Petrology and geochemistry magmatic rocks of Lattan Mountain, North of Shahrekord, Sanandaj-sirjan Zone, West of IranMaryam Ahankouba*, Yoshihiro Asaharab, Motohiro TsuboiC

a. Department of Geology, Payame Noor University, Islamic Republic of Iran.b. Department of Earth and Environmental Sciences, Graduate School of Environmental Studies,

Nagoya University, Nagoya 464-8601, Japanc. Department of Applied Chemistry for Environment, School of Science and Technology, Kwansei

Gakuin University, Sanda 669-1337, Japan*corresponging author: +989133845117, E-mail:M.ahankoub@pnu.ac.ir

Abstract Mesozoic igneous rocks are scatter developed in the central part of the Sanandaj-Sirjan Zone, in Charmahal and Bakhtiari province, west Iran. Based on the mineralogy, texture and geochemical composition these rocks are divided into two main groups including subvolcanic, volcanic and plutonic rocks. Volcanic rocks are dominantly basalts, andesitic basalts, and andesites with porphyritic to microlithic porphyry and vitrophyric textures and the second group, consisting of dolerite, diorite, gabbro, microdiorite with granular to micro-granular and intersecral to intergranular texture. The chemical compositions of these rocks are metaluminous with affinity calc-alkaline to transition and enrichment in LIL elements (Rb, Ba, Th, U, and Pb) and depletion in Nb, Ti, and Zr, as evident in spider diagrams normalized to a primitive mantle. Also, it has enrichment LREE to HREE pattern. These rocks are 87Sr/86Sr and 143Nd/144Nd ratios range from (0.704851 to 0.715133). (0.512534 to 0.512710) respectively. The characteristic in Nd and Sr isotopic composition indicates a mixing of enriched mantle array and crustal component. Primary magmas for magmatic rocks could be derived from metasomatized enriched MORB-like sources. Magmatic rocks formed related island arc setting of the subduction of the neothetys ocean plate. Petrology and geochemistry data suggest a mantle lithospheric source that was metasomatized by fluids derived from a Neo-Tethyan subducted slab.Ker Word: island arc magmatism, Mesozoic, Volcanic, Plutonic, Subduction, Neothetys, Sanandaj-Sirjan Zone.

1. Introduction Neothetys orogenic belt which developed as result of geodynamic processes in the Mesozoic and Cenozoic, include several phases of subduction, obduction, micro-plate accretion, conti-nent–continent collision and exhumation (Dercourt et al.1986; Hafkenschied et al. 2006). Af-ter closed paleo-Tethys the eastern European margin was composed of Gondwanan derived microcontinents which had been accreted to the Scythian platform during the Triassic–Juras-sic Cimmerian orogenic cycle (Sengor et al. 1984; Stampfli and Borel 2002; Golonka 2007).The Jurassic northeastward subduction of the Neotethys below the eastern European, i.e., Eurasian margin caused continuous active arc magmatism along the eastern Pontides, the Lesser Caucasus and the Sanandaj–Sirjan Zone (Kazmin et al. 1986, Ustaömer and Robertson 1999, Mahmoudi et al. 2011). The SSZ is a narrow belt of high deformed rocks in the Zagros orogeny with NW-SE structure trend (Mohajjel and Fergusson 2000). This zone can be subdi-vided into two parts (Eftekharnejad 1981): (1) the southern part (South SSZ) consists of rocks deformed and metamorphosed in Middle to Late Triassic; (2) The northern part (North SSZ), deformed in the Late Cretaceous, contains many intrusive felsic rocks (such as the Alvand, Borojerd, Arak and Malayer plutons). South SSZ was accompanied low to medium pressure metamorphism, andesitic intrusions and volcanism ranging from gabbro to granite (Berberian and Berberian 1981). These Magmatic activities indicate the subduction of Neo-Tethys be-

