Document Type : Original Research Paper


1 Department of Geology, Faculty of Sciences, University of Hormozgan, Bandarabbas, Iran

2 Department of Geology, Faculty of Sciences, University of Shahid Bahonar, Kerman, Iran

3 Laboratory of Iran Mineral Processing Research Center, Karaj, Iran


Andesites are located in the north of shahr-e-babak , central Iran, Urumieh- Dokhtar belt. The main texture in these rocks is porphyry and their phenocrysts are plagioclase (Andesine to Labradorite), pyroxene (Augite), amphibol (Tschermakite and Magnesiohornblende). These properties are signatures of calc- alkaline series formed in a volcanic arc setting. Based on geochemical studies, the rocks show enrichment in LREE rather than HREE. The lack of significant Eu anomalies in REE pattern indicates  oxidation state of magma during crystallization. Based on geochemical studies, the clinopyroxenes are Augite and have been crystallized from magma with almost 10% H2O. Fe3+ values of the clinopyroxenes reveal high oxygen fugacity in the magma. Based on the mineral chemistry data, pressure estimates from the clinopyroxenes in the range of 6-10 Kbr and composition yield the crystalization temperatures that range from 900-1100 OC.  Typically, clinopyroxenes occure at calc-alkaline orogenic igneous rocks. The plagioclase composition yield the crystalization temperatures that range from 650-750 OC. According to the present study, the rocks are probably the result of the subduction of the Neo-Tethys oceanic lithosphere below the Sanandaj-Sirjan zone, during the Eocene and in a volcanic arc environment.


