، 1972; Jabbari، 1997; Pirnia Naeini، 2006; Torabi، 2012; Shirdashtzadeh، 2006). In this ophiolite، the leucogabbro intrusions crosscut all other rock units. Mineralogical analyses were conducted by wavelength-dispersive EPMA (JEOL JXA-8800R) at the Cooperative Centre of Kanazawa University (Japan). The analyses were performed under an accelerating voltage of 15 kV and a beam current of 15 nA. JEOL software using ZAF corrections was employed for data reduction. Natural and synthetic minerals of known composition are used as standards. The Fe3+ content in minerals was estimated by assuming mineral stoichiometry. In the contact zone of leucogabbros and mantle peridotites of the Naein ophiolite، wehrlite and olivine clinopyroxenite are formed. Rock-forming minerals of these wehrlites are olivine (chrysolite)، clinopyroxene (diopside)، Cr-spinel، serpentine، amphibole (tremolite and tremolitic hornblende)، epidote and magnetite. Comparison of mineral chemistry of olivine، clinopyroxene and chromian spinel in wehrlites and mantle peridotites indicate that chemical composition of clinopyroxene and olivine in these rocks are different، but chemistry of Cr-spinels in harzburgite and wehrlite are nearly same. According to the resistance of Cr-spinel against the metamorphism and alteration، it can be concluded that the wehrlites in contact zone of gabbros and mantle peridotites are formed at the expense of harzburgite. Olivine and clinopyroxene of wehrlites are formed by serpentine metamorphism and interaction of serpentine and calcium of gabbro، respectively. Field study of the research area shows that the leucogabbro intrudes the harzburgite. This research shows that after the serpentinization of mantle harzburgite، the gabbro intrusions crosscut the serpentinized peridotites، and wehrlite and olivine clinopyroxenite formed in the contact zone.

The Nain and Ashin ophiolites are located in northeastern Isfahan province، in western Central-East Iranian Microplate. Pillow lavas are one of the most significant Cretaceous rock units. The lower partial melting degree in mantle peridotites of Ashin ophiolite، and the derived melt by melting their clinopyroxene caused a more basic (basalt) and enriched nature for the Ashin pillow lavas، whereas higher partial melting degree and consequently incongruent melting of orthopyroxene and increment of silica in the ascending melt، together with aqueous fluids led to formation of more acidic (andesite – basaltic andesite) and depleted melts (in trace elements) in Nain ophiolite. The REE content of Nain samples have IAT chemical affinity، but the samples from Ashin show MORB characteristics. Based on petrograhic observations، lower Eu/Eu* of clinopyroxene phenocrystals of Ashin، calculated Kd of clinopyroxene together with HREE enrichment in the melt in equilibrium with clinopyroxene (especially in Ashin when compared with Nain)، the plagioclase crystallization was primer and higher in comparison with clinopyroxene، especially in Ashin compared with Nain. The melt in equilibrium with clinopyroxene in Ashin was similar to MORB composition، whereas it is similar to IAT in Nain. Thus، despite the proximity of these two ophiolitic series and some field and petrographic similarities، pillow lavas from them are different from each other in both primary melt composition and the processes of differentiation and the tectonic setting.

In the northwest of the Central-East Iranian Microcontinent (CEIM)، southwest of Jandaq، the Toveireh Oligocene alkaline basalt with NW-SE to W-E trend is outcropped. This alkaline basalt with porphyritic، poikilitic and microlithic porphyritic textures have olivine (chrysolite)، clinopyroxene (diopside and augite)، plagioclase (labradorite) and spinel as primary minerals and titanomagnetite، serpentine and zeolite as secondary phases. The rock in question is enriched in alkalies (Na2O+K2O)، TiO2، LILE (Cs، Rb and Ba)، HFSE (Ti، Nb، Hf and Zr) with high ratio of LREE/HREE (Light Rare Earth Elements/Heavy Rare Earth Element) (La/Yb=9. 64-12. 68). The chemical composition of theses rocks indicates that the primary magma of the Toveireh alkaline basalt is produced by partial melting of carbonated garnet lherzolite of asthenospheric mantle. The geological situation of the study area suggests that the subduction of oceanic crust along the Great Kavir Fault from the Triassic to the Eocene caused carbonate metasomatism and mantle enrichment. The presence of abundant xenoliths، xenocrysts and the reaction textures show fast magma rising. The activity of Great Kavir and the Toveireh faults in an extensional system in the NW of CEIM can be accounted for the Oligocene alkaline magmatism.