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neath the South SSZ by the Late Jurassic–Early Cretaceous (Şengör 1990).The data of the volcanic rocks of SSZ is mainly restricted to ophiolite successions and small-scale volcanic sequences. There are widespread occurrences of arc-related volcanic rocks of Kermanshah ophiolites, Cretaceous volcanic rocks in the northwest Iran, along with the SSZ (Babaie et al. 2001, Azizi and Jahangiri 2008, Shahbazi et al. 2010, Esna-Ashari et al. 2012). The Sanan-daj-Sirjan zone preserves the record of magmatic activity of a complete orogenic cycle re-lated to (1) Permocarboniferous rifting of Gondwana and the opening of the Neo-Tethyan ocean, (2) subduction of the oceanic crust, (3) continental collision and (4) post-collision/post-orogenic activities(Sepahi et al. 2014). There is the new theory about the tectonic setting for the Sanandaj-Sirjan zone, which suggests that during ocean–ocean subduction (from Jurassic to Cretaceous) an immature island arc developed before the closure of Neo-Tethys ocean(Zarasvandi et al. 2015). Zagros thrusts are associated with the great counter thrust sys-tem (Heim and Gansser 1939, Gansser 1964), which marks the southern boundary of the SSZ in southeastern central Iran and separates Tethyan rocks from those representing the distal northern continental margin of Iran (Fig.1). This fault system is locally referred to as the Za-grous thrust system. At Zagrous it consists of a series of south dipping thrusts that place up-per Triassic sandstones and phyllites of affinity over fragments of the intra-Tethyan subduc-tion system and Arabic–Iran collision-related sediments (Yin et al. 1999).There are some reports about volcanic rocks in the north of Shahrekord (Emami et al. 2009). There are little belt of black and green-colored magmatism rocks in of the SSZ with NW–SE striking in north of chaharmahal and bakhtiyari province that it is parallel to the main Zagros fault and in 35 km distance of its and in the Lattan mountain (Fig.1). There are exposed mag-matic, sedimentary and metamorphic rocks (Fig.2). There are no detailed geochemical and isotopic studies on Lattan mountain the magmatic rocks, their nature; age and origin are yet poorly constrained. The aim of this paper is to present new results on the mineralogy, petrology, geochemical and isotopic signatures of the igneous rocks of the Lattan mountain.

2. Geological setting and samples The Lattan mountain, situated between east longitude 46°00' to 46°30' and north latitude 35°20' to 35°40' (Fig.2), that lies within the highly deformed subzone of the Sanandaj-Sirjan (Zahedi et al.1992). Typical lithology of the study area is similar of the sanandaj-sirjan terrine rocks that are also exposed further to the east around zagrous thrusts fault. The major lithological units of this area include phyllites, schists, crystallized limestones, and a dolomite rock intruded by unites magmatic rocks. The igneous rocks of Lattan Mountain are represented by small to large singular outcrops.These magmatic rocks are green, colour and grey in colour as distinguished in the field. These rocks are of black to dark gray, green-gray with a porphyric or serial-porphyric structure. The volcanic rocks are represented by the various intermediate to basic rocks. The subvolcanic and plutonic are composed of microgabbro, microdiorite and dolerite. No pillow structures have been observed. Microgabbro and microdiorite sills and dikes distinguished with chilled margins.

3. Analytical methods In this paper, whole-rock analysis for major and trace elements and 87Sr/86Sr and 144Nd/143Nd isotope ratios was performed for 10 ten samples. Rock samples were grinded to smaller than 250 microns. Major elements were analyzed by XRF, ten samples at, Nagoya University, Japan by (Rigaku ZSX PrimusII). Loss of ignition (LOI) was calculated by weight difference after ignition at temperature at 950°C for both groups. A 0.5 g sample of each rock powder was mixed with 5.0 g of lithium. Tetra borate and the glass bead were prepared for XRF anal-ysis. The loss on ignition (LOI) was calculated from the weight difference after ignition at

