Document Type : Original Research Paper


1 Associate Professor Islamic Azad University, Eslam-shahr Branch, Tehran, Iran

2 Ph.D, Tarbiat Modares University, Basic Sciences Faculty, Department of Geology, Tehran, Iran

3 Assistant Professor, Tarbiat Modares University, Basic Sciences Faculty, Department of Geology, Tehran, Iran


Miocene to Pliocene volcanic rocks in the Raveh region have exposed northern part of the Urumieh - Dokhtar Magmatic Belt. Neogene volcanic rocks are situated on Upper Red Formation. Magmatic activity separated in two phase. The first phase is composed of basic to intermediate volcanic rocks such as basaltic-andesite to andesitic lavas and pyroclastics (Ngv1).The second phase has intermediate to acidic rocks as well as andesite, quartz andesite and dacite (Ngv2).According to geochemical data, these samples show magmatic affinities to the calc-alkaline series. REE and trace element patterns show LREE enrichment relative to HREE, depletion in Nb, Ta and Ti, and also high Th/Yb and Th/Nb ratios relative to MORB and OIB. The parent magma of the Raveh volcanic rocks, with calc-alkaline compositions, has been originated probably from the metasomatized mantle with effective of fluids and sediment resulted from the Neothytian subducting slab. After collision between Arabian plate and Central Iran Block in Early Cenozoic, region experienced of crustal thickening and volcanism activity formed in relation to localized extensional basin in Early Miocene to Early Pliocene. The volcanism postdates continental collision, occurring in transtentional tectonic setting.


Agard, P., Omrani, J., Jolivet, L. & Mouthereau, F., 2005- Convergence history across Zagros (Iran): constraints from collisional and earlier deformation, Int. J. Earth Sci, 94: 401-419.
Alaii Mahabadi, S., 2000 - Geological map of the Salafchegan-Khorhe, Scale 1:100,000. Geological Survey of Iran.
Allen, M. B., Jackson, J. & 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.
Berberian, M. & King, G. C. P., 1981- Towards a paleogeography and tectonic evolution of Iran. Can. J. Earth Sciences, 18: 210-265.
Cabanis, B. & Lecolle, M., 1989- Le diagramme La/10-Y/15-Nb/8: un outil pour la discrimination des series volcaniques et la mise en evidence des processus de melange et/ou de contamination crustale. C.R. Acad. Sci., 309: 2023-2029.
Davoudzadeh, M., Soffel, H. & Schmidt, K., 1981- On the rotation of the Central-East Iran microplate. N. Jb. Geol. Palaont. Mh., 3: 180-192.
Deer, W. A., Howie, R. A. & Zussman, J., 1991- An introduction to the rock-forming minerals, Longman Scientific Technical, New York, 528.
Emami, M. H. & Hajian, J., 1991- Geological map of the Qom, Scale 1:250,000. Geological Survey of Iran, Sheet No. NI 39-6.
Emami, M. H., 1991- Explanatory text of the Qom, quadrangle map 1:250,000. Geological Survey of Iran, 179 pp (in Persian).
Emami, M. H., 1981- Geologie de la region de Qom-Aran (Iran) contribution a l etude dynamique et geochimique du volcanisme tertiaire de l Iran Central, These Doctorat Etat Grenoble, 489 pp.
Finger, L.W., 1979- The uncertainty in the calculated ferric iron content of microprobe analysis, Carnegie Inst., Washington Yearb, 71 : 600-603.
Hajian, J., 1970- Geologie de la région d'e Tafresh (NW de l Iran Central). These Doctorat Etat, Lyon, 295 pp.
Hajian, J., 1996- Paleocene – Eocene in Iran, Geological Survey of Iran. No. 28.
Hasanzadeh, J., 1978 - Geology and petrology of igneous rocks in Ghamsar region south of Kashan (Central Iran). MS. Thesis, University of Tehran.
Jackson, J., Hains, J. & Holt, W., 1995- The accommodation of Arabia-Eurasia plate. J. Geophys. Res, 100: 15,205-15,219.
Kuno, H., 1968 - Differentiation of basaltic magma. In Hess, H.H., et Poldervaart, A., edit, Basalts, 2, 623-688.
Leake, B. E., Woolley, A. R., Arps, C. E. S., Birch, W. D., Gilbert, M. C., Grice, J. D., Hawthorne, F. C., Kato, A., Kisch, H. J., Krivovichev, V. G., Linthout, K., Laird, J., Mandarino, J., Maresch, W. V., Nickel, E. H., Rock, N. M. S., Schumacher, J. C., Smith, D. C., Stephenson, N. C. N., Ungaretti, L., Whittaker, E. J. W. & Youzhi, G., 1997- Nomenclature of amphiboles: report of the subcommittee on amphiboles of the International Mineralogical Association Commission on new minerals and mineral names, Mineralogical Magazine, 61: 295-321.
Meschede, M., 1986- A method of discriminating between different types of mid-ocean ridge basalts and continental tholeiites with the Nb-Zr-Y diagram. Chem. Geol., 56: 207-218.
Mohajel, M., Fergusson, C. L. & Sahandi, M. R., 2003- Cretaecous-Tertiary convergence and continental collision,sanandaj-sirjan zone,west Iran, J. Asian Earth Sciences,21:397-419
Nogole Sadat, M. A. A., 1988- Review of tectonosedimentary zonation in Iran. Abstract volume 29th International Geological Congress, Washington. Vol.2, 522.
Pearce, J. A., 1982- Trace element characteristics of lavas from destructive plate boundaries. In: Thorpe R.S. (Eds.) Andesites: Orogenic Andesites and Related Rocks, Wiley, New York, 525-548 pp.
Peccerillo, A. & Taylor, S. R., 1976- Geochemistry of Eocene calc-alkaline volcanic rocks from the Kastamonu area, northern Turkey, Contribution to Mineralogy and Petrology, 58: 63-81.
Saunders, A. & Tarney, J., 1991- Back-arc basins. In: Floyd, P.A. (Eds.), Oceanic basalts, Blackie and Son Ltd., 219-263.
Shahrokh, J., 1996- Petrology and petrogenesis of Neogene volcanic rocks in Salafchegan - Ashtian region. MS. Thesis, University of Tarbiyat Moalem, 136 pp.
Sojodi Keismi, H., 1993- Geology and petrology of igneous rocks in south of Qom (Naragh, Bidhand regions). MS. Thesis, University of Tarbiyat Moalem, 140 pp.
Stocklin, J., 1977- Structural correlation of the Alpine range between Iran and Central Asia. Memoire Hors-Serve No.8 dela Societe Geologique de France, 8 : 333-353.
Sun, S. S. & McDonough, W. F., 1989- Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. In: Saunders, A. D. 7 Norry, M.J. (Eds.). Magmatism in Ocean Basins. Geol. Soc. Spec. Publ. London. 313 – 345.
Winchester, J. A. & Floyd, P. A., 1977- Geochemical discrimination of different magma series and their differentiation products using immobile elements. Chemical Geology.20:325–343.
Wood, D. A., 1980- The application of a Th-Hf-Ta diagram to problems of tectonomagmatic classification and to establishing the nature of crustal contamination of basaltic lavas of the British Tertiary Volcanic Province, Earth and Planetary Science Letters, 50: 11-30.