Main Subjects

Agard, P., Omrani, J., Jolivet, L., and Mouthereau, F., 2005. Convergence history across Zagros (Iran): constraints from collisional and earlier deformation, Int. J. Earth Sci, 94: 401-419.
Allen, M.B., Jackson, J., and Walker, R., 2004. Late Cenozoic reorganization of the Arabia-Eurasia collision and the comparison of short-term and long-term deformation rates, Tectonics, 23: 1-16. doi:10.1029/2003TC001530.
Aoki, K., and Shiba, I., 1973. Pyroxenes from lherzolite inclusions of Itinome-gata Japan. Lithos, 6: 41-51. doi:10.1016/0024-4937(73)90078-9.
Beccaluva, L., Macciotta, G., Piccardo, G.B., and Zeda , O., 1989. Clinopyroxene composition of ophiolite basalts as petrogenetic indicator, Chemical Geology, 77(3), 165-182. doi:10.1016/0009-2541(89)90073-9.
Berberian, M., and King, G.C.P., 1981. Towards a paleogeography and tectonic evolution of Iran. Can. J. Earth Sciences, 18: 210-265. doi:10.1139/e81-019.
Best, M., 2003. Igeneous and metamorphic petrology. Black, 729pp.
Botcharnikov, R.E., Koepke, J., Holtz, F., McCammon, C., and Wilk, M., 2005. The effect of water activity on the oxidation and structural state of Fe in a ferro-basaltic melt, Geochimica et Cosmochimica Act, 69(21), 5071-5085. doi:10.1016/j.gca.2005.04.023.
Cameron, M., and Papike, J.J., 1981. Structural and chemical variations in pyroxenes, American Mineralogist, 66 (1-2), 1-50. doi:
Cornelius, T., Ntaflos, Th.V., and Akinin, V., 2011. Polybaric petrogenesis of Neogene alkaline magmas in an extensional tectonic environment: Viliga Volcanic Field, northeast Russia. Lithos 122 , 13 –24. doi : 10.1016/j.lithos.2010.11.009.
Davoudzadeh, M., Soffel, H., and Schmidt, K., 1981. On the rotation of the Central-East Iran microplate. N. Jb. Geol. Palaont. Mh., 3: 180-192. doi: 10.1127/njgpm/1981/1981/180.
Dimitrijevic, M.D., 1973. Geology of Kerman region. Geol. Surv. Iran, Yu/52, 334p.
Esperanca S., Crisci M., de Rosa R., and Mazzuli R., 1992. The role of the crust in the magmatic evolution of the island Lipari (Aeolian Islands, Italy). Contributions to Mineralogy and Petrology 112, 450–462. BF00310777.
France, L., Ildefonse, B., Koepke, J., and Bech, F., 2010. A new method to estimate the oxidation state of basaltic series from microprobe analyses. Journal of Volcanology and Geothermal Research, 189(3), 340-346. doi: 10.1016 /j.jvolgeores.2009.11.023.
Ghorbani, M.R., 2006. Lead enrichment inNeotethyan volcanic rocks from Iran: the implications of a descending slab, Geochemical Journal 40 (6) ,557-68. doi :
Helz, R.T., 1973. Phase relations of basalts in their melting ranges at pH2O=5kb as a function of oxygen fugacity, Part I. Mafic Phases, Journal of Petrology, 14, 249-302. doi:
Irvine, T. N., and Baragar, W. R. A., 1971. A guid tochemical classification of the common volcanic rocks. Canadian Journal of Earth Sciences 8: 523–548. Doi: 10.1007/BF00321755
Jackson, J., Hains, J., and Holt, W., 1995. The accommodation of Arabia-Eurasia plate. Journal of Geophysical Research, 100: 15,205-15,219. doi:10.1029/95JB01294. 
Koroll, H., 1993. Evangelakakkis, C. and Voll, Two feldspar Geothermometry: a review and revision for slowly cooled rocks. Contributions to Mineralogy and Petrology, 510-518. doi: 1971CaJES8523I.
Kuno, H., 1968. Origin of Cenozoic petrologic provinces of Japon and surrounding areas. Bull. Volcano. 20, 37-76.
Kuscu, G.G., and Geneli, F., 2010. Review of post-collisional volcanism in the central Anatolian volcanic province (Turkey), with special reference to the Tepekoy volcanic complex, International Journal of Earth Sciences 99(3), 593-621. doi:10.1007/s00531-008-0402-4.
Kushiro, I., 1960. Si-Al relation in clinopyroxenes from igneous rocks, American Journal of Science 258: 548-554. doi:
Le Bas, M.J., 1962. The role of aluminium in igneous clinopyroxenes with relation to their parentage. American Journal of Science 260: 267-288.
Le Bas, M.J., LeMaitre, R.W., Streckeisen, A., and Zanettin, B., 1986. A chemical classification of volcanic rocks based on the total alkali silica diagram, Journal of Petrology, 27, 745-750. /petrology/27.3.745.
Le Terrier, J., Maury, R.C., Thonon, P., Girard, D., and Marchal, M., 1982. Clinopyroxene composition as a method of identification of the magmatic affinities of paleo-volcanic series, Earth and Planetary Science Letters, 59, 139-54.
Leak, B.E., Woolley, A.R., Birch, W.C., Gilbert, M.C., Grice, J.D., Hawthone, F.C., Kato, A., Kish, H.J., Krivovicher, V.G., Linthout, K., Laird, J., and Mandario, J., 1997 "Nomenclature of amphiboles", Report of the subcommitte on amphiboles of International Mineralogical Assocciation. Mineralogical Magazine, Volume 61 , Issue 405 , pp. 295 - 310.
Lindsley, D.H., 1983. Pyroxene thermometry. American Mineralogists 68, 477-493. doi: http://www.
Moretti, R., 2005. Polymerisation, basicity, oxidation state and their role in ionic modelling of silicate melts. Annals of Geophysics geology, Edition techniq, Paris, 58 P.
Morimoto, N., Fabrise, J., Ferguson, A., Ginzburg, I.V., Ross, M., Seifert, F.A., Zussman, J., Akoi, K., and Gottardi, G., 1988. Nomenclature of pyroxenes, Mineralogical Magazine, 52, 535-550. 1988.052.367.15.
Muller, D., and Groves, D.I., 1997. Potassic igneous rocks and associated gold copper mineralization, Spring Verlage, 241 p.
Nelson, S.T., and Montana, A., 1992. Sieve textured plagioclase in voleanic rocks produced by rapid decompression, American Mineralogist 77,1242-1249. doi: pdf.
Omrani, J., Agard, P., Whitechurch, H., Benoit, M., Prouteau, G., and Jolivet, L., 2008. Arc-magmatism and subduction history beneath Zagros: New report of adakites and geodynamic consequences. Lithos, 106: 380-398.
Ottonello, G., Moretti, R., Marini, L., and Vetuschi Zuccolini, M., 2001. Oxidation state of iron in silicate glasses and melts: a thermochemical model. Chemical geology, 174(1), 157-179.
Peng, T., Wang, Y., Zhao, G., Fan, W., and Peng, B., 2008. Arc-like volcanic rocks from the southern Lancangjiang zone, SW China: Geochronological and geochemical constraints on their petrogenesis and tectonic implication , Lithos, 102 358-373. doi : 10.1016/j.lithos.2007.08.012.  
Schweitzer, E.L., Papike, J,J., and Bence, A. E., 1979. Statitical analysis of clinopyroxenes from deep-sea basalts, American Mineralogist, 64, 501-513. doi: 64/5-6/501/41015.
Soesoo, A.A., 1997. Multivariate statistical analysis of clinopyroxene composition: empirical coordinates for the crystallisation PT-estimations. Geological Society of Sweden (Geologiska Foreningen) 119: 55-60. doi: 10.1080 /11035899709546454.
Sun, S.S., and McDonough, W.F., 1989. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. In: Saunders, A.D., Norry, M.J. Eds., Magmatism in Ocean Basins, Geological Society London Special Publication, London, 313-345. doi:10.1144/GSL.SP.1989.042.01.19.
Tatsumi, Y., and Hanyu, T., 2003. Geochemical modeling of dehydration and partial melting of subducting lithosphere: Toward a comprehensive understanding of high-Mg andesite formation in the setouchi volcanic belt, SW Japan, Geochemistry, Geophysics, Geosystems 4 (9) 1-19. doi:10.1029/2003GC000530.
Temel, A., Gondogdu, M.N., and Gourgaud ,A., 1998. Petrological and geochemical cheracteristics of Cenozoic high-K calkalkaline volcanism in Konya,Central Antolia, Turkey, Journal of Volcanology and Geothermal Research 85, 327-357.
Thompson, R.N., 1974. Some high-pressure pyroxenes. Mineral0gical Magazine 39: 768-787. doi: /10.1180/minmag.1974.039.307.04.
Varekamp, J.C., Hess, A., and Mandeville, C.W., 2010. Back-arc basalts from the Loncopue graben (Province of Neuquen, Argentina, Journal of Volcanology and Geothermal Research 197 313-328. doi:10.1016/j.jvolgeores. 2010.04.003.
Wayer, S., Munker, C., and Meger, K., 2003. Nb/Ta, Zr/Hf and REE in the depleted mantle: implications for the differentiation history of the crust-mantel system, Earth and Planetary Science Letters 205, 24-309. doi: 10.1016 /S0012-821X(02)01059-2.
Wood, D.A., 1980. The application of a Th-Hf-Ta diagram to problems of tectonomagmatic classification and to establishing the nature of crustalcontamination of basaltic lavas of the british Tertiary volcanic province, Earth and Planetary Science Letter, 50, 11-30.