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950 °C. Results are presented in Table 1.ten samples were analyzed using ICP mass spec-trometry (ICP-MS). The samples were prepared through lithium metaborate/tetraborate fu-sion and nitric acid digestion at Nagoya University. Ten samples were prepared through hy-drofluoric acid treatment at the Nagoya University (Japan). For trace element analysis and Sr–Nd isotope analysis, about 100 –mg powdered sample was decomposed in two steps to as-sure complete decomposition. First, it was decomposed in HF + HClO4 in a covered PTFE beaker. Then, the dried sample was dissolved in 10 ml of 2.4 M HCl, and the sample solution was moved to a polypropylene (PP) centrifuge tube to separate residue (A) and clear upper portion (B). The residue (A) was then moved into a smaller PTFE vessel and dried. The sec-ond decomposed residue (A) was treated in HF + HClO4 and kept in a steel-jacketed bomb at 180 °C for 2– 5days to be completely decomposed. The decomposed material was dried and then dissolved in 3 ml of 6 M HCl. This solution was mixed with the solution (B) and kept at 80–100 °C for 1 h to be homogenized. The mixed sample solution was split into two aliquots: one for trace elements including REEs and the other for Sr and Nd isotopes. The concentra-tions of trace elements and REEs for the six samples were analyzed by ICP-MS (Agilent 7700x). Data for trace element concentrations and REEs are presented in Table 1. The results of ten samples analyzed for Sr and Nd isotopes in Nagoya University (Japan) are listed in Ta-ble 2. Isotope ratio measurements have analytical precisions about ±2s. Separation of Rb, Sr, Sm and Nd are conducted using a two column ion-change technique. Sr and Nd isotopic ra-tios were corrected for mass fractionation relative to 86Sr/88Sr=0.119410 and 146Nd/144Nd=0.7219. BCR-2 standard yielded an 87Sr/86Sr ratio of 0.704959 ± 36 and 143Nd/144Nd ra-tio of 0.512613 ± 19, compared with its reported 87Sr/86Sr ratio of 0.704958 and 143Nd/144Nd ratio of 0.512633(Raczek et al. 2003). The Sr–Nd isotopic data were obtained using a Nu Plasma HR multi-collector mass spectrometer at the State Key Laboratory of Continental Dy-namics at the Northwest University and using a thermal ionization mass spectrometer (TIMS), VG Sector 54-30 and GVI IsoProbe-T, at Nagoya University for Sr and Nd respec-tively. The mass fractionation during the Sr and Nd isotope measurements is corrected based on 86Sr/88Sr = 0.1194 and 146Nd/144Nd = 0.7219, respectively. For the samples wich analysed at Nagoya university, NIST-SRM987 and JNdi-1 were adopted as the natural Sr and Nd iso-tope ratio standards, respectively(Tanaka et al. 2000). The isotopic ratios (see Table 3) are calculated and illustrated using the GCDkit software(Janoušek et al.2011).

4. Petrography The major mineralogy phases of the igneous rocks of Lattan mountaion are plagioclase, clinopyroxene, orthopyroxene; amphibole and olivine, also there are biotite, apatite, zircon, and opaque as the accessory minerals. Textures of rocks are mainly composed of porphyritic, hypocrystalline porphyritic, hyalo-porphyritic and hyalo-microlithic porphyritic.Plagioclase dominates the megacryst and phenocrysts assemblage (up to 60%). Plagioclase grains are mostly subhedral and exhibit twining. Zoning is relatively less common as compared to twin-ing. Plagioclase phenocrysts also show a ‘dusty’ or ‘fritted’ zone mantling of the grains encir-cled by a fresh rim. Clinopyroxene is the other major phenocrysts constituent mineral that mostly occurred as microphenocrysts or within the groundmass. Olivin is mostly anhedral and/or corroded crystals. Olivine present in basalts and basaltic andesites. Dark colored min-erals in these rocks are monoclinic and rhombic pyroxenes or basaltic hornblende and rarely biotite. The aphyric basalts are formed of clinopyroxene aggregates either or not associated with plagioclase set in a glass-rich groundmass which includes isolated plagioclase microphe-nocrysts. The basalts consist of plagioclase laths, olivines and pyroxene glomeroporphyric aggregates embedded in a glass-poor groundmass which contains small rounded vesicles filled with smectites + epidote + chalcedony (Fig, 2A). The size of the plagioclase laths is highly variable and ranges from 0.1 to 1 mm. The aphyric basalts are formed of clinopyroxen

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aggregates either or not associated with plagioclase set in a glass-rich groundmass which in-cludes isolated plagioclase microphenocrysts (Fig.2B). Basaltic andesite is formed of plagio-clase and clinopyroxen phenocrysts. The dolerites exhibit ophitic to intersertal textures and are composed of plagioclase laths enclosed in anhedral clinopyroxen. Subhedral clinopyroxen and anhedral Fe–Ti oxides may occur as large crystals up to 1 cm and 0.5 cm, respectively. Andesites are the numbers of plagioclase grains with ‘fritted’ rims are more common in an-desite. The width of the ‘fritted’ rim also varies from mm-thin to cm-thick bands. Plagioclase is the main minerals as phenocrysts and in the matrix, and is mostly replaced with epidote, white mica and clay minerals (Fig.2D).Plagioclase occurs as fresh, unreacted grains or as resorbed, reacted resorbed grains (Fig.2E). In some samples, clinopyroxene remains fresh while orthopyroxene is replaced by smectites-chlorites when altered, clinopyroxene is replaced by smectites, chlorites or colorless actinolite. There are some mineralization malachite, azurite, hematite and magnetite. Some of the igneous rocks of lattan mountain are metamorphosed to a low-grade zeolite and prehnite–pumpellyite facies, and igneous textures are always preserved. In a number of samples, hornblende displays opaque rims, and in some, the amphibole is completely pseudomorphed by finely crystalline opaque minerals (Fig.2F).

5. GeochemistryMajor and trace element for 10 samples of the lattan mountain magmatic rocks is presented in Table 1 and 2. The rocks have SiO2 content ranging from 47.34 to 52.35 wt%. The Harker diagram shows a different correlation between SiO2 and Al2O3, Fe2O3, TiO2, CaO, MnO, MgO, Na2O, K2O, Ba, MgO, Sr and Eu, Rb (Fig.3). The negative correlation between SiO2

and some major oxides (e.g., MgO, Fe2O3, CaO, Al2O3, and MnO) suggest that these rocks experienced fractionation. In AFM diagram, Lattan Mountain sample plote in the calc-Alkaline domain (Fig.4). In AFM diagram, sample plote in the calc-Alkaline domain (Fig.4a). The boundary between tholeiitic and calc-alkaline is from Irvine and Baragar (1971). On the alkalis vs. silica classification diagram of TAS (Cox et al. 1979), the rocks plot dominantly at the basalt – basalt andesite and andesite rocks (Fig.4B). In the diagram [Al/ (Ca + Na + K)]–[Al/ (Na + K)](Shand 1947), the samples plot in the metaluminous fields (Fig.4C).In the diagram of the Chondrite-normalized (Boynton 1984), samples show enriched in LREE relative to HREE, which is typical of calc-alkaline suites. Samples show weak negative Eu anomalies probably associated with plagioclase fractionation (Fig.5A). In Primitive mantle-normalized pattern from McDonough and Sun (1995), all samples show a prominent Nb trough. Also, samples are enriched in Rb, Ba, K, and Sr relative to primitive mantle-normalized, but they are depleted in Nb, Zr, Hf, and Ti. As well as samples show positive Ba and Sr anomalies. Many of the major and trace elements (e.g., Si, Na, K, Ca, Cs, Rb, Ba, Sr) are easily mobilised during post-magmatic processes; however, the HFSEs (e.g., Th, Ti, Zr, Nb), REEs and transition elements (V, Cr, Ni and Sc), are considered as being relatively immobile during low-grade metamorphism or alteration processes (Bédard, 1994). Therefore, the subsequent petrogenetic and geochemical interpretations, as well as tectonic setting discrimination of samples are mostly based on immobile HFSE and REEs, which have similar chemical and physical properties to each other. It was shown Th vs Yb and La vs Yb diagrams position of the field boundaries (Ross and Bedard, 2009). In these diagrams, samples plot in calc-alkaline to transitional fields.The contribution of Nb/Y vs. Zr/Y and Zr/Yb vs. Nb/Yb diagrams the samples are collectively plotted near the N-MORB array and below, indicating a mantle origin for approximately all of the Zr and Y contents(Viruete et al.2010) (Figs. 7A and B). Isotopic data of the lattan mountain area display variable Nd ratios which range between 0.512534 to 0.512710 and Sr ratios (87Sr=86Sr)i ratios (0.704851 to

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0.715133), (Table 3). Plot samples in 143Nd/144Nd vs 87Sr/86Sr display mantle array to crustal nature (Fig.7)

6. Discussion Magmatic rocks of the Lattan Mountain exposed near Zagruos main fault. Major element chemistry is belonging to the andesite, andesi-basalt and basalt calc-alkaline to transitional series. The majority of analysed samples are silica saturated and metaluminous. Major element trends in Harker diagrams are shown linear relationships for all elements relative to SiO2 except Na2O which shows a nonlinear as SiO2 increases.Study area magmatic rocks are containing low amounts of Ni, Cr, Zr, Ti, Ba, Nb.Prominent Nb trough characteristic of subduction zone magmas. This depletion of Nb relative to the large-ion lithophile elements (LILE; e.g., Rb, Ba, K) can be attributed primarily to two processes: (1) the addition of a LIL Enriched, Nb-poor fluid component to the mantle wedge or (2) the preferential retention of Nb in amphibole relative to other phases in the mantle source (Borg et al. 1997a , b). Similar processes are inferred for the general depletion of the high field strength elements (HFSE)—Zr, Ti, and Y—with respect to the LILE in arc magmas (Pearce and Peate, 1995).These patterns suggest that the studied rocks are derived from magmas that originated from the partial melting of the lithospheric mantle, which was modified by fluids and sediments from a subduction zone. Sr behaves as an incompatible element with increasing differentiation when plagioclase crystallization is limited. A number of petrological and geochemical features point to high water contents in the magmas at high concentrations of fluid-mobile elements (Sr, Ba, Rb) in mafic samples are consistent with melt generation from hydrated mantle(Pearce 1982), and the presence of amphibole and biotite requires high water contents (>3 wt %) in the crystallising magmas(Barclay and Carmichael 2004, Moore and Carmichael 1998, Sisson and Grove 1993). Plagioclase is suppressed at high water contents, and occurs as a liquidus phase at lower temperatures and pressures in hydrous basalts than in anhydrous equivalents(Gaetani et al. 1993).Slab melts and aqueous fluids from subducted slabs can enrich the mantle by metasomatism (Kepezhinskas et al. 1995; McInnes et al. 2001; Pearce and Peate 1995; Rapp et al. 1999).Under high pressure and temperature conditions (1250°C, 15–25 kb), aqueous fluids derived from a dehydrating slab are capable of carrying significant mass fractions of mobile elements. Under such conditions, aqueous fluids and silicate melts may be entirely miscible, and would have similar solvent properties (Ayers and Eggler 1995, Bureau and Keppler 1999). It, therefore, makes it difficult to discriminate between slab melt and hydrous metasomatism on the basis of trace and major elements alone. In fact, the presence of arc-like Ba and Sr enrichments in basalts. Also assimilation-fractional Crystallization Effect As a result of heat transfer from hot magma to the cold crust, magmas, which are undergone fractional crystallization and assimilated around the crust, is very common (DePaolo 1981, Spera and Bohrson 2001, Kuritani et al. 2005). Most of the large-volume continental silicic magmas are the combination of continental rocks and mantle-derived basaltic melts(DePaolo et al. 1992). Mantle-derived magmas are subjected to contamination when they rise through the thick crust and therefore, are affected by the contamination with the certain degree. For the lattan mountain magmatic rocks, as shown from the diagram, the rocks are calc-alkaline to transitional rock which were isotopic data ratios confirm interference crustal material in the magmatic process. Hofmann and White (1982) state that enriched isotope compositions of oceanic island basalts are due to old crust material sent back to the mantle. Anderson (1994) proposed convective mantle that is represented by trace element and isotope characteristics (like DMM) depleted prior to ascension and interacted at the beginning with

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shallow and enriched mantle. This portion proposed is below the thermal boundary layer or within the asthenosphere(Anderson 1994). The same author also states that enriched part of the shallow mantle may correspond to chemical characteristics of a source region similar to continental basaltic or OIB magmatism. In addition, the observation that magmatic rocks is closely associated with strike-slip tectonism in the region may indicate that this system possibly contributes to the magma rising. The mechanism suggested for the melt generation is rather similar to that proposed for the east and west Anatolian volcanisms (Keskin 2003, Pearce et al. 1990, Aldanmaz et al. 2000). Arc magmatism is the most distinctive component of the Sanandaj-Sirjan zone, which includes voluminous calc-alkaline plutons and volcanic rocks, mainly of Jurassic age, which as demonstrated below culminated around 170 Ma(Hassanzadeh and Wernicke 2016). Geological data on the early Mesozoic formations indicate to volcanism in late Triassic –early Jurassic (Emami et al. 2009).On the basis of geothermobarometric calculations, amphiboles in volcanic and subvolcanic rocks belong to upper Jurassic (Emami et al. 2009). Using Hamarstrom, Schmidt, Johnson - Rutherford and Hollister methods, amphiboles have crystallized about 635 to 715 °C and 2.68 to 7.5 kbar at the depth about 17 to 25 km(Emami et al. 2009). The result of calculations has moderate accuracy. The lower Fet/ (Fet + Mg) ratio in amphiboles is characteristic of calc-alkaline magma suites. Calculated temperatures, pressures, and depths for amphiboles are coinciding with a subduction tectonical environment. The maximum depth of crystallization of amphiboles is 25km and subduction angle is lower than 45 km on the basis of 35 km distance between this volcanic belt and main Zagros fault. The amounts of Aliv amphiboles are higher than 1.5 that indicates an island arc suite. Also, isotopes suggest seawater involvement in the generation of some island arc magmatism indicates that they may be derived from altered subducted oceanic crust and assimilation of old continental crust. The geochemical characteristics of lattan mountain volcanic rocks indicate LILE and water enrichment of the mantle by slab-derived fluids (or melts) during the dehydration of subducting slab of Neo-Tethys oceanic lithosphere; most samples are characterized by relatively low Nd/Pb and Ce/Pb values resulted from source enrichment by slab-derived fluids (Bonev and Stampfli 2008). The M/Yb vs. Nb/Yb diagrams has been widely used in previous studies to evaluate the contribution of mantle and slab-derived components (Pearce and Peate 1995, Viruete et al. 2006, Maurice et al. 2012); here the M refers to conservative (i.e., HFSE) or nonconservative (i.e., LILE or LREE) elements of interest. Samples of lattan mountain are collectively plotted above the N-MORB and non plum source. As mentioned earlier, samples have relatively high LOI values; such values can highlight the role of alteration during post-eruption processes, the effects of alteration and consequently elemental mobility can be traced on the primitive mantle-normalized multi-element spider diagram (Fig.8).

Conclusion

In the lattan mountain region west of Iran, igneous rocks units out crop as volcanic and sub-volcanic. These units intrude the Mesozoic shale and carbonate formation, and correspond to andesite, basaltic andesite, and basalt, diorite, microdiorite, and gabbro. Geochemistry studies indicate rocks of these units are metaluminous calc-alkaline to affinity transitiona of the is-land arc. Enrichment in LREE to HREE in chondrite normalized pattern and significant en-richment in LIL elements (Rb, Ba, Th, U and K) and LREE’s and relatively depletion in HFS elements (Ta, Nb, Ti and Hf) attributed to the effect of subduction component in the source region or crustal contamination. Also depletion of Hf and Ti with respect to other HFS ele-ments can be explained with mantle enrichment in intracontinental processes or derivation from a source with small degree partial melts. This is also confirmed by tectonic discrimina-

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tion diagrams, in which the magma composition varies between three end-member compo-nents: a depleted MORB mantle, a subduction zone component and an enriched mantle com-ponent. The Sr-Nd isotopic data of lattan mountain magmatic rocks shows compositional characteristics of mantel array magmas, with affinities to crustal. An enrichment of Pb and relatively low Nd/Pb and Ce/Pb values with slight enrichment of LREE relative to HREE and tectonic discrimination plots strongly support an island arc calc alkaline0-transitional signa-ture. The low Zr and Th abundance, with low Th/Yb and Zr/Yb values, indicate little sedi-ment input to melt generation in the mantle wedge and provide evidence for the long distance to continental margin. Data suggest that, during ocean–ocean subduction, an immature island arc developed before the ocean closure.

AcknowledgmentThis work supported by a research grant in 2013 Payam Noor University. We would like to express our sincere thanks to Profs. Yamamoto from the Nagoya University of Corporation. We are highly thanked for constructive and insightful comments by some anonymous reviewers.

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Fig. 1. Geological map Zagros orogenic belt. Modified from(Alavi 2004).

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Fig. 2. Geological map Latan Mountain, study area.461462

Fig.2. Microscopic views from,A:coarse-grained olivine in basalte XPL, B:Pyroxen in gabbro, C: alter-ation plagioclase in andesite, D: phenocrest Plagioclas and epidotein andesi-bsalt, E, plagioclase in an-

desite , F: amphibol in andesite(Whitney and Evans 2010).

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Table 1: Major element of whole rocks of Lattan Mountain.Sample La1 La2 La3 La4 La5 La6 La7 La8 La9 La10

Major element (wt%)

SiO2 47.34 46.00 46.9442.1

9 52.30 43.989 48.640 50.00 46.46 46.44

TiO2 0.78 0.77 0.86 0.60 0.81 0.634 0.828 0.80 0.83 0.81

Al2O3 16.87 17.08 18.6514.0

6 17.75 15.338 16.242 17.10 18.32 17.32

Fe2O3* 9.86 7.46 10.04 5.99 7.81 6.199 9.432 9.25 8.47 8.27

MnO 0.16 0.14 0.15 0.17 0.19 0.144 0.197 0.19 0.14 0.15

MgO 7.37 5.88 7.12 5.14 4.80 4.457 9.361 8.58 6.20 7.20

CaO 11.89 11.83 8.9618.7

3 10.23 17.609 8.590 6.38 10.57 10.87

Na2O 1.66 1.96 2.51 2.40 2.93 2.251 1.430 2.61 2.61 2.41

K2O 0.76 3.25 1.79 1.38 1.84 1.925 1.915 2.21 1.56 1.36

P2O5 0.20 0.27 0.24 0.23 0.28 0.248 0.266 0.21 0.26 0.25

Total 96.91 94.63 97.2690.9

0 98.94 92.793 96.900 97.33 95.41 95.07

L.O.I 3.09 5.37 2.74 9.10 1.06 7.207 3.100 2.67 4.59 4.93

476

Fig 3.Harker (1909) diagram of lattan mountain samples.

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Fig. 4. (a) Chemical classification diagrams for the lattan mountain samples, a) AFM diagram(Irvine and Baragar 1971); b) TAS(Cox et al.1979); c) and A/NK vs. A/CNK diagram(Shand 1947).

484485486487488489490491492493494495496497498499500501502503504505506507508509510

Table 2: Trace element of whole rocks of lattan mountain area.Sam-ple La1 La2 La3 La4 La5 La6 La7 La8 La9 La10

Trace element (ppm

Ba 127.60 540.51 259.95276.4

4 170.31 277.498333.28

7 529.54 279.15 268.13

Rb 23.94 76.47 60.49 36.95 67.12 50.017 78.460 68.27 48.55 49.52

Sr 1364.48 660.32 603.12364.9

4 453.41 441.543278.77

5 476.86 413.11 410.11

Zr 47.23 51.22 61.19 47.17 59.70 46.426 64.413 58.71 59.30 56.31

Nb 1.00 1.00 1.00 1.00 1.00 1.000 1.000 1.00 1.00 1.00

Ni 162.87 75.61 200.01 59.79 124.50 54.329136.50

4 114.81 147.42 123.28

Co 46.42 31.79 56.88 17.42 21.02 18.902 54.098 49.11 39.59 37.43

Zn 68.13 60.58 77.14 50.10 72.27 44.035 75.170 73.32 72.71 70.62

Cr 340.15 270.12 482.99315.8

1 358.61 299.398361.93

4 237.78 470.91 465.72

La 16.30 17.49 15.46 15.79 16.12 15.083 19.161 15.11 16.36 15.47

Ce 37.49 40.47 36.74 35.13 38.51 33.799 40.839 33.79 36.96 34.76

Pr 4.71 5.09 4.64 4.41 4.25 4.261 5.269 4.26 4.66 4.86

Nd 20.58 21.74 20.30 19.09 21.37 18.178 22.676 18.73 20.28 20.53

Sm 4.38 4.67 4.48 4.16 4.24 4.174 5.052 4.04 4.45 4.53

Eu 1.22 1.37 1.44 1.21 1.26 1.257 1.451 1.16 1.43 1.48

Gd 4.14 4.24 4.28 3.91 3.89 4.073 5.870 3.99 4.31 4.36

Tb 0.60 0.57 0.59 0.59 0.61 0.595 0.874 0.58 0.61 0.58

Dy 3.67 3.75 3.87 3.46 3.24 3.792 5.573 3.52 3.94 3.51

Ho 0.78 0.78 0.81 0.70 0.68 0.769 1.188 0.74 0.83 0.81

Er 2.27 2.20 2.41 2.22 2.42 2.282 3.515 2.17 2.39 2.98

Tm 0.33 0.32 0.35 0.29 0.29 0.325 0.465 0.34 0.33 0.35

Yb 2.12 2.09 2.21 1.95 2.10 2.106 2.858 2.12 2.25 2.55

Lu 0.33 0.32 0.32 0.30 0.26 0.299 0.409 0.35 0.36 0.36

Y 19.89 19.86 20.34 19.20 18.34 20.392 31.610 19.41 20.38 20.30

Th 2.28 3.00 1.77 3.07 2.86 2.740 1.910 1.68 1.41 1.42

V 250.28 261.09 289.62193.9

8 251.43 224.022257.81

4 256.72 308.15 304.54

Cu 61.24 29.35 81.02 50.87 68.79 52.003 87.442 118.94 93.25 90.56

Pb 18.04 9.42 13.24 14.01 15.64 22.448179.11

8 8.59 8.76 10.61

Ni 162.87 75.61 200.01 59.79 63.50 54.329136.50

4 114.81 147.42 140.56

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Fig.5A) Chondrite-normalized REE patterns (Boynton 1984);B)Primitive mantle-normalized extended trace element spider patterns of the lattan mountain samples (McDonough and Sun 1995).

Fig.6.Display of the lattan mountain samples in A: Th versus Yb diagram (Barrett and MacLean 1999), B: La versus Yb diagram (Ross and Bedard 2009).

Fig.7. Display of the lattan mountain samples in A: Nb/Y vs. Zr/Y diagram, B: Zr/Yb vs. Nb/Yb diagram (Viruete et al. 2010).

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Table3. Sr and Nd isotopic compositions of the Lattan Mountain.Sample Rb(ppm) Sr(ppm) 87Sr/86Sr(p) 2 SE Nd(ppm) Sm(ppm) 143Nd/144Nd(p) 2 SE

La1 23.9412 1364.48 0.704851 0.000014 20.5805 4.375833 0.512534 0.000009

La2 76.4699 660.321 0.705354 0.000014 21.74069 4.670941 0.512573 0.000008

La3 60.4943 603.12 0.705484 0.000013 20.30406 4.483205 0.512598 0.000008

La4 36.9462 364.937 0.705508 0.000014 19.08743 4.155638 0.512609 0.000008

La5 13.3766 167.304 0.705542 0.000013 9.236203 2.374078 0.512615 0.000007

La6 50.017 441.543 0.705548 0.000014 18.1784 4.174201 0.512616 0.000008

La7 78.4604 278.775 0.705645 0.000014 22.67585 5.05219 0.512616 0.000008

La8 68.2705 476.861 0.705689 0.000013 18.73186 4.044998 0.512618 0.000008

La9 48.5494 413.106 0.706621 0.000013 20.28376 4.453826 0.512631 0.000013

La10 167.2614 410.114 0.715133 0.000013 20.52838 4.531826 0.512710 0.000009

Fig8. 143Nd/144Nd vs 87Sr/86Sr observable Earth for lattan mountain samples (DePaolo and Wasserburg 1976